Beyond benefit sharing: Place attachment and the importance of access to protected areas for surrounding communities
- Cundill, Georgina, Bezerra, Joana C, de Vos, Alta, Ntingana, Nokuthula
- Authors: Cundill, Georgina , Bezerra, Joana C , de Vos, Alta , Ntingana, Nokuthula
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416265 , vital:71334 , xlink:href="https://doi.org/10.1016/j.ecoser.2017.03.011"
- Description: The concept of place attachment can assist to integrate relational values into ecosystem service research, and assist us to rethink the notion of benefits in contemporary protected area thinking. We present a case study from South Africa, where the concept of two-dimensional place attachment was used to understand the relationship between a protected area and a land claimant community that now owns part of this protected area but does not have physical access to the land. A place attachment lens helps refocus access to protected areas as cornerstone to long term sustainability of such areas. Such access must be considered in the context of spatially and economically differentiated users, including a focus on trade-offs between such users. Our findings highlight that when communities previously displaced from protected areas respond to offers of ‘benefit sharing’ with demands for access and recognition as land owners, they are asking for a recognition of relational values, and identity, based on close interaction with nature. A place attachment and relational values perspective raises questions about the extent to which traditional conservation practice can accommodate such values, and therefore meet local people’s expectations and remain viable in the long term.
- Full Text:
- Date Issued: 2017
- Authors: Cundill, Georgina , Bezerra, Joana C , de Vos, Alta , Ntingana, Nokuthula
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416265 , vital:71334 , xlink:href="https://doi.org/10.1016/j.ecoser.2017.03.011"
- Description: The concept of place attachment can assist to integrate relational values into ecosystem service research, and assist us to rethink the notion of benefits in contemporary protected area thinking. We present a case study from South Africa, where the concept of two-dimensional place attachment was used to understand the relationship between a protected area and a land claimant community that now owns part of this protected area but does not have physical access to the land. A place attachment lens helps refocus access to protected areas as cornerstone to long term sustainability of such areas. Such access must be considered in the context of spatially and economically differentiated users, including a focus on trade-offs between such users. Our findings highlight that when communities previously displaced from protected areas respond to offers of ‘benefit sharing’ with demands for access and recognition as land owners, they are asking for a recognition of relational values, and identity, based on close interaction with nature. A place attachment and relational values perspective raises questions about the extent to which traditional conservation practice can accommodate such values, and therefore meet local people’s expectations and remain viable in the long term.
- Full Text:
- Date Issued: 2017
Exploring the effect of the indigenous technology of oil extraction on Grade 10 Biology learners’ perspectives and sense making of enzymes
- Authors: Nyamakuti, Martha Ndeyatila
- Date: 2021-10-29
- Subjects: Biology Study and teaching (Secondary) , Enzymes , Traditional ecological knowledge Namibia , Culturally relevant pedagogy Namibia , Reasoning , Contiguity Argumentation Theory (CAT) , Namibian National Curriculum for Basic Education(NCBE) , Socio-cultural theory
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192019 , vital:45188
- Description: The current status quo is that African learners’ local indigenous knowledge (IK) and experiences from home (cultural heritage) are not considered in science classrooms. In the context of Namibia, it seems that the Namibian curriculum policies do little or nothing to decolonise and address the issues of equity and social injustice in Namibian schools. For instance, although the Namibian National Curriculum for Basic Education (NCBE) claims that it “embraces traditional knowledge”, it does not specify how this should be done in schools. As a result, little or no integration of IK is enacted in many of our schools in Namibia. Resultantly, learners seem to find science inaccessible and irrelevant to their everyday lives. It is against this background that in this study I sought to explore how the mobilisation of the indigenous technology of oil extraction (okuyenga) from marula nuts and melon seeds influences (or not) Grade 10 Biology learners’ conceptions, dispositions and sense making of the topic of enzymes. The study was located within the interpretive and indigenous research paradigms. Central to the interpretive paradigm is the development of a greater understanding of how people make sense of the contexts in which they live and work. On the other hand, central to indigenous research paradigms are belief systems based on the lived experiences, values, and histories of the participants. The Ubuntu perspective or approach in which respect and humble togetherness is emphasised is critical in indigenous research paradigms especially when researchers are working with and in communities as I did in this study. The study was conducted in an under resourced school in Walvis Bay, Namibia. A qualitative case study approach was used and data were derived from a focus group interview, participatory classroom observations, learners’ reflections, and a stimulated recall interview. Vygotsky’s socio-cultural theory was employed as a theoretical framework. Within the socio-cultural theory, mediation of learning, social interactions, and the zone of proximal development (ZPD) were used as analytical lenses. The conceptual framework comprised of perspectives (conceptions, dispositions) and sense making of enzymes by the learners. Criteria were also adapted from Atallah, Bryant, and Dada to analyse learners’ perspectives. A thematic approach to analysis was employed to come up with categories and sub-themes and thereafter, common sub-themes were combined to form themes. The findings of the study revealed that the presentations on the indigenous technology of oil extraction by the expert community members influenced learners’ conceptions, dispositions, and sense making of enzymes and other associated science concepts. This was noticed when learners extracted emerging science concepts from the indigenous technology of oil extraction. The implication of this study is that there is a need for science teachers to consider learners’ cultural heritage and integrate local IK in their Biology classrooms in order to make science accessible and relevant to learners. Moreover, the integration of local IK is critical for learners to embrace and respect their cultural heritage. This study thus recommends that teachers should make efforts to collaborate with expert community members who are the custodians of local IK and tap into their cultural heritage and wisdom to enrich teaching in their science classrooms. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Nyamakuti, Martha Ndeyatila
- Date: 2021-10-29
- Subjects: Biology Study and teaching (Secondary) , Enzymes , Traditional ecological knowledge Namibia , Culturally relevant pedagogy Namibia , Reasoning , Contiguity Argumentation Theory (CAT) , Namibian National Curriculum for Basic Education(NCBE) , Socio-cultural theory
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192019 , vital:45188
- Description: The current status quo is that African learners’ local indigenous knowledge (IK) and experiences from home (cultural heritage) are not considered in science classrooms. In the context of Namibia, it seems that the Namibian curriculum policies do little or nothing to decolonise and address the issues of equity and social injustice in Namibian schools. For instance, although the Namibian National Curriculum for Basic Education (NCBE) claims that it “embraces traditional knowledge”, it does not specify how this should be done in schools. As a result, little or no integration of IK is enacted in many of our schools in Namibia. Resultantly, learners seem to find science inaccessible and irrelevant to their everyday lives. It is against this background that in this study I sought to explore how the mobilisation of the indigenous technology of oil extraction (okuyenga) from marula nuts and melon seeds influences (or not) Grade 10 Biology learners’ conceptions, dispositions and sense making of the topic of enzymes. The study was located within the interpretive and indigenous research paradigms. Central to the interpretive paradigm is the development of a greater understanding of how people make sense of the contexts in which they live and work. On the other hand, central to indigenous research paradigms are belief systems based on the lived experiences, values, and histories of the participants. The Ubuntu perspective or approach in which respect and humble togetherness is emphasised is critical in indigenous research paradigms especially when researchers are working with and in communities as I did in this study. The study was conducted in an under resourced school in Walvis Bay, Namibia. A qualitative case study approach was used and data were derived from a focus group interview, participatory classroom observations, learners’ reflections, and a stimulated recall interview. Vygotsky’s socio-cultural theory was employed as a theoretical framework. Within the socio-cultural theory, mediation of learning, social interactions, and the zone of proximal development (ZPD) were used as analytical lenses. The conceptual framework comprised of perspectives (conceptions, dispositions) and sense making of enzymes by the learners. Criteria were also adapted from Atallah, Bryant, and Dada to analyse learners’ perspectives. A thematic approach to analysis was employed to come up with categories and sub-themes and thereafter, common sub-themes were combined to form themes. The findings of the study revealed that the presentations on the indigenous technology of oil extraction by the expert community members influenced learners’ conceptions, dispositions, and sense making of enzymes and other associated science concepts. This was noticed when learners extracted emerging science concepts from the indigenous technology of oil extraction. The implication of this study is that there is a need for science teachers to consider learners’ cultural heritage and integrate local IK in their Biology classrooms in order to make science accessible and relevant to learners. Moreover, the integration of local IK is critical for learners to embrace and respect their cultural heritage. This study thus recommends that teachers should make efforts to collaborate with expert community members who are the custodians of local IK and tap into their cultural heritage and wisdom to enrich teaching in their science classrooms. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
A decision-making model to guide securing blockchain deployments
- Authors: Cronje, Gerhard Roets
- Date: 2021-10-29
- Subjects: Blockchains (Databases) , Bitcoin , Cryptocurrencies , Distributed databases , Computer networks Security measures , Computer networks Security measures Decision making , Ethereum
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188865 , vital:44793
- Description: Satoshi Nakamoto, the pseudo-identity accredit with the paper that sparked the implementation of Bitcoin, is famously quoted as remarking, electronically of course, that “If you don’t believe it or don’t get it, I don’t have time to try and convince you, sorry” (Tsapis, 2019, p. 1). What is noticeable, 12 years after the famed Satoshi paper that initiated Bitcoin (Nakamoto, 2008), is that blockchain at the very least has staying power and potentially wide application. A lesser known figure Marc Kenisberg, founder of Bitcoin Chaser which is one of the many companies formed around the Bitcoin ecosystem, summarised it well saying “…Blockchain is the tech - Bitcoin is merely the first mainstream manifestation of its potential” (Tsapis, 2019, p. 1). With blockchain still trying to reach its potential and still maturing on its way towards a mainstream technology the main question that arises for security professionals is how do I ensure we do it securely? This research seeks to address that question by proposing a decision-making model that can be used by a security professional to guide them through ensuring appropriate security for blockchain deployments. This research is certainly not the first attempt at discussing the security of the blockchain and will not be the last, as the technology around blockchain and distributed ledger technology is still rapidly evolving. What this research does try to achieve is not to delve into extremely specific areas of blockchain security, or get bogged down in technical details, but to provide a reference framework that aims to cover all the major areas to be considered. The approach followed was to review the literature regarding blockchain and to identify the main security areas to be addressed. It then proposes a decision-making model and tests the model against a fictitious but relevant real-world example. It concludes with learnings from this research. The reader can be the judge, but the model aims to be a practical valuable resource to be used by any security professional, to navigate the security aspects logically and understandably when being involved in a blockchain deployment. In contrast to the Satoshi quote, this research tries to convince the reader and assist him/her in understanding the security choices related to every blockchain deployment. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Cronje, Gerhard Roets
- Date: 2021-10-29
- Subjects: Blockchains (Databases) , Bitcoin , Cryptocurrencies , Distributed databases , Computer networks Security measures , Computer networks Security measures Decision making , Ethereum
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188865 , vital:44793
- Description: Satoshi Nakamoto, the pseudo-identity accredit with the paper that sparked the implementation of Bitcoin, is famously quoted as remarking, electronically of course, that “If you don’t believe it or don’t get it, I don’t have time to try and convince you, sorry” (Tsapis, 2019, p. 1). What is noticeable, 12 years after the famed Satoshi paper that initiated Bitcoin (Nakamoto, 2008), is that blockchain at the very least has staying power and potentially wide application. A lesser known figure Marc Kenisberg, founder of Bitcoin Chaser which is one of the many companies formed around the Bitcoin ecosystem, summarised it well saying “…Blockchain is the tech - Bitcoin is merely the first mainstream manifestation of its potential” (Tsapis, 2019, p. 1). With blockchain still trying to reach its potential and still maturing on its way towards a mainstream technology the main question that arises for security professionals is how do I ensure we do it securely? This research seeks to address that question by proposing a decision-making model that can be used by a security professional to guide them through ensuring appropriate security for blockchain deployments. This research is certainly not the first attempt at discussing the security of the blockchain and will not be the last, as the technology around blockchain and distributed ledger technology is still rapidly evolving. What this research does try to achieve is not to delve into extremely specific areas of blockchain security, or get bogged down in technical details, but to provide a reference framework that aims to cover all the major areas to be considered. The approach followed was to review the literature regarding blockchain and to identify the main security areas to be addressed. It then proposes a decision-making model and tests the model against a fictitious but relevant real-world example. It concludes with learnings from this research. The reader can be the judge, but the model aims to be a practical valuable resource to be used by any security professional, to navigate the security aspects logically and understandably when being involved in a blockchain deployment. In contrast to the Satoshi quote, this research tries to convince the reader and assist him/her in understanding the security choices related to every blockchain deployment. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10-29
Photodynamic therapy activity of zinc phthalocyanine linked to folic acid and magnetic nanoparticles
- Matlou, Gauta G, Oluwole, David O, Prinsloo, Earl, Nyokong, Tebello
- Authors: Matlou, Gauta G , Oluwole, David O , Prinsloo, Earl , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234429 , vital:50195 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2018.07.025"
- Description: In this work, the photodynamic therapy (PDT) activities (using human carcinoma adherent MCF-7 cells) of zinc phthalocyanine derivatives: complexes 1 (Zn mono cinnamic acid phthalocyanine) and 2 (zinc mono carboxyphenoxy phthalocyanine) when covalently linked to folic acid (FA) and amine functionalized magnetic nanoparticles (AMNPs) are reported. The covalent linkage of asymmetric zinc cinnamic acid Pc (1) to FA (1-FA) through an amide bond is reported for the first time. Complex 1 is insoluble in water, but upon linkage to FA, (to form 1-FA) the molecule become water soluble, hence the UV–Vis spectrum and singlet oxygen quantum yield for 1-FA were also done in water since water solubility is essential for biological applications. The reported 2-FA is also water soluble. Linking complexes 1 and 2 to FA and AMNPs decreased the dark toxicity of 1 and 2 on MCF-7 cells. Pc-FA (1-FA and 2-FA) conjugates had better singlet oxygen quantum yields (Φ∆) in DMSO as compared to Pc-AMNPs (1-AMNPs and 2-AMNPs). The water- soluble 1-FA and 2-FA also achieved a better photodynamic therapy (PDT) activity as compared to 1-AMNPs and 2-AMNPs. Folic acid targeting on the tumor cells may have also facilitated better bioavailability of 1-FA and 2-FA and improved PDT activity on MCF-7 cells over AMNPs carriers.
- Full Text:
- Date Issued: 2018
Photodynamic therapy activity of zinc phthalocyanine linked to folic acid and magnetic nanoparticles
- Authors: Matlou, Gauta G , Oluwole, David O , Prinsloo, Earl , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234429 , vital:50195 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2018.07.025"
- Description: In this work, the photodynamic therapy (PDT) activities (using human carcinoma adherent MCF-7 cells) of zinc phthalocyanine derivatives: complexes 1 (Zn mono cinnamic acid phthalocyanine) and 2 (zinc mono carboxyphenoxy phthalocyanine) when covalently linked to folic acid (FA) and amine functionalized magnetic nanoparticles (AMNPs) are reported. The covalent linkage of asymmetric zinc cinnamic acid Pc (1) to FA (1-FA) through an amide bond is reported for the first time. Complex 1 is insoluble in water, but upon linkage to FA, (to form 1-FA) the molecule become water soluble, hence the UV–Vis spectrum and singlet oxygen quantum yield for 1-FA were also done in water since water solubility is essential for biological applications. The reported 2-FA is also water soluble. Linking complexes 1 and 2 to FA and AMNPs decreased the dark toxicity of 1 and 2 on MCF-7 cells. Pc-FA (1-FA and 2-FA) conjugates had better singlet oxygen quantum yields (Φ∆) in DMSO as compared to Pc-AMNPs (1-AMNPs and 2-AMNPs). The water- soluble 1-FA and 2-FA also achieved a better photodynamic therapy (PDT) activity as compared to 1-AMNPs and 2-AMNPs. Folic acid targeting on the tumor cells may have also facilitated better bioavailability of 1-FA and 2-FA and improved PDT activity on MCF-7 cells over AMNPs carriers.
- Full Text:
- Date Issued: 2018
Being moved by a way the world is not
- Authors: Jones, Ward E
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275631 , vital:55064 , xlink:href="https://doi.org/10.1007/s11229-009-9522-z"
- Description: At the end of Lecture 3 of The Empirical Stance, Bas van Fraassen suggests that we see the change of view involved in scientific revolutions as being, at least in part, emotional. In this paper, I explore one plausible way of cashing out this suggestion. Someone’s emotional approval of a description of the world, I argue, thereby shows that she takes herself to have reason to take that description seriously. This is true even if she is convinced—as a scientific community is when it considers alternative theories—that this description is false, that it is not the way the world is.
- Full Text:
- Date Issued: 2011
- Authors: Jones, Ward E
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275631 , vital:55064 , xlink:href="https://doi.org/10.1007/s11229-009-9522-z"
- Description: At the end of Lecture 3 of The Empirical Stance, Bas van Fraassen suggests that we see the change of view involved in scientific revolutions as being, at least in part, emotional. In this paper, I explore one plausible way of cashing out this suggestion. Someone’s emotional approval of a description of the world, I argue, thereby shows that she takes herself to have reason to take that description seriously. This is true even if she is convinced—as a scientific community is when it considers alternative theories—that this description is false, that it is not the way the world is.
- Full Text:
- Date Issued: 2011
Wisdom as an aim of higher education
- Authors: Jones, Ward E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275765 , vital:55077 , xlink:href="https://doi.org/10.1007/s10790-014-9443-z"
- Description: A central concern of theoretical speculation about education is the kind of epistemic states that education can and should aim to achieve. One such epistemic state, long neglected in both education theory and philosophy, is wisdom. Might wisdom be something that educators should aim for? And might it be something that their students can achieve? My answer will be a qualified yes.
- Full Text:
- Date Issued: 2015
- Authors: Jones, Ward E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275765 , vital:55077 , xlink:href="https://doi.org/10.1007/s10790-014-9443-z"
- Description: A central concern of theoretical speculation about education is the kind of epistemic states that education can and should aim to achieve. One such epistemic state, long neglected in both education theory and philosophy, is wisdom. Might wisdom be something that educators should aim for? And might it be something that their students can achieve? My answer will be a qualified yes.
- Full Text:
- Date Issued: 2015
Religiosity and sexual risk-taking behaviour among Black female students attending university
- Authors: Yona, Nombeko
- Date: 2009-02
- Subjects: College students -- Sexual behavior , Women college students , Risk-taking (Psychology)
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10353/25129 , vital:63980
- Description: The degree to which religious identity acts as a protective buffer against sexual risk - taking in late adolescence and young adults was investigated among 100 Black female university students. Allport and Ross’ Religious Orientation Scale was used to examine the relationship among religiosity, sexual activity and condom use. The results indicated that greater intrinsic and extrinsic religiosity were associated with less sexual activity and condom use. Religious identification therefore protected respondents from sexual risk- taking but sexually active students with high levels of intrinsic and extrinsic religiosity were less likely to use condoms. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2009
- Full Text:
- Date Issued: 2009-02
- Authors: Yona, Nombeko
- Date: 2009-02
- Subjects: College students -- Sexual behavior , Women college students , Risk-taking (Psychology)
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10353/25129 , vital:63980
- Description: The degree to which religious identity acts as a protective buffer against sexual risk - taking in late adolescence and young adults was investigated among 100 Black female university students. Allport and Ross’ Religious Orientation Scale was used to examine the relationship among religiosity, sexual activity and condom use. The results indicated that greater intrinsic and extrinsic religiosity were associated with less sexual activity and condom use. Religious identification therefore protected respondents from sexual risk- taking but sexually active students with high levels of intrinsic and extrinsic religiosity were less likely to use condoms. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2009
- Full Text:
- Date Issued: 2009-02
(Ferrocenylpyrazolyl) zinc (II) benzoates as catalysts for the ring opening polymerization of ε-caprolactone
- Obuah, Collins, Lochee, Yemanlall, Jordaan, Johan H L, Otto, Daniel P, Nyokong, Tebello, Darkwa, James
- Authors: Obuah, Collins , Lochee, Yemanlall , Jordaan, Johan H L , Otto, Daniel P , Nyokong, Tebello , Darkwa, James
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189515 , vital:44853 , xlink:href="https://doi.org/10.1016/j.poly.2015.02.007"
- Description: The reaction of Zn(OAc)2 and C6H5COOH or 3,5-NO2-C6H3COOH with 3-ferrocenylpyrazolyl-methylenepyridine (L1), 3-ferrocenyl-5-methylpyrazolyl-methylenepyridine (L2), 3-ferrocenylpyrazolyl-ethylamine (L3) and 3-ferrocenyl-5-pyrazolyl-ethylamine (L4) afford the corresponding complexes [Zn(C6H5COO)2(L1)] (1), [Zn(C6H5COO)2(L2)] (2), [Zn(3,5-NO2-C6H3COO)2(L1)] (3), [Zn(3,5-NO2-C6H3 COO)2(L2)] (4), [Zn(C6H5COO)2(L3)] (5), [Zn(C6H5COO)2(L4)] (6), [Zn(3,5-NO2-C6H3COO)2(L3)] (7) and [Zn(3,5-NO2-C6H3COO)2(L4)] (8). These complexes behave as catalysts for the ring opening polymerization of e-caprolactone to produce polymers with molecular weight that range from 1480 to 7080 g mol1 and exhibited moderate to broad PDIs. Evidence of these complexes acting as catalysts was obtained from both the polymerization data and kinetic studies. The polymerization data show that variation of the [CL]/[C] from 100 to 800 produced PCL with relatively the same molecular weight indicative of a catalyst behavior. The appearance of induction period in kinetic plots strengthens the fact that these complexes are catalysts rather than initiators. MALDI-TOF MS and 1 H NMR data show di-hydroxy end groups, which support the coordination mechanism rather than insertion mechanism. To understand the broad PDIs obtained for some of the polymer, the electronic properties of the zinc complexes were investigated using cyclic voltammetry. The results show that the zinc complexes containing amine based ligands are highly electrophilic therefore making them unstable, hence the broad PDIs observed for zinc complexes containing amine based ligands. Among the eight complexes investigated, complex 7 is the most active catalyst with kp value of 1.18 107 h1 mol1 at 110 C.
- Full Text:
- Date Issued: 2015
- Authors: Obuah, Collins , Lochee, Yemanlall , Jordaan, Johan H L , Otto, Daniel P , Nyokong, Tebello , Darkwa, James
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189515 , vital:44853 , xlink:href="https://doi.org/10.1016/j.poly.2015.02.007"
- Description: The reaction of Zn(OAc)2 and C6H5COOH or 3,5-NO2-C6H3COOH with 3-ferrocenylpyrazolyl-methylenepyridine (L1), 3-ferrocenyl-5-methylpyrazolyl-methylenepyridine (L2), 3-ferrocenylpyrazolyl-ethylamine (L3) and 3-ferrocenyl-5-pyrazolyl-ethylamine (L4) afford the corresponding complexes [Zn(C6H5COO)2(L1)] (1), [Zn(C6H5COO)2(L2)] (2), [Zn(3,5-NO2-C6H3COO)2(L1)] (3), [Zn(3,5-NO2-C6H3 COO)2(L2)] (4), [Zn(C6H5COO)2(L3)] (5), [Zn(C6H5COO)2(L4)] (6), [Zn(3,5-NO2-C6H3COO)2(L3)] (7) and [Zn(3,5-NO2-C6H3COO)2(L4)] (8). These complexes behave as catalysts for the ring opening polymerization of e-caprolactone to produce polymers with molecular weight that range from 1480 to 7080 g mol1 and exhibited moderate to broad PDIs. Evidence of these complexes acting as catalysts was obtained from both the polymerization data and kinetic studies. The polymerization data show that variation of the [CL]/[C] from 100 to 800 produced PCL with relatively the same molecular weight indicative of a catalyst behavior. The appearance of induction period in kinetic plots strengthens the fact that these complexes are catalysts rather than initiators. MALDI-TOF MS and 1 H NMR data show di-hydroxy end groups, which support the coordination mechanism rather than insertion mechanism. To understand the broad PDIs obtained for some of the polymer, the electronic properties of the zinc complexes were investigated using cyclic voltammetry. The results show that the zinc complexes containing amine based ligands are highly electrophilic therefore making them unstable, hence the broad PDIs observed for zinc complexes containing amine based ligands. Among the eight complexes investigated, complex 7 is the most active catalyst with kp value of 1.18 107 h1 mol1 at 110 C.
- Full Text:
- Date Issued: 2015
Representation of the twentieth century socio-economic and political history of Red Location New Brighton (Port Elizabeth) 1903-1963
- Authors: Maliza, Nokuzola Thozama
- Date: 2012-01
- Subjects: History -- Economic conditions , World politics -- South Africa , Squatter settlements -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26415 , vital:65306
- Description: This study sets out to recapture the rich history and diverse culture of Red Location, New Brighton. Port Elizabeth. It explains the reasons for the establishment of Red Location in 1903, and goes on to look at the Economic and Social life of the Community. Two chapters are then devoted to political struggles in Red Location and New Brighton, long regarded as one of the most militant African townships in the apartheid era. Finally, we look at the way in which Red Location has been represented in the substantial Red Location Museum project, and the extent to which the Museum reflects the historical reality. , Thesis (MHIS) -- Faculty of Humanities, 2012
- Full Text:
- Date Issued: 2012-01
- Authors: Maliza, Nokuzola Thozama
- Date: 2012-01
- Subjects: History -- Economic conditions , World politics -- South Africa , Squatter settlements -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26415 , vital:65306
- Description: This study sets out to recapture the rich history and diverse culture of Red Location, New Brighton. Port Elizabeth. It explains the reasons for the establishment of Red Location in 1903, and goes on to look at the Economic and Social life of the Community. Two chapters are then devoted to political struggles in Red Location and New Brighton, long regarded as one of the most militant African townships in the apartheid era. Finally, we look at the way in which Red Location has been represented in the substantial Red Location Museum project, and the extent to which the Museum reflects the historical reality. , Thesis (MHIS) -- Faculty of Humanities, 2012
- Full Text:
- Date Issued: 2012-01
Electrocatalytic oxidation of cysteine by molybdenum (V) phthalocyanine complexes
- Mafatle, Tsukutlane J, Nyokong, Tebello
- Authors: Mafatle, Tsukutlane J , Nyokong, Tebello
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293369 , vital:57079 , xlink:href="https://doi.org/10.1016/0022-0728(95)04519-8"
- Description: Chemically modified electrodes, constructed by incorporating oxomolybdenum(V) phthalocyanine (OMo(V)(OH)Pc, Pc = phthalocyanine dianion) into graphite powder were used to catalyse the oxidation of cysteine. Solution catalysis of cysteine by oxomolybdenum(V) tetrasulfophthalocyanine, [OMo(V)(OH)TSPc]4−, was also investigated. A considerable reduction in overpotential for cysteine oxidation was observed. Cysteine oxidation occurred at 0.26 and 0.28 V vs. Ag/vbAgCl for catalysis by Omo(V)(OH)Pc and [OMo(V)(OH)TSPc]4− respectively as opposed to 0.77 V vs. Ag/vbAgCl observed on CoPc chemically modified electrodes. The anodic peak currents vary linearly with cysteine concentration in the range 0.02 to 0.08 mol dm−3 and 0.008 to 0.02 mol dm−3 for [OMo(V)(OH)TSPc]4− and OMo(V)Pc respectively.
