Collaborative research in contexts of inequality: the role of social reflexivity
- Leibowitz, Brenda, Bozalek, Vivienne, Farmer, Jean, Garraway, James, Herman, Nicoline, Jawitz, Jeff, McMillan, Wendy, Mistri, Gita, Ndebele, Clever, Nkonki, Vuyisile, Quinn, Lynn, Van Schalkwyk, Susan, Vorster, Jo-Anne, Winberg, Chris
- Authors: Leibowitz, Brenda , Bozalek, Vivienne , Farmer, Jean , Garraway, James , Herman, Nicoline , Jawitz, Jeff , McMillan, Wendy , Mistri, Gita , Ndebele, Clever , Nkonki, Vuyisile , Quinn, Lynn , Van Schalkwyk, Susan , Vorster, Jo-Anne , Winberg, Chris
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66634 , vital:28973 , https://doi.org/10.1007/s10734-016-0029-5
- Description: publisher version , This article reports on the role and value of social reflexivity in collaborative research in contexts of extreme inequality. Social reflexivity mediates the enablements and constraints generated by the internal and external contextual conditions impinging on the research collaboration. It fosters the ability of participants in a collaborative project to align their interests and collectively extend their agency towards a common purpose. It influences the productivity and quality of learning outcomes of the research collaboration. The article is written by fourteen members of a larger research team, which comprised 18 individuals working within the academic development environment in eight South African universities. The overarching research project investigated the participation of academics in professional development activities, and how contextual, i.e. structural and cultural, and agential conditions, influence this participation. For this sub-study on the experience of the collaboration by fourteen of the researchers, we wrote reflective pieces on our own experience of participating in the project towards the end of the third year of its duration. We discuss the structural and cultural conditions external to and internal to the project, and how the social reflexivity of the participants mediated these conditions. We conclude with the observation that policy injunctions and support from funding agencies for collaborative research, as well as support from participants’ home institutions are necessary for the flourishing of collaborative research, but that the commitment by individual participants to participate, learn and share, is also necessary.
- Full Text: false
- Date Issued: 2017
- Authors: Leibowitz, Brenda , Bozalek, Vivienne , Farmer, Jean , Garraway, James , Herman, Nicoline , Jawitz, Jeff , McMillan, Wendy , Mistri, Gita , Ndebele, Clever , Nkonki, Vuyisile , Quinn, Lynn , Van Schalkwyk, Susan , Vorster, Jo-Anne , Winberg, Chris
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66634 , vital:28973 , https://doi.org/10.1007/s10734-016-0029-5
- Description: publisher version , This article reports on the role and value of social reflexivity in collaborative research in contexts of extreme inequality. Social reflexivity mediates the enablements and constraints generated by the internal and external contextual conditions impinging on the research collaboration. It fosters the ability of participants in a collaborative project to align their interests and collectively extend their agency towards a common purpose. It influences the productivity and quality of learning outcomes of the research collaboration. The article is written by fourteen members of a larger research team, which comprised 18 individuals working within the academic development environment in eight South African universities. The overarching research project investigated the participation of academics in professional development activities, and how contextual, i.e. structural and cultural, and agential conditions, influence this participation. For this sub-study on the experience of the collaboration by fourteen of the researchers, we wrote reflective pieces on our own experience of participating in the project towards the end of the third year of its duration. We discuss the structural and cultural conditions external to and internal to the project, and how the social reflexivity of the participants mediated these conditions. We conclude with the observation that policy injunctions and support from funding agencies for collaborative research, as well as support from participants’ home institutions are necessary for the flourishing of collaborative research, but that the commitment by individual participants to participate, learn and share, is also necessary.
- Full Text: false
- Date Issued: 2017
Spectroscopic and electrochemical characterization of thio binuclear phthalocyanine complexes
- Authors: Makinde, Zainab Olusola
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59287 , vital:27541
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2017
- Authors: Makinde, Zainab Olusola
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59287 , vital:27541
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2017
Reader in comedy
- Authors: Krueger, Anton
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/225684 , vital:49248 , xlink:href="https://doi.org/10.1080/10137548.2017.1409523"
- Description: I really enjoyed this selection of excerpts on comedy. In 64 extracts, this comprehensive anthology covers 2375 years of mainly philosophical texts in 375 dense pages. From 360 BCE (Plato’s Philebus) to just the other day (Romanska’s Disability in Tragic and Comic Frame [2015]), this is an immense resource covering a lot of ground. The extracts don’t all apply specifically to theatre, though this is where the discussion begins, with the ancients. Later on, as new genres emerge, there are also entries relating to prose, film, story-telling and stand-up; but mainly, the writings have to do with laughter itself, and the role and function of comedy.
