Identification of novel compounds against Plasmodium falciparum Cytochrome bc1 Complex inhibiting the trans-membrane electron transfer pathway: an In Silico study
- Authors: Chebon, Lorna Jemosop
- Date: 2022-10-14
- Subjects: Malaria , Plasmodium falciparum , Molecular dynamics , Antimalarials , Molecules Models , Docking , Cytochromes , Drug resistance , Computer simulation , Drugs Computer-aided design , System analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365666 , vital:65774 , DOI https://doi.org/10.21504/10962/365666
- Description: Malaria continues to be a burden globally with a myriad of challenges deterring eradication efforts. With most antimalarials facing drug resistance, such as atovaquone (ATQ), alternative compounds that can withstand resistance are warranted. The Plasmodium falciparum cytochrome b (PfCytb), a subunit of P. falciparum cytochrome bc1 complex, is a validated drug target. Structurally, cytochrome b, cytochrome c1, and iron sulphur protein (ISP) subunits form the catalytic domain of the protein complex having heme bL, heme bH and iron-sulphur [2FE-2S] cluster cofactors. These cofactos have redox centres to aid in the electron transfer (ET) process. These subunits promote ET mainly through the enzyme’s ubiquinol oxidation (Qo) and ubiquinone reduction (Qi) processes in the catalytic domain. ATQ drug has been used in the prevention and treatment of uncomplicated malaria by targeting PfCytb protein. Once the mitochondrial transmembrane ET pathway is inhibited, it causes a collapse in its membrane potential. Previously reported ATQ drug resistance has been associated with the point mutations Y268C, Y268N and Y268S. Thus, in finding alternatives to the ATQ drug, this research aimed to: i) employ in silico approaches incorporating protein into phospholipid bilayer for the first time to understand the parasites’ resistance mechanism; ii) determine any sequence and structural differences that could be explored in drug design studies; and iii) screen for PfCytb-iron sulphur protein (Cytb-ISP) hit compounds from South African natural compound database (SANCDB) and Medicines for Malaria Venture (MMV) that can withstand the identified mutations. Using computational tools, comparative sequence and structural analyses were performed on the cytochrome b protein, where the ultimate focus was on P. falciparum cytochrome b and its human homolog. Through multiple sequence alignment, motif discovery and phylogeny, differences between P. falciparum and H. sapiens cytochrome b were identified. Protein modelling of both P. falciparum and H. sapiens cytochrome b - iron sulphur protein (PfCytb-ISP and HsCytb-ISP) was performed. Results showed that at the sequence level, there were few amino acid residue differences because the protein is highly conserved. Important to note is the four-residue deletion in Plasmodium spp. absent in the human homolog. Motif analysis discovered five unique motifs in P. falciparum cytochrome b protein which were mapped onto the predicted protein model. These motifs were not in regions of functional importance; hence their function is still unknown. At a structural level, the four-residue deletion was observed to alter the Qo substrate binding pocket as reported in previous studies and confirmed in this study. This deletion resulted in a 0.83 Å structural displacement. Also, there are currently no in silico studies that have performed experiments with P. falciparum cytochrome b protein incorporated into a phospholipid bilayer. Using 350 ns molecular dynamics (MD) simulations of the holo and ATQ-bound systems, the study highlighted the resistance mechanism of the parasite protein where the loss of active site residue-residue interactions was identified, all linked to the three mutations. The identified compromised interactions are likely to destabilise the protein’s function, specifically in the Qo substrate binding site. This showed the possible effect of mutations on ATQ drug activity, where all three mutations were reported to share a similar resistance mechanism. Thereafter, this research work utilised in silico approaches where both Qo active site and interface pocket were targeted by screening the South African natural compounds database (SANCDB) and Medicines for Malaria Venture (MMV) compounds to identify novel selective hits. SANCDB compounds are known for their structural complexity that preserves the potency of the drug molecule. Both SANCDB and MMV compounds have not been explored as inhibitors against the PfCytb drug target. Molecular docking, molecular dynamics (MD) simulations, principal component, and dynamic residue network (DRN; global and local) analyses were utilised to identify and confirm the potential selective inhibitors. Docking results identified compounds that bound selectively onto PfCytb-ISP with a binding energy ≤ -8.7 kcal/mol-1. Further, this work validated a total of eight potential selective compounds to inhibit PfCytb-ISP protein (Qo active site) not only in the wild-type but also in the presence of the point mutations Y268C, Y268N and Y268S. The selective binding of these hit compounds could be linked to the differences reported at sequence/residue level in chapter 3. DRN and residue contact map analyses of the eight compounds in holo and ligand-bound systems revealed reduced residue interactions and decreased protein communication. This suggests that the eight compounds show the possibility of inhibiting the parasite and disrupting important residue-residue interactions. Additionally, 13 selective compounds were identified to bind at the protein’s heterodimer interface, where global and local analysis confirmed their effect on active site residues (distal location) as well as on the communication network. Based on the sequence differences between PfCytb and the human homolog, these findings suggest these selective compounds as potential allosteric modulators of the parasite enzyme, which may serve as possible replacements of the already resistant ATQ drug. Therefore, these findings pave the way for further in vitro studies to establish their anti-plasmodial inhibition levels. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Chebon, Lorna Jemosop
- Date: 2022-10-14
- Subjects: Malaria , Plasmodium falciparum , Molecular dynamics , Antimalarials , Molecules Models , Docking , Cytochromes , Drug resistance , Computer simulation , Drugs Computer-aided design , System analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365666 , vital:65774 , DOI https://doi.org/10.21504/10962/365666
- Description: Malaria continues to be a burden globally with a myriad of challenges deterring eradication efforts. With most antimalarials facing drug resistance, such as atovaquone (ATQ), alternative compounds that can withstand resistance are warranted. The Plasmodium falciparum cytochrome b (PfCytb), a subunit of P. falciparum cytochrome bc1 complex, is a validated drug target. Structurally, cytochrome b, cytochrome c1, and iron sulphur protein (ISP) subunits form the catalytic domain of the protein complex having heme bL, heme bH and iron-sulphur [2FE-2S] cluster cofactors. These cofactos have redox centres to aid in the electron transfer (ET) process. These subunits promote ET mainly through the enzyme’s ubiquinol oxidation (Qo) and ubiquinone reduction (Qi) processes in the catalytic domain. ATQ drug has been used in the prevention and treatment of uncomplicated malaria by targeting PfCytb protein. Once the mitochondrial transmembrane ET pathway is inhibited, it causes a collapse in its membrane potential. Previously reported ATQ drug resistance has been associated with the point mutations Y268C, Y268N and Y268S. Thus, in finding alternatives to the ATQ drug, this research aimed to: i) employ in silico approaches incorporating protein into phospholipid bilayer for the first time to understand the parasites’ resistance mechanism; ii) determine any sequence and structural differences that could be explored in drug design studies; and iii) screen for PfCytb-iron sulphur protein (Cytb-ISP) hit compounds from South African natural compound database (SANCDB) and Medicines for Malaria Venture (MMV) that can withstand the identified mutations. Using computational tools, comparative sequence and structural analyses were performed on the cytochrome b protein, where the ultimate focus was on P. falciparum cytochrome b and its human homolog. Through multiple sequence alignment, motif discovery and phylogeny, differences between P. falciparum and H. sapiens cytochrome b were identified. Protein modelling of both P. falciparum and H. sapiens cytochrome b - iron sulphur protein (PfCytb-ISP and HsCytb-ISP) was performed. Results showed that at the sequence level, there were few amino acid residue differences because the protein is highly conserved. Important to note is the four-residue deletion in Plasmodium spp. absent in the human homolog. Motif analysis discovered five unique motifs in P. falciparum cytochrome b protein which were mapped onto the predicted protein model. These motifs were not in regions of functional importance; hence their function is still unknown. At a structural level, the four-residue deletion was observed to alter the Qo substrate binding pocket as reported in previous studies and confirmed in this study. This deletion resulted in a 0.83 Å structural displacement. Also, there are currently no in silico studies that have performed experiments with P. falciparum cytochrome b protein incorporated into a phospholipid bilayer. Using 350 ns molecular dynamics (MD) simulations of the holo and ATQ-bound systems, the study highlighted the resistance mechanism of the parasite protein where the loss of active site residue-residue interactions was identified, all linked to the three mutations. The identified compromised interactions are likely to destabilise the protein’s function, specifically in the Qo substrate binding site. This showed the possible effect of mutations on ATQ drug activity, where all three mutations were reported to share a similar resistance mechanism. Thereafter, this research work utilised in silico approaches where both Qo active site and interface pocket were targeted by screening the South African natural compounds database (SANCDB) and Medicines for Malaria Venture (MMV) compounds to identify novel selective hits. SANCDB compounds are known for their structural complexity that preserves the potency of the drug molecule. Both SANCDB and MMV compounds have not been explored as inhibitors against the PfCytb drug target. Molecular docking, molecular dynamics (MD) simulations, principal component, and dynamic residue network (DRN; global and local) analyses were utilised to identify and confirm the potential selective inhibitors. Docking results identified compounds that bound selectively onto PfCytb-ISP with a binding energy ≤ -8.7 kcal/mol-1. Further, this work validated a total of eight potential selective compounds to inhibit PfCytb-ISP protein (Qo active site) not only in the wild-type but also in the presence of the point mutations Y268C, Y268N and Y268S. The selective binding of these hit compounds could be linked to the differences reported at sequence/residue level in chapter 3. DRN and residue contact map analyses of the eight compounds in holo and ligand-bound systems revealed reduced residue interactions and decreased protein communication. This suggests that the eight compounds show the possibility of inhibiting the parasite and disrupting important residue-residue interactions. Additionally, 13 selective compounds were identified to bind at the protein’s heterodimer interface, where global and local analysis confirmed their effect on active site residues (distal location) as well as on the communication network. Based on the sequence differences between PfCytb and the human homolog, these findings suggest these selective compounds as potential allosteric modulators of the parasite enzyme, which may serve as possible replacements of the already resistant ATQ drug. Therefore, these findings pave the way for further in vitro studies to establish their anti-plasmodial inhibition levels. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Cultural and social factors affecting crop production at Gqumahashe and Melani, Alice District
- Komanisi, Mzwandile Paul 0000-0003-0866-666X
- Authors: Komanisi, Mzwandile Paul 0000-0003-0866-666X
- Date: 2016-06
- Subjects: Sharecropping , Food crops
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23023 , vital:55001
- Description: Over the years, sharecropping and work-parties have been seen as variables that maintain social cohesion among people and maximize agricultural production. This study seeks to validate the authenticity of this assertion in the context of two neighbouring villages. Although there are other variables that affect crop production in the study areas, Lower Gqumahashe and Melani, in the light of time constraints and the insignificant impact of these variables, the study focused only on sharecropping and work-parties. The study adopted empirical research design. The researcher realised that empirical research design would offer him an opportunity for intense or prolonged contact with informants in order to have a holistic picture of their behaviour. The researcher did not choose theoretical research design because it would not allow him to have an extensive interaction with informants since it relies on secondary data. The findings of the study suggest that sharecropping and work parties are the main variables that hinder the rate of crop production in the study areas. However, there are other secondary variables hindering crop production but they have insignificant impact. These are clan and kinship relations, political structure, religion and social identity. This study concludes that although local informants were in favour of sharecropping and work-parties in the past, they have discontinued them due to exploitation and hoodwinking. , Thesis (PhD) -- Faculty of Social Science and Humanities, 2016
- Full Text:
- Date Issued: 2016-06
- Authors: Komanisi, Mzwandile Paul 0000-0003-0866-666X
- Date: 2016-06
- Subjects: Sharecropping , Food crops
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23023 , vital:55001
- Description: Over the years, sharecropping and work-parties have been seen as variables that maintain social cohesion among people and maximize agricultural production. This study seeks to validate the authenticity of this assertion in the context of two neighbouring villages. Although there are other variables that affect crop production in the study areas, Lower Gqumahashe and Melani, in the light of time constraints and the insignificant impact of these variables, the study focused only on sharecropping and work-parties. The study adopted empirical research design. The researcher realised that empirical research design would offer him an opportunity for intense or prolonged contact with informants in order to have a holistic picture of their behaviour. The researcher did not choose theoretical research design because it would not allow him to have an extensive interaction with informants since it relies on secondary data. The findings of the study suggest that sharecropping and work parties are the main variables that hinder the rate of crop production in the study areas. However, there are other secondary variables hindering crop production but they have insignificant impact. These are clan and kinship relations, political structure, religion and social identity. This study concludes that although local informants were in favour of sharecropping and work-parties in the past, they have discontinued them due to exploitation and hoodwinking. , Thesis (PhD) -- Faculty of Social Science and Humanities, 2016
- Full Text:
- Date Issued: 2016-06
Parents and personnel’s partnership in early childhood education provisioning in the East London Education District
- Mudziwapasi, Lilymore https://orcid.org/0000-0002-7978-8499
- Authors: Mudziwapasi, Lilymore https://orcid.org/0000-0002-7978-8499
- Date: 2022-02
- Subjects: Education, Preschool -- Parent participation , Education, Preschool
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21700 , vital:51743
- Description: Early childhood development is fundamental to human development and success in later life. Several stakeholders influence that development. Developmental policies are advocating for formal education provision at that early childhood age. Therefore, relationships and interactions of these stakeholders are of paramount importance in ensuring effective early childhood education provisioning – especially between parents and practitioners. Yet it has been reported that sharing of information concerning children’s educational development is not happening between parents and ECD practitioners. ECD centres are said to face many problems such as poor teaching and learning which may result in weak childhood educational development. Some of these challenges can be addressed through enhancing the partnership between parents and the ECD practitioners. The purpose of this study was therefore to explore the parents and practitioners’ partnership in early childhood education provisioning in ECD centres in the East London district. This study used the mixed method approach in the sampling, data collection and data analysis processes. The study focused on the partnership between parents and ECD practitioners, on how they work together, their views, how they communicate, on decision making and the strategies to enhance the partnership of parents and practitioners. Research questions in this study required both qualitative and quantitative data and analysis techniques. Quantitative data was collected from the ECD practitioners and principals by using questionnaires and qualitative data was collected through interviews with the parents. Quantitative data was analysed using SPSS and qualitative data was analysed using the thematic approach. The findings indicated that both parents and practitioners are working together in supporting learning and development. Parents are said to provide resources for use at the centre. Parents and practitioners are using different modes of communication for the learning and development of the children, including technology-based WhatsApp and emails. Practitioners are said to include parents in some decision making. The results indicated that even though some parents are working together with practitioners, while other parents are still showing ignorance and lack of knowledge on how they can partner for the educational development of the children. , Thesis (PhD) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-02
- Authors: Mudziwapasi, Lilymore https://orcid.org/0000-0002-7978-8499
- Date: 2022-02
- Subjects: Education, Preschool -- Parent participation , Education, Preschool
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21700 , vital:51743
- Description: Early childhood development is fundamental to human development and success in later life. Several stakeholders influence that development. Developmental policies are advocating for formal education provision at that early childhood age. Therefore, relationships and interactions of these stakeholders are of paramount importance in ensuring effective early childhood education provisioning – especially between parents and practitioners. Yet it has been reported that sharing of information concerning children’s educational development is not happening between parents and ECD practitioners. ECD centres are said to face many problems such as poor teaching and learning which may result in weak childhood educational development. Some of these challenges can be addressed through enhancing the partnership between parents and the ECD practitioners. The purpose of this study was therefore to explore the parents and practitioners’ partnership in early childhood education provisioning in ECD centres in the East London district. This study used the mixed method approach in the sampling, data collection and data analysis processes. The study focused on the partnership between parents and ECD practitioners, on how they work together, their views, how they communicate, on decision making and the strategies to enhance the partnership of parents and practitioners. Research questions in this study required both qualitative and quantitative data and analysis techniques. Quantitative data was collected from the ECD practitioners and principals by using questionnaires and qualitative data was collected through interviews with the parents. Quantitative data was analysed using SPSS and qualitative data was analysed using the thematic approach. The findings indicated that both parents and practitioners are working together in supporting learning and development. Parents are said to provide resources for use at the centre. Parents and practitioners are using different modes of communication for the learning and development of the children, including technology-based WhatsApp and emails. Practitioners are said to include parents in some decision making. The results indicated that even though some parents are working together with practitioners, while other parents are still showing ignorance and lack of knowledge on how they can partner for the educational development of the children. , Thesis (PhD) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-02
Improving governance and service delivery in Nelson Mandela Metropolitan Municipality: a quest for a clean audit opinion
- Ntsundwana, Kanyisa Zime Dadewabobonke
- Authors: Ntsundwana, Kanyisa Zime Dadewabobonke
- Date: 2022-12
- Subjects: Service delivery -- Nelson Mandela Metropolitan Municipality -- Port Elizabeth , Municipal finance--Auditing--Law and legislation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59644 , vital:62297
- Description: The purpose of the study was to investigate how Nelson Mandela Bay Metropolitan Municipality (NMBMM) can improve its governance and service delivery to obtain a clean audit outcome. In addition, the study explored the role of auditing in the functioning and performance of municipalities. NMBMM public officials and political office-bearers are expected in terms of Chapter 7 of the Constitution of South Africa Act 108 of 1996 to promote the general welfare of the community by meeting its needs, expectations and demands. The qualitative (non-empirical) research methodology followed in the study was based on a desktop approach. The annual documents reviewed to answer the research objectives were the Consolidated General Reports on the Local Government Audit Outcome and the Reports of the Auditor-General to the Eastern Cape Provincial Legislature and the council on the NMBMM and its municipal entity for the financial period 2015/2016 to 2019/2020. The problem was that the NMBMM did not obtain a clean audit opinion during this period. The study findings indicated that the main contributing factors that prevented the NMBMM from improving governance, service delivery and obtaining a clean audit outcome were as follows: poor management of accounting practices (financial management); inadequate financial statements and performance reports; a lack of adherence to predetermined objectives and legislation; and unauthorised, fruitless, wasteful and irregular expenditure. To attain a clean audit outcome, NMBMM municipal officials and political officebearers need to perform their mandated duties diligently and overcome the challenges that have barred them from obtaining an unqualified audit opinion. Such an endeavour would be consistent with the Operation Clean Audit (OPCA) campaign, which was introduced by the former Minister of Cooperative Governance and Traditional Affairs, Sicelo Shiceka, in 2009. In other words, the NMBMM must improve its governance and service delivery because a municipality without good governance lacks accountability, which has a direct negative impact on the delivery of services to its communities. Hence, it is recommended inter alia that the NMBMM seeks advice from iii the Auditor-General on strategies to improve its audit outcomes, maintains infrastructure, addresses criminal activities and improves its internal controls. , Thesis (MSc) -- Faculty of Humanities, School of Governmental and Social sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Ntsundwana, Kanyisa Zime Dadewabobonke
- Date: 2022-12
- Subjects: Service delivery -- Nelson Mandela Metropolitan Municipality -- Port Elizabeth , Municipal finance--Auditing--Law and legislation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59644 , vital:62297
- Description: The purpose of the study was to investigate how Nelson Mandela Bay Metropolitan Municipality (NMBMM) can improve its governance and service delivery to obtain a clean audit outcome. In addition, the study explored the role of auditing in the functioning and performance of municipalities. NMBMM public officials and political office-bearers are expected in terms of Chapter 7 of the Constitution of South Africa Act 108 of 1996 to promote the general welfare of the community by meeting its needs, expectations and demands. The qualitative (non-empirical) research methodology followed in the study was based on a desktop approach. The annual documents reviewed to answer the research objectives were the Consolidated General Reports on the Local Government Audit Outcome and the Reports of the Auditor-General to the Eastern Cape Provincial Legislature and the council on the NMBMM and its municipal entity for the financial period 2015/2016 to 2019/2020. The problem was that the NMBMM did not obtain a clean audit opinion during this period. The study findings indicated that the main contributing factors that prevented the NMBMM from improving governance, service delivery and obtaining a clean audit outcome were as follows: poor management of accounting practices (financial management); inadequate financial statements and performance reports; a lack of adherence to predetermined objectives and legislation; and unauthorised, fruitless, wasteful and irregular expenditure. To attain a clean audit outcome, NMBMM municipal officials and political officebearers need to perform their mandated duties diligently and overcome the challenges that have barred them from obtaining an unqualified audit opinion. Such an endeavour would be consistent with the Operation Clean Audit (OPCA) campaign, which was introduced by the former Minister of Cooperative Governance and Traditional Affairs, Sicelo Shiceka, in 2009. In other words, the NMBMM must improve its governance and service delivery because a municipality without good governance lacks accountability, which has a direct negative impact on the delivery of services to its communities. Hence, it is recommended inter alia that the NMBMM seeks advice from iii the Auditor-General on strategies to improve its audit outcomes, maintains infrastructure, addresses criminal activities and improves its internal controls. , Thesis (MSc) -- Faculty of Humanities, School of Governmental and Social sciences, 2022
- Full Text:
- Date Issued: 2022-12
Consumerism, authenticity and African communalism
- Smook, E https://orcid.org/0000-0003-4226-6029
- Authors: Smook, E https://orcid.org/0000-0003-4226-6029
- Date: 2022-09
- Subjects: Consumption (Economics) , Authenticity (Philosophy) , Philosophy, African
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23958 , vital:62022
- Description: Let me state, from the outset, that the issues raised below may be considered from various vantage points – Capitalism, Marxism, etc. However, this thesis is an endeavour to account for the loss of authenticity due to the most salient features of the consumer paradigm, which is the manufactured object, the production line and the proliferation of said objects. True relationships, or shall we say authentic dialogue, is based upon a difference of viewpoints – or epistemic distance – between the interlocutors. This difference of opinion, it may be argued, allows for a cognitive jostling between the subjects involved and represents, as it were, the reciprocal back and forth movement of ideas that betokens actively engaged dialogue. Crucial, then, to true, and by extension authentic, relationships is an epistemic distance steeped in variegated, heterogeneous points of view. For it is in sharing the differences in our points of view or interpretations of the world that we may start a dialogue far removed from each other and then sustain said dialogue in an attempt to reconcile our differences. The continuation of the dialogue, then, depends upon difference. Without the latter difference, the conditions of true dialogue, which is also a marker of authentic relationships, the need for sustained debate is forfeited and the dialogue ceases to serve a purpose – for the subjects involved in the intellectual jostling and exchange of ideas may already anticipate the thoughts of the other. In so anticipating the thoughts of the other, what is brought to the fore is not the ideas of the other, and by extension the other’s existence distinct from mine, but rather my own existence and thoughts. Were I and the other to share a constellation of beliefs, I am left with only that which I already believe in and so only with my own thoughts. The other’s differing opinion is crucial to their appearing to me as an element discreet and distinct from me. For if the other’s being is in essence of the same ilk as mine – and with that I mean if the other’s points of view and adopted systems of praxis mirror mine – we are like trees in a forest. The existence of collective nouns attests to this latter remark; we are prone to see the forest, not the similar trees that constitute it. Now the question arises as to the constitution of the self; what is it that makes up the character and nature of a person and how, if at all, may subjects be said to differ epistemically? According to Sartre, the ego is a transcendent object for consciousness, meaning that it exists out there in the world just like other objects. This is the case because consciousness is essentially empty. Recall Sartre’s famous claim that existence precedes essence, which in turn means that consciousness, or the ego, is filled up inchmeal with contents outside itself. In other words, that with which we are engaged constitutes the contents of consciousness. Repeated exposure to certain objects, or phenomena, brings about the cultivation of states and qualities – these, as it were, constituting the ego in the end. Moreover, these states and qualities, as arisen from repeated exposure to like phenomena, will instil in the subject a certain proclivity for a certain manner of action under specific conditions. As such, having been presented with something disagreeable many times over, a state of repulsion might gain a foothold in my ego regarding the phenomenon in question. This in turn will dictate how I act in the presence of said phenomenon or any other phenomena that include, adumbrationally, some of the qualities of the original phenomenon. As such, then, my actions are reflections of the states that I experience in the presence of certain objects or phenomena and, it may be argued, reflexively represent the world around me as that which constitutes my ego. The facticity of the world, then, has a great bearing upon the manner in which I perceive and engage the world. However, claims Sartre, facticity is but one side of the coin. The world and its meaning are constituted by what Sartre calls brute meaning. This refers to the fact that meaning is a matter of public opinion and does not precede the phenomenon or object itself – the latter being, in essence, but a bare, pliable, monstrous mass of being-in-itself. Due to this occurrence of meaning being man made, we are in a unique position of freedom. We are, he further claims, capable of transcending these brute meanings, enabling us to avail ourselves of the objects or phenomena in question in a bespoke manner. Freedom to choose how we interact with and interpret the world is thus the ontological ground of choice. We have, on the one side, the world in its undifferentiated state – being-in-itself – and on the other the possibility to give this world a specific meaning in accordance with our intentions – being-for-itself. Freedom to choose, so construed, thus ontologically underlies the very fabric of our existence, hence the claim that we are condemned to be free. Choosing whether to continue along the path set out by our original factual condition or to transcend it and make of it something different altogether is thus not a choice at all, but the obligatory condition of the human condition. Once again, this is the case because consciousness, as per Sartre, is empty to start with and can only be filled with the contents of phenomena or objects in accordance with our intentional engagement of them. However, Sartre continues, this freedom of meaning and the fact that brute existents represent nothing more than the convergence of publicly ascribed meaning awaken in the subject a certain nausea – a nausea born of the fact that we, the people, are at every junction in a position where we have to choose the meaning of life. Determinism, thusly, does not exist and we are not only free to choose the meanings of our own lives, but are responsible for what our lives become. This realisation proves to be too much for most to stomach and leads them along a specific path of choice: over-identification with either their factual realities or with the possibility to transcend the latter. Either way, what they aim to achieve with this overidentification is the suppression of the nauseating reality that reality is nought but what we make it to be and we are thus responsible for what it becomes. Sartre calls this bad faith. Pandering to this proclivity towards bad faith, or alternatively, the propensity for overidentification with either side on the facticity/transcendence dichotomy, we find consumerism. The consumer paradigm delineates happiness as an objective ideal, attainable through the acquisition of specific markers of demonstrable happiness. At the same time, it also provides an answer to the nauseating reality that we, humans, are never fully determined beings, but find ourselves vacillating between our factual constraints and our transcendences thereof. It offers us the crystalised means of becoming this or that individual by way of populating our immediate and personal surroundings with signifiers of happiness. Considering, moreover, that a liberalist conception of human being clearly indicates that individuation of each subject is an important aspect of existence, authenticity in terms of rights emerge as a corollary of said individuation. Each individual, so construed, is given the opportunity, the right, to acquire said markers of happiness and individuation. Obtaining these, it may be argued, allows the individual two things: firstly, to quell the nausea that haunts our dualistic lives by concretising it altogether and so doing highlighting the factual side of things; and secondly, to become discreet and individuated subjects, authentic in their beings. However, the authenticity so begotten provides nought but a thin veneer of idiosyncrasy, as the markers of said authenticity are publicly available and so the same for everyone. The problem, thus, of self-individuation is resolved by providing the subject the means of over-identification with their factual realities whilst convincing them, the consumers, that the objects on offer will afford them a degree of happiness and set them apart from their fellow subjects. The unfortunate upshot of this is that subjects all avail themselves of the same set of objects in an attempt to quell the nausea that besets the individual plunged into an undifferentiated existence. We are here at the heart of the matter. Due to the proliferation of like objects throughout the life-world, a specific system of praxis is implied. So as to navigate the life-world and utilise the similar objects that populate it, consumers are driven towards shared ideologies and courses of action. Moreover, their intentions also converge, as they all seek to establish a web of objects around them that would bespeak their individuation and happiness. Where the life-world has become such a homogeneous landscape, it may be argued, in line with Sartrean thought, that the contents of consciousness would also be similar for all. And where the contents of consciousness is similar for all, we may argue that reasoning would be similar for all. It is at this point that dialogue breaks down, for there is nothing epistemically to separate interlocutors and therefore no differences of opinion to sustain true dialogue. If, as it was reasoned some pages prior, it is the case that sustained dialogue provides the predicate upon which authentic relationships are to be based, the collapse of this epistemic distance between consumers must then also lead to a collapse of authentic relationships. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022-09
- Authors: Smook, E https://orcid.org/0000-0003-4226-6029
- Date: 2022-09
- Subjects: Consumption (Economics) , Authenticity (Philosophy) , Philosophy, African
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23958 , vital:62022
- Description: Let me state, from the outset, that the issues raised below may be considered from various vantage points – Capitalism, Marxism, etc. However, this thesis is an endeavour to account for the loss of authenticity due to the most salient features of the consumer paradigm, which is the manufactured object, the production line and the proliferation of said objects. True relationships, or shall we say authentic dialogue, is based upon a difference of viewpoints – or epistemic distance – between the interlocutors. This difference of opinion, it may be argued, allows for a cognitive jostling between the subjects involved and represents, as it were, the reciprocal back and forth movement of ideas that betokens actively engaged dialogue. Crucial, then, to true, and by extension authentic, relationships is an epistemic distance steeped in variegated, heterogeneous points of view. For it is in sharing the differences in our points of view or interpretations of the world that we may start a dialogue far removed from each other and then sustain said dialogue in an attempt to reconcile our differences. The continuation of the dialogue, then, depends upon difference. Without the latter difference, the conditions of true dialogue, which is also a marker of authentic relationships, the need for sustained debate is forfeited and the dialogue ceases to serve a purpose – for the subjects involved in the intellectual jostling and exchange of ideas may already anticipate the thoughts of the other. In so anticipating the thoughts of the other, what is brought to the fore is not the ideas of the other, and by extension the other’s existence distinct from mine, but rather my own existence and thoughts. Were I and the other to share a constellation of beliefs, I am left with only that which I already believe in and so only with my own thoughts. The other’s differing opinion is crucial to their appearing to me as an element discreet and distinct from me. For if the other’s being is in essence of the same ilk as mine – and with that I mean if the other’s points of view and adopted systems of praxis mirror mine – we are like trees in a forest. The existence of collective nouns attests to this latter remark; we are prone to see the forest, not the similar trees that constitute it. Now the question arises as to the constitution of the self; what is it that makes up the character and nature of a person and how, if at all, may subjects be said to differ epistemically? According to Sartre, the ego is a transcendent object for consciousness, meaning that it exists out there in the world just like other objects. This is the case because consciousness is essentially empty. Recall Sartre’s famous claim that existence precedes essence, which in turn means that consciousness, or the ego, is filled up inchmeal with contents outside itself. In other words, that with which we are engaged constitutes the contents of consciousness. Repeated exposure to certain objects, or phenomena, brings about the cultivation of states and qualities – these, as it were, constituting the ego in the end. Moreover, these states and qualities, as arisen from repeated exposure to like phenomena, will instil in the subject a certain proclivity for a certain manner of action under specific conditions. As such, having been presented with something disagreeable many times over, a state of repulsion might gain a foothold in my ego regarding the phenomenon in question. This in turn will dictate how I act in the presence of said phenomenon or any other phenomena that include, adumbrationally, some of the qualities of the original phenomenon. As such, then, my actions are reflections of the states that I experience in the presence of certain objects or phenomena and, it may be argued, reflexively represent the world around me as that which constitutes my ego. The facticity of the world, then, has a great bearing upon the manner in which I perceive and engage the world. However, claims Sartre, facticity is but one side of the coin. The world and its meaning are constituted by what Sartre calls brute meaning. This refers to the fact that meaning is a matter of public opinion and does not precede the phenomenon or object itself – the latter being, in essence, but a bare, pliable, monstrous mass of being-in-itself. Due to this occurrence of meaning being man made, we are in a unique position of freedom. We are, he further claims, capable of transcending these brute meanings, enabling us to avail ourselves of the objects or phenomena in question in a bespoke manner. Freedom to choose how we interact with and interpret the world is thus the ontological ground of choice. We have, on the one side, the world in its undifferentiated state – being-in-itself – and on the other the possibility to give this world a specific meaning in accordance with our intentions – being-for-itself. Freedom to choose, so construed, thus ontologically underlies the very fabric of our existence, hence the claim that we are condemned to be free. Choosing whether to continue along the path set out by our original factual condition or to transcend it and make of it something different altogether is thus not a choice at all, but the obligatory condition of the human condition. Once again, this is the case because consciousness, as per Sartre, is empty to start with and can only be filled with the contents of phenomena or objects in accordance with our intentional engagement of them. However, Sartre continues, this freedom of meaning and the fact that brute existents represent nothing more than the convergence of publicly ascribed meaning awaken in the subject a certain nausea – a nausea born of the fact that we, the people, are at every junction in a position where we have to choose the meaning of life. Determinism, thusly, does not exist and we are not only free to choose the meanings of our own lives, but are responsible for what our lives become. This realisation proves to be too much for most to stomach and leads them along a specific path of choice: over-identification with either their factual realities or with the possibility to transcend the latter. Either way, what they aim to achieve with this overidentification is the suppression of the nauseating reality that reality is nought but what we make it to be and we are thus responsible for what it becomes. Sartre calls this bad faith. Pandering to this proclivity towards bad faith, or alternatively, the propensity for overidentification with either side on the facticity/transcendence dichotomy, we find consumerism. The consumer paradigm delineates happiness as an objective ideal, attainable through the acquisition of specific markers of demonstrable happiness. At the same time, it also provides an answer to the nauseating reality that we, humans, are never fully determined beings, but find ourselves vacillating between our factual constraints and our transcendences thereof. It offers us the crystalised means of becoming this or that individual by way of populating our immediate and personal surroundings with signifiers of happiness. Considering, moreover, that a liberalist conception of human being clearly indicates that individuation of each subject is an important aspect of existence, authenticity in terms of rights emerge as a corollary of said individuation. Each individual, so construed, is given the opportunity, the right, to acquire said markers of happiness and individuation. Obtaining these, it may be argued, allows the individual two things: firstly, to quell the nausea that haunts our dualistic lives by concretising it altogether and so doing highlighting the factual side of things; and secondly, to become discreet and individuated subjects, authentic in their beings. However, the authenticity so begotten provides nought but a thin veneer of idiosyncrasy, as the markers of said authenticity are publicly available and so the same for everyone. The problem, thus, of self-individuation is resolved by providing the subject the means of over-identification with their factual realities whilst convincing them, the consumers, that the objects on offer will afford them a degree of happiness and set them apart from their fellow subjects. The unfortunate upshot of this is that subjects all avail themselves of the same set of objects in an attempt to quell the nausea that besets the individual plunged into an undifferentiated existence. We are here at the heart of the matter. Due to the proliferation of like objects throughout the life-world, a specific system of praxis is implied. So as to navigate the life-world and utilise the similar objects that populate it, consumers are driven towards shared ideologies and courses of action. Moreover, their intentions also converge, as they all seek to establish a web of objects around them that would bespeak their individuation and happiness. Where the life-world has become such a homogeneous landscape, it may be argued, in line with Sartrean thought, that the contents of consciousness would also be similar for all. And where the contents of consciousness is similar for all, we may argue that reasoning would be similar for all. It is at this point that dialogue breaks down, for there is nothing epistemically to separate interlocutors and therefore no differences of opinion to sustain true dialogue. If, as it was reasoned some pages prior, it is the case that sustained dialogue provides the predicate upon which authentic relationships are to be based, the collapse of this epistemic distance between consumers must then also lead to a collapse of authentic relationships. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022-09
The experiences of clinical psychologists in treating traumatic stress at a tertiary psychiatric hospital in the Eastern Cape: A qualitative research study
- Authors: Munishvaran, Kuriesha
- Date: 2021-10-29
- Subjects: Post-traumatic stress disorder Treatment South Africa Eastern Cape , Secondary traumatic stress Treatment South Africa Eastern Cape , Phenomenological psychology , Clinical psychologists Mental health South Africa Eastern Cape , Psychiatric hospitals South Africa Eastern Cape , Psychiatric hospital patients South Africa Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190271 , vital:44979
- Description: Traumatic encounters are highly prevalent within the South African population. Clinical psychologists working with these trauma narratives, within a psychiatric context, are therefore at risk of experiencing vicarious trauma, Post Traumatic Stress-Disorder (PTSD), and secondary traumatic stress. This study aimed to explore the lived experiences of clinical psychologists who treat patients that are either trauma survivors or perpetrators in a psychiatric hospital. Individual semi-structured interviews and follow-up interviews were conducted with three clinical psychologists based at a psychiatric hospital in the Eastern Cape. Data was analysed using Interpretive Phenomenological Analysis. All participants reported experiencing symptoms of vicarious trauma and secondary traumatic stress while treating both victims and perpetrators. The findings also discovered an element of danger, as well as socio-political factors that clinical psychologists experience. Participants also reported experiencing vicarious post-traumatic growth, enhanced by their coping strategies, while providing psychological services to traumatised patients. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Munishvaran, Kuriesha
- Date: 2021-10-29
- Subjects: Post-traumatic stress disorder Treatment South Africa Eastern Cape , Secondary traumatic stress Treatment South Africa Eastern Cape , Phenomenological psychology , Clinical psychologists Mental health South Africa Eastern Cape , Psychiatric hospitals South Africa Eastern Cape , Psychiatric hospital patients South Africa Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190271 , vital:44979
- Description: Traumatic encounters are highly prevalent within the South African population. Clinical psychologists working with these trauma narratives, within a psychiatric context, are therefore at risk of experiencing vicarious trauma, Post Traumatic Stress-Disorder (PTSD), and secondary traumatic stress. This study aimed to explore the lived experiences of clinical psychologists who treat patients that are either trauma survivors or perpetrators in a psychiatric hospital. Individual semi-structured interviews and follow-up interviews were conducted with three clinical psychologists based at a psychiatric hospital in the Eastern Cape. Data was analysed using Interpretive Phenomenological Analysis. All participants reported experiencing symptoms of vicarious trauma and secondary traumatic stress while treating both victims and perpetrators. The findings also discovered an element of danger, as well as socio-political factors that clinical psychologists experience. Participants also reported experiencing vicarious post-traumatic growth, enhanced by their coping strategies, while providing psychological services to traumatised patients. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
Physiological winners and losers in an ocean warming hotspot: a Case study on argyrosomus off the Namibian coast, with implications for their future management
- Authors: Pringle, Brett Andrew
- Date: 2021-10
- Subjects: Argyrosomus Benguela Current , Ocean temperature Benguela Current , Sciaenidae Benguela Current , Argyrosomus Physiology Benguela Current , Argyrosomus Geographical distribution Climatic factors Benguela Current , Argyrosomus Effect of temperature on Benguela Current , Sciaenidae fisheries Namibia , Fishery management Namibia , Sustainable fisheries Namibia
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188987 , vital:44804
- Description: Anthropogenic-induced climate change is having a profound impact on aquatic ecosystems, and the resilience of fish populations will be determined by how they respond to these impacts. Changes in ocean water temperature is regarded as the most pervasive change, and affects the biological, physiological and distribution response of species, particularly ectotherms. The increasingly variable biological responses to a changing environment suggest that some species and populations will likely prove to be more tolerant than others. The northern Namibian coast is an ocean warming hotspot, with temperatures rising at approximately ten times the global average. These rapid changes are predicted to have a considerable impact on the marine fauna. One recently documented change in distribution is a southern extension of the sciaenid, Argyrosomus coronus, from southern Angola into northern Namibian waters, where it now overlaps with the closely related Namibian species, Argyrosomus inodorus. Understanding how these species perform at current and future temperatures and where they overlap is vital to optimise any adaptive management for the Argyrosomus species, which forms a large component of Namibia’s coastal commercial, recreational and subsistence fisheries. The aim of this study was to quantify the aerobic scope of both species (A. coronus and A. inodorus), to determine which Argyrosomus species will be a winner at the current and future climate predictions and to provide recommendations for the sustainable management of the Namibian Argyrosomus fishery. Intermittent flow-through respirometry was used to quantify standard and maximum metabolic rates for both species across a range of temperatures. Results showed that metabolic rates scaled positively with temperature. It appears that the aerobic scope of A. inodorus was notably higher at most temperatures (12, 15, 18 and 21˚C), while that of A. coronus was only higher at the warmest test temperature of 24˚C. This corresponded with the contemporary biogeographic patterns of each species. Based on these findings, it is likely that the warming ocean conditions in northern Namibia and the cold Lüdertiz upwelling cell south of Walvis Bay will constrain these fish to central Namibia. While both species demonstrated signs of resilience to high temperatures, it is likely that the warming conditions will increasingly favour A. coronus, and that the leading edge of their distribution will shift southward in Namibia. The distribution of A. inodorus is likely to contract, as the energy budget of those on the northern trailing edge will be compromised. To promote the sustainable utilisation of the complex Argyrosomus fishery, adaptive management strategies need to be implemented. This will only be possible with a comprehensive monitoring program, including the collection of genetic data to inform the changing proportions of the two species. To maintain the A. coronus population, the current regulations need to be re-assessed, and harvest slots should be introduced to protect juvenile A. coronus and the fecund large females of both species. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Pringle, Brett Andrew
- Date: 2021-10
- Subjects: Argyrosomus Benguela Current , Ocean temperature Benguela Current , Sciaenidae Benguela Current , Argyrosomus Physiology Benguela Current , Argyrosomus Geographical distribution Climatic factors Benguela Current , Argyrosomus Effect of temperature on Benguela Current , Sciaenidae fisheries Namibia , Fishery management Namibia , Sustainable fisheries Namibia
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188987 , vital:44804
- Description: Anthropogenic-induced climate change is having a profound impact on aquatic ecosystems, and the resilience of fish populations will be determined by how they respond to these impacts. Changes in ocean water temperature is regarded as the most pervasive change, and affects the biological, physiological and distribution response of species, particularly ectotherms. The increasingly variable biological responses to a changing environment suggest that some species and populations will likely prove to be more tolerant than others. The northern Namibian coast is an ocean warming hotspot, with temperatures rising at approximately ten times the global average. These rapid changes are predicted to have a considerable impact on the marine fauna. One recently documented change in distribution is a southern extension of the sciaenid, Argyrosomus coronus, from southern Angola into northern Namibian waters, where it now overlaps with the closely related Namibian species, Argyrosomus inodorus. Understanding how these species perform at current and future temperatures and where they overlap is vital to optimise any adaptive management for the Argyrosomus species, which forms a large component of Namibia’s coastal commercial, recreational and subsistence fisheries. The aim of this study was to quantify the aerobic scope of both species (A. coronus and A. inodorus), to determine which Argyrosomus species will be a winner at the current and future climate predictions and to provide recommendations for the sustainable management of the Namibian Argyrosomus fishery. Intermittent flow-through respirometry was used to quantify standard and maximum metabolic rates for both species across a range of temperatures. Results showed that metabolic rates scaled positively with temperature. It appears that the aerobic scope of A. inodorus was notably higher at most temperatures (12, 15, 18 and 21˚C), while that of A. coronus was only higher at the warmest test temperature of 24˚C. This corresponded with the contemporary biogeographic patterns of each species. Based on these findings, it is likely that the warming ocean conditions in northern Namibia and the cold Lüdertiz upwelling cell south of Walvis Bay will constrain these fish to central Namibia. While both species demonstrated signs of resilience to high temperatures, it is likely that the warming conditions will increasingly favour A. coronus, and that the leading edge of their distribution will shift southward in Namibia. The distribution of A. inodorus is likely to contract, as the energy budget of those on the northern trailing edge will be compromised. To promote the sustainable utilisation of the complex Argyrosomus fishery, adaptive management strategies need to be implemented. This will only be possible with a comprehensive monitoring program, including the collection of genetic data to inform the changing proportions of the two species. To maintain the A. coronus population, the current regulations need to be re-assessed, and harvest slots should be introduced to protect juvenile A. coronus and the fecund large females of both species. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries, 2021
- Full Text:
- Date Issued: 2021-10
Financing tools, firm life cycle and growth of small, medium and micro enterprises in selected sub-Sahara African economies
- Ngonisa, Phillip https://orcid.org/0000-0002-0145-9062
- Authors: Ngonisa, Phillip https://orcid.org/0000-0002-0145-9062
- Date: 2022-03
- Subjects: Small business -- Finance , Small business -- Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21794 , vital:51754
- Description: Finance is of paramount importance for small, medium and micro enterprises’ (SMMEs) growth, without which many firms fail to move along their growth continuum. Against this background, the study sought to examine the growth effects of financing tools across the different phases of SMMEs' life cycle in Sub Sahara Africa (SSA) economies for the period spanning from 2003 to 2019. Firstly, due to the inherent heterogeneity nature of the SMMEs' financing landscapes across the world, the study starts by identifying the commonly used financing tools in the context of Sub-Saharan Africa. These were found to be internal finance, bank debt, trade credit, non-bank finance and informal finance, with internal finance being the most prevalent financing tool. The second aspect of the study was to examine the growth effects of the identified financing tools on SMMEs' performance in Sub Sahara Africa. In achieving this objective, several panel estimation techniques were employed, which are the feasible generalised least squares (FGLS), cross-sectional dependence (SCC), random effects model (REM) and pooled ordinary least squares (POLS). The empirical results show that internal finance or savings, bank financing, trade credit, non-bank financing and informal financing are positive and statistically significant in explaining SMMEs growth in the region, with stronger evidence for a positive relationship between external finance (trade credit and bank finance) on SMMEs growth in Sub-Saharan African region. The third objective of the study was to investigate the growth effects of SMMEs’ financing tools across different phases of the firm life cycle. The same panel techniques as used in achieving the previous objective were utilized again. The empirical findings show that the growth effects of SMME financing tools evolve as SMMEs move along their growth continuum, and only bank finance proved to be a fundamental variable for SMMEs growth throughout the different phases of firm growth. Finally, motivated by SMMEs’ high dependence on internal finance or savings, the study explored the saving practices of SMMEs in Sub Saharan Africa using thematic analysis. The study findings show that SMMEs in Sub Sahara African economies systematically save through formal and informal financial systems. These findings are contrary to conventional wisdom, which suggests that SMMEs are a financial basket case. Basing on the study findings, policies aimed at reducing or lessening the burden of accessing finance are important to stimulate the growth of SMMEs. Most importantly, there is a need for lenders and sponsors to understand the firm life cycle-financing tool nexus to ensure SMMEs growth. Moreover, SMMEs in Sub Sahara African economies need to cultivate a spirit of thrift to minimize firm attrition rate, thereby promoting SMMEs' growth in the region. , Thesis (PhD) -- Faculty of Management and Commerce, 2022
- Full Text:
- Date Issued: 2022-03
- Authors: Ngonisa, Phillip https://orcid.org/0000-0002-0145-9062
- Date: 2022-03
- Subjects: Small business -- Finance , Small business -- Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21794 , vital:51754
- Description: Finance is of paramount importance for small, medium and micro enterprises’ (SMMEs) growth, without which many firms fail to move along their growth continuum. Against this background, the study sought to examine the growth effects of financing tools across the different phases of SMMEs' life cycle in Sub Sahara Africa (SSA) economies for the period spanning from 2003 to 2019. Firstly, due to the inherent heterogeneity nature of the SMMEs' financing landscapes across the world, the study starts by identifying the commonly used financing tools in the context of Sub-Saharan Africa. These were found to be internal finance, bank debt, trade credit, non-bank finance and informal finance, with internal finance being the most prevalent financing tool. The second aspect of the study was to examine the growth effects of the identified financing tools on SMMEs' performance in Sub Sahara Africa. In achieving this objective, several panel estimation techniques were employed, which are the feasible generalised least squares (FGLS), cross-sectional dependence (SCC), random effects model (REM) and pooled ordinary least squares (POLS). The empirical results show that internal finance or savings, bank financing, trade credit, non-bank financing and informal financing are positive and statistically significant in explaining SMMEs growth in the region, with stronger evidence for a positive relationship between external finance (trade credit and bank finance) on SMMEs growth in Sub-Saharan African region. The third objective of the study was to investigate the growth effects of SMMEs’ financing tools across different phases of the firm life cycle. The same panel techniques as used in achieving the previous objective were utilized again. The empirical findings show that the growth effects of SMME financing tools evolve as SMMEs move along their growth continuum, and only bank finance proved to be a fundamental variable for SMMEs growth throughout the different phases of firm growth. Finally, motivated by SMMEs’ high dependence on internal finance or savings, the study explored the saving practices of SMMEs in Sub Saharan Africa using thematic analysis. The study findings show that SMMEs in Sub Sahara African economies systematically save through formal and informal financial systems. These findings are contrary to conventional wisdom, which suggests that SMMEs are a financial basket case. Basing on the study findings, policies aimed at reducing or lessening the burden of accessing finance are important to stimulate the growth of SMMEs. Most importantly, there is a need for lenders and sponsors to understand the firm life cycle-financing tool nexus to ensure SMMEs growth. Moreover, SMMEs in Sub Sahara African economies need to cultivate a spirit of thrift to minimize firm attrition rate, thereby promoting SMMEs' growth in the region. , Thesis (PhD) -- Faculty of Management and Commerce, 2022
- Full Text:
- Date Issued: 2022-03
Lateral and vertical mineral-chemical variation in high-grade ores of the Kalahari Manganese Field, and implications for ore genesis and geometallurgy
- Authors: Motilaodi, Donald
- Date: 2022-10-14
- Subjects: Manganese ores , Geometallurgy , Hydrothermal alteration , Petrology , Mineralogy , Geochemistry
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362972 , vital:65379
- Description: The Kalahari Manganese Field (KMF) is a world-class resource of manganese ore hosted by the Paleoproterozoic Hotazel banded iron formation. KMF ores are categorised into two main types, i.e., low-grade, carbonate rich, braunitic ore (Mn≤40wt%) and carbonate-free, high-grade, Ca-braunite+hausmannite ore (Mn≥44wt%). High-grade ores, also known as Wessels type from the homonymous mine in the northernmost KMF, are thought to have formed from variable degrees of hydrothermal carbonate and silica leaching from a low-grade ore precursor, termed Mamatwan-type after the homonymous mine in the southernmost KMF. This project aims to conduct a mineralogical and mineral-chemical study of representative manganese ore samples from a suite of drillcores intersecting both the upper and the lower layers in the northern KMF, covering the areas of Wessels, N’chwaning and Gloria mines. Petrographically, the high-grade Mn ore displays great variability in three-dimensional space. Texturally, the ores exhibit a great variety of textures which may or may not show preservation of the laminated and ovoidal textures that typify the postulated low-grade protore. There is also significant variation in the mineralogical and geochemical characteristics of the high-grade Mn ores both vertically and laterally. Vertical variation includes, probably for the first time, variability between the upper and lower ore layers within individual drillcores of the Hotazel sequence. Mineralogically, the ores contain variable modal abundances of the ore-forming minerals braunite (I, II, “new”) and hausmannite, and much less so of bixbyite, marokite and manganite. Common accessories include andradite, barite and low-Mn carbonate minerals. Chemically, the dominant ore minerals braunite and hausmannite, contain Fe up to 22 and 15wt% respectively, which accounts for the bulk of the iron contained in the ores. Braunite compositions also exhibit a large range with respect to their ratio of Ca/Si. Mineral-specific trace element concentrations for the same minerals measured by LA-ICP-MS, reveal generally large variations from one element to the other. When normalized against the trace element composition of bulk low-grade precursor ore, strong enrichments are recorded for both hausmannite and braunite in selected alkali/alkali earth elements, transition metals and lanthanides, such as Sc, Co, Zn, Cu, Pb, La, and Ce. These are akin to enrichments recorded in average high-grade ore. Although there is also no obvious relationship between Fe content in both hausmannite and braunite and their trace element abundances, the drillcore that captures high-grade ore with the highest trace element concentrations appears to be located most proximal to a major fault. Results collectively suggest that high-grade Mn ores of the KMF have undergone a complex hydrothermal history with a clear and significant metasomatic addition of trace elements into ore-forming minerals. First order trends in the mineralogical and mineral-chemical distribution of the ores in space, suggest hausmannite-dominated ores near the Hotazel suboutcrop, and an apparent decline in ore quality with braunite II-andradite-barite-calcite ores as the major graben fault is approached in a southwesterly direction. The latter trend appears to be at odds with prevailing fault-controlled alteration models. Elucidating that hydrothermal history of the Wessels-type high grade Mn ores of the KMF, will be crucial to understanding the compositional controls of these ores in space, and the potential impact thereof in terms of geometallurgy. , Thesis (MSc) -- Faculty of Science, Geology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Motilaodi, Donald
- Date: 2022-10-14
- Subjects: Manganese ores , Geometallurgy , Hydrothermal alteration , Petrology , Mineralogy , Geochemistry
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362972 , vital:65379
- Description: The Kalahari Manganese Field (KMF) is a world-class resource of manganese ore hosted by the Paleoproterozoic Hotazel banded iron formation. KMF ores are categorised into two main types, i.e., low-grade, carbonate rich, braunitic ore (Mn≤40wt%) and carbonate-free, high-grade, Ca-braunite+hausmannite ore (Mn≥44wt%). High-grade ores, also known as Wessels type from the homonymous mine in the northernmost KMF, are thought to have formed from variable degrees of hydrothermal carbonate and silica leaching from a low-grade ore precursor, termed Mamatwan-type after the homonymous mine in the southernmost KMF. This project aims to conduct a mineralogical and mineral-chemical study of representative manganese ore samples from a suite of drillcores intersecting both the upper and the lower layers in the northern KMF, covering the areas of Wessels, N’chwaning and Gloria mines. Petrographically, the high-grade Mn ore displays great variability in three-dimensional space. Texturally, the ores exhibit a great variety of textures which may or may not show preservation of the laminated and ovoidal textures that typify the postulated low-grade protore. There is also significant variation in the mineralogical and geochemical characteristics of the high-grade Mn ores both vertically and laterally. Vertical variation includes, probably for the first time, variability between the upper and lower ore layers within individual drillcores of the Hotazel sequence. Mineralogically, the ores contain variable modal abundances of the ore-forming minerals braunite (I, II, “new”) and hausmannite, and much less so of bixbyite, marokite and manganite. Common accessories include andradite, barite and low-Mn carbonate minerals. Chemically, the dominant ore minerals braunite and hausmannite, contain Fe up to 22 and 15wt% respectively, which accounts for the bulk of the iron contained in the ores. Braunite compositions also exhibit a large range with respect to their ratio of Ca/Si. Mineral-specific trace element concentrations for the same minerals measured by LA-ICP-MS, reveal generally large variations from one element to the other. When normalized against the trace element composition of bulk low-grade precursor ore, strong enrichments are recorded for both hausmannite and braunite in selected alkali/alkali earth elements, transition metals and lanthanides, such as Sc, Co, Zn, Cu, Pb, La, and Ce. These are akin to enrichments recorded in average high-grade ore. Although there is also no obvious relationship between Fe content in both hausmannite and braunite and their trace element abundances, the drillcore that captures high-grade ore with the highest trace element concentrations appears to be located most proximal to a major fault. Results collectively suggest that high-grade Mn ores of the KMF have undergone a complex hydrothermal history with a clear and significant metasomatic addition of trace elements into ore-forming minerals. First order trends in the mineralogical and mineral-chemical distribution of the ores in space, suggest hausmannite-dominated ores near the Hotazel suboutcrop, and an apparent decline in ore quality with braunite II-andradite-barite-calcite ores as the major graben fault is approached in a southwesterly direction. The latter trend appears to be at odds with prevailing fault-controlled alteration models. Elucidating that hydrothermal history of the Wessels-type high grade Mn ores of the KMF, will be crucial to understanding the compositional controls of these ores in space, and the potential impact thereof in terms of geometallurgy. , Thesis (MSc) -- Faculty of Science, Geology, 2022
- Full Text:
- Date Issued: 2022-10-14
Barriers Inhibiting The Implementation Of Gender Equity And Accessibility Of Female Teachers To Management Positions In Oliver Reginald Tambo Inland District
- Authors: Mandi, Sisiwe
- Date: 2019-00
- Subjects: Gender
- Language: English
- Type: Master's/Doctoral theses , text
- Identifier: http://hdl.handle.net/11260/6665 , vital:47200
- Description: The purpose of the study was to examine the barriers inhibiting the implementation of gender equity and accessibility of female teachers to management positions. This study was conducted in the OR Tambo inland, which is one of the Education Districts in the Eastern Cape Province of South Africa. It should be noted that in terms of intelligence, requisite skills to influence and motivate the workers to accomplish the organisational goals is not linked to gender. It is for this backdrop that motivated me to examine the factors prohibiting and limiting thereof the females from being offered and occupy the management positions in most organisational institutions. This study is aimed to promote a paradigm shift and transformation in overlooking the gender equity by the role-players in the societies and various institutions. Furthermore, the study intends to promote the awareness to stake holders and enactment that the management positions are for everyone who possesses the leadership and management skills. The feminist and social constructivism theories were employed in engaging with the literature reviewed in this research. The survey research design was adopted in this study. A mixed methods research was used to gather and analyse the collected data. Principals, deputy principals and heads of departments were the target population from which the sample was drawn. There were 90 subjects from which data were collected, where 78 were subjected to questionnaires while 12 of them were interviewed. The sample was purposefully selected from 4 high schools that are geographically located in the OR Tambo inland: one from circuit 9, one from circuit 11 and two from circuit 3 schools. The tools used for the gathering of the data were questionnaires, observation and interviews. The analyses of the two data sets were done separately and later put together for discussion. This implies that sequential data analysis was performed. Qualitative data were analysed using content analysis. The quantitative data collected through questionnaire were analysed by using valid percentages, and tables generated by the Statistical Package for Social Sciences (SPSS). The use of SPSS helped me to summarise the collected quantitative data in examining the relationships of variables towards the problem under study. The descriptive and inferential statistics were considered for quantitative data analysis. Upon the completion of the quantitative data analyses, the qualitative data were analysed using content analysis. The findings from this study reveal that the social and cultural stereotypes of female managers; females’ lack of capacity and motivation; male dominance and cultural perceptions/beliefs; union and school governing bodies (SGBs) interference and institutional policies are barriers inhibiting the implementation of gender equity and accessibility of female teachers to management positions. Based on the emerged findings, it is recommended that policy-makers, the administration officers and immediate supervisors encourage the panellists for short-listing and interviews to comply with the legislative that requires the transformation and adherence to gender equity in all recruitment processes and practices. It is also recommended that workshops about the compliance on the implementation of gender equity by the role-players in education sector are widely and often conducted. It is further recommended that through distribution of circulars and school newsletters, conducting of imbizo or the role-players about the adherence to gender equity and constant dialogue with the communities, teacher’ unions, parents and youth in meetings could improve their perceptions and understanding that management positions for employees should be based on efficiency, competence and professional qualification but not on gender perspective. , Thesis (D.Ed) -- Faculty of Education Sciences, 2019
- Full Text:
- Date Issued: 2019-00
- Authors: Mandi, Sisiwe
- Date: 2019-00
- Subjects: Gender
- Language: English
- Type: Master's/Doctoral theses , text
- Identifier: http://hdl.handle.net/11260/6665 , vital:47200
- Description: The purpose of the study was to examine the barriers inhibiting the implementation of gender equity and accessibility of female teachers to management positions. This study was conducted in the OR Tambo inland, which is one of the Education Districts in the Eastern Cape Province of South Africa. It should be noted that in terms of intelligence, requisite skills to influence and motivate the workers to accomplish the organisational goals is not linked to gender. It is for this backdrop that motivated me to examine the factors prohibiting and limiting thereof the females from being offered and occupy the management positions in most organisational institutions. This study is aimed to promote a paradigm shift and transformation in overlooking the gender equity by the role-players in the societies and various institutions. Furthermore, the study intends to promote the awareness to stake holders and enactment that the management positions are for everyone who possesses the leadership and management skills. The feminist and social constructivism theories were employed in engaging with the literature reviewed in this research. The survey research design was adopted in this study. A mixed methods research was used to gather and analyse the collected data. Principals, deputy principals and heads of departments were the target population from which the sample was drawn. There were 90 subjects from which data were collected, where 78 were subjected to questionnaires while 12 of them were interviewed. The sample was purposefully selected from 4 high schools that are geographically located in the OR Tambo inland: one from circuit 9, one from circuit 11 and two from circuit 3 schools. The tools used for the gathering of the data were questionnaires, observation and interviews. The analyses of the two data sets were done separately and later put together for discussion. This implies that sequential data analysis was performed. Qualitative data were analysed using content analysis. The quantitative data collected through questionnaire were analysed by using valid percentages, and tables generated by the Statistical Package for Social Sciences (SPSS). The use of SPSS helped me to summarise the collected quantitative data in examining the relationships of variables towards the problem under study. The descriptive and inferential statistics were considered for quantitative data analysis. Upon the completion of the quantitative data analyses, the qualitative data were analysed using content analysis. The findings from this study reveal that the social and cultural stereotypes of female managers; females’ lack of capacity and motivation; male dominance and cultural perceptions/beliefs; union and school governing bodies (SGBs) interference and institutional policies are barriers inhibiting the implementation of gender equity and accessibility of female teachers to management positions. Based on the emerged findings, it is recommended that policy-makers, the administration officers and immediate supervisors encourage the panellists for short-listing and interviews to comply with the legislative that requires the transformation and adherence to gender equity in all recruitment processes and practices. It is also recommended that workshops about the compliance on the implementation of gender equity by the role-players in education sector are widely and often conducted. It is further recommended that through distribution of circulars and school newsletters, conducting of imbizo or the role-players about the adherence to gender equity and constant dialogue with the communities, teacher’ unions, parents and youth in meetings could improve their perceptions and understanding that management positions for employees should be based on efficiency, competence and professional qualification but not on gender perspective. , Thesis (D.Ed) -- Faculty of Education Sciences, 2019
- Full Text:
- Date Issued: 2019-00
A comparative appraisal of access and quality of sexual and reproductive health services for gays and lesbians in Bulawayo (Zimbabwe) and Pretoria (South Africa)
- Authors: Jasi, Phineas
- Date: 2021-11
- Subjects: Reproductive health , Sexual health
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21959 , vital:51854
- Description: This study investigated the extent to which gays and lesbians access quality sexual and reproductive health (SRH) services in Pretoria and Bulawayo. The study also examines the facilitators and barriers for accessing the same services. Theoretically, the study was grounded in the Health Belief Model (Hochbaum, 1958, modified by Rosenstock, 1974 and Siddiqui, 2016). To answer the research questions, a mixed methods approach was applied involving both qualitative and quantitative data collection methods. A total of 30 key informant interviews, eight focus group discussions and 387 questionnaires were administered using purposive, time location and snowball sampling approaches in the two cities. The study found that the most commonly available sexual and reproductive health (SRH) services were contraceptive services, sexually transmitted infections (STI) services and Human immunodeficiency syndrome (HIV) services. The services were provided at public health facilities, drop-in centres and through outreach activities operated by Civil Society Organizations (CSOs). The least available services that gays and lesbians required as part of a comprehensive package were access to information, education and communications (IEC) materials and mental health and psychosocial support services (MHPSS). Several service providers were not adhering to the World Health Organization (WHO) guidelines for provision of comprehensive services for key populations including gays and lesbians. Critical gaps noted included the absence of key populations-only service hours, lack of options for clinicians to attend to them, presence of a stigma and discrimination free environment and provision of comprehensive package of services under one roof. Most of the referral facilities had limited drugs, equipment and supplies for cancer screening and they had no HIV prevention, sex change, in-vitro fertilization, and sterilization services and procedures. The quality of physical facilities and SRH services in both cities did not meet the expectations of gays and lesbians, acting as a barrier to their health seeking behaviour. Stigma and discrimination from healthcare workers was a huge barrier affecting access across all public health facilities. The acts of stigmatisation and discrimination affected the perceptions that gays and lesbians had regarding the quality of the services and compromised access of the same. In view of these health system challenges, the study recommends that there is need for public authorities in both cities to address the bottlenecks and barriers affecting access to SRH services and products such as lubricants, affordable quality condoms, dental dams and latex gloves while reinforcing the facilitating factors promoting access. Healthcare workers need further training on how to provide comprehensive services for gays and lesbians according to the WHO guidelines. Public health authorities in Bulawayo and Pretoria should build upon the identified factors which facilitated the access to SRH services and use of products such as condoms and lubricants. These factors require strengthening of community-based organizations and networks that work directly with gays and lesbians in both Bulawayo and Pretoria. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-11