- Full Text:
- Date Issued: 1996
- Authors: Mafatle, Tsukutlane J , Nyokong, Tebello
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293369 , vital:57079 , xlink:href="https://doi.org/10.1016/0022-0728(95)04519-8"
- Description: Chemically modified electrodes, constructed by incorporating oxomolybdenum(V) phthalocyanine (OMo(V)(OH)Pc, Pc = phthalocyanine dianion) into graphite powder were used to catalyse the oxidation of cysteine. Solution catalysis of cysteine by oxomolybdenum(V) tetrasulfophthalocyanine, [OMo(V)(OH)TSPc]4−, was also investigated. A considerable reduction in overpotential for cysteine oxidation was observed. Cysteine oxidation occurred at 0.26 and 0.28 V vs. Ag/vbAgCl for catalysis by Omo(V)(OH)Pc and [OMo(V)(OH)TSPc]4− respectively as opposed to 0.77 V vs. Ag/vbAgCl observed on CoPc chemically modified electrodes. The anodic peak currents vary linearly with cysteine concentration in the range 0.02 to 0.08 mol dm−3 and 0.008 to 0.02 mol dm−3 for [OMo(V)(OH)TSPc]4− and OMo(V)Pc respectively.
- Full Text:
- Date Issued: 1996
The role of local economic development in poverty alleviation: a case of Buffalo City Metropolitan Municipality
- Authors: Mkanyeli, Vuyokazi
- Date: 2021-04
- Subjects: Economic development -- South Africa -- Buffalo City , Poverty -- Economic aspects -- South Africa -- Buffalo City
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53478 , vital:45157
- Description: The primary purpose of Local Economic Development is centred on the improvement of the quality of life for all. Thus, LED plays a fundamental role in poverty alleviation in communities, if utilised effectively and efficiently. The present study was conducted in Buffalo City Metropolitan Municipality, which is located in the Eastern Cape Province of South Africa. The chosen case study is characterised by high unemployment and poverty. Thus, this study explored the role of LED strategies in alleviating poverty within the municipality. The study adopted a qualitative research methodology with the use of a case study research design. Data was collected through interviews with LED officials within the municipality and analysed through thematic analysis. The study findings showed that in as much as the BCMM is characterised by poverty, it strives to alleviate poverty through employing various LED strategies such as agriculture, tourism, Small, Medium and Micro Enterprises, and the Metro Growth and Development Strategy. The findings also revealed that the municipality is confronted with a myriad of challenges that hinder effective implementation of these strategies. If the strategies are effectively implemented, the study participants argued that it will result in job creation, income generation and skills development. The challenges include limited resources, lack of investments, lack of skilled personnel and lack of connectivity. The study recommends infrastructure development, establishment of mechanisms to attract investments and focusing more on building capabilities. The municipality should also implement more LED strategies as well as engage in more partnerships. This will ensure poverty alleviation within the Buffalo City Metropolitan Municipality. , Thesis (MPA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mkanyeli, Vuyokazi
- Date: 2021-04
- Subjects: Economic development -- South Africa -- Buffalo City , Poverty -- Economic aspects -- South Africa -- Buffalo City
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53478 , vital:45157
- Description: The primary purpose of Local Economic Development is centred on the improvement of the quality of life for all. Thus, LED plays a fundamental role in poverty alleviation in communities, if utilised effectively and efficiently. The present study was conducted in Buffalo City Metropolitan Municipality, which is located in the Eastern Cape Province of South Africa. The chosen case study is characterised by high unemployment and poverty. Thus, this study explored the role of LED strategies in alleviating poverty within the municipality. The study adopted a qualitative research methodology with the use of a case study research design. Data was collected through interviews with LED officials within the municipality and analysed through thematic analysis. The study findings showed that in as much as the BCMM is characterised by poverty, it strives to alleviate poverty through employing various LED strategies such as agriculture, tourism, Small, Medium and Micro Enterprises, and the Metro Growth and Development Strategy. The findings also revealed that the municipality is confronted with a myriad of challenges that hinder effective implementation of these strategies. If the strategies are effectively implemented, the study participants argued that it will result in job creation, income generation and skills development. The challenges include limited resources, lack of investments, lack of skilled personnel and lack of connectivity. The study recommends infrastructure development, establishment of mechanisms to attract investments and focusing more on building capabilities. The municipality should also implement more LED strategies as well as engage in more partnerships. This will ensure poverty alleviation within the Buffalo City Metropolitan Municipality. , Thesis (MPA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
Fuel wood use in South Africa: Where to in the 21st Century?
- Williams, Anthony, Shackleton, Charlie M
- Authors: Williams, Anthony , Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183026 , vital:43905 , xlink:href="https://doi.org/10.1080/20702620.2002.10434611"
- Description: South Africa is well known for the dichotomous nature of its economy, with its juxtaposed first and third world characteristics, perhaps nowhere more starkly evident than in the energy sector. South Africa produces and consumes over 60% of the total electrical energy on the African continent, and is ranked twelfth in the world in terms of carbon emissions (EIA, 2002). Yet the majority of the South African population does not have access to electricity, and despite the enormous strides taken since 1994 to increase household access to electricity (NER, 2001), newly electrified households, more often than not, cannot afford the appliances nor the monthly costs required to significantly improve their quality of life (White et al., 1997). Thus, most rural and many peri-urban households continue to use fuelwood as their primary energy source (Griffin et al., 1992; Dyer, 1996; Kotze, 1996; Williams et al., 1996). Fuelwood use presents both opportunities and risks.
- Full Text:
- Date Issued: 2002
- Authors: Williams, Anthony , Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183026 , vital:43905 , xlink:href="https://doi.org/10.1080/20702620.2002.10434611"
- Description: South Africa is well known for the dichotomous nature of its economy, with its juxtaposed first and third world characteristics, perhaps nowhere more starkly evident than in the energy sector. South Africa produces and consumes over 60% of the total electrical energy on the African continent, and is ranked twelfth in the world in terms of carbon emissions (EIA, 2002). Yet the majority of the South African population does not have access to electricity, and despite the enormous strides taken since 1994 to increase household access to electricity (NER, 2001), newly electrified households, more often than not, cannot afford the appliances nor the monthly costs required to significantly improve their quality of life (White et al., 1997). Thus, most rural and many peri-urban households continue to use fuelwood as their primary energy source (Griffin et al., 1992; Dyer, 1996; Kotze, 1996; Williams et al., 1996). Fuelwood use presents both opportunities and risks.
- Full Text:
- Date Issued: 2002
Perceptions of mental illness among the residents of the Eastern Cape Province in South Africa: The influence of culture and religion on their coping strategies.: subtitle if needed. If no subtitle follow instructions in manual
- Authors: Sikrweqe, Odwa
- Date: 2023-04
- Subjects: Mental illness , Mental illness--Religious aspects , Mental illness-- Culture aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60445 , vital:65507
- Description: Mental illness has become a global concern, with consequences that may result in a mental health pandemic. Studies conducted on mental illness suggest that religious and cultural beliefs not only affect the expression of mental illness, but also the diagnosis and treatment of mental conditions. South Africa is a country imbued with cultural and religious diversity, which creates different groupings of people, holding diverse beliefs regarding mental illness. In many contexts, supernatural beliefs, traditional healing and indigenous medicines and treatments are considered in the treatment of the symptoms associated with mental illnesses, especially on contexts where there is a reliance on religio-cultural beliefs. Even though there has been a significant increase in the contribution to research focusing on mental health in diverse contexts, much of this research has focused on subjective experiences. Little to no information is available on population-based studies in South Africa regarding mental illness in diverse contexts, thus limiting the generalisation of findings related to cultural and religious influences on mental illness. This dearth of information further limits the development of psychological interventions. The study aimed to explore how mental illness is perceived by the participants and thereafter explored the influence of culture and religion in coping with mental illness by the residents of the Eastern Cape. The study was quantitative in nature and adopted an exploratory-descriptive design. The researcher made use of a questionnaire as a research tool and QuestionPro was utilized as a platform. A convenience sampling technique was utilised. In ensuring rigour of the study, the researcher ensured maximal validity (accurate representation of the data) and reliability (ability to repeat the research procedure). Ethical principles have been adhered to as per the principles on the Belmont Report, to ensure safety of the participants and this includes anonymity, confidentiality and the right to withdraw from participation in the study. Data has been analysed using descriptive and inferential statistics. A sample size of 101 participants from the general population of residents of the Eastern Cape completed the online survey. The results of the study revealed that the residents of the Eastern Cape have substantial knowledge pertaining the cause of mental illness and indicated both positive and negative attitudes towards the mentally ill and possess coping strategies to deal with a mental illness. In addition, the results show that there is a relation between religion/culture and coping with a mental illness by the participants of the study. The findings of this study emphasize the necessity of public education efforts that understand and respect people's cultural diversity, as well as teamwork among traditional and medical professionals. Future studies should focus on the use of discourse analysis to better investigate indigenous groups' conceptions of mental illness and their views about its aetiology and treatment. , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural Science, 2023
- Full Text:
- Date Issued: 2023-04
- Authors: Sikrweqe, Odwa
- Date: 2023-04
- Subjects: Mental illness , Mental illness--Religious aspects , Mental illness-- Culture aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60445 , vital:65507
- Description: Mental illness has become a global concern, with consequences that may result in a mental health pandemic. Studies conducted on mental illness suggest that religious and cultural beliefs not only affect the expression of mental illness, but also the diagnosis and treatment of mental conditions. South Africa is a country imbued with cultural and religious diversity, which creates different groupings of people, holding diverse beliefs regarding mental illness. In many contexts, supernatural beliefs, traditional healing and indigenous medicines and treatments are considered in the treatment of the symptoms associated with mental illnesses, especially on contexts where there is a reliance on religio-cultural beliefs. Even though there has been a significant increase in the contribution to research focusing on mental health in diverse contexts, much of this research has focused on subjective experiences. Little to no information is available on population-based studies in South Africa regarding mental illness in diverse contexts, thus limiting the generalisation of findings related to cultural and religious influences on mental illness. This dearth of information further limits the development of psychological interventions. The study aimed to explore how mental illness is perceived by the participants and thereafter explored the influence of culture and religion in coping with mental illness by the residents of the Eastern Cape. The study was quantitative in nature and adopted an exploratory-descriptive design. The researcher made use of a questionnaire as a research tool and QuestionPro was utilized as a platform. A convenience sampling technique was utilised. In ensuring rigour of the study, the researcher ensured maximal validity (accurate representation of the data) and reliability (ability to repeat the research procedure). Ethical principles have been adhered to as per the principles on the Belmont Report, to ensure safety of the participants and this includes anonymity, confidentiality and the right to withdraw from participation in the study. Data has been analysed using descriptive and inferential statistics. A sample size of 101 participants from the general population of residents of the Eastern Cape completed the online survey. The results of the study revealed that the residents of the Eastern Cape have substantial knowledge pertaining the cause of mental illness and indicated both positive and negative attitudes towards the mentally ill and possess coping strategies to deal with a mental illness. In addition, the results show that there is a relation between religion/culture and coping with a mental illness by the participants of the study. The findings of this study emphasize the necessity of public education efforts that understand and respect people's cultural diversity, as well as teamwork among traditional and medical professionals. Future studies should focus on the use of discourse analysis to better investigate indigenous groups' conceptions of mental illness and their views about its aetiology and treatment. , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural Science, 2023
- Full Text:
- Date Issued: 2023-04
Computational analysis of known drug resistant mutants of Plasmodium falciparum Dihydrofolate Reductase (PfDHFR) and screening for novel antifolates against the enzyme
- Authors: Tata, Rolland Bantar
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/234184 , vital:50170
- Description: Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Tata, Rolland Bantar
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/234184 , vital:50170
- Description: Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-08
Effect of doping vs covalent linking of a low symmetry zinc phthalocyanine to silica nanoparticles on singlet oxygen production
- Peteni, Siwaphiwe, Nyokong, Tebello
- Authors: Peteni, Siwaphiwe , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187873 , vital:44705 , xlink:href="https://doi.org/10.1016/j.ica.2018.06.029"
- Description: Tris[(4-(pyridin-4-ylthio)-2-thio-4-methylthiazol-5-yl)acetic acid phthalocyaninato] zinc (II) (3) was covalently linked to and doped onto SiNPs. An increase in triplet quantum yields for 3-SiNPs (linked) with decreasing lifetimes was observed. For 3-SiNPs (doped) there was a decrease in both the triplet quantum yield and lifetimes when compared to 3 alone. There was an increase in singlet oxygen quantum yields for 3-SiNPs (linked) compared to 3 from 0.67 to 0.80, while there was a decrease for 3-SiNPs (doped) to 0.25.
- Full Text:
- Date Issued: 2018
- Authors: Peteni, Siwaphiwe , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187873 , vital:44705 , xlink:href="https://doi.org/10.1016/j.ica.2018.06.029"
- Description: Tris[(4-(pyridin-4-ylthio)-2-thio-4-methylthiazol-5-yl)acetic acid phthalocyaninato] zinc (II) (3) was covalently linked to and doped onto SiNPs. An increase in triplet quantum yields for 3-SiNPs (linked) with decreasing lifetimes was observed. For 3-SiNPs (doped) there was a decrease in both the triplet quantum yield and lifetimes when compared to 3 alone. There was an increase in singlet oxygen quantum yields for 3-SiNPs (linked) compared to 3 from 0.67 to 0.80, while there was a decrease for 3-SiNPs (doped) to 0.25.
- Full Text:
- Date Issued: 2018
Effectiveness of private land conservation areas in maintaining natural land cover and biodiversity intactness
- Shumba, Tafadzwa, de Vos, Alta, Biggs, Reinette, Esler, Karen J, Ament, Judith M, Clements, Hayley S
- Authors: Shumba, Tafadzwa , de Vos, Alta , Biggs, Reinette , Esler, Karen J , Ament, Judith M , Clements, Hayley S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415852 , vital:71294 , xlink:href="https://doi.org/10.1016/j.gecco.2020.e00935"
- Description: Private land conservation areas (PLCAs) are increasingly looked to for meeting the deficit left by state-owned protected areas in reaching global conservation targets. However, despite the increasing extent and recognition of PLCAs as a complementary conservation strategy, little research has been done to quantify their effectiveness; a critical consideration if they are to be counted towards international biodiversity conservation targets. The long history of PLCAs in South Africa provides an interesting case study to address this knowledge gap. Here, we quantified the effectiveness of South African PLCAs by comparing losses in natural land cover and biodiversity intactness within PLCAs with different levels of protection to that of unprotected control points. Points within PLCAs were matched with unprotected control points to test the prediction that if PLCAs offer effective protection, losses in natural land cover and biodiversity intactness would be significantly lower within their boundaries in comparison to unprotected controls exposed to similar conditions. Consequences of natural land cover loss on biodiversity intactness were thus assessed, thus advancing standard approaches for quantifying effectiveness.
