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An investigation of how natural sciences teachers mediate learning of chemical reactions in Grade 9: a case study

  • Authors: Xipu, Bukelwa
  • Date: 2012
  • Subjects: Science -- Study and teaching (Secondary) Science -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Chemical reactions Science teachers -- South Africa -- Eastern Cape Science teachers -- Rating of -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1631 , http://hdl.handle.net/10962/d1003513
  • Description: This research study involves two Grade 9 Natural Sciences teachers from two schools in the Lady Frere District of the Eastern Cape. The reason for selecting these two teachers is that in 2009 they, like me, obtained an Advanced Certificate in Education (Science and Maths) from Rhodes University. As a result, we have a good working relationship. Furthermore, both teachers are actively involved in the Natural Sciences curriculum in the District and their schools are not far from the District Office where I work. The principal objective of this study was to investigate how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9. It was triggered by the transformation in curriculum in South Africa as well as by my experience of working with Natural Sciences teachers in our rural district. The study is informed by an interpretive paradigm using a qualitative case study approach. The data was gathered by administering analysis of documents, semi-structured interviews, observations, field notes and journals. During the data analysis process, patterns and themes were illuminated using the inductive analysis method. Rich data sets in relation to the main research question on how Natural Sciences teachers mediated learning in order to enhance conceptual development and understanding of chemical reactions in Grade 9 emerged from the analysed data. The conclusions that can be drawn from the study indicate that when teaching chemical reactions, teachers should have adequate content knowledge as well as pedagogical content knowledge. It is thus recommended that teachers consider the prior knowledge of learners, use a variety of teaching and learning approaches including practical activities, to make learning meaningful. The major limitation of this study is that the two selected teachers do not represent the whole population of Grade 9 teachers in the Lady Frere District. Therefore, the findings cannot be generalized to represent the larger population. It is recognised, however, that within the qualitative inquiry, reliability and generalizability play a minor role.
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  • Date Issued: 2012

On the Wiener index of bicyclic graphs and graphs with fixed segment sequence

  • Authors: Xhanti, Sinoxolo
  • Date: 2021-10-29
  • Subjects: Graph theory , Chemistry Mathematics , Chemistry Graphic methods , Wiener index‎ , Bicyclic graphs‎ , Fixed segment sequence‎ , Degree sequence‎ , Circumference‎ , Core‎
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/190700 , vital:45019
  • Description: Wiener index is defined as the sum of the distances between all unordered pairs of vertices in a graph. The study of the Wiener index is motivated by its application in chemistry. This thesis focuses on finding extremal bicyclic graphs relative to Wiener index under various conditions such as fixed circumference (length of the longest cycle) or fixed size of the core (maximal subgraph with no degree less than 2). A segment of a graph G is either a path whose end vertices have degree 1 or at least 3 in G and all the internal vertices have degree 2 in G, or a cycle where all the vertices have degree 2 in G except possibly one. The lengths of all the segments of G form it segment sequence. We also discuss extremal graphs with given segment sequence. , Thesis (MSc) -- Faculty of Science, Mathematics, 2021
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  • Date Issued: 2021-10-29

The developmental impact of non-contributory social grants in South Africa : a study of Ezibeleni, Queenstown

  • Authors: Xaba, Mzingaye Brilliant
  • Date: 2015
  • Subjects: Economic assistance, Domestic -- South Africa , Poor -- South Africa -- Queenstown , Poverty -- South Africa -- Queenstown , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994-
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:3402 , http://hdl.handle.net/10962/d1018919
  • Description: Amartya Sen argued that poverty was the “deprivation” of the capability to lead a “good life”, therefore ending poverty meant meeting basic physical and social needs, and enabling meaningful economic and political choices. The principal objective of this research was to investigate whether (and if so, in what ways) post-apartheid state-provided non-contributory cash social grants in South Africa reduced “poverty” in Sen’s sense. This thesis used Ezibeleni, a historically black working class township at Queenstown, in the Eastern Cape, as a reference area. Using in-depth interviews, it found that social grants did help reduce poverty, both in terms of helping meet basic needs and enabling grant recipients to make more choices, including facilitating job searches and small businesses. However, it was also found that grants fall short of ending poverty, as the grants were too small to adequately cover basic needs in the context of large family sizes, a serious and long-term lack of resources, persistent unemployment, and high indebtedness, and could also enable only a limited expansion of choices. The grants played a positive role, but were inadequate to remove the “unfreedoms” facing the poor.
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  • Date Issued: 2015

The impact of land restitution and resettlement in the Eastern Cape, South Africa: restoring dignity without strengthening livelihoods?

  • Authors: Xaba, Mzingaye Brilliant
  • Date: 2019
  • Subjects: Reparations for historic injustices -- South Africa , Land reform -- Law and legislation -- South Africa , Land reform -- South Africa -- Social aspects , Agricultural development projects -- South Africa -- Social aspects , Land tenure -- Law and legislation -- South Africa
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/96336 , vital:31264
  • Description: Land reform in South Africa, which is comprised of land redistribution, land tenure reform, and land restitution, continues to be an emotive subject and has largely racially polarised South Africa. The slow pace of land reform, expropriation, the amount of land to be returned to black people, debates around the role of the Constitution in land reform, the market-based approach and the perceived negative attitude of white farmers have dominated the debates on land reform. There is, therefore, a huge chorus on the struggles for land acquisition and less on what happens when people are given land. A few studies on post-settlement livelihoods experience have managed to close this gap slightly in the literature by showing that land reform has contributed little or no material and livelihood benefits to beneficiaries and that many farms are lying idle after land reform, especially land restitution, projects. These studies on post-settlement livelihoods experiences of land reform beneficiaries have not managed to capture fully the “voices” of beneficiaries on land and livelihoods. This dissertation seeks to provide a sociological documentation of the post-settlement livelihood experiences of land restitution beneficiaries. It does this by primarily tracing the ability and/or the inability of land restitution beneficiaries of Macleantown, about 40 kilometres northwest of East London, in the Eastern Cape to reconstruct livelihoods after resettlement, bearing in mind that these land restitution beneficiaries have been resettled twice, during forced removals in the 1970s and after land restitution, post-1994. Therefore, the study engages with questions of whether or in what ways land compensated restitution beneficiaries have managed to reconstruct livelihoods after land transfer. To capture the livelihood experiences of land restitution beneficiaries fully, I also studied the Salem restitution case, which is 20km away from Grahamstown in the Eastern Cape. Because land restitution involves resettlement, I decided to use two resettlement theories, namely Thayer Scudder’s four stages model and Michael Cernea’s Impoverishment Risks and Reconstruction (IRR), to understand risks associated with resettlement. Additionally, since this dissertation seeks to understand and document livelihood reconstruction and poverty reduction within the context of restitution resettlement, I also utilised the Sustainable Livelihoods approach and Amartya Sen’s capabilities approach. This thesis is based on multiple research methods that include documentary study, focus group discussions, conversations, archival research, in-depth interviews, transect walks, participant observation and life histories. My findings show that land transfer under the land restitution programme has largely not enabled land beneficiaries in Macleantown and Salem to reconstruct land-based livelihoods after settlement. I also established that land restitution beneficiaries face risks that are identified by resettlement theorists such as lack of proper planning, resettling trauma, struggles in community reconstruction and poverty. Beneficiaries have not managed to reap any meaningful benefits from the land, meaning that restitution has not led to self-sufficiency for these beneficiaries because all land beneficiaries are heavily dependent on social grants. However, one needs to emphasize that land restitution has restored the dignity of beneficiaries because beneficiaries have accessed their forefathers’ land that they fought for. This is because beneficiaries believed that it was their duty to fight for their land on behalf of their ancestors. I reach the conclusion that the whole idea that restitution claimants who are scattered all over can be grouped into a Community Property Association (CPA) and farm collectively as a ‘community’ to improve livelihoods is a misleading romanticisation of the envisaged outcomes of the land restitution project. Time has passed after land dispossession and land claimants are different human beings to what they were before land dispossession, i.e. far from the agrarian society they were before land dispossession. Group dynamics, lack of adequate post-settlement support (PSS), land reform designs, lack of commercial agricultural skills, as well as entitlement syndrome, old age of beneficiaries, infighting and marginality of agricultural business has made it nearly impossible for restitution beneficiaries to reconstruct land-based livelihoods. Additionally, the government appears to be more interested in ‘correcting apartheid’ rather than creating viable farms. It is important to state that this thesis does not advocate for the erasure of the restitution programme or to belittle land beneficiaries but argues for the rethinking of the restitution model in the context of massive failures, as well as coming up with a new and flexible model of land restitution that will meet the modern needs of beneficiaries. This thesis contributes to an understanding of the risks and the challenges of livelihoods reconstruction faced by resettling communities through an investigation into the post-settlement livelihoods experiences of land restitution beneficiaries through ‘thick descriptions’.
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  • Date Issued: 2019

The interface of history and fiction in Russel Brownlee’s Garden of the plagues, Ingrid Winterbach’s To hell With Cronjé, and Etienne van Heerden’s The long silence of Mario Salviati

  • Authors: Wyrill, Beth Alexandra
  • Date: 2014
  • Subjects: Brownlee, Russel -- Criticism and interpretation , Winterbach, Ingrid -- Criticism and interpretation , Van Heerden, Etienne, 1954- -- Criticism and interpretation , South African fiction (English) -- History and criticism , South African fiction (English) -- 20th century -- History and criticism , African fiction (English) -- 21st century -- History and criticism , Brownlee, Russel -- Garden of the plagues , Winterbach, Ingrid -- Niggie -- English , Van Heerden, Etienne, 1954- -- Swye van Mario Salviati -- English , Historical fiction -- History and criticism , Magic realism (Literature)
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2323 , http://hdl.handle.net/10962/d1015517
  • Description: Both historiographical and literary practices have undergone revision in recent years in attempting to address the inheritance of nineteenth-century realism. Since the object of realist stylistics, employed in both the writing of fiction and history, is to render authorship authoritative or even invisible, the ideological import of these narratives is often such that the constructedness of the historical record and its absences are veiled. In developments beginning in the 1980s with the advent of ‘New Historicism’ and with the emergence of postmodern literary techniques, the interface of literature and history became of seminal importance, since both were now credited as being products of narrative and discourse, and hence, to varying degrees, of the literary imagination. This movement intersects interestingly with developments in postcolonial studies, since it is the voices of the marginalized and disempowered colonized peoples that are routinely co-opted and excised from nineteenth-century realist histories. These concerns are now being fully explored in the literature of the contemporary post-transitional South African moment, since authors in this country seemingly now feel freed up to look back to histories that precede the immediate traumas of apartheid. The concern, in relation to apartheid developments but also on a broader universal scale, is this: if history is viewed as perpetual emergences of modernities, then one of the great absences in the record is the historical determinants of any given epistemology. The attempt to recreate such an epistemological genealogy is thus simultaneously postcolonial, historiographical, and literary. Russel Brownlee’s Garden of the Plagues (2005), Ingrid Winterbach’s To Hell with Cronjé (2010), and Etienne van Heerden’s The Long Silence of Mario Salviati (2002) attempt to bridge this gap in the recorded sensibilities of any historical moment by representing a ‘lived experience’ of the past, and in the process imaginatively recreating the cultural, historical and psychological locations of the proponents of an emerging modernity. This study concerns itself with the ways in which these authors address the influence of realist historiography through the use of literary innovations that allow for the departure from realist stylistics. Most commonly, all three authors draw on forms of magic realism, but multiple refigurings and recombinations of notions of temporality, narrative, and characterization likewise work to defamiliarize the once stable discourse of history.
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  • Date Issued: 2014

The archival turn: rereading the Guy Butler Collection in the National English Literary Museum

