Probing the binding sites of novel 2-substituted imidazole-4,5-dicarboxylic acids : Towards new imidazole-based drugs
- Authors: Clark, Candyce Raine
- Date: 2021
- Subjects: Heterocyclic compounds Coordination compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50848 , vital:42957
- Description: A series of benzimidazole and imidazole-4,5-dicarboxylic acids were prepared using known and adapted protocols. Novel ligands synthesised in this study include 2-tert-butyl-benzimidazole, 2-tert-butyl-imidazole-4,5-dicarboxylic acid, an intermediate in the synthesis of 1,2- bis(2-benzimidazyl)-1,2,-dihydroxyethane and 2-(2-hydroxyphenyl)-benzimidazole with a salicylic acid co-crystallisate. All ligands prepared were reacted with metal salt solutions in order to prepare metal coordination compounds. Complexes with Cu(II), Ag(I), Mn(II), Ni(II) and Cd(II) ions and 2-phenyl-imidazole-4,5-dicarboxylic acid were prepared, as well as Cu(II) and Mn(II) with 2-trifluoro-methyl-imidazole-4,5-dicarboxylic acid and Cu(II) ions with 2-(2- hydroxyphenyl)-benzimidazole. The ligands and complexes were characterised by means of single-crystal X-ray diffraction studies, NMR analysis, UV spectrophotometric analysis and IR spectroscopy. DFT studies were carried out for selected ligands in order to provide theoretical values for comparison. Antimicrobial studies were performed on some of the ligands and complexes and these results show promise for the future development of new imidazole-based drugs.
- Full Text:
- Date Issued: 2021
A housing affordability and tenure of choice quantum deliverable model in South Africa
- Authors: Kabundu, Emmanuel Kizito
- Date: 2020
- Subjects: Housing -- Prices -- South Africa Housing -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49606 , vital:41740
- Description: The aim of this research was to develop a model that practically determines the tenure of choice and affordability of households in South Africa, which will thus help towards informed decision making by analysts and housing officials. Presently, there is no clear systematic means (except for simplistic ratios) of determining the degree of the effect of changes in the housing market (such as implemented policies) on the tenure of choice and affordability decisions of households. The research set out to improve upon the usage of ratios by basing its analysis on the theoretical underpinnings of both user costs of occupancy and an assumption of endogeneity between tenure of choice and affordability. The research used the general household survey data from Statistics South Africa for the analysis and validation. Generalized joint binary regression (on assumption of endogeneity between tenure of choice and affordability) was used as a check against the user costs of occupancy modelling. An independent market analysis carried out showed that South Africa has consistently faced increasing problems of acute housing shortages and housing affordability. Never the less, apart from subsidy programs, the option to promote renting, coupled with use of innovative building technologies showed promise of significantly alleviating these problems. More living space is especially more vital than ever, amid the current crisis of COVID-19 pademic. Statistical tests indicated strong evidence suggesting that the developed user costs of occupancy model (dynamic tenure model) is reliable at correctly recovering the tenure statuses of the households, with its recovery rates being better than those of the regression model. Both models provided useful unique, but different insights into the housing market and also correctly predicted the behavioural patterns of South African housing markets, such as significantly worsening affordability, and a market that is biased towards home ownership. The analysis also showed that affordability and tenure of choice were significantly affected by locational factors, household characteristics (such as race and age of household head), and most significantly, the age of the household head (which is a proxy to household income). The research successfully met its goal of model building but also recognized the need to merge these two models (dynamic tenure model and the regression model) into one model for more comprehensive housing related analysis. The research also recognized a need to fully operationalize the optimization, Monte Carlo and parallelization modules in order to improve the practical usefulness and effectiveness of the model. The significance of the study is that it it underpins the basis for proper tenure and affordability analysis, by assuming endogeneity between the two (2), and provides a modelling framework based on these criteria, that are useful for meaningful housing market analysis.
- Full Text:
- Date Issued: 2020
An examination of practices and experiences of teacher educators in the supervision of a national early childhood home based programme
- Authors: Annatolia, Misi
- Date: 2020
- Subjects: Early childhood education -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49362 , vital:41695
- Description: Zimbabwean teacher educators are, by the nature of their job description, required to supervise student teachers doing teaching practicum for the 0-3 home based programme. However, analysis of supervision reports of the home based programme indicates some inconsistencies in comments made by different supervisors, whereby the descriptors and supervision overall scores do not tally. It seems the supervision of the home based teacher education programme is not being implemented as expected. Hence, the purpose of this qualitative case study was to examine practices and experiences of teacher educators in the supervision of a National Early Childhood Development Home Based Teacher Education Programme (NECDHBTEP). The objective of the study was to address the key question: ‘What are the practices and experiences of teacher educators in the supervision of a NECDHBTEP. In addressing the question, the researcher used supervision as a conceptual framework. The theoretical framework which informed the study was Contextual Supervision (CS) which has its philosophical foundations in constructivism, beneficence and justice. Purposive sampling was employed in the study where two primary teachers’ colleges were selected. From each college, ten teacher educators were selected for semi-structured interviews, two focus group discussions and document analysis on teacher educators’ supervision reports. Triangulation of the data was done so as to enhance its trustworthiness. Three major themes emerged from the study, namely, the influence of home context, experience of supervisors on NECDHBTEP and supervision approaches. The study discovered that the home context, to some extent, influences supervision of the NECDHBTEP. The study also established that teacher educators face multiple challenges when supervising student teachers on the ECD home based programme. The researcher made some recommendations from the findings. One of the recommendations was for colleges to develop a specific supervision instrument for the home based ECD supervision (0-3 years category). Furthermore, there is need for Zimbabwean primary teachers’ colleges to engage in rigorous in-service training for lecturers who are not knowledgeable about the NECDHBTEP.
- Full Text:
- Date Issued: 2020
Girls here and boys there : participatory visual methodology as pedagogy to facilitate gender sensitive practices with pre-service foundation phase teachers
- Authors: Notshulwana, Robin Anne
- Date: 2020
- Subjects: Gender identity -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49385 , vital:41700
- Description: This study explores how participatory visual methodology (PVM) might facilitate a deeper understanding of gender sensitive practices (GSP) in Foundation Phase (FP) pre-service teachers. Foundation Phase classrooms are not impervious to unequal gender practices and despite policies that promote gender equitable practices in schools and in society in general, most South African schools still engage in gendered practices that perpetuate inequality and gender based violence (GBV). While the topic of gender currently features in a South African university FP curriculum with the intention of promoting social justice, the pedagogy used to enable pre-service FP teachers to understand how gender works in schools seems to do nothing more than describe the problem and give cursory suggestions for creating gender equitable practices. Teachers are often unaware of how their own gendered identity influences their facilitation of the curriculum in a gendered way. This is important in South Africa, where gender inequality remains a problem and GBV is rife. This study adopted a qualitative approach and is located within the critical paradigm applying the principles of PVM. It drew on feminist poststructuralism and feminist pedagogy as theoretical lenses to frame the study and to make meaning of the data. Participants in the study were five female pre-service FP teachers who were purposively selected. Data were generated through the visual methods of family photo album, drawing and participatory video, which were first analysed using participatory analysis, and then using thematic analysis. The main purpose of the research was to explore how PVM can facilitate a deeper awareness of GSP in pre-service FP teachers. The secondary aim was to explore their understandings of gender and GSP and how these understandings might facilitate or inhibit GSP among pre-service FP teachers. The pre-service FP teachers’ understandings of gender were elicited using the self as an entry point to explore their own gendered identities which demonstrated their somewhat narrow understanding of how gender is reified in society through mechanisms such as dress and particular performances. They further understood that their own gendered selves can shift and change with time and context. Their understanding of gender further informed their understanding of GSP. The pre-service FP teachers understood GSP as going beyond interchanging roles of girls and boys and that it meant constantly engaging with their own understandings of gender; to review their constructions of FP learners, to see pedagogical moments to teach gender sensitivity, and to recognise that GSP extends beyond the classroom. Finally, the pre-service FP teachers articulated the circumstances that might enable or inhibit their GSP in their classrooms. They recognised how the powerful constructions of gender in a society influence their work, and how, in turn their work might influence society. This translated into them understanding how the ethos of the school might mirror and sustain the hegemonic discourse of society and at the same time how they might begin to question and disrupt the discourse sustained in school. The teacher education programme, with a vested interest in gender equality, is an important mechanism to begin disrupting hegemonic discourses perpetuated in schools. The findings suggest that through its potential for reflexivity and criticality, PVM enabled the pre-service FP teachers to see how their constructions of gender influence their own practices in schools. The findings have implications for FP teacher education programmes in the South African context. Faculties of education could revisit their curriculum to ensure that gender is infused throughout the curriculum, but more importantly, could consider ‘starting with the self’ (Kirk, 2009) as an impetus to learn about how gender is reified in society and in schools. In doing so, faculties of education could also consider tools of analysis such as a feminist poststructural theory to enable the pre-service FP teachers to deepen their understandings but also support the potential to articulate and make meaning of their experiences. Teacher educators could revisit their curriculum content to determine whether the content might perpetuate a narrow view of learning and learners especially with regards to gender and considering pedagogical choices that develop pre-service teachers’ ability to cultivate classroom environments that promote gender equality. Starting with the self is an entry point for pre-service FP teachers to examine their own understanding of gender and see how this might enable GSP in their professional work. PVM, aligned with a feminist pedagogy and feminist poststructuralism, facilitated such a process.
- Full Text:
- Date Issued: 2020
Towards a community-based model for Agricultural development in Uganda : a case study of Kumi and Gomba districts
- Authors: Kiggundu, Joseph
- Date: 2020
- Subjects: Agricultural development projects -- Uganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48654 , vital:41056
- Description: This study intended to design a community-based model for agricultural development in Uganda, using Kumi and Gomba districts as case studies. The surge in attention towards community-based development is attributed to the growing challenges posed by the traditional approaches to community development, dominated by top-down mechanisms during the planning, implementation, management, monitoring, and evaluation phases of community development programmes. Driven by Robert Chambers and Conway’s theoretical perspectives, this study discusses that a community-based model is capable of filling knowledge gaps, not only in scientific research, but also in the community development process of many developing nations, such as Uganda. In this study particularly, a community-based approach has been identified as the better option in aiding and facilitating the current government efforts to transform the agricultural sector from its predominantly subsistence nature to commercial orientation. It has been acknowledged that the Ugandan government and its development partners do realise the significant role agriculture plays in directly or indirectly impacting the social welfare of Ugandans. The agricultural sector has been identified as a major source of livelihood for most rural Ugandans (over 95% depend on it for food, employment and income). Unfortunately, even with such recognition, coupled with many reforms initiated by government and supported by various development partners who have invested huge sums of money into the sector, agricultural productivity and profitability has remained extremely low. Most rural Ugandans still languish in abject poverty, hunger, malnutrition, vulnerability and powerlessness. This study has established that, while the agricultural sector in Uganda suffers from enormous institutional, technological, market, research and land-oriented challenges, if all these factors are kept constant, an effective community-based approach is capable of facilitating effective planning, implementation, management, monitoring, and evaluation of agricultural reforms, for increased agricultural productivity and profitability hence the improved quality of life of Ugandans. A qualitative elicitation interviewing technique involving in-depth discussions with agricultural extension workers, community development officers, representatives from NGOs, local farmers, farmers’ associations, local and religious leaders as well as key persons from the Ministry of Agriculture and other line ministries was conducted. The participants were selected through chain referrals until the level of theoretical saturation. In addition, directed field observations, document analysis and key informant interviews with other respondents selected through theoretical sampling enhanced the robustness of data acquisition methods. Group-based participatory data analysis and reflexive pragmatism also enhanced the rigour and quality of research findings intended to balance the knowledge generated from the recognised scientific audience and the views of the important but unknown “knowledge generators” (the local experts).The key findings indicate that, historically and currently, agriculture has been and is the predominant community development activity at household, community and national levels in Uganda. It is also anticipated that agriculture will remain a major contributor to the national economic development of Uganda even over the next hundred years. The efforts by government and its development partners to transform the sector are therefore justified by the sector’s strategic importance. It has been found out that although the sector faces huge challenges, there are numerous opportunities for the sector to become a driver of Uganda’s socio-economic development. A community-based model has been proposed as a viable option for facilitating faster agricultural development in Uganda, where technocratic developers tend to impose development reforms on local people. With the traditional approaches to planning and implementation, it was thought that local people do not know what they want, they are illiterate and ignorant and therefore incapable of driving government crafted programmes for effective change. From the proposed model, government technocratic development agents should engage local farmers who practically experience poverty, powerlessness, hunger, malnutrition and vulnerability, to jointly craft effective agricultural reforms that are not only life-changing, but also relevant and sustainable within the confines of community needs. Under this approach, the designers, planners, implementers, monitors, and evaluators, whether of government-initiated reforms, or initiatives from other development agencies, should learn to treat local people as subjects of the community development processes, as opposed to the traditional top-down mechanisms which view them as objects to be used and abused. The involvement of local experts during the planning, implementation, and management of development reforms, should cease to be applied as merely routine fulfilment of donor conditionality and requirements. Rather, the participation of local farmers during all phases of community programming should become intentional and consciously aimed at empowering local people to actively participate in the making of decisions critical to their own development.
- Full Text:
- Date Issued: 2020
Co-Production of trust for effective local Governance: a case study of Nelson Mandela Bay Municipality
- Authors: Salie-Jakoet, Amina
- Date: 2018
- Subjects: Corporate governance--South Africa--Nelson Mandela Bay Municipality Economic development--South Africa--Nelson Mandela Bay Municipality , Municipal officials and employees--South Africa-- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20308 , vital:29228
- Description: This study acknowledged that while it might be true that protests often turn violent after formal channels have been exhausted, there is an underlying problem of lack of public participation, coproduction and a general lack of trust in and within local government institutions in South Africa. The study therefore proposes that public participation in the municipal governing process is more complex than anticipated. For purposes of data collection, a mixed methods research methodology was adopted and a number of salient recommendations are provided to address the levels of trust within local government. A normative model to enhance coproduction of trust between communities and local government has been proposed. The research is scientifically worthy of distribution to the broader academic community and a number of papers both nationally and internationally have been presented from it.
- Full Text:
- Date Issued: 2018
Co-production of trust for effective local governance: a case study of the Nelson Mandela Bay Municipality
- Authors: Jakoet-Salie, Amina
- Date: 2018
- Subjects: Public participation -- South Africa -- Nelson Mandela Bay Local government -- South Africa -- Nelson Mandela Bay
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20297 , vital:29227
- Description: The primary aim of this study was to establish whether co-production of public services will lead to trust in service delivery and ultimately to trust in government, with specific reference to the Nelson Mandela Bay Municipality (NMBM). Furthermore, this research investigatedthe fundamental reasons for the mistrust in government, in lieu of the ongoing service delivery protests and officials who are at times not held accountable for their actions. This study acknowledges that there is an underlying problem of lack ofpublic participation and co-production at the sphere of local government.This research is solely based on the assumption thatif co-production is non-existent or problematic and if communities lose trust in the performance of municipalities, any attempts by the government to address these challenges relating to effective governance would be ineffective.The studyprovidesan in-depth theoretical review on co-production, public participation, citizen engagement and trust, with reference to both the national and international context. The study employed both quantitative and qualitative research approaches to validate the research questions and authenticate the problem statement. The triangulation approach allowed the researcher to effectively engage the strengths of both research methodologies. The research findings from the empirical survey were statistically analysed using statistical procedures. The data analysis, derived from the qualitative research approach, involved thematic content analysis. The sample populations for the study comprised councillors selected senior officials and ward committee members. For the quantitative approach, questionnaires were employed for the councillors and the officials. Focus group interviews were conducted with ward committee members as the qualitative component of the study. The findings of the study revealed that as a result of communities’ increasing lack of trust and confidence in local government, service delivery protests are increasing.The study further indicated thatcommunities in the NMBM are generally not well informed about the development plans of the municipality and do not adequately participate in local government activities.The findings from the focus group interviewsconcluded that the working relationship between the ward councillors and ward committee members was somewhat strained and this could have a negative impact on service delivery and ultimately trust levels.Recommendations emanating from the empirical survey and focus group interviews are presented to promote public participation and co-production which essentially could lead to an increase in trust in local government. Legislative prescriptions require that communitiesshould actively participate in the decision-making processes at the local sphere of government. In this regard, a normative model is proposed to further enhance this requirement.
- Full Text:
- Date Issued: 2018
A collaboratively constructed process model for understanding and supporting the work of the community volunteer in a community school
- Authors: Damons, Bruce Peter
- Date: 2017
- Subjects: Volunteer workers in education -- South Africa Community schools -- South Africa , Volunteers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15049 , vital:28116
- Description: This thesis sought to explore how community volunteers could be recruited, supported and sustained to assist a community school operating in difficult socioeconomic conditions in achieving basic school functionality. Through a collaborative process, the participants in the study attempted to address a significant gap in the literature, namely how this could be achieved in a way that would be beneficial both to the community volunteers and to the school itself. Based on existing literature, the vast majority of South African schools are struggling to reach the basic functionality levels required in terms of legislation. My interest in this topic was piqued while serving as principal of one such school; hence the focus in this thesis on whether schools would benefit in terms of achieving functionality if they partnered with the communities in which they are located. However, communities are seldom actively involved in the schools and school activities on an ongoing daily basis. In this thesis, I argue for an opportunity for schools and the community to collaborate in a way that would be mutually beneficial. In this, I was guided by the School-Based Complementary Learning Framework (SBCLF) in gaining a greater understanding of how multiple stakeholders could support a school to obtain basic functionality. A key stakeholder is the community in which a school is located, and the multidimensional framework provided a framework to understand why the community would want to get involved in the school. Following a Participatory Action Learning and Action Research (PALAR) design, I recruited 15 community volunteers from the existing pool at my then school; some of whom had been volunteering for over twelve years. We formed an action learning set where we collaboratively sought to understand the processes and conditions needed to recruit, support and sustain community volunteers and their involvement in the school. From this action learning set emerged a key advisors’ set, comprising five members of the action learning set, who were entrusted with the responsibility of planning, preparing and analysing the action learning set meetings. Transcripts and visual artefacts from the action learning set meetings and a focus group meeting of the school management team were analysed to generate data, complemented by secondary sources, such as documents. This participatory approach to data generation allowed the voice of every participant to be heard; agency was increased through active participation; and the sense of affiliation to the group was deepened. The iterative design of the research process further ensured that the participants also engaged in a critical discourse analysis of the emerging data, of which the trustworthiness was enhanced through the use of dialogic and process, catalytic, rhetoric, democratic and outcome validity. The emergence of the data through this collaborative engagement was underpinned by the ethical values of mutual respect; equality and inclusion; democratic participation; active learning; making a difference; collective action; and personal integrity. The findings revealed that community volunteers did add immense value to the school by supporting teaching and learning processes. However, the community volunteers also harboured expectations of material support and opportunities to develop skills. In addition, the study revealed that the hierarchical culture and structures present in most South African schools need to become more democratic and collaborative, with those working to make the school more functional, including community volunteers, being valued, acknowledged and supported. The participants also constructed their understanding of what a community school should be and do and how it should serve the interests of the children from the community. A process model was constructed from these findings regarding on ways to recruit, sustain and support community volunteers involved in community schools, specially designed so that schools could adapt it to suit individual contexts. This study is unique; I am not aware of any similar study ever having been conducted in a community school in South Africa. Furthermore, the collaborative approach used in the study helped ensure that the methodology used could be of value to principals and other school stakeholders in addressing the various complex challenges that confront schools in these contexts. Also, the findings will add to the theoretical body of knowledge around volunteerism, especially in difficult socioeconomic conditions.
- Full Text:
- Date Issued: 2017
A framework to implement social entrepreneurship activities in higher education institutions
- Authors: Tai Hing, Paul
- Date: 2017
- Subjects: Social entrepreneurship -- Education (Higher) -- South Africa Business enterprises -- Education (Higher) -- South Africa , Social responsibility of business -- Education (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15923 , vital:28291
- Description: The development of social enterprises are recognised by the broader community as an effective tool for addressing social problems. As a result, the development and emergence of social enterprise sectors have taken various paths in different geographic regions in the world. For the African context, the withdrawal of funding from the state as a result of external conditions imposed by foreign actors as well as the institutional support provided by foreign aid organisations were the key drivers behind the emergence of the social enterprise sector in Africa. Within the South African context, job creation and poverty alleviation are pressing priorities, both politically and economically, so providing an environment that is conducive for the development of social enterprises or social entrepreneurship. Implementing social entrepreneurship activities in higher education is important as universities are under increasing pressure to become responsive to student needs, and there is a growing scrutiny of their engagement, supportive, and economic role in local communities. By supporting local communities, institutions can broaden the student experience and create an economic impact. In addition, as the student experience entails more than curricular learning opportunities, social entrepreneurship practices are an important dimension for higher learning. This study used a series of case studies of social entrepreneurship projects that were implemented in the classroom of the first and second year Management students on the 2nd Avenue Campus of the Nelson Mandela Metropolitan University (NMMU). These case studies highlighted the possibilities of how classroom space and students can be utilised to set-up social enterprises to improve the conditions of the many disadvantaged and disenfranchised communities within which the university functions. At the same time, learning takes place through the practical application of the theory taught in the classroom. From the seven case studies highlighted in the study, a framework was developed to implement social entrepreneurship activities in the context of higher education. This framework includes five steps, namely, motivation and inspiration to develop social enterprises in the classroom, student involvement in creating and developing a product for sale, use of appropriate teaching strategies to provide the learning experience, provision of adequate mentoring and control of the social enterprises and, finally, assessment of the social enterprises. With the funds generated from the projects, communities benefited, for example, the upgrading of community facilities. Educators in higher education institutions are responsible for developing future business leaders. Given the increasing importance of social issues, especially poverty, this educational experience ensured that the students were made aware of the importance of using the powers yielded by business to solve some of these social issues, and thus contribute to the improvement of the South African economy. As a result, social entrepreneurship has a role to play in addressing social and economic issues. For example, the entrepreneurship part of the business will help to alleviate the unemployment strain placed upon the South African economy, whereas, the social part of the business will assist in alleviating poverty. Regarding the implementation of social entrepreneurship activities within the environment of higher education, it is evident from the case studies that successful social enterprises can be established within the classroom and sufficient funds generated to effect positive change within disadvantaged communities. Other higher education institutions in South Africa may find the implementation of social entrepreneurship activities more problematic as they might not possess a similar university culture as the NMMU.
- Full Text:
- Date Issued: 2017
A framework to incorporate sustainability into South African consumer protection policy
- Authors: Best, Laura Anne
- Date: 2017
- Subjects: Consumer protection -- Law and legislation -- South Africa Corporate governance -- Law and legislation , Business ethics Sustainability -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14565 , vital:27766
- Description: Consumer protection policy measures can enable consumer behaviour shifts in favour of more sustainable choices. Whilst government is responsible for developing consumer protection policy in a particular country, business is central in the implementation of such policy. In South Africa, there is disassociation in consumer protection policy and environmental policy where consumer protection policy is the responsibility of the Department of Trade and Industry, whilst sustainability is located under the Department of Environmental Affairs. As a result, South African consumer protection policy does not holistically incorporate sustainability. A six-step qualitative research process was adopted to develop a framework to implement sustainability into consumer protection policies. First, a theoretical framework for incorporating sustainability into consumer protection policy was developed to structure the qualitative research. Four dimensions for incorporating sustainability into consumer protection were then identified. Qualitative data was collected using an open-ended questionnaire and also content analysis of existing data. Two sets of experts further reviewed and critiqued the proposed framework. The results of the qualitative enquiry, in particular, showed that for all the countries examined, some at least had sustainability consideration elements in their policies, but this was evident to a lesser extent in African countries, particularly those with less-developed economies. On the other hand, policy mechanisms that promoted sustainability were more evident in the policies and laws of developed countries. In the case of most African countries, basic needs were foregrounded as the primary concerns of consumers, ahead of sustainability concerns. Further, poverty limited consumer choices, particularly if more sustainably produced and eco-efficient goods came at a higher price. The research also underscored the importance and centrality of consumer education and stakeholder engagement for achieving sustainability policy intentions. It further confirmed that the basic needs of poor consumers in South Africa, and the impact of poverty on sustainability policy intentions must underpin the proposed framework. Factors that created an enabling environment for the implementation of the framework were identified as policy harmonisation within government policy domains, joined-up government, good corporate governance and shared value that considered the needs of future generations and consumer education. These factors would create an enabling environment for policy implementation. Consumer policy could play a key role in the choices that consumers make and, if well-designed and implemented, could direct consumer spending in support of the goal of sustainability and sustainable consumption. The proposed framework provides a foundation on which to futher refine and develop consumer protection policy that incorporates the well-being of consumers and social justice. Using consumer spending to drive sustainability requires a deliberate intention on the part of policy makers to move away from the more conventional framing of consumer policy, which has tended to focus on the economic interests of consumers, such as price, quality, choice and redress. However, modern business is shifting towards a more holistic conceptualisation of sustainability, as a value that needs to be deliberately and consciously built into the design and essence of a business. Doing so is not only good corporate citizenship, but offers a competitive advantage, which could drive product demand and attract consumers.
- Full Text:
- Date Issued: 2017
A historical analysis of the impact of the 1966 Ugandan constitutional crisis on Buganda’s monarchy
- Authors: Musisi, Fred
- Date: 2017
- Subjects: Uganda -- Politics and government -- 1962-1971 Uganda -- History Buganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20703 , vital:29377
- Description: 1966 was a particularly tumultuous year in the East African country of Uganda. After an era of relative peace and stability, the country was plagued by a range of tragedies that resulted in a constitutional crisis after the 24 May attack on the palace of the King of Buganda. This was the first time in Uganda's short history that the state had deliberately and systematically turned its guns on its own people. As a point of departure the study advances that existing historical analyses on the crisis lack detail. Consequently, the core of the study was to provide a more focused detailed and multi-faceted historical account of the 1966 crisis on the Buganda’s monarchy. The study yielded insights into the political and socio-economic impacts of the 1966 political turmoil on the people of Buganda. Using the historical method to inform the research design; the study employed an archival history methodology to examine how both the colonial legacy and the internal dynamics of the Ugandan society combined to lead to a serious and dramatic conflict between the kingdom of Buganda and State of Uganda. Furthermore, the study demonstrates that the political turmoil left an indelible scar on the Kingdom of Buganda. The study offers clarity on why and how the crisis occurred and contributes a better understanding of the ‘grey area’ of knowledge and insights into what the abolition of the Kingdom meant to the Baganda.
- Full Text:
- Date Issued: 2017
A new synthetic approach for preparation of Efavirenz
- Authors: Chada, Sravanthi
- Date: 2017
- Subjects: Antiretroviral agents , Asymmetric synthesis , Enzyme inhibitors , HIV (Viruses) -- Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15512 , vital:28265
- Description: Efavirenz, a drug that is still inaccessible to millions of people worldwide, is potent non nucleoside reverse transcriptase inhibitor (NNRTI), is one of the preferred agents used in combination therapy for first-line treatment of the human immunodeficiency virus (HIV). NNRTIs attach to and block an HIV enzyme called reverse transcriptase, by blocking reverse transcriptase; NNRTIs prevent HIV from multiplying and can reduce the amount of HIV in the body. Efavirenz can't cure HIV/AIDS, but taken in combination with other HIV medicines (called an HIV regimen) every day helps people with HIV live longer healthier lives. Efavirenz also reduces the risk of HIV transmission and can be used by children who are suffering from HIV/AIDS. All the above therapeutic uses of efavirenz prompted us to identify the novel and hopefully cost efficient synthetic methodology for the preparation of efavirenz. In this thesis a new synthetic method for asymmetric synthesis of efavirenz is described. This route started from commercially available starting materials and it is first established in traditional batch chemistry and further the parameters transferred to a semi continuous flow protocol for optimization.
- Full Text:
- Date Issued: 2017
A spiritual intelligence model for operational humanitarian leadership development in conflict-affected areas
- Authors: Els, Deon André
- Date: 2017
- Subjects: Development leadership Conflict management , Peace-building Spiritual life
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15534 , vital:28267
- Description: The scale and cadence of crises that demand international humanitarian response are on the rise and pose increasingly hostile and complex challenges to operational humanitarian leaders. The international responses to humanitarian crises since 2011 recognised the need for successful humanitarian leadership development that emphasises the importance of ethical and effective leadership. The under-achievement of operational humanitarian leaders in conflict-affected areas has long been a chief concern amongst humanitarian organisations and leadership scholars. Several approaches to the development of operational humanitarian leaders have been presented as possible solutions such as establishing new financing mechanisms; improving technical abilities, academic knowledge, simulation training, conflict management skills; conflict prevention training; and enhancing the capacity for collaborative networks. Despite various efforts, it is reported that ineffective and incompetent leadership is still a major constraint on the success and effectiveness of operational humanitarian response in conflict-affected areas. This research effort attempted to contribute to improving operational humanitarian leadership by considering a “human or people-centred approach”. The primary objective was to identify the factors that influence the successful development of the spiritual intelligence (SQ) of humanitarian leaders working in conflict-affected areas. The primary objective was, therefore, to improve the abilities and skills of humanitarian leaders by validating and analysing factors that should contribute to the development of spiritually intelligent leaders and, subsequently, improve humanitarian leadership performance. There is growing consensus that values, ethical behaviour, self-awareness, motivation, compassion, humility, empathy, co-ordination and the empowerment of others have a significant impact on the effectiveness of operational humanitarian leadership which emphasises the need for human or people-centred approaches in developing humanitarian leaders. The striking similarities between abilities pertaining to effective, operational, humanitarian leadership and the capabilities of a spiritually intelligent individual suggested an opportunity to investigate the development of a spiritual intelligence model for humanitarian leaders. The frequency, duration and intensity of humanitarian crises between 2004 and 2016 further emphasised the urgent need for operational leaders to develop and apply abilities based on spiritual intelligence in the humanitarian sector. Some scholars argue that the development of spiritually intelligent leaders should play an instrumental role in successfully responding to global crises.
- Full Text:
- Date Issued: 2017
A theoretical model for successful management of revenue for beneficiary communities of renewable energy companies in South Africa
- Authors: Amansure, Ricardo Julian
- Date: 2017
- Subjects: Strategic planning -- South Africa , Social responsibility of business -- South Africa , Renewable energy sources -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7408 , vital:21351
- Description: The Renewable Energy (RE) sector is one of the fastest growing new industries in the Republic of South Africa (RSA). The Bloomberg New Energy Finance Climate Scope Report recently ranked RSA third globally, behind China and Brazil, and first among African countries for investment in clean energy (Glickman, 2014). However, one of the main benefits to be derived from the industry, that of socio-economic and enterprise development, is not being achieved owing to unsuccessful management of revenue for beneficiary communities in the renewable energy sector in RSA. Challenges relating to good governance and long-term planning are causing significant harm to communities that are already vulnerable, and are threatening to have a negative effect on the industry’s ability to fulfil its obligation to alleviate and, ultimately, eradicate poverty in some of the poorest communities in RSA.The primary objective of this study is to develop a model for the successful management of revenue for beneficiary communities in the renewable energy sector in South Africa. The model will provide guidance for enterprises, stakeholders, industry experts and community development practitioners within the renewable energy sector towards a pro-active, effective, and relevant decision-making process to achieve success in managing revenue for beneficiary communities. To address the primary objective, a number of secondary objectives were established by developing a conceptual model comprising variables identified in a comprehensive survey of the related literature. A path diagram, based on the formulation of appropriate hypotheses, was constructed between the independent variable and subsequent intervening and dependent variables. Primary data sourced from the identified national and international population of project management practitioners were collected by means of an electronic measuring instrument. The data were analysed and tested empirically by means of Structural Equation Modelling (SEM). The determinants that were identified through a review of the literature as influencing the success of managing revenue for beneficiary communities of renewable energy companies in South Africa included: the use of outside advice, strategic financial services, strategic planning, strategic partnerships, infrastructure development and project management. In order to achieve the objective, the following research questions were formulated: What is the influence of external factors such as outside advisers and support services on the perceived success of managing revenue for beneficiary communities of renewable energy companies in South Africa? The purpose of this research, therefore, was to evaluate and recommend new methodologies to the renewable energy sector by introducing a model of perceived success in managing revenue for beneficiary communities of renewable energy companies in South Africa. The study provided new insight into managing revenue for beneficiary communities in RSA. With the renewable energy sector being one of the fastest growing sectors in the RSA, and the RSA Government being determined to link the location of renewable energy facilities to economic development, this research has given new insight into managing revenue for SED and ED. The objectives of multi-sector participation, transformational change and sustainable initiatives for beneficiary communities could ensure greater consideration and care when managing beneficiary revenue. Thereby, the opportunity presented by the RE industry for beneficiary communities can change these communities dramatically for the better. The study makes a valuable contribution to the body of knowledge about managing revenue for beneficiary communities. The proposed model has led to a better understanding of the determinants that influence the success of managing revenue for beneficiary communities, namely: distinctive benefits (a combination of two variables: outside advice and support services), financial management, developmental benefits (a combination of two variables: infrastructure development and education), human development, project management and strategic planning. The study has also opened up new avenues of research into this subject.
- Full Text:
- Date Issued: 2017
An analysis of the implementation of the integrated approach in a Luganda language classroom in Uganda
- Authors: Ssembatya, Henry Hollan
- Date: 2017
- Subjects: Ganda language -- Study and teaching -- Uganda African languages -- Study and teaching , Language acquisition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14422 , vital:27590
- Description: This qualitative study set out to examine how the integrated approach to language teaching led to an enhancement in Luganda language practices in selected ordinary level secondary schools in the Kampala district of Uganda. The study was positioned within an interpretive paradigm, and employed a phenomenological approach in its intention to uncover the lived experiences and common hidden meanings that participants attached to the phenomena. Purposeful sampling was used to identify 30 teachers from 15 schools and 3 inspectors of school curricula who participated in the study. Data generation strategies included personal interviews and observations which were analyzed according to transcendental phenomenological data analysis methods such as bracketing, horizontalization, clustering into themes, textual description, structural description and textual-structural essence of the study. This study is located in the field of language education and informed by the theoretical framework of the cognitive constructivist theory of learning. In terms of the integrated approach in a Luganda language classroom, the findings show firstly, that teachers held positive perceptions towards the integrated approach in a Luganda language classroom and, as such, they perceived it as a basis for teaching language content and literacy practices collectively through various interactive strategies. Secondly, teachers implemented the integrated approach in a Luganda language classroom as a practical-based activity where learners are engaged in tasks which promote meaningful and real communication in the form of content, task-based instruction, literary texts or readers and contextual or experiential learning. Thirdly, findings on the enhancement of language practices in an integrated Luganda language classroom show that if teachers adopted and implemented the principles of the integrated approach, learners would be motivated to acquire not only the four language practices, but also other related practices such as cognitive, social and interpersonal practices which collectively simplify the language use. Lastly, while teachers are aware of what learners could achieve in an integrated Luganda language classroom, findings indicate that they are demotivated by the many challenges in the implementation process which stem from the teachers, the education system, the learners, and the integrated approach itself. The major implications and recommendations of this study’s findings include: firstly, teachers’ perceptions on the use of the integrated approach in a Luganda language classroom imply that since language learning is a function of social and meaningful classroom interactions learning activities should recognize a teacher as a reflective practitioner, consultant or facilitator of learning rather than an instructor. Secondly, the implementation of the integrated approach in a language classroom would require teachers to be grounded in both practical and theoretical instructional strategies which form a basis for monitoring and engaging learners’ oral and interactive practices. Thirdly, the enhancement of language practices is an outcome of classroom motivation and active interactions which involve creative and critical thinking. Thus, creating and sustaining situations for the enhancement of language practices in a language classroom would require effective branding of learners’ interactive activities with ample opportunities for practice as well as instructional support. Fourthly, considering the perceived challenges in the implementation of the integrated approach, the overall recommendation would be that those challenges need to be resolved if the integrated approach is to be successfully implemented in the context of the Luganda language. An awareness of such challenges provides teachers, educators and policy-makers with insightful ideas in terms of how to manage or change instructional strategies in the classroom.
- Full Text:
- Date Issued: 2017
An evaluation of the impact of the Consumer Protection Act 68 of 2008 on the relationship between franchisors and franchisees
- Authors: Biggs, Lynn
- Date: 2017
- Subjects: South Africa -- Consumer Protection Act, 2008 Consumer protection -- Law and legislation -- South Africa , Franchises (Retail trade) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14642 , vital:27810
- Description: The franchising business model is an attractive option for both franchisors and franchisees. Franchisors grant the rights to use their intellectual property and business system to franchisees for a fee. Franchisees buy into the tried-and-tested business system, receive ongoing training and support and operate under an established trade mark or trade name. Fundamental characteristics of the franchise relationship include: the contractual nature thereof, the use of the franchisor‘s intellectual property by the franchisee, operating the franchise outlet according to the franchisor‘s business system, providing training and support to the franchisee, and paying for the use of the franchisor‘s intellectual property and business system. These characteristics have resulted in inherent tensions between franchisors and franchisees, which arise by virtue of, inter alia, the control exercised by the franchisor over the use of its intellectual property, franchisor opportunism, poor franchisee selection, franchisee free-riding, inadequate training and support, or the sunk investments made by the franchisee. The franchisor and franchisee generally use a franchise agreement to regulate their relationship. However, the franchise agreement itself can also lead to conflict between the parties, such as that arising from poor drafted clauses relating to territorial rights, renewal, payment, termination, restraint of trade, or confidentiality. The franchise agreement is typically drafted in the standard-form, resulting in franchisees faced with unequal bargaining power. The common law of contract is based on principles of freedom of contract and sanctity of contract and is, therefore, limited in its ability to resolve the tensions between the parties. Various models for regulating the franchising industry can be adopted, for example, self-regulation, statutory regulation, or co-regulation. Australia and Canada have adopted the statutory model by enacting franchise-specific legislation and New Zealand has followed the self-regulation model with no legislation regulating its franchising industry. South Africa did not formally regulate the franchise relationship through legislation until the enactment of its consumer protection legislation, the Consumer Protection Act 68 of 2008 (CPA), which includes a franchisee within the definition of consumer. This entails that all franchisees enjoy the protection of the CPA and all franchise agreements must comply with the provisions of the CPA. The South African economy is unique in that it is burdened by the social ills of its discriminatory past, such as high levels of unemployment, illiteracy and inequality. The country is faced with a slow growing economy with little development and promotion of entrepreneurship among small businesses. Despite the burdensome economy within which the franchising industry is required to operate, the industry‘s contribution to the Gross Domestic Product (GDP) of the country has remained stable. The South African government has identified the franchising industry as an opportunity for job creation, economic empowerment and promotion of entrepreneurship. The aim of the study is to ascertain whether the CPA is the correct legislative vehicle to regulate the franchise relationship, while enhancing the growth and development of the franchising industry. This thesis concludes that the introduction of fundamental consumer rights and rights of redress for franchisees through the provisions of the CPA has contributed to, or assisted in, the removal of the tensions inherent in the franchise relationship. In particular, the CPA has adequately addressed the lack of formal regulation of the franchise relationship through its disclosure requirements and its regulations. The thesis also proposes amendments to some of the CPA regulations, which will further enhance the disclosure requirements, and aid in curtailing the conflict caused by the terms of the franchise agreement. The thesis further proposes that the application of the CPA to franchise agreements should be limited to small, inexperienced or unsophisticated franchisees that are in need of the protection. An essential premise is that the CPA aims to protect ordinary consumers, including juristic persons, in day-to-day transactions (up to the threshold amount), to avoid suppliers taking advantage of them. Larger, more sophisticated or experienced franchisees, with stronger bargaining power and access to legal advice, do not necessarily require the protection of the CPA. The criteria relating to the size of class of micro-, very small and small enterprises, but not medium enterprises, within the different sectors or sub-sectors in terms of the National Small Enterprises Act, 102 of 1996, should be considered and used as a guide to determine whether the CPA applies to a franchise agreement. The development, growth and success of the franchising industry depends on the education of prospective franchisees wanting to adopt the franchising business model and invest in the industry. The CPA does not recognise or promote the roles of the various stakeholders (franchisors, franchisees and the government) with regard to the provision of education, training, ongoing support and assistance to prospective franchisees. This thesis proposes that mechanisms to enhance the education of prospective franchisees should be promoted, such as tandem franchising, obtaining advice undertakings from prospective franchisees before concluding franchise agreements, and increasing the role of the Consumer Commission in providing franchising education.
- Full Text:
- Date Issued: 2017
An HRM model for enhancing psychological capital in South African organisations during a psychological recession
- Authors: Theron, Anthonie Van Straaten
- Date: 2017
- Subjects: Industrial psychology Personnel management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20823 , vital:29404
- Description: The rationale behind this study was to identify various positive Human Resource Management (HRM) practices that contribute to the development and enhancement of psychological capital (PsyCap) during a psychological recession. A psychological recession, which is defined as a negative cognitive and emotional condition perpetuated by prolonged socio-economic hardships and amplified by the media, (Bardwick, 2008) could negatively affect employees’ PsyCap. While there has been no systematic study of the impact of various HRM practices on PsyCap (Gupta, 2013), a need existed to investigate and formulate best HRM practices for the development of employees’ PsyCap during a psychological recession. Furthermore, this study also aimed to investigate the potential buffering effect of HRM practices on the negative experiences and perceptions associated with a psychological recession. This research study took the form of a quantitative, cross-sectional design, using a composite questionnaire to measure personal vulnerability and exposure to the negative experiences associated with a psychological recession, the organisation’s application of various positive HRM practices, and employees’ levels of PsyCap. The target population consisted of all permanent and contract clinical and support staff employed at 43 fixed Primary Health Care (PHC) clinics situated in the West Rand District Municipality (WRDM) (n = 318). Exploratory factor analysis (EFA) was employed to determine the factor loadings on the overall scales and based on these factor loadings, main factors were extracted. Reliability analysis indicated that the newly structured measurement instruments would produce consistent results with continued application. The hypotheses were tested through the application of Pearson’s product moment correlation analysis, structural equation modelling (SEM), multiple regression analysis and a one-sample t-test. The empirical results indicated that all respondents included in the study experienced some degree of a psychological recession. Although significant correlations were uncovered between psychological recession and PsyCap, personal exposure and vulnerability with regards to organisational change and psychological uncertainty was identified as a major factor that negatively affected employees’ PsyCap. The inferential results identified competence development practices as a crucial intervention for the enhancement of PsyCap during a psychological recession. Lastly, the inferential results revealed that employee recognition and empowerment are fundamental practices in order to negate the negative impact of a psychological recession. Based on the results of this study, organisations have to proactively respond to a psychological recession by re-evaluating the effectiveness of their HRM actions and practices, in order to effectively enhance and maintain the PsyCap of their employees during a psychological recession.
- Full Text:
- Date Issued: 2017
An ICT strategy to support a patient-centred approach to diabetes care
- Authors: Petratos, Anastasia
- Date: 2017
- Subjects: Medical care -- Technological innovations -- Developing countries Health services administration -- Developing countries -- Data processing , Telecommunication in medicine Diabetes -- Treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14466 , vital:27650
- Description: Factors such as poverty, ethnicity, socio-economic status, poor infrastructure and governance, etc., are some of the reasons that effective and proven prevention and treatment interventions for most of the major causes of mortality and morbidity in the developing world continue to fail. Chronic diseases require complex interventions that these countries simply cannot maintain. Diabetes mellitus (DM) is a chronic disease that is on the rise worldwide. This disease is a lifestyle disease, which means, that it is brought on by poor health habits. Statistics show that 285 million (6.4%) people aged between 20 and 79 years will be affected by Diabetes in 2010 and a staggering 439 million (7.7%) by 2030. This is a projected growth of 69% in developing countries and 20% in developed countries. The findings from studies conducted from 1993 to 2003 in Sub-Saharan Africa, particularly in South Africa, around the health care services for diabetes highlights many challenges. Sadly, the challenges 10 years after that study, are very similar. The conditions of people with Diabetes can be improved through regular monitoring of patients, improvement and monitoring of health care provided, education on healthy lifestyle, as well as education on the importance of adherence to treatment plans for the successful management of the condition. The diabetes endemic in South Africa is exacerbated by the manual functions that are performed in all aspects of monitoring and management of the disease. With the advancements that have been made in ICT and the many apps that already exist for healthcare, it is sensible to state that ICT can assist in the monitoring and management of diabetes. Another factor that is considered is that of patient-centred care. The huge number of people who need acute care and treatment in hospitals and clinics have forced a previously caring environment, to turn into a cold, almost production line affair. The sick wait in long queues and are ushered in and out of the consulting rooms as fast as possible without even as much as a “hallo”. This has left a void in the healthcare delivery to South Africans which should never have been removed in the first place, namely patient-centred care. This means that the patient is at the centre of the treatment and fully involved in the decisions about his/her health. Every patient deserves to be recognised as a human-being and treated with dignity and respect. Treatment plans for long term chronic care patients such as diabetics, should be thoroughly discussed with the patient and they should believe and comit themselves to the treatment plan. These plans are life-long and require dedication and as it is vital that patients are part of decision making and understand fully what they are expected to do. Bearing this in mind, this study has investigated the needs and care plans for people with diabetes. Specialist in the field of diabetes were interviewed and recognised care plans for diabetes such as those from WHO, IDF and SEMSDA were studied. This study also established, that by practising a patient-centred approach the adherence to a treatment plan is likely to be higher. The strategy developed involves the person with diabetes, the healthcare worker and the support structure in the care plan of the diabetic. The use of ICT as part of the solution must consider the patient-centred requirements for using IT so that the people using the strategy are comfortable and not intimidated by the technology. The need to incorporate e-health into governments’ healthcare plans has been growing over the last decade. The GSMA conducted research into mobile health opportunities in South Africa and found that SA now has a penetration of 98% and that this is the ideal medium to address the inaccessibility and inequality of healthcare in SA. The causes identified as playing a major role in the rise in diabetes were identified and it was determined that through the implementation of an ICT strategy for diabetes care, many of these can be addressed. These include the use of technology for, improved monitoring and management, increased diabetes awareness and education, and promotion of healthy lifestyle. The study focuses on the self-management aspect of diabetes and produces a strategy that incorporates various ICT solutions that would assist in the daily aspects of diabetes care, as well as follow a patient-centred approach to diabetes care. This strategy developed in this study does not need any intervention from government as it is driven by the people who have diabetes and their healthcare workers, with the aid of the technology that they currently have on hand.
- Full Text:
- Date Issued: 2017
An in vitro evaluation of anti-breast cancer activity of novel, heterocyclic aromatic compounds in combination with curcumin
- Authors: Pereira, Melanie Claire
- Date: 2017
- Subjects: Breast -- Cancer Heterocyclic compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20416 , vital:29284
- Description: Nearly two thirds of breast cancers are classified as estrogen receptor positive. Estrogen receptor (+) breast cancer is usually treated with anti-estrogen therapy, using Tamoxifen as the primary standard of treatment. Unfortunately, resistance to Tamoxifen is known to occur after 1 to 3 years of Tamoxifen therapy. For this reason, improved treatment strategies for ER (+) breast cancer are urgently needed. The general toxicity exerted by most anti-cancer drugs on proliferating cells, as well as some normal cells, restricts their therapeutic use. Novel cytotoxic agents developed with unique mechanisms of action have not been therapeutically suitable, since many of these compounds lack tumour selectivity. The adverse effects and the inefficacies of most chemotherapeutic therapies have motivated extensive investigations of alternatives. Numerous studies have demonstrated the advantages of using combination therapy with naturally-derived agents as an alternative, due to the higher therapeutic efficacy; with the added benefit of lower drug usage and reduction in drug-resistance development. An excellent example of a naturally derived and common dietary agent is curcumin, the active constituent of turmeric. Curcumin is known to modulate several signalling pathways in addition to displaying a diverse range of anti-tumour activities against a number of cancer cells. Several reports point to curcumin being beneficial if used in addition to chemotherapeutic drugs. In this study, synthetic aminonaphthoquinone derivatives (coded Rau 008, Rau 010, Rau 015 and Rau 018) were tested individually and in combination with curcumin for the potential as anti-breast cancer agents in different tumour cell lines. Notably, the aminonaphthoquinone class of compounds have shown potential as anti-cancer agents in various tumour cell lines. This study was thus aimed at screening the Rau compounds (and selected combinations with curcumin) for anti-cancer activity using a range of in vitro biological assays, and was not mechanistic in nature. The IC50 values of the individual and combined drugs were determined from dose-response curves using non-linear regression analyses. Synergistic, additive and antagonistic drug interactions were assessed using combination index and isobologram approaches. Based on these interactions, selected drug combinations were then further analysed for their potential anti-estrogenic, cytotoxic, anti-angiogenic and anti-metastatic effects against the ER(-) MDA-MB-231 and ER(+) MCF-7 breast cancer cell lines. The potential anti-cancer effects of the selected drug combinations on other estrogen-responsive models, such as the osteosarcoma (MG-63) and endometrial cancer (HEC-1A) cell lines, were also investigated. Overall, the findings of this study indicated that the sensitivity of the tumour cells to the various test compounds was significantly enhanced when combined with curcumin. For instance, in the presence of curcumin, Rau 008 or Rau 010 reduced the metastatic capability of ER(-) breast cancer cells significantly. The anti-proliferative effect of the Rau 015+curcumin combination was enhanced in ER(+) and ER(-) breast cancer, including oteosarcoma cells, while a combination of Rau 015 and curcumin induced a significant cytotoxic effect in ER(-) breast cancer and endometrial cancer-derived cells. A combination of Rau 018 and curcumin inhibited the proliferation of ER(+) breast cancer, and the combined effect was significantly more enhanced compared to individual treatment. A similar effect was noted in osteosarcoma-derived cells. Further, the Rau 018+curcumin combination exerted a marked cytotoxic and anti-angiogenic effect in ER(-) breast cancer, osteosarcoma and endometrial cancer in addition to inhibiting the attachment of ER(-) breast cancer cells to collagen. Notably, curcumin enhanced the anti-proliferative effect of Tamoxifen in breast cancer (MCF-7 and MDA-MB-231), osteosarcoma and endometrial cancer, and also induced a significant cytotoxic effect against ER(+) breast cancer and osteosarcoma, whilst also reducing the invasive potential of ER(-) breast cancer. A combination of 17β-estradiol and curcumin induced a marked anti-proliferative effect in ER(+) and ER(-) breast cancer, reduced the adhesion of ER(-) breast cancer to laminin, and elicited a significant cytotoxic and anti-angiogenic effect against endometrial cancer. Notably all the selected combinations (except Rau 018 and curcumin) inhibited bone mineralization. These findings point to the vital influence of curcumin in the responsiveness of ER(+) and ER(-) tumours towards the relative test agents. Further, among the Rau+curcumin combinations tested in this study, the anti-cancer activity of Rau 015+curcumin and Rau 018+curcumin appeared to be the most effective in the different cell lines tested. Nonetheless, it appears that a combination of 30 μM Rau 018 with 100 μM curcumin may be more promising as an anti-breast cancer agent against ER(+) and perhaps triple negative breast cancer, and warrants further investigation.
- Full Text:
- Date Issued: 2017
Application of the theory of critical distance technique to predict fracture toughness in friction stir welded Ti-6Al-4V sheet
- Authors: Rall, William Henry
- Date: 2017
- Subjects: Friction stir welding Fracture mechanics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20351 , vital:29266
- Description: With modern day socioeconomic pressures to deliver more cost effective, higher performance and energy efficient mechanisms and structures, light weight design is coming more to the forefront of design methodologies. These methodologies need to apply lightweight materials in unison with a defect tolerant design strategy. Titanium is certainly not a new material and was used in large quantities in the 1960’s and ‘70s, but mostly in military applications. The main drawback of this material was cost, however due to current design needs as mentioned the consumption of the material is rising rapidly. Friction stir welding is by no means a new technique anymore, however, relatively speaking it is still in its infancy when compared to other traditional welding techniques. It has been applied mostly to low melting temperature metals, more specifically aluminium; however, its application to higher melting temperatures has started to enjoy more attention over the last few years. The lower temperatures at which the weld occurs, when compared to conventional processes, is the main reason for applying this technique to materials melting at a higher temperature such as titanium. Fracture mechanics allows modern-day designers and maintenance engineers to operate structures with an inherent flaw. These flaws may be due to geometric features of the design; fabrication defects or defects such as cracks that have developed over time within an operational structure. Fracture mechanics has evolved significantly since Griffith first proposed it in the early 20th century. The application of the method is often complex and determining the material properties for fracture resistance can be problematic and costly. Many techniques have been proposed over time to simplify the application of this method and one of these techniques would be the theory of critical distance. Since the technique is relatively new and has mostly been applied to more brittle materials, this study aimed not only to apply this technique to a more ductile material but additionally to one that is classified as a sheet material. The initial tests of this study investigated if a common convergent point could be determined by using three notches varying in size. The technique does not have a standard that governs its application. The initial tests did not yield a common intersecting point thus a second study was applied to see if sample width would influence the results. The results from the study indicated that wider samples seemed to yield similar apparent fracture toughness results, however a common convergence point could still not be established. This prompted a more in-depth study which involved various sample widths coupled with varying notch depths. Sharper notches were also applied and samples with controlled cracks were also tested. The results clearly showed that as the plastic zone size increases in relation to the ligament length of the sample, the critical distance becomes larger. The results also suggested that it would perhaps be best to use sample sizes with notches which allow fracture of the sample before the nett section stress reaches the material’s yield strength. The final tests involved testing the friction stir welded material. Various other studies were also done to corroborate the fracture toughness results. The stress relieved samples showed a reduction in the fracture toughness due to possible precipitation hardening during the stress relieving heat treatment process. The welded material showed an increase in the apparent fracture toughness when compared to the parent plate. The results indicate that residual stresses have an influence on the fracture toughness. In terms of the critical distance, it would appear that the value stays unchanged from the parent plate to the welded material; however, what is significant was that the value seemed to stay more or less constant as long as the nett section stress of the notched samples stayed below the yield stress of the material.
- Full Text:
- Date Issued: 2017