- Authors: Jasi, Phineas
- Date: 2021-11
- Subjects: Reproductive health , Sexual health
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21959 , vital:51854
- Description: This study investigated the extent to which gays and lesbians access quality sexual and reproductive health (SRH) services in Pretoria and Bulawayo. The study also examines the facilitators and barriers for accessing the same services. Theoretically, the study was grounded in the Health Belief Model (Hochbaum, 1958, modified by Rosenstock, 1974 and Siddiqui, 2016). To answer the research questions, a mixed methods approach was applied involving both qualitative and quantitative data collection methods. A total of 30 key informant interviews, eight focus group discussions and 387 questionnaires were administered using purposive, time location and snowball sampling approaches in the two cities. The study found that the most commonly available sexual and reproductive health (SRH) services were contraceptive services, sexually transmitted infections (STI) services and Human immunodeficiency syndrome (HIV) services. The services were provided at public health facilities, drop-in centres and through outreach activities operated by Civil Society Organizations (CSOs). The least available services that gays and lesbians required as part of a comprehensive package were access to information, education and communications (IEC) materials and mental health and psychosocial support services (MHPSS). Several service providers were not adhering to the World Health Organization (WHO) guidelines for provision of comprehensive services for key populations including gays and lesbians. Critical gaps noted included the absence of key populations-only service hours, lack of options for clinicians to attend to them, presence of a stigma and discrimination free environment and provision of comprehensive package of services under one roof. Most of the referral facilities had limited drugs, equipment and supplies for cancer screening and they had no HIV prevention, sex change, in-vitro fertilization, and sterilization services and procedures. The quality of physical facilities and SRH services in both cities did not meet the expectations of gays and lesbians, acting as a barrier to their health seeking behaviour. Stigma and discrimination from healthcare workers was a huge barrier affecting access across all public health facilities. The acts of stigmatisation and discrimination affected the perceptions that gays and lesbians had regarding the quality of the services and compromised access of the same. In view of these health system challenges, the study recommends that there is need for public authorities in both cities to address the bottlenecks and barriers affecting access to SRH services and products such as lubricants, affordable quality condoms, dental dams and latex gloves while reinforcing the facilitating factors promoting access. Healthcare workers need further training on how to provide comprehensive services for gays and lesbians according to the WHO guidelines. Public health authorities in Bulawayo and Pretoria should build upon the identified factors which facilitated the access to SRH services and use of products such as condoms and lubricants. These factors require strengthening of community-based organizations and networks that work directly with gays and lesbians in both Bulawayo and Pretoria. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-11
Exploring integration for the topic of stoichiometry in South African natural sciences and physical sciences school curricula
- Authors: Mgolozeli, Kwanele
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405330 , vital:70162
- Description: Many developing countries, including South Africa, have identified the provision and implementation of strong science curricula as central to their developmental needs. Stoichiometry is a fundamental chemistry topic because the concepts involved form the basis of later topics such as chemical equilibrium, rates of reactions, redox reactions, and acid-base reactions. School students consistently demonstrate lack of understanding of stoichiometry-related concepts and skills such as the particulate nature of matter and related mathematical problem-solving. The poor performance of high school students in central science topics such as stoichiometry is problematic for their further study of chemistry and for the country meeting its need for science graduates. Successive examiner reports pointed to the lack of integration of stoichiometry concepts across the grades being the main problem. However, no study could be found which explores how stoichiometry is integrated in the South African Natural Sciences and Physical Sciences curriculum across the grades. This provided the rationale for the current study. The case study reported in this thesis thus aimed to explore integration of stoichiometry concepts in South African Natural Sciences and Physical Sciences school curricula. It involved document analysis as the method of collecting data. The research adopted the social realist paradigm, with its realist ontology and relativist epistemology. Legitimation Code Theory provided the theoretical framing. Chemistry concepts that are foundational to the understanding of stoichiometry according to literature, were chosen as root concepts for the concept mapping undertaken to identify types of integration. The concept maps revealed four stoichiometry integration themes: integration of stoichiometry concepts with symbols, integration of stoichiometry concepts with explanations, integration with applications in a chemistry context, and integration with an everyday context. These themes provided integration categories. A semantic gravity translation device was then developed for characterising the types of integration in terms of the degree of contextualisation. The results of this study show that stoichiometry integration of weaker semantic gravity is legitimated more strongly over other semantic gravity codes in the Natural Sciences and Physical Sciences curricula across all grade levels. While this has advantages in terms of knowledge-building potential, the consequence is that the integration occurs at very abstract levels that are far removed from learners’ everyday lives. The practical implication for curriculum developers involves increasing the instances of integration of stoichiometry concepts at stronger levels of semantic gravity, for a more even semantic gravity range of integration types. Natural Sciences and Physical Sciences teachers also need to source and include real-life examples for explanations and applications of stoichiometry concepts when teaching, in light of current curriculum documents focusing more on abstract forms of integration. Methodologically, this study contributes to the increased utility of semantic gravity through its exploration of integration in relation to knowledge-building potential of curriculum for hierarchical knowledge structures such as chemistry. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mgolozeli, Kwanele
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405330 , vital:70162
- Description: Many developing countries, including South Africa, have identified the provision and implementation of strong science curricula as central to their developmental needs. Stoichiometry is a fundamental chemistry topic because the concepts involved form the basis of later topics such as chemical equilibrium, rates of reactions, redox reactions, and acid-base reactions. School students consistently demonstrate lack of understanding of stoichiometry-related concepts and skills such as the particulate nature of matter and related mathematical problem-solving. The poor performance of high school students in central science topics such as stoichiometry is problematic for their further study of chemistry and for the country meeting its need for science graduates. Successive examiner reports pointed to the lack of integration of stoichiometry concepts across the grades being the main problem. However, no study could be found which explores how stoichiometry is integrated in the South African Natural Sciences and Physical Sciences curriculum across the grades. This provided the rationale for the current study. The case study reported in this thesis thus aimed to explore integration of stoichiometry concepts in South African Natural Sciences and Physical Sciences school curricula. It involved document analysis as the method of collecting data. The research adopted the social realist paradigm, with its realist ontology and relativist epistemology. Legitimation Code Theory provided the theoretical framing. Chemistry concepts that are foundational to the understanding of stoichiometry according to literature, were chosen as root concepts for the concept mapping undertaken to identify types of integration. The concept maps revealed four stoichiometry integration themes: integration of stoichiometry concepts with symbols, integration of stoichiometry concepts with explanations, integration with applications in a chemistry context, and integration with an everyday context. These themes provided integration categories. A semantic gravity translation device was then developed for characterising the types of integration in terms of the degree of contextualisation. The results of this study show that stoichiometry integration of weaker semantic gravity is legitimated more strongly over other semantic gravity codes in the Natural Sciences and Physical Sciences curricula across all grade levels. While this has advantages in terms of knowledge-building potential, the consequence is that the integration occurs at very abstract levels that are far removed from learners’ everyday lives. The practical implication for curriculum developers involves increasing the instances of integration of stoichiometry concepts at stronger levels of semantic gravity, for a more even semantic gravity range of integration types. Natural Sciences and Physical Sciences teachers also need to source and include real-life examples for explanations and applications of stoichiometry concepts when teaching, in light of current curriculum documents focusing more on abstract forms of integration. Methodologically, this study contributes to the increased utility of semantic gravity through its exploration of integration in relation to knowledge-building potential of curriculum for hierarchical knowledge structures such as chemistry. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
The Primacy of Effective Human Capital Management to the Growth of Entrepreneurship Ventures. A Study of Cases from the Fast Food Restaurant Sector in Cape Town
- Asoba, Samson Nambei, Patricia, Nteboheng Mefi
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Entrepreneurship Human capital Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/8135 , vital:61400 , xlink:href="https://www.abacademies.org/articles/the-primacy-of-effective-human-capital-management-to-the-growth-of-entrepreneurship-ventures-a-study-of-cases-from-the-fast-food-r-10259.html"
- Description: This paper draws on two fields, human resources management and entrepreneurship to examine the observed problem of stalled established business ownership even despite favourable Total Early Stage entrepreneurship (TEA) among many nations. The aim of the study was to established the perceptions of entrepreneurs on the influence of human capital on the growth and sustainability of entrepreneurial ventures from the restaurant sector in Cape Town. The study adopted a qualitative research design which was based on interviews to infer the entrepreneurs’ perceptions on the role of effective human capital management to growth of entrepreneurial ventures. Fifteen interviews were conducted and analysed following a thematic analyse procedure. Various themes and sub themes which pointed to the critically of effective human capital management were established. It was found the people possess certain social, philosophical, psychological and ideological attributes that cannot be found from other resources. At the end of the analysis, it was established that human resources are central to the growth of entrepreneurial ventures as they possess certain exploitable entrepreneurial talents, are capable of unlocking the value of other resources and also they are the drivers of growth. Following these findings, it was recommended that entrepreneurs should centralise effective human capital management for growth. Keywords: Entrepreneurship, Human Capital, Small Businesses, Business Growth, Competitive Advantage
- Full Text:
- Date Issued: 2021
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Entrepreneurship Human capital Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/8135 , vital:61400 , xlink:href="https://www.abacademies.org/articles/the-primacy-of-effective-human-capital-management-to-the-growth-of-entrepreneurship-ventures-a-study-of-cases-from-the-fast-food-r-10259.html"
- Description: This paper draws on two fields, human resources management and entrepreneurship to examine the observed problem of stalled established business ownership even despite favourable Total Early Stage entrepreneurship (TEA) among many nations. The aim of the study was to established the perceptions of entrepreneurs on the influence of human capital on the growth and sustainability of entrepreneurial ventures from the restaurant sector in Cape Town. The study adopted a qualitative research design which was based on interviews to infer the entrepreneurs’ perceptions on the role of effective human capital management to growth of entrepreneurial ventures. Fifteen interviews were conducted and analysed following a thematic analyse procedure. Various themes and sub themes which pointed to the critically of effective human capital management were established. It was found the people possess certain social, philosophical, psychological and ideological attributes that cannot be found from other resources. At the end of the analysis, it was established that human resources are central to the growth of entrepreneurial ventures as they possess certain exploitable entrepreneurial talents, are capable of unlocking the value of other resources and also they are the drivers of growth. Following these findings, it was recommended that entrepreneurs should centralise effective human capital management for growth. Keywords: Entrepreneurship, Human Capital, Small Businesses, Business Growth, Competitive Advantage
- Full Text:
- Date Issued: 2021
Optical limiting properties of zinc phthalocyanines in solution and solid PMMA composite films
- Tekin, Sezen, Kürüm, Ulaş, Durmus, Mahmut, Yaglioglu, H Gul, Nyokong, Tebello, Elmali, Ayhan
- Authors: Tekin, Sezen , Kürüm, Ulaş , Durmus, Mahmut , Yaglioglu, H Gul , Nyokong, Tebello , Elmali, Ayhan
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249071 , vital:51775 , xlink:href="https://doi.org/10.1016/j.optcom.2010.07.003"
- Description: The nonlinear absorption and optical limiting (OL) performance of tetra- and octasubstituted zinc phthalocyanine complexes were described in solution and in the solid state using the open-aperture Z-scan technique. The measurements were performed using collimated 4 ns pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. The polymeric films exhibit a much larger effective nonlinear absorption coefficient in comparison with solution. However, the parameters of the ratio of the excited to ground state absorption cross section and energy-dependent saturation in solution are much better compared to properties in the polymeric film. In terms of the ratio of the excited to ground state absorption cross section, the peripherally substituted complexes show better OL performance than the non-peripherally substituted derivative.
- Full Text:
- Date Issued: 2010
- Authors: Tekin, Sezen , Kürüm, Ulaş , Durmus, Mahmut , Yaglioglu, H Gul , Nyokong, Tebello , Elmali, Ayhan
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249071 , vital:51775 , xlink:href="https://doi.org/10.1016/j.optcom.2010.07.003"
- Description: The nonlinear absorption and optical limiting (OL) performance of tetra- and octasubstituted zinc phthalocyanine complexes were described in solution and in the solid state using the open-aperture Z-scan technique. The measurements were performed using collimated 4 ns pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. The polymeric films exhibit a much larger effective nonlinear absorption coefficient in comparison with solution. However, the parameters of the ratio of the excited to ground state absorption cross section and energy-dependent saturation in solution are much better compared to properties in the polymeric film. In terms of the ratio of the excited to ground state absorption cross section, the peripherally substituted complexes show better OL performance than the non-peripherally substituted derivative.
- Full Text:
- Date Issued: 2010
The role of funding composition on efficiency in public universities in South Africa
- Nkohla, Tumi Vuyolwethu https://orcid.org/0000-0003-2426-9509
- Authors: Nkohla, Tumi Vuyolwethu https://orcid.org/0000-0003-2426-9509
- Date: 2020-08
- Subjects: Education, Higher -- Finance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20373 , vital:45659
- Description: Studies on the relationship between funding and efficiency of public universities in South Africa were triggered mainly by the decline of government spending on public universities while the enrolment of financially needy students is increasing. This increase is a product of government’s initiatives to redress the imbalances in access and success caused by the apartheid regime. However, the government seems to be grappling to strike a balance between its initiatives and funding. While the government’s HE transformation initiatives are appreciated, public universities are caught in a dilemma: their revenue is no longer sufficient for the operations given the increase in the number of unfunded and financially constrained students. It is with this background that the study evaluates the efficiency of public South African universities for the period 2009–2016 and how funding composition affects their efficiency. The study contributes to the existing literature in various ways First, a recent study on this subject matter found a decline in the average technical efficiency (TE) score of the South African public universities from 83percent in 2009 to 78percent in 2013. However, the study did not include non-academic staff among other input variables that are assumed to potentially influence performance outcomes of the universities. We therefore developed an argument that a biased conclusion on the subject matter is likely, if academic staff are assumed to dominate efficiency of public universities in South Africa while the efforts of non-academic staff are not considered. Using a Data Envelopment Analysis (DEA) model, the findings of this study revealed that over the study period the average TE of public universities in South Africa increased from 91percent to 95percent. These results suggest that academic and non-academic staff can be deemed as mutually inclusive variables and therefore neglecting either of them can lead to biased estimated average TE scores. The efficiency levels provided in this study can be used as performance benchmarks for identifying potential improvements required to reach a satisfactory level of efficiency. Second, the literature argues that different streams of revenue utilised for funding universities’ activities can provide alternative incentives which might have an impact on efficiency. However, none of the studies examined comparatively the impact of different revenue streams on the efficiency of the public universities in South Africa. Using a fixed-effects regression model, this study found that only traditional universities’ efficiency can be affected by student fees and private income, while government funding does not seem to bear a significant impact on the efficiency of all universities irrespective of their category. Precisely, student fees enhance the efficiency of traditional universities while private income is deleterious on the efficiency of the traditional universities. The study concluded that traditional universities use students’ fees efficiently to deliver quality academic services in a bid to safeguard their reputation and image while revenue from private funders is not efficiently utilised due to the principal-agent problem. In terms of state funding, it was concluded that government spending on public universities is yet to reach a minimum threshold level at which it can contribute significantly to the efficiency of the universities. Third, recent literature used Stochastic Frontier Analysis (SFA) efficiency scores to determine the drivers of efficiency of public universities in South Africa. Although SFA can control for the stochastic error component in the econometric estimation, the model imposes several theoretical assumptions in the production function which may lead to biased estimations. As a result, several studies on efficiency analysis of Higher Education Institutions (HIEs) around the globe have reverted to using DEA. Using DEA efficiency scores and a Tobit model, this study found that that quality of staff, government funding, student fees, private income, and GDP per capita are positive factors of efficiency while the share of non-white to white staff was found as the determinant of inefficiency. It was concluded that adequate funding and proper management of income by the universities, economic growth and employment of highly educated academic staff can increase efficiency levels of public universities in South Africa, whereas an increase of non-white to white staff in South African public universities is a threat to the universities’ efficiency. Overall, the findings of this study suggest that a cost-sharing framework is inevitable in the South African higher education (HE) system, particularly now that the government is heavily burdened due to the prevailing economic turmoil in the country. As a results, private funders and parents and/guardians are encouraged to honour their portion of obligations with universities. Due to limited funding across all sources, efforts dedicated to strengthen managerial competencies of public universities in South Africa can eliminate the principle-agent problem and therefore promote managerial efficiency. The South African government is encouraged to support its transformation initiatives on HEIs with adequate funding, otherwise the initiatives need to be revisited and revised to suit the current economic environment. Revision of these initiatives may include adjustment of the education standards such that state funding can be allocated to deserving students in terms of both finances and students’ performance starting from matric. , Thesis (PhD) -- Faculty of Management and Commerce, 2020
- Full Text:
- Date Issued: 2020-08
- Authors: Nkohla, Tumi Vuyolwethu https://orcid.org/0000-0003-2426-9509
- Date: 2020-08
- Subjects: Education, Higher -- Finance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20373 , vital:45659
- Description: Studies on the relationship between funding and efficiency of public universities in South Africa were triggered mainly by the decline of government spending on public universities while the enrolment of financially needy students is increasing. This increase is a product of government’s initiatives to redress the imbalances in access and success caused by the apartheid regime. However, the government seems to be grappling to strike a balance between its initiatives and funding. While the government’s HE transformation initiatives are appreciated, public universities are caught in a dilemma: their revenue is no longer sufficient for the operations given the increase in the number of unfunded and financially constrained students. It is with this background that the study evaluates the efficiency of public South African universities for the period 2009–2016 and how funding composition affects their efficiency. The study contributes to the existing literature in various ways First, a recent study on this subject matter found a decline in the average technical efficiency (TE) score of the South African public universities from 83percent in 2009 to 78percent in 2013. However, the study did not include non-academic staff among other input variables that are assumed to potentially influence performance outcomes of the universities. We therefore developed an argument that a biased conclusion on the subject matter is likely, if academic staff are assumed to dominate efficiency of public universities in South Africa while the efforts of non-academic staff are not considered. Using a Data Envelopment Analysis (DEA) model, the findings of this study revealed that over the study period the average TE of public universities in South Africa increased from 91percent to 95percent. These results suggest that academic and non-academic staff can be deemed as mutually inclusive variables and therefore neglecting either of them can lead to biased estimated average TE scores. The efficiency levels provided in this study can be used as performance benchmarks for identifying potential improvements required to reach a satisfactory level of efficiency. Second, the literature argues that different streams of revenue utilised for funding universities’ activities can provide alternative incentives which might have an impact on efficiency. However, none of the studies examined comparatively the impact of different revenue streams on the efficiency of the public universities in South Africa. Using a fixed-effects regression model, this study found that only traditional universities’ efficiency can be affected by student fees and private income, while government funding does not seem to bear a significant impact on the efficiency of all universities irrespective of their category. Precisely, student fees enhance the efficiency of traditional universities while private income is deleterious on the efficiency of the traditional universities. The study concluded that traditional universities use students’ fees efficiently to deliver quality academic services in a bid to safeguard their reputation and image while revenue from private funders is not efficiently utilised due to the principal-agent problem. In terms of state funding, it was concluded that government spending on public universities is yet to reach a minimum threshold level at which it can contribute significantly to the efficiency of the universities. Third, recent literature used Stochastic Frontier Analysis (SFA) efficiency scores to determine the drivers of efficiency of public universities in South Africa. Although SFA can control for the stochastic error component in the econometric estimation, the model imposes several theoretical assumptions in the production function which may lead to biased estimations. As a result, several studies on efficiency analysis of Higher Education Institutions (HIEs) around the globe have reverted to using DEA. Using DEA efficiency scores and a Tobit model, this study found that that quality of staff, government funding, student fees, private income, and GDP per capita are positive factors of efficiency while the share of non-white to white staff was found as the determinant of inefficiency. It was concluded that adequate funding and proper management of income by the universities, economic growth and employment of highly educated academic staff can increase efficiency levels of public universities in South Africa, whereas an increase of non-white to white staff in South African public universities is a threat to the universities’ efficiency. Overall, the findings of this study suggest that a cost-sharing framework is inevitable in the South African higher education (HE) system, particularly now that the government is heavily burdened due to the prevailing economic turmoil in the country. As a results, private funders and parents and/guardians are encouraged to honour their portion of obligations with universities. Due to limited funding across all sources, efforts dedicated to strengthen managerial competencies of public universities in South Africa can eliminate the principle-agent problem and therefore promote managerial efficiency. The South African government is encouraged to support its transformation initiatives on HEIs with adequate funding, otherwise the initiatives need to be revisited and revised to suit the current economic environment. Revision of these initiatives may include adjustment of the education standards such that state funding can be allocated to deserving students in terms of both finances and students’ performance starting from matric. , Thesis (PhD) -- Faculty of Management and Commerce, 2020
- Full Text:
- Date Issued: 2020-08
Mechanistic analysis of two cytotoxic thiazolidinones as novel inhibitors of Triple-Negative Breast Cancer
- Authors: Vukea, Nyeleti
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365734 , vital:65780
- Description: Thesis embargoes. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Vukea, Nyeleti
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365734 , vital:65780
- Description: Thesis embargoes. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
An educational intervention for professional nurses on the use of surgical attire in the prevention of surgical site infections in the operating theatres
- Authors: Alayemi, Joshua
- Date: 2020-04
- Subjects: Surgical wound infections--Prevention , Surgery, Aseptic and antiseptic --South africa , Operating room nursing--South Africa
- Language: English
- Type: Master's theses
- Identifier: http://hdl.handle.net/10948/55522 , vital:52754
- Description: Infection control and prevention is an issue that is of utmost importance to every health practitioner, including professional nurses, as patients who undergo surgeries could develop sepsis, leading to failure of multiple organs and possibly death. Surgical site infections acquired from operating theatres are often introduced when there is lack of application of and adherence to the necessary control measures, sterile principles and techniques, including the appropriate use of surgical attire. This study aimed to contextualize, implement and evaluate an existing educational intervention regarding the use of surgical attire in operating theatres, in order to establish whether the educational intervention enhanced the practices of professional nurses in operating theatres regarding the use of surgical attire. A quantitative research design, using a quasi-experimental two-group pre-test, post-test intervention approach was employed for the study. The study consisted of three phases. The study is underpinned by the Promoting Action on Research Implementation (PARiHS) framework. The research sample consisted of all professional nurses working in the public and private operating theatres in the Nelson Mandela Bay Municipality. Purposive sampling was used to select the hospitals in control (Hospitals 2 and 3) and intervention groups (Hospitals 4 and 5), ensuring an equal number of public and iv private hospitals in each group. Data was collected through self-administered pre- and post-questionnaires. An existing educational intervention based on the Association of Perioperative Registered Nurses (AORN’s) guidelines was contextualized through review by three professional nurses with a specialty in operating theatre. The educational intervention was implemented for the intervention group, while the control group only received the summary of the AORN guidelines. Reliability and validity were ensured through the conduct of a pilot study, and expert review by three professional nurses with a specialty in operating theatre in order to check the validity and reliability of the data collection instrument and educational intervention. This means that the educational intervention had a positive effect in terms of improving the professional nurses’ practices on the use of surgical attire to prevent surgical site infections in operating theatres. , Thesis (MA) -- Faculty of Health Sciences Clinical Care and Medicinal Science, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Alayemi, Joshua
- Date: 2020-04
- Subjects: Surgical wound infections--Prevention , Surgery, Aseptic and antiseptic --South africa , Operating room nursing--South Africa
- Language: English
- Type: Master's theses
- Identifier: http://hdl.handle.net/10948/55522 , vital:52754
- Description: Infection control and prevention is an issue that is of utmost importance to every health practitioner, including professional nurses, as patients who undergo surgeries could develop sepsis, leading to failure of multiple organs and possibly death. Surgical site infections acquired from operating theatres are often introduced when there is lack of application of and adherence to the necessary control measures, sterile principles and techniques, including the appropriate use of surgical attire. This study aimed to contextualize, implement and evaluate an existing educational intervention regarding the use of surgical attire in operating theatres, in order to establish whether the educational intervention enhanced the practices of professional nurses in operating theatres regarding the use of surgical attire. A quantitative research design, using a quasi-experimental two-group pre-test, post-test intervention approach was employed for the study. The study consisted of three phases. The study is underpinned by the Promoting Action on Research Implementation (PARiHS) framework. The research sample consisted of all professional nurses working in the public and private operating theatres in the Nelson Mandela Bay Municipality. Purposive sampling was used to select the hospitals in control (Hospitals 2 and 3) and intervention groups (Hospitals 4 and 5), ensuring an equal number of public and iv private hospitals in each group. Data was collected through self-administered pre- and post-questionnaires. An existing educational intervention based on the Association of Perioperative Registered Nurses (AORN’s) guidelines was contextualized through review by three professional nurses with a specialty in operating theatre. The educational intervention was implemented for the intervention group, while the control group only received the summary of the AORN guidelines. Reliability and validity were ensured through the conduct of a pilot study, and expert review by three professional nurses with a specialty in operating theatre in order to check the validity and reliability of the data collection instrument and educational intervention. This means that the educational intervention had a positive effect in terms of improving the professional nurses’ practices on the use of surgical attire to prevent surgical site infections in operating theatres. , Thesis (MA) -- Faculty of Health Sciences Clinical Care and Medicinal Science, 2020
- Full Text:
- Date Issued: 2020-04
The effect of Cannabis extract on the morphological and metabolic characteristics of various fat depots in diet-induced Obese and STZ-induced male wistar rats
- Authors: Ramlugon, Sonaal
- Date: 2023-04
- Subjects: Rats as laboratory animals , Diabetes in practice , Cannabis -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/61282 , vital:70044
- Description: To investigate the potential anti-diabetic/obesity properties of oral cannabis administration in an obese and streptozotocin (STZ)-induced diabetic rat model, as well as an obese rat model, and to determine the mechanism of action, with a focus on the peritoneal and intramuscular fat depots. Experimental Design: Obese and STZ-induced diabetic rats were allocated a high fat diet (HFD) and intraperitoneally injected with STZ to mimic an obese and diabetic state. The rats were then orally administered cannabis extract (CE) of 1.25, 2.5 and 5.0 mg/kg body weight (relative to tetrahydrocannabinol (THC) content) or metformin as a positive control. For the obese rat model, the rats were allocated either a high carbohydrate diet (HCD) or high fat diet (HFD) and orally administered with cannabis extract of 1.25 mg/kg body weight (relative to THC content). Weight, blood and insulin-resistant parameters of the rats were monitored. The mitochondrial to genomic DNA ratio (MT:18S DNA), average adipocyte area of the various adipose tissues, citrate synthase and carnitine palmitoyltransferase 1 (CPT1) enzyme activities of the peritoneal and intramuscular fat were measured. Gene expression levels of uncoupling protein 1 (UCP1), cell-death inducing DNA fragmentation factor alpha like effector-a (Cidea), perilipin, hormone-sensitive lipase (HSL) and mitochondrial transcription factor A (TFAM) were measured in peritoneal fat, intramuscular fat and brown adipose tissue (BAT). Main Findings: Obese and STZ-induced diabetic rat model: Due to the biphasic nature of cannabinoids, cannabis dosage plays an important role in the observed effects. CE1.25 was the only cannabis treatment effective in improving the insulinresistant parameters of the rats unlike the other higher cannabis concentrations (CE2.5 and CE5.0). In the peritoneal fat, CE1.25 increased MT:18S DNA, increased citrate synthase activity, and decreased the average adipocyte area when compared to the STZ group. CE1.25 also induced fat beigeing by upregulating gene expression levels of UCP1 and Cidea. XIX Furthermore, an increase in gene expression levels of perilipin, HSL, and TFAM showed increased fat mobilization and metabolic activity. In the intramuscular fat, CE1.25 also reduced the average adipocytes area. However, a different mechanism of action was observed where CE1.25 did not induce fat beigeing, but instead increased both citrate synthase and CPT1 enzyme activities and gene expression levels of HSL, thereby indicating increased fat oxidation and mitochondrial activity. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-04
- Authors: Ramlugon, Sonaal
- Date: 2023-04
- Subjects: Rats as laboratory animals , Diabetes in practice , Cannabis -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/61282 , vital:70044
- Description: To investigate the potential anti-diabetic/obesity properties of oral cannabis administration in an obese and streptozotocin (STZ)-induced diabetic rat model, as well as an obese rat model, and to determine the mechanism of action, with a focus on the peritoneal and intramuscular fat depots. Experimental Design: Obese and STZ-induced diabetic rats were allocated a high fat diet (HFD) and intraperitoneally injected with STZ to mimic an obese and diabetic state. The rats were then orally administered cannabis extract (CE) of 1.25, 2.5 and 5.0 mg/kg body weight (relative to tetrahydrocannabinol (THC) content) or metformin as a positive control. For the obese rat model, the rats were allocated either a high carbohydrate diet (HCD) or high fat diet (HFD) and orally administered with cannabis extract of 1.25 mg/kg body weight (relative to THC content). Weight, blood and insulin-resistant parameters of the rats were monitored. The mitochondrial to genomic DNA ratio (MT:18S DNA), average adipocyte area of the various adipose tissues, citrate synthase and carnitine palmitoyltransferase 1 (CPT1) enzyme activities of the peritoneal and intramuscular fat were measured. Gene expression levels of uncoupling protein 1 (UCP1), cell-death inducing DNA fragmentation factor alpha like effector-a (Cidea), perilipin, hormone-sensitive lipase (HSL) and mitochondrial transcription factor A (TFAM) were measured in peritoneal fat, intramuscular fat and brown adipose tissue (BAT). Main Findings: Obese and STZ-induced diabetic rat model: Due to the biphasic nature of cannabinoids, cannabis dosage plays an important role in the observed effects. CE1.25 was the only cannabis treatment effective in improving the insulinresistant parameters of the rats unlike the other higher cannabis concentrations (CE2.5 and CE5.0). In the peritoneal fat, CE1.25 increased MT:18S DNA, increased citrate synthase activity, and decreased the average adipocyte area when compared to the STZ group. CE1.25 also induced fat beigeing by upregulating gene expression levels of UCP1 and Cidea. XIX Furthermore, an increase in gene expression levels of perilipin, HSL, and TFAM showed increased fat mobilization and metabolic activity. In the intramuscular fat, CE1.25 also reduced the average adipocytes area. However, a different mechanism of action was observed where CE1.25 did not induce fat beigeing, but instead increased both citrate synthase and CPT1 enzyme activities and gene expression levels of HSL, thereby indicating increased fat oxidation and mitochondrial activity. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-04
A multispectral and machine learning approach to early stress classification in plants
- Authors: Poole, Louise Carmen
- Date: 2022-04-06
- Subjects: Machine learning , Neural networks (Computer science) , Multispectral imaging , Image processing , Plant stress detection
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232410 , vital:49989
- Description: Crop loss and failure can impact both a country’s economy and food security, often to devastating effects. As such, the importance of successfully detecting plant stresses early in their development is essential to minimize spread and damage to crop production. Identification of the stress and the stress-causing agent is the most critical and challenging step in plant and crop protection. With the development of and increase in ease of access to new equipment and technology in recent years, the use of spectroscopy in the early detection of plant diseases has become notably popular. This thesis narrows down the most suitable multispectral imaging techniques and machine learning algorithms for early stress detection. Datasets were collected of visible images and multispectral images. Dehydration was selected as the plant stress type for the main experiments, and data was collected from six plant species typically used in agriculture. Key contributions of this thesis include multispectral and visible datasets showing plant dehydration as well as a separate preliminary dataset on plant disease. Promising results on dehydration showed statistically significant accuracy improvements in the multispectral imaging compared to visible imaging for early stress detection, with multispectral input obtaining a 92.50% accuracy over visible input’s 77.50% on general plant species. The system was effective at stress detection on known plant species, with multispectral imaging introducing greater improvement to early stress detection than advanced stress detection. Furthermore, strong species discrimination was achieved when exclusively testing either early or advanced dehydration against healthy species. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Poole, Louise Carmen
- Date: 2022-04-06
- Subjects: Machine learning , Neural networks (Computer science) , Multispectral imaging , Image processing , Plant stress detection
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232410 , vital:49989
- Description: Crop loss and failure can impact both a country’s economy and food security, often to devastating effects. As such, the importance of successfully detecting plant stresses early in their development is essential to minimize spread and damage to crop production. Identification of the stress and the stress-causing agent is the most critical and challenging step in plant and crop protection. With the development of and increase in ease of access to new equipment and technology in recent years, the use of spectroscopy in the early detection of plant diseases has become notably popular. This thesis narrows down the most suitable multispectral imaging techniques and machine learning algorithms for early stress detection. Datasets were collected of visible images and multispectral images. Dehydration was selected as the plant stress type for the main experiments, and data was collected from six plant species typically used in agriculture. Key contributions of this thesis include multispectral and visible datasets showing plant dehydration as well as a separate preliminary dataset on plant disease. Promising results on dehydration showed statistically significant accuracy improvements in the multispectral imaging compared to visible imaging for early stress detection, with multispectral input obtaining a 92.50% accuracy over visible input’s 77.50% on general plant species. The system was effective at stress detection on known plant species, with multispectral imaging introducing greater improvement to early stress detection than advanced stress detection. Furthermore, strong species discrimination was achieved when exclusively testing either early or advanced dehydration against healthy species. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04-06
Improved nonlinear optical behaviour of ball type indium (III) phthalocyanine linked to glutathione capped nanoparticles
- Nwaji, Njemuwa, Oluwole, David O, Mack, John, Louzada, Marcel, Khene, Samson M, Britton, Jonathan, Nyokong, Tebello
- Authors: Nwaji, Njemuwa , Oluwole, David O , Mack, John , Louzada, Marcel , Khene, Samson M , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239654 , vital:50752 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.01.066"
- Description: The synthesis of ball–type indium phthalocyanine (complex 4) and its covalent attachment to glutathione (GSH–) capped (Ag, Au, CdTeSe, CdTeSe/ZnO) nanoparticles are reported in this work. Furthermore, their photophysical and nonlinear optical behaviour were investigated. We observed a decrease in the fluorescence quantum yield with corresponding increase in the triplet quantum yield of the nanoconjugates in comparison to complex 4 alone. The reverse saturable absorption was found to be dependent on excited state absorption. The optical limiting threshold ranges from 0.40–0.78 (J/cm2). The nanoconjugate of the complex 4 with GSH–CdTeSe/ZnO (QD1) accounted for the most improved triplet state parameters and nonlinear optical behaviour in comparison to complex 4 and the other nanoconjugates studied in this work.
- Full Text:
- Date Issued: 2017
- Authors: Nwaji, Njemuwa , Oluwole, David O , Mack, John , Louzada, Marcel , Khene, Samson M , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239654 , vital:50752 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.01.066"
- Description: The synthesis of ball–type indium phthalocyanine (complex 4) and its covalent attachment to glutathione (GSH–) capped (Ag, Au, CdTeSe, CdTeSe/ZnO) nanoparticles are reported in this work. Furthermore, their photophysical and nonlinear optical behaviour were investigated. We observed a decrease in the fluorescence quantum yield with corresponding increase in the triplet quantum yield of the nanoconjugates in comparison to complex 4 alone. The reverse saturable absorption was found to be dependent on excited state absorption. The optical limiting threshold ranges from 0.40–0.78 (J/cm2). The nanoconjugate of the complex 4 with GSH–CdTeSe/ZnO (QD1) accounted for the most improved triplet state parameters and nonlinear optical behaviour in comparison to complex 4 and the other nanoconjugates studied in this work.
- Full Text:
- Date Issued: 2017