  • Authors: Wyrill, Beth
  • Date: 2020
  • Subjects: National English Literary Museum (South Africa) , Butler, Guy, 1918-2001 , Archives -- South Africa , Archives -- Philosophy , Memory (Philosophy)
  • Language: English
  • Type: Thesis , Doctoral , PHD
  • Identifier: http://hdl.handle.net/10962/145746 , vital:38463
  • Description: This thesis takes as its theoretical springboard the ‘archival turn’ in South African historical studies, a moment that arguably reached its culmination in 2002 with the publication of Refiguring the Archive. The archival turn posits that, rather than using it as an unproblematic source of original material, scholars might begin to investigate the archive itself, including its processes of construction and organisation. This theoretical model also proposes that the archive might reflect the cultural beliefs and epistemologies common to the era in which it was set up. It seems that the time is ripe for a reconsideration of the insights gleaned from this academic moment in South Africa, given the recent contestation over the meanings of history and our cultural markers of heritage in the public domain, largely grouped under the term ‘Fallism.’ As such, a fresh look at South African museums, which in this country are often rooted in colonial practices of knowledge production, seems apt. This work uses the case of Guy Butler, founder of many South African English cultural institutes and arts bodies, as a conduit and lens for thinking through these problematics. One of Butler’s institutional ‘offspring,’ born from his overarching work on behalf of the English cultural and literary cause in South Africa in the twentieth century, is the National English Literary Museum (NELM). Investigating the founding context and practices of NELM is a useful way of exploring the impact of Butler’s life’s work on literary heritage in South Africa. Issues such as the way in which NELM and Grahamstown continue to signify as loci of thought and practice in the contemporary South African literary landscape will be addressed. The study draws extensively on the Butler collection at NELM, and spends much time investigating Butler’s positioning in a South African literary historical context in the twentieth century, to better understand the forces at work during the time of NELM’s coming-into-being. Derrida’s seminal work on the function of archives, in Archive Fever, is mined for a theoretical basis for the study, as is Deleuze and Guattari’s thought on how bodies (taking the NELM institution here to represent a ‘body’) form, change, and interact, explicated in the work A Thousand Plateaus. The study offers some insights into how the NELM archive was formed, and which forces continue to shape its work in the South African spheres of English literature and heritage.
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  • Date Issued: 2020

Composition portfolio

  • Authors: Wynne, Donovan
  • Date: 2006
  • Subjects: Music -- South Africa Composition (Music) String quartets -- Scores
  • Language: English
  • Type: Thesis , Masters , MMus
  • Identifier: vital:2658 , http://hdl.handle.net/10962/d1003121
  • Description: Introductory remarks: Being a middle-class white South African, I grew up on a diet of predominantly "white" music: rock, pop and Western classical music. I was later introduced to a broader range of musics: blues, jazz, kwaito and traditional Southern African idioms. I found myself particularly attracted to the traditional music of the amaXhosa (especially that of the uhadi bow), possibly due to the fact that this music is hexatonic (that is, based on two major triads whose tonics are one tone apart), a system that bears certain resemblances to the Western tonal idiom. However, much of my musical experience tended to be entrenched in the piano and flute music I played: mostly works by composers who were neatly ensconced in the traditional Western canon. Therefore, despite the broad range of musics with which I was familiarisedduring my tertiary studies, I feel that this early experiential background is the reason I feel most comfortable with Western-influenced music. More recently, I discovered a whole new genre to explore: film music, particularly the work of Elliot Goldenthal, Danny Elfman, John Williams and Philip Glass, whose unique brand of minimalism has extended from the concert hall to thefilm theatre. I am fascinated by the ways in which film scores function. A "main titles" theme usually appears as the film opens, upon which most of the subsequent music is based. This is not a linear process, like a theme and its variations, but a lateral, where the main titles theme is the core that engenders other themes that all share a familial resemblance.
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  • Date Issued: 2006

The impact of leadership on job satisfaction at a specific bank in the Eastern Cape

  • Authors: Wyngaard, Shaun Peter
  • Date: 2018
  • Subjects: Leadership , Bank employees Job satisfaction , Labor turnover , Transformational leadership , Bank management South Africa Eastern Cape
  • Language: English
  • Type: text , Thesis , Masters , MBA
  • Identifier: http://hdl.handle.net/10962/62050 , vital:28099
  • Description: This study aimed at investigating the relationship between leadership and employee job satisfaction in the banking sector of South Africa. The study drew from the fact that there is a growing emphasis in organisations to reduce employee turnover by keeping their employees satisfied. The ultimate performance, effectiveness and competitiveness of an organisation are directly related to an organisation’s ability to keep its employees optimally productive and satisfied. Numerous research studies have been conducted on transformational, transactional and passive-avoidant leadership to determine the significance of their respective relationship with the job satisfaction of employees in different scenarios. Results show that the transformational leadership style has a significant relationship with job satisfaction; while the transactional leadership style or the passive-avoidant style are applied according to changing circumstances. The study adopted a quantitative approach, using online questionnaires as an instrument for collecting primary data. The target population of the study was 380 bank employees, and the target sample was 218; 121 questionnaires were completed and used as the actual final sample. Questionnaires were completed from managers and employees of the selected bank, with the two population groups being investigated using different scales. SPSS was used in analysing the collected data. The findings of this research showed that the leadership styles under investigation have a direct impact on the job satisfaction of employees. Transformational leadership was found to have a significant positive relationship with job satisfaction, while the relationship between transactional leadership and job satisfaction was positive but moderate. A significant negative relationship was found between passive-avoidant leadership and job satisfaction. It is thus the responsibility of the financial institution under investigation to highlight the significant links and benefits of this leadership style to its management to ensure increased job satisfaction and lower turnover of employees in the institution. Literature explored in this study supported the close link between the different leadership styles and job satisfaction.
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  • Date Issued: 2018

Understanding Generation Y : an investigation of how Hilton College can use technology for communication

  • Authors: Wyngaard, Richard Clive
  • Date: 2013
  • Subjects: Generation Y -- South Africa -- KwaZulu-Natal Cell phones -- Social aspects Mobile communication systems -- Social aspects Information technology -- South Africa -- KwaZulu-Natal
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:796 , http://hdl.handle.net/10962/d1004332
  • Description: Background to the academic research. Hilton College is an all boys private school in the Kwa-Zulu Natal Midlands. Since the beginning of 2012 boys have been permitted to carry their phones during the school day, (Thomson, 2012). Wireless internet access was also extended across the campus to allow boys and staff to bring their own devices to class and have access to the internet (Machlachlan, 2012). In the past, communication between staff and boys was either verbal or through the use of a daily notice, called the Daily Routine Order (DRO). The DRO is placed at the dining room tables each day and boys are expected to check for any notices that may pertain to them. These notices are emailed to a secretary who prints them out and places them in the dining room each day at lunch. 2. Objectives to the research. This research sought to establish whether current communication methods were effective or whether the prevalence of mobile phones and wireless devices had presented the school with a more effective method. It was important therefore, to investigate what devices were on campus, how those devices were used and when they were used. In addition to this, the research sought to establish communication preference among staff and boys. 3. Research Methodology. The research was conducted through the use of a qualitative survey that was conducted among both staff and boys. Staff and boys were surveyed to establish generation, device prevalence, device usage and device preference. This data was collected using an anonymous qualitative survey that was administered through the use of Google docs in the school labs. 187 Boys in 3 grades 8 and 9 participated in the survey along with 18 staff members. The data was then analysed and compared to data from similar research that had been conducted elsewhere in the world. Because of significant age differences between boys and staff it was critical to establish whether device usage among staff and boys was tied to their generation. Of particular interest were the device behaviours associated with the Millennial generation, who were born between 1982-2002 (Strauss 2005:10). This generational ‘benchmark’ allowed the researcher to compare the Hilton College cohort to those whose device behaviours and usage had occurred and been discussed in generational research elsewhere. It also allowed for certain assumptions to be made about staff and boys based on their generational profile. 4. Findings It was found that staff and boys exhibited communication traits that were consistent with their generation and consistent with other research in this field. It was also found that staff and boys preferred mobile and digital forms of communication over verbal announcements and the DRO system. For this reason, it was recommended that the Hilton College establish a system that took advantage of technology to improve on communication. Various recommendations were given by the researcher that took advantage of current technologies. These included the use of SMS, Instant Messaging, Social Networks and email. It was also recommended that the school consider prescribing devices that allow for communication between staff and boys.
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  • Date Issued: 2013

Elephants, compassion, and the largesse of literature

  • Authors: Wylie, Dan
  • Date: 2011
  • Language: English
  • Type: Text
  • Identifier: vital:582 , http://hdl.handle.net/10962/d1018924
  • Description: [From the text] Why is it that we do not raise a monument, a mausoleum, nor even a humble gravestone, to mark the death of every elephant? We habitually, even compulsively, do this for other humans, occasionally for treasured pets. Yet we do not do it for the most charismatic, gigantic, culturally resonant land animal we will ever encounter. Why not? Some possible answers. One: too much work. Another: we regard other animals as less conscious than ourselves; we are the only creatures who deserve to have our deaths so commemorated. A third: wild animals are part of wild ecosystems; it is ‘natural’ for them to die and to be reabsorbed namelessly back into those ecosystems. We humans, on the other hand, consider ourselves somehow separate from those ecosystems: we shield ourselves from ‘Nature’ with bricks and literatures while we live, with marble and epitaphs after we die.
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  • Date Issued: 2011

White writers and Shaka Zulu

  • Authors: Wylie, Dan
  • Date: 1996
  • Subjects: Shaka, Zulu Chief, 1787?-1828 In literature Shaka, Zulu Chief, 1787?-1828 Zulu (African people) -- History
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2233 , http://hdl.handle.net/10962/d1002276
  • Description: The figure of Shaka (c. 1780-1828) looms massively in the historical and symbolic landscapes of Southern Africa. He has been unquestioningly credited, in varying degrees, with creating the Zulu nation, murderous bloodlust, and military genius, so launching waves of violence across the subcontinent (the "mfecane"). The empirical evidence for this is slight and controversial. More importantly, however, Shaka has attained a mythical reputation on which not only Zulu self-conceptions, but to a significant degree white settler self-identifications have been built. This study describes as comprehensively as possible the genealogy of white Shakan literature, including eyewitness accounts, histories, fictions and poetry. The study argues that the vast majority of these works are characterised by a high degree of incestuous borrowing from one another, and by processes of mythologising catering primarily to the social-psychological needs of the writers. So coherent is this genealogy that the formation of an idealised notion of settler identity can be discerned, especially through the common use of particular textual "gestures". At the same time, while conforming largely to unquestioning modes of discourse such as popularised history and romance fiction, individual writers have attempted to adjust to socio-political circumstances; this study includes four close studies of individual texts. Such close stylistic attention serves to underline the textually-constructed nature of both the figure of Shaka and the "selves" of the writers. The study makes no attempt to reduce its explorations to a single Grand Unified Explanation, and takes eclectic theoretical positions, but it does seek throughout to explore the social-psychological meanings of textual productions of Shaka - in short, to explore the question, Why have white writers written about Shaka in these particular ways?
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  • Date Issued: 1996

The experiences of recently diagnosed HIV-positive individuals, as shared on an online forum

  • Authors: Wylde, Charlotte Anne
  • Date: 2018
  • Subjects: HIV-positive persons Social networks , HIV infections Diagnosis Psychological aspects , HIV infections Social aspects , HIV infections Electronic discussion groups , Internet Social aspects , Stigma (Social psychology) , Phenomenological psychology
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/60222 , vital:27756
  • Description: An HIV-positive diagnosis can be an overwhelming and traumatic experience. This study explores the experiences of receiving an HIV-positive diagnosis. Employing an Interpretative Phenomenological Analysis (IPA), a sample of the initial posts from threads on an online forum, was collected and explored, in order to determine the dominant themes from the experiences expressed in the posts, as well as the support sought from the forum. The online forum was accessed as an unobtrusive observer, and posts from January to December 2015 were explored. The online forum provides a platform for disclosure following an HIV-positive diagnosis, when anxiety and fear of stigma can impact on an individual’s ability to disclose to their social support network of family and friends. The experiences expressed on the online forum reflect the emotional, mental and physical impact of an HIV-positive diagnosis on an individual. The findings in this study reflected themes of shock, guilt and hopelessness, and concerns and fears regarding disclosure and stigma associated with HIV, as well as the importance of social support for the coping mechanisms of individuals after receiving an HIV-positive diagnosis. This research demonstrates the importance of Internet accessibility for information and support for chronic illnesses, such as HIV, and the role of the online forum platform for providing a safe environment for individuals recently diagnosed HIVpositive.
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  • Date Issued: 2018

Boma Pass road

Development of a novel in situ CPRG-based biosensor and bioprobe for monitoring coliform β-D-Galactosidase in water polluted by faecal matter

  • Authors: Wutor, Victor Collins
  • Date: 2008
  • Subjects: Biosensors Molecular probes Enterobacteriaceae Feces -- Microbiology Water -- Pollution -- Environmental aspects Environmental monitoring Chromogenic compounds
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3944 , http://hdl.handle.net/10962/d1004003
  • Description: The ultimate objective of this work was to develop a real-time method for detecting and monitoring β-D-galactosidase as a suitable indicator of the potential presence of total coliform bacteria in water environments. Preliminary comparison of the chromogenic substrate, chlorophenol red β-D-galactopyranoside and the fluorogenic substrate, MuGAL, revealed unreliable results with the fluorogenic technique due to interference from compounds commonly found in environmental water samples. Thus, the chromogenic assay was further explored. Hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside by β-D-galactosidase to yield chlorophenol red was the basis of this assay. Fundamental studies with chlorophenol red β-Dgalactopyranoside showed that β-D-galactosidase occurs extracellularly and in low concentrations in the polluted water environment. A direct correlation between enzyme activity and an increase in environmental water sample volume, as well as enzyme activity with total coliform colony forming unit counts were observed. Spectrophotometric detection was achieved within a maximum period of 24 h with a limit of detection level of 1 colony forming unit 100 ml[superscript -1]. This enzyme also exhibited physical and kinetic properties different from those of the pure commercially available β-D-galactosidase. Cell permeabilisation was not required for releasing enzymes into the extracellular environment. PEG 20 000 offered the best option for concentrating β-D-galactosidase. The source of β-D-galactosidase in the polluted environmental water samples was confirmed as Escherichia coli through SDS-PAGE, tryptic mapping and MALDI-TOF, thus justifying the further use of this method for detecting and/or monitoring total coliforms. Several compounds and metal ions commonly found in environmental water samples (as well as those used in water treatment processes) did have an effect on β-D-galactosidase. All the divalent cations except Mg [superscript 2+], at the concentrations studied, inhibited the relative activity of β-D-galactosidase in both commercial β-D-galactosidase and environmental samples. Immobilisation of chlorophenol red β-D-galactopyranoside onto a solid support material for the development of a strip bioprobe was unsuccessful, even though the nylon support material yielded some positive results. A monthly (seasonal) variation in β-Dgalactosidase activity from the environmental water samples was observed, with the highest activity coinciding with the highest monthly temperatures. Electro-oxidative detection and/or monitoring of chlorophenol red was possible. Chlorophenol red detection was linear over a wide range of concentrations (0.001-0.01 μg ml[superscript -1]). Interference by chlorophenol red β-D-galactopyranoside in the reduction window affected analysis. A range of phthalocyanine metal complexes were studied in an attempt to reduce fouling and/or increase the sensitivity of the biosensor. The selected phthalocyanine metal complexes were generally sensitive to changes in pH with a reduction in sensitivity from acidic pH to alkaline pH. The tetrasulphonated phthalocyanine metal complex of copper was, however, more stable with a minimum change of sensitivity. The phthalocyanine metal complexes were generally stable to changes in temperature. While only two consecutive scans were possible with the unmodified glassy carbon electrode, 77 consecutive scans were performed successfully with the CuPc-modified glassy carbon electrode. Among the phthalocyanine metal complexes studied, the CuPc-modified glassy carbon electrode therefore provided excellent results for the development of a biosensor. The CuPc modified-glassy carbon electrode detected 1 colony forming unit 100 ml[superscript -1] in 15 minutes, while the plain unmodified glassy carbon electrode required 6 hours to detect the equivalent number of colony forming units. CoPc, ZnPc and CuTSPc required 2, 2.25 and 1.75 h, respectively, to detect the same numbers of colony forming units. The CuPcmodified glassy carbon electrode detected 40 colony forming units 100 ml[superscript -1] instantly. In general, a direct correlation between colony forming units and current generated in the sensor was observed (R2=0.92). A higher correlation coefficient of 0.99 for 0-30 coliform colony forming units 100 ml[superscript -1] was determined. Current was detected in some water samples which did not show any colony forming units on the media, probably due to the phenomenon of viable but non-culturable bacteria, which is the major disadvantage encountered in the use of media for detecting indicator microorganisms. This novel biosensor therefore presents a very robust and sensitive technique for the detection and/or monitoring of coliform bacterial activity in water.
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  • Date Issued: 2008

An investigation into the utility of the ImPACT neurocognitive screening tool with patients diagnosed with multiple sclerosis

  • Authors: Wurz, Carl
  • Date: 2017
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/5366 , vital:20918
  • Description: Objective: The objective of this study was to investigate the utility of the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT) assessment tool in the neurocognitive screening of patients with Multiple Sclerosis (MS). Participants and Method: Patients diagnosed with Multiple Sclerosis (n = 29) were compared with a healthy control group (n = 20) of equivalent age, years of education, quality of education and estimated premorbid IQ. Measures included five ImPACT composite scores, the ImPACT Design Memory Delayed Recall subtest, the Symbol Digit Modalities Test (SDMT) that has shown prior sensitivity to cognitive dysfunction in MS groups, and the SDMT Delayed Recall test. T-test analyses compared test performances of the MS patient group with the control group; correlational analyses investigated the construct similarities between the ImPACT and SDMT tests. Results: There was a consistent trend for the MS patient group to perform worse than controls on all the neurocognitive tests. Significant differences accompanied by medium to high effect sizes were in evidence for ImPACT Reaction Time, ImPACT Cognitive Efficiency Index, ImPACT Design Memory Delayed Recall, SDMT, and SDMT Delayed Recall test. Correlational analyses revealed construct comparability between the ImPACT tests calling upon processing speed and the SDMT, as well as the IMPACT and SDMT delayed recall tasks. Conclusions: The results support the utility of the ImPACT test as a screening instrument for the detection of cognitive dysfunction in patients with MS. Tests tapping general cognitive efficiency, processing speed, reaction time, and delayed recall rather than immediate recall reveal particular utility as neurocognitive screening aids for patients with MS.
  • Full Text:
  • Date Issued: 2017

Atmospheric ionization by precipitated electrons

  • Authors: Wulff, Annemarie
  • Date: 1973 , 2013-10-31
  • Subjects: Ionization , Electrons
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5503 , http://hdl.handle.net/10962/d1007229 , Ionization , Electrons
  • Description: From Introduction: Precipitation of energetic particl es into the upper atmosphere is known to cause aurora at high latitudes. Sanae is situated in the vicinity of the South Atlantic Geomagnetic Anomaly (Gledhill and Van Rooyen (1963)) where the magnetic field intensity is very low and it is felt that this phenomenon may enhance the loss of particles from the trapping zone into the upper atmosphere. Previous work at Rhodes has shown that it is extremely likely that particle precipitation could be the cause of some ionospheric effects at Sanae. Gledhill and Torr (1966) found that a "disturbed" ionosphere at Sanae was linked with "high" fluxes of precipitated electrons in the area conjugate to Sanae. Later papers by Gledhill, Torr and Torr (1967), and Torr and Torr (1967a, 1968a) established that electrons are precipitated over a large part of the earth's surface and this phenomenon is probably responsible for an average of about 30% of F-layer disturbances. The frequency of precipitation and corresponding disturbances is most pronounced in the South Atlantic Geomagnetic Anomaly . , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
  • Full Text:
  • Date Issued: 1973

A holistic approach in understanding the effects of dietary protein sources on the growth and reproductive development of farmed abalone, Haliotis midae

  • Authors: Wu, Yu
  • Date: 2020
  • Subjects: Abalones -- Nutrition , Abalones -- Reproduction , Abalones -- Growth , Abalone culture , Haliotis midae -- Nutrition , Haliotis midae -- Reproduction , Haliotis midae -- Growth , Haliotis midae fisheries
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/167719 , vital:41506
  • Description: The combination of fishmeal and soya in the formulated feed of farmed South African abalone, Haliotis midae, not only improved abalone growth, but also the sustainability of the compound diets by reducing the reliance on fishmeal. However, the presence of soya produced larger gonads compared to those of abalone fed kelp or single-source protein diets. There is an increasing drive to control sexual maturation and reduce undesirable spawning events in farmed abalone. However, the reasons for the reported effects of soya inclusion on the reproductive development of farmed H. midae remain unresolved. The aim of this research was to use a combination of techniques to contribute to the understanding of the relationship between growth, reproductive and nutritional physiology of farmed H. midae fed diets of varying protein sources. These techniques included stable isotope analysis (SIA), fatty acid analysis, gonad histological assessments and haemolymph sexsteroid hormone analysis. The objectives were to examine the allocation of protein and nutritional components to somatic and reproductive tissues. This study also included the first attempt to investigate the role that sex steroid hormones play during gametogenesis. Abalone (40 – 50 g abalone-1) were fed one of four diets: either a single-source protein-based diet, i.e., (1) fishmeal-only (FM) or (2) soya-only (S), or a combination diet of (3) fishmeal-soya (FM S) or (4) fishmeal-sunflower meal (FM SM). Sampling occurred in 45-day intervals over one year. Dietary protein source had an effect on the growth of abalone, with enhancements in growth linked to the combination of fishmeal and a plant-protein source. The fishmeal ingredient was the most utilised protein source throughout the temporal changes in protein allocation into somatic and reproductive tissue, followed by soya and then sunflower meal. The mean whole- body mass of abalone was significantly influenced by an interaction between time and dietary treatment, with average whole-body mass changing differently over time between treatments (RM-ANOVA, F(24, 96) = 2.13, p = 0.005). Overall, abalone that were fed FM S had higher mean whole-body mass values than abalone that were fed the single-protein based diets, while abalone that were fed FM SM were similar to animals from all dietary treatments (RMANOVA, F(3, 12) = 5.75, p = 0.01). Male abalone had significantly higher gonad bulk index (GBI) values compared to females (RM-ANOVA, F(1, 24) = 49.03, p < 0.001) and this was independent of dietary treatment. Within each sex, female abalone fed the FM S diet (15.92 ± 1.88 mm3 g-1) had significantly higher GBI values than abalone fed S (9.76 ± 1.08 mm3 g-1), while abalone fed FM (11.96 ± 1.71 mm3 g-1) and FM SM (11.90 ± 0.80 mm3 g-1) were similar to abalone from all other dietary treatments (Tukey’s HSD, p < 0.05). Male abalone fed the FM S (21.59 ± 2.10 mm3 g-1) and FM SM diet (19.30 ± 2.63 mm3 g-1) had similar GBI values and they were significantly higher than in abalone fed the S diet (14.74 ± 1.27 mm3 g-1), while abalone fed FM S had significantly higher GBI values than abalone that consumed the FM diet (15.08 ±1.63mm3 g-1) ( Tukey’s HSD, p < 0.05). Although sunflower meal was poorly utilised, it produced similar overall growth to abalone that were fed the FM S diets. Yet, feed conversion ratio values were significantly lower for abalone fed FM S (1.30 ± 0.13) compared to those in the other three treatments, with ratios ranging from 1.65 – 1.72 over the one-year. The fatty acid compositions of the somatic and gonadal tissues were similar between treatments (PERMANOVA, p = 0.21), while fatty acid composition was influenced by sampling day, tissue type and abalone sex (PERMANOVA, p < 0.05). The essential fatty acids (EFAs) eicosadienoic acid and a-linolenic acid were present in abalone tissue, but they were not detected in the diets, suggesting the important role that an alternate food source (e.g. farmed abalone also had access to diatoms) may have played and the ability that H. midae may have in converting long-chain polyunsaturated fatty acids from C18 precursors. A change in the abundance of EFAs in the gonad tissue during highest and lowest GBI values suggested that arachidonic, eicosapentaenoic, g-linolenic and linoleic acid were important in females, while eicosapentaenoic, eicosadienoic and a-linolenic acid were important for male reproductive development. Dietary protein sources had an effect on the frequency distribution of maturity stages, where females that were fed FM S produced more ripe gonads and more males that were fed FM SM contained testes that showed signs of ripeness over the one-year study. Although dietary protein influenced the sex steroid concentrations in females and males, exhibiting fluctuations throughout the one-year period, no distinct pattern linked to gametogenesis were observed. The results from this study illustrate: (1) the importance of conducting laboratory studies when implementing SIA and mixing models in aquaculture nutrition; (2) conducting nutritional studies on mature, grow-out abalone; and (3) assessing the importance of naturally occurring diatoms in their diet and their contribution to growth and reproduction. The novel contribution of this research towards abalone nutritional physiology, the implications of these findings to industry as well as potential considerations for future studies were addressed.
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  • Date Issued: 2020

The effects of dietary soya and crystalline phytoestrogens on the growth, gonad development and histology of farmed abalone, Haliotis midae

  • Authors: Wu, Yu
  • Date: 2015
  • Subjects: Haliotis midae , Haliotis midae -- Feeding and feeds , Haliotis midae -- Growth , Haliotis midae -- Histology , Haliotis midae -- Effect of chemicals on , Soybean as feed , Phytoestrogens
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5380 , http://hdl.handle.net/10962/d1017225
  • Description: The inclusion of soya as a dietary protein source in the formulated feed, Abfeed® S34 (Marifeed Pty (Ltd), Hermanus) for farmed abalone, Haliotis midae has resulted in larger gonads during reproductive seasons compared to the gonads of abalone fed kelp or diets that included fishmeal as the only main protein source. The aim of this study was to determine if the isoflavones present in the soya were responsible for this increase in gonad size and the subsequent effects on farmed abalone growth. Animals weighing between 40-50 g were fed one of seven isonitrogenous and isoenergetic diets containing either 0, 25, 50 or 100 percent of the soya component of the commercial feed (Abfeed® S34, Marifeed Pty (Ltd), Hermanus) from September 2013 to March 2014. An additional three diets were formulated to include crystalline isoflavone (ISO). These diets were identical to the 0 percent soya diet (i.e. the fishmeal only diet - FM), only ISO was included at the same rate that ISO occurred in the three soya diets. Data were analysed using a multiple forward stepwise regression analysis (MSR) to test the effects of ISO concentration, soya concentration, time, sex, time by concentration interaction and sex by concentration interaction on growth and gonad development and to identify those variables that most contributed to the model. The inclusion of crystalline ISO failed to promote larger gonads and had no effect on abalone growth, while growth and gonad development was dose dependent on soya inclusion rates with sex and time contributing to the models. Mean monthly weight gain in males correlated with increasing soya concentrations (c) (MSR, y = 3.24 + 0.002c, r2 = 0.23, p = 0.03), ranging from 3.11 ± 0.55 g abalone-1 month-1 to 4.43 ± 0.46 g abalone-1 month-1, while both male and female monthly length gain was not influenced by soya concentration with an overall mean of 1.62 ± 0.05 mm abalone-1 month-1 (MSR, p = 0.05 and p = 0.81, respectively). By December, the whole body mass, meat mass and visceral mass in both males and females decreased with increasing soya levels. However, by February, female whole body mass, meat mass and visceral mass positively correlated with soya levels. At the end of the study, male abalone fed FM with soya equivalent to the commercial feed had the highest whole body mass (69.00 ± 2.48 g abalone-1), meat mass (41.80 ± 1.12 g abalone-1), visceral mass (9.00 ± 2.47 g abalone-1) and gonad bulk index (42.70 ± 9.82 g abalone-1), while females were not influenced by soya concentrations with an overall whole body mass of 63.46 ± 0.79 g abalone-1. Weight loss was observed in all treatments between February and March, probably due to a spawning event. The moisture content in the meat was not influenced by treatment, however, visceral water loss was effected by both ISO and soya concentration with time and sex contributing to the model. The visceral water loss of females fed graded levels of soya decreased as a function of soya from December to March, and from December to February for males, whereas females fed ISO-enriched diets decreased as a function of ISO concentration (c) at the end of the study from 74.98 ± 0.88 to 73.10 ± 0.75 percent (MSR, y = 74.97 – 0.0025c, r2 = 0.20, p = 0.048). The inclusion of crystalline ISO had no significant effect on oogenesis in female farmed Haliotis midae, while the distribution of the predominant oocyte stage, stage 7 (second last stage prior to spawning) was dose-dependent in abalone fed increasing soya concentration (c) (MSR, y = 33.38 + 0.03c, r2 = 0.32, F(1, 18) = 8.52, p = 0.01). The increase in stage 7 oocytes in abalone fed FM with soya did not reduce the number of oocytes (44.96 ± 3.01 oocytes mm-2) present within the lumen, while the number of oocytes (o) in abalone fed the FM-only based diets decreased with increasing abundance of stage 7 oocytes (MSR, y = 58.28 – 0.48c, r2 = 0.38, F(1, 18) = 12.51, p = 0.002), possibly due to the increase in size of the oocytes with thicker jelly coats. This study provided evidence that crystalline isoflavone had no influence on abalone gonad development over five months, while soya had a dose-dependent effect on growth, gonad mass and oogenesis in farmed Haliotis midae. Formulated abalone feed could be manipulated at certain times of the year to obtain maximum growth. These implications and further studies were discussed.
  • Full Text:
  • Date Issued: 2015

An investigation into the neuroprotective effects of estrogen and progesterone in a model of homocysteine-induced neurodegeration

  • Authors: Wu, Wing Man
  • Date: 2006
  • Subjects: Homocysteine , Estrogen , Estrogen -- Therapeutic use , Progesterone , Hormone receptors , Methyl aspartate , Oxidative stress , Alzheimer's disease -- Treatment , Nervous system -- Degeneration -- Prevention
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3806 , http://hdl.handle.net/10962/d1003284 , Homocysteine , Estrogen , Estrogen -- Therapeutic use , Progesterone , Hormone receptors , Methyl aspartate , Oxidative stress , Alzheimer's disease -- Treatment , Nervous system -- Degeneration -- Prevention
  • Description: Homocysteine (Hcy) is a sulfur containing amino acid and is a potent neurotoxin. It has been shown that elevated levels of Hcy, termed hyperhomocysteinemia, plays a role in the pathologies of Alzheimer’s disease (AD) and age-related cognitive decline. Hcy is a glutamate agonist, which causes in increase in Ca[superscript (2+)] influx via the activation of NMDA class of excitatory amino acid receptors, which results in neuronal cell death and apoptosis. Estrogen and progesterone are female hormones that are responsible for reproduction and maternal behaviour. However, in the last decade, it is evident that both female hormones have neuroprotective properties in many animal models of neurodegeneration. Collectively, both estrogen and progesterone reduce the consequences of the oxidative stress by enhancing the antioxidant defence mechanisms, reducing excitotoxicity by altering glutamate receptor activity and reducing the damage caused by lipid peroxidation. However, the mechanisms by which estrogen and progesterone provide such neuroprotection probably depend on the type and concentration of hormone present. Moreover, numerous studies have shown that hormone replacement therapy (HRT, estrogen and progestins) or estrogen-only replacement therapy (ERT) may prevent or delay the onset of AD and improve cognition for women with AD. Clinical trials have also shown that women taking HRT may modify the effects of Hcy levels on cognitive functioning. Oxidative stress increases in the aging brain and thus has a powerful effect on enhanced susceptibility to neurodegenerative disease. The detection and measurement of lipid peroxidation and superoxide anion radicals in the brain tissue supports the involvement of free radical reactions in neurotoxicity and in neurodegenerative disorders. The hippocampus is an important region of the brain responsible for the formation of memory. However, agents that induce stress in this area have harmful effects and could lead to dementia. This study aims to investigate and clarify the neuroprotective effects of estrogen and progesterone, using Hcy-induced neurodegenerative models. The initial studies demonstrate that estrogen and progesterone have the ability to scavenge potent free radicals. Histological studies undertaken reveal that both estrogen and progesterone protect against Hcy-induced neuronal cell death. In addition, immunohistochemical investigations show that Hcy-induced apoptosis in the hippocampus can be inhibited by both estrogen and progesterone. However, estrogen also acts at the NMDA receptor as an agonist, while progesterone blocks at the NMDA receptor. These mechanisms reduce the ability of Hcy to cause damage to neurons, since Hcy-induced neurotoxicity is dependent on the overstimulation of the NMDA receptor. SOD and GPx are important enzymatic antioxidants which can react with ROS and neutralize them before these inflict damage in the brain. Hcy can increase oxidative stress by inhibiting expression and function of these antioxidants. However, it has been shown that the antioxidant abilities of both estrogen and progesterone can up-regulate the activities of SOD and GPx. These results provide further evidence that estrogen and progesterone act as antioxidants and are free radical scavengers. The discovery of neuroprotective agents is becoming important as accumulating evidence indicates the protective role of both estrogen and progesterone in Hcy-induced neurodegeneration. Thus further work in clinical trials is needed to examine whether reducing Hcy levels with HRT can become the treatment of neurodegenerative disorders, such as Alzheimer’s disease.
  • Full Text:
  • Date Issued: 2006

Ultraviolet specular reflectance, electronic absorption and the excitation of fluorescence in single crystals of anthracene

  • Authors: Wright, W H
  • Date: 1966
  • Subjects: Anthracene crystals -- Fluorescence , Ultraviolet spectroscopy -- Absorption , Reflectance
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5544 , http://hdl.handle.net/10962/d1013366
  • Description: From introduction: The Fluorescence Excitation Spectrum or anthracene is known to vary considerably with the age and condition or the crystal. This thesis represents an attempt to improve the understanding of these variations. To put the problem on a quantitative basis it was found necessary to know both the ultraviolet reflection and absorption spectra. Reports of the reflection spectrum appear to have been confined to the case of polarised incident light. In addition the reflectivity measurements are always reported for a freshly cleaved surface. For these reasons the reflectivity of anthracene for various conditions of the reflecting surface was measured with unpolarised light. These varying reflectivities were used to further knowledge of the chemical processes at the crystal surface, as well as being used directly in the calculation of fluorescence excitation spectra. Reflection spectra with a- and b- crystallographic axis polarisations were also obtained. Since such spectra are reported in the literature it was possible, by comparison, to conclude that the experimental methods used in this thesis yielded valid results. The polarised measurements were used to obtain optical constants for the crystal. In the interests of readability most of the complicated process of converting the reflectivities to optical constants is dealt with in three appendices to the thesis.
  • Full Text:
  • Date Issued: 1966
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