- Full Text:
- Date Issued: 2020
- Authors: Shumba, Tafadzwa , de Vos, Alta , Biggs, Reinette , Esler, Karen J , Ament, Judith M , Clements, Hayley S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415852 , vital:71294 , xlink:href="https://doi.org/10.1016/j.gecco.2020.e00935"
- Description: Private land conservation areas (PLCAs) are increasingly looked to for meeting the deficit left by state-owned protected areas in reaching global conservation targets. However, despite the increasing extent and recognition of PLCAs as a complementary conservation strategy, little research has been done to quantify their effectiveness; a critical consideration if they are to be counted towards international biodiversity conservation targets. The long history of PLCAs in South Africa provides an interesting case study to address this knowledge gap. Here, we quantified the effectiveness of South African PLCAs by comparing losses in natural land cover and biodiversity intactness within PLCAs with different levels of protection to that of unprotected control points. Points within PLCAs were matched with unprotected control points to test the prediction that if PLCAs offer effective protection, losses in natural land cover and biodiversity intactness would be significantly lower within their boundaries in comparison to unprotected controls exposed to similar conditions. Consequences of natural land cover loss on biodiversity intactness were thus assessed, thus advancing standard approaches for quantifying effectiveness.
- Full Text:
- Date Issued: 2020
Anti-cancer and anti-trypanosomal properties of alkaloids from the root bark of Zanthoxylum leprieurii Guill and Perr
- Eze, Fabian I, Siwe-Noundou, Xavier, Isaacs, Michelle, Patala, Srivinas, Osadebe, Patience O, Krause, Rui W M
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Isaacs, Michelle , Patala, Srivinas , Osadebe, Patience O , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193352 , vital:45324 , xlink:href="http://dx.doi.org/10.4314/tjpr.v19i11.19"
- Description: Purpose: To isolate the anti-cancer and anti-trypanosomal principles of Zanthoxylum leprieurii, a medicinally versatile wild tropical plant used for managing tumours, African trypanosomiasis, and inflammation in southeastern Nigeria. Methods: The pure compounds were isolated using chromatographic methods. The structural elucidation of the pure compounds was based on their NMR (1D and 2D) and mass spectral data as well as chemical test results. Structure-activity relationships were based on the structural differences among the compounds. The cytotoxicity of the extracts and compounds (1, 2, 3, and 4) was evaluated in HeLa (human cervix adenocarcinoma) cell line while the trypanocidal activities were evaluated on Trypanosoma brucei brucei. Results: Two acridone alkaloids, 1-hydroxy-3-methoxy-10-methylacridin-9 (10H)-one, named fabiocinine (1), and 1-hydroxy-2,3-dimethoxy-10-methylacridin-9 (10H)-one (arborinine, 2), together with a furoquinoline alkaloid, skimmianine (3), and a chelerythrine derivative, 6-acetonyl-5,6-dihydrochelerythrine (4) were isolated from the root bark of Zanthoxylum leprieurii. Skimmianine (3) exhibited cytotoxicity and anti-trypanosomal IC50 of 12.8 and 13.2 µg/mL respectively (p less than 0.05). Compound (1) and arborinine (2) were selectively cytotoxic to HeLa cells with cytotoxicity IC50 of 28.49 and 62.71 µg/mL, respectively, while (4) did not show significant activity (p less than 0.05). Conclusion: Zanthoxylum leprieurii root bark contains cytotoxic and trypanocidal compounds, and is thus a potential source of anti-cancer and anti-trypanosomal leads.
- Full Text:
- Date Issued: 2020
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Isaacs, Michelle , Patala, Srivinas , Osadebe, Patience O , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193352 , vital:45324 , xlink:href="http://dx.doi.org/10.4314/tjpr.v19i11.19"
- Description: Purpose: To isolate the anti-cancer and anti-trypanosomal principles of Zanthoxylum leprieurii, a medicinally versatile wild tropical plant used for managing tumours, African trypanosomiasis, and inflammation in southeastern Nigeria. Methods: The pure compounds were isolated using chromatographic methods. The structural elucidation of the pure compounds was based on their NMR (1D and 2D) and mass spectral data as well as chemical test results. Structure-activity relationships were based on the structural differences among the compounds. The cytotoxicity of the extracts and compounds (1, 2, 3, and 4) was evaluated in HeLa (human cervix adenocarcinoma) cell line while the trypanocidal activities were evaluated on Trypanosoma brucei brucei. Results: Two acridone alkaloids, 1-hydroxy-3-methoxy-10-methylacridin-9 (10H)-one, named fabiocinine (1), and 1-hydroxy-2,3-dimethoxy-10-methylacridin-9 (10H)-one (arborinine, 2), together with a furoquinoline alkaloid, skimmianine (3), and a chelerythrine derivative, 6-acetonyl-5,6-dihydrochelerythrine (4) were isolated from the root bark of Zanthoxylum leprieurii. Skimmianine (3) exhibited cytotoxicity and anti-trypanosomal IC50 of 12.8 and 13.2 µg/mL respectively (p less than 0.05). Compound (1) and arborinine (2) were selectively cytotoxic to HeLa cells with cytotoxicity IC50 of 28.49 and 62.71 µg/mL, respectively, while (4) did not show significant activity (p less than 0.05). Conclusion: Zanthoxylum leprieurii root bark contains cytotoxic and trypanocidal compounds, and is thus a potential source of anti-cancer and anti-trypanosomal leads.
- Full Text:
- Date Issued: 2020
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
The macroeconomic impact of ocean economy financing in South Africa
- Authors: Matekenya, Weliswa
- Date: 2022-12
- Subjects: Macroeconomics , Maritime –- South Africa
- Language: English
- Type: Doctoral's theses , Thesis
- Identifier: http://hdl.handle.net/10948/60305 , vital:64343
- Description: The global ocean is responsible for providing seafood and employment to the world’s population and is the key driver of global gross domestic product. The ocean economy (blue economy) has been identified as key to unlocking the growth potential of many economies. It is in this context that both the South African government and the private sector have invested in the ocean economy with the purpose of sustaining it and making it more productive. To this end, the government established the Operation Phakisa programme which is meant to fast-track ocean economy development. In line with operation Phakisa imperatives, the South African government began a series of budget allocations towards the various sectors of the oceans economy. This flow of public funds towards oceans economy sectors was with a view to reduce unemployment, grow the economy, increase trade as well as boost entrepreneurship. It is for this reason that the financing of the ocean economy needs to be assessed in terms of its role in ensuring sustainable economic growth through ocean economy activities. While the ocean economy is becoming a new focal point in the discourse on growth and sustainable development both globally and locally, it remains faced with a series of challenges in South Africa. These include inadequate economic incentives, outdated infrastructure, ineffective governance institutions, lack of technological advances, and insufficient management tools. All of these have led to unregulated competition among users, albeit in the context of extensive opportunities offered by the rising demand for seafood. The specific focus of the study is the macroeconomic impact of ocean economy financing in South Africa during the 1994 to 2019 period. The study employed ARDL to test long and short-run relationships. The results show that ocean economy financing in South Africa during this time to have had a positive effect on economic growth, and a negative relationship on unemployment, although the latter is statically insignificant, while ocean economy financing has a negative relationship with entrepreneurship, to have a positive relationship with total trade, and statistically significant. Based on the findings of the study recommendations are made for the South African government to continue investing in oceans economy marine infrastructure and to address any constraints that hinder the growth and sustainability of the country’s ocean economy. In order to ensure the economic viability of ocean ii economy financing four areas need attention, namely economic growth, entrepreneurship, job creation, and total trade. This study recommends that in order to grow the South African economy, a comprehensive growth strategy that looks beyond ocean economy should be adopted. Regarding entrepreneurship ease of doing business should be improved and all factors inhibiting entrepreneurship should be addressed. The requisite skills through human capital investment should be harnessed and decent and sustainable jobs in the ocean sector should be created. It is a well-known fact that an aggressive drive towards economic growth is not without negative externalities e.g pollutions, unreported, unregulated, and over-exploitation of ocean resources. Ocean governance is vital in preventing such negative externalities. The results of the study show that ocean governance boosts trade and reduces unemployment. , Thesis (PHD) -- Faculty of Business and Economic Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Matekenya, Weliswa
- Date: 2022-12
- Subjects: Macroeconomics , Maritime –- South Africa
- Language: English
- Type: Doctoral's theses , Thesis
- Identifier: http://hdl.handle.net/10948/60305 , vital:64343
- Description: The global ocean is responsible for providing seafood and employment to the world’s population and is the key driver of global gross domestic product. The ocean economy (blue economy) has been identified as key to unlocking the growth potential of many economies. It is in this context that both the South African government and the private sector have invested in the ocean economy with the purpose of sustaining it and making it more productive. To this end, the government established the Operation Phakisa programme which is meant to fast-track ocean economy development. In line with operation Phakisa imperatives, the South African government began a series of budget allocations towards the various sectors of the oceans economy. This flow of public funds towards oceans economy sectors was with a view to reduce unemployment, grow the economy, increase trade as well as boost entrepreneurship. It is for this reason that the financing of the ocean economy needs to be assessed in terms of its role in ensuring sustainable economic growth through ocean economy activities. While the ocean economy is becoming a new focal point in the discourse on growth and sustainable development both globally and locally, it remains faced with a series of challenges in South Africa. These include inadequate economic incentives, outdated infrastructure, ineffective governance institutions, lack of technological advances, and insufficient management tools. All of these have led to unregulated competition among users, albeit in the context of extensive opportunities offered by the rising demand for seafood. The specific focus of the study is the macroeconomic impact of ocean economy financing in South Africa during the 1994 to 2019 period. The study employed ARDL to test long and short-run relationships. The results show that ocean economy financing in South Africa during this time to have had a positive effect on economic growth, and a negative relationship on unemployment, although the latter is statically insignificant, while ocean economy financing has a negative relationship with entrepreneurship, to have a positive relationship with total trade, and statistically significant. Based on the findings of the study recommendations are made for the South African government to continue investing in oceans economy marine infrastructure and to address any constraints that hinder the growth and sustainability of the country’s ocean economy. In order to ensure the economic viability of ocean ii economy financing four areas need attention, namely economic growth, entrepreneurship, job creation, and total trade. This study recommends that in order to grow the South African economy, a comprehensive growth strategy that looks beyond ocean economy should be adopted. Regarding entrepreneurship ease of doing business should be improved and all factors inhibiting entrepreneurship should be addressed. The requisite skills through human capital investment should be harnessed and decent and sustainable jobs in the ocean sector should be created. It is a well-known fact that an aggressive drive towards economic growth is not without negative externalities e.g pollutions, unreported, unregulated, and over-exploitation of ocean resources. Ocean governance is vital in preventing such negative externalities. The results of the study show that ocean governance boosts trade and reduces unemployment. , Thesis (PHD) -- Faculty of Business and Economic Sciences, 2022
- Full Text:
- Date Issued: 2022-12
Perceptions of blended learning by academic staff in the Health Sciences Faculty at Nelson Mandela University
- Authors: Barry, Janet
- Date: 2021-04
- Subjects: Blended learning -- South Africa -- Nelson Mandela Bay Municipality -- Faculty , Medical sciences -- South Africa -- Nelson Mandela Bay Municipality -- Faculty
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50999 , vital:43199
- Description: Numerous studies have investigated the use of blended learning by academic staff at tertiary institutions. The purpose of this study was to examine the perceptions of blended learning by academic staff at the Faculty of Health Sciences at Nelson Mandela University. A related objective was to identify barriers and facilitators to the adoption of blended learning by academic staff. A sequential, exploratory mixed-methods design was adopted for this study whereby Phase 1 (focus groups) was used to inform Phase 2 (questionnaire) of the study. Results were analysed from both phases and organised according to strategies, support, and structure of a blended learning adoption framework. Existing support structures to assist with blended learning adoption, understanding of what blended learning is, confidence in using blended learning tools, and time to attend training were some of the findings of the study. The researcher concluded that academic staff in the Health Sciences Faculty at Nelson Mandela University are positioned in the second stage of the blended learning adoption framework, namely the early adoption stage of blended learning. These findings imply that existing strategies and support within the Faculty and the University need to be further developed, and structures put into place to move to an advanced stage of adoption of blended learning by academic staff in Health Sciences Faculty of Nelson Mandela University. , Thesis (MPharm) -- Faculty of Health Sciences, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Barry, Janet
- Date: 2021-04
- Subjects: Blended learning -- South Africa -- Nelson Mandela Bay Municipality -- Faculty , Medical sciences -- South Africa -- Nelson Mandela Bay Municipality -- Faculty
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50999 , vital:43199
- Description: Numerous studies have investigated the use of blended learning by academic staff at tertiary institutions. The purpose of this study was to examine the perceptions of blended learning by academic staff at the Faculty of Health Sciences at Nelson Mandela University. A related objective was to identify barriers and facilitators to the adoption of blended learning by academic staff. A sequential, exploratory mixed-methods design was adopted for this study whereby Phase 1 (focus groups) was used to inform Phase 2 (questionnaire) of the study. Results were analysed from both phases and organised according to strategies, support, and structure of a blended learning adoption framework. Existing support structures to assist with blended learning adoption, understanding of what blended learning is, confidence in using blended learning tools, and time to attend training were some of the findings of the study. The researcher concluded that academic staff in the Health Sciences Faculty at Nelson Mandela University are positioned in the second stage of the blended learning adoption framework, namely the early adoption stage of blended learning. These findings imply that existing strategies and support within the Faculty and the University need to be further developed, and structures put into place to move to an advanced stage of adoption of blended learning by academic staff in Health Sciences Faculty of Nelson Mandela University. , Thesis (MPharm) -- Faculty of Health Sciences, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04