- Full Text:
- Date Issued: 2017
- Authors: Krueger, Anton
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/225684 , vital:49248 , xlink:href="https://doi.org/10.1080/10137548.2017.1409523"
- Description: I really enjoyed this selection of excerpts on comedy. In 64 extracts, this comprehensive anthology covers 2375 years of mainly philosophical texts in 375 dense pages. From 360 BCE (Plato’s Philebus) to just the other day (Romanska’s Disability in Tragic and Comic Frame [2015]), this is an immense resource covering a lot of ground. The extracts don’t all apply specifically to theatre, though this is where the discussion begins, with the ancients. Later on, as new genres emerge, there are also entries relating to prose, film, story-telling and stand-up; but mainly, the writings have to do with laughter itself, and the role and function of comedy.
- Full Text:
- Date Issued: 2017
Synthesis, photophysical and nonlinear optical properties of a series of ball-type phthalocyanines in solution and thin films
- Nwaji, Njemuwa, Mack, John, Britton, Jonathan, Nyokong, Tebello
- Authors: Nwaji, Njemuwa , Mack, John , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188976 , vital:44803 , xlink:href="https://doi.org/10.1039/C6NJ03662G"
- Description: In this study, we report on the enhanced nonlinear optical properties of novel tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato zinc(II)) (4), tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato gallium chloride) (5) and tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato indium chloride) (6) both in solution and when embedded in polymer thin films. Complexes 5 and 6 bearing heavy atoms showed enhanced triplet quantum yield and nonlinear optical response. The nonlinear third-order susceptibility and second-order hyperpolarizability values are also reported. Time dependent density functional theory (TD-DFT) calculations were performed in order to explain the origin of the observed UV-vis and magnetic circular dichroism (MCD) spectra of the complexes.
- Full Text:
- Date Issued: 2017
- Authors: Nwaji, Njemuwa , Mack, John , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188976 , vital:44803 , xlink:href="https://doi.org/10.1039/C6NJ03662G"
- Description: In this study, we report on the enhanced nonlinear optical properties of novel tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato zinc(II)) (4), tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato gallium chloride) (5) and tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato indium chloride) (6) both in solution and when embedded in polymer thin films. Complexes 5 and 6 bearing heavy atoms showed enhanced triplet quantum yield and nonlinear optical response. The nonlinear third-order susceptibility and second-order hyperpolarizability values are also reported. Time dependent density functional theory (TD-DFT) calculations were performed in order to explain the origin of the observed UV-vis and magnetic circular dichroism (MCD) spectra of the complexes.
- Full Text:
- Date Issued: 2017
Examining the nature of learning within an afterschool mathematics club : a case study of four learners
- Pohamba, Penehafo K, Graven, Mellony, Stott, Deborah A, Ashipala, Daniel O
- Authors: Pohamba, Penehafo K , Graven, Mellony , Stott, Deborah A , Ashipala, Daniel O
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70121 , vital:29623 , http://dx.doi.org/10.5430/irhe.v2n1p21
- Description: This study examined the nature of learning within an afterschool mathematics club established by the South African Numeracy Chair project. This study sought to establish what sort of progress in mathematical learning occurred in a grade 3 afterschool maths club, using assessment instruments associated with the Learning Framework in Number. The study also sought to understand the nature and effects of mentor mediation in the maths club, using Vygotsky’s notion of the Zone of Proximal Development (ZPD) together with the notion and practice of scaffolding. This study was interpretive in nature drawing on qualitative methods with some elements of quantification in relation to learners’ progression. The club consists of 10 learners of mixed ability (5 girls and 5 boys) at a township school in Graham’s town, South Africa. Learners in this case study were selected through purposive sampling. As part of the data collection strategies, the learners were interviewed twice in terms of their numeracy proficiency. The assessment interview results revealed that, in terms of proficiency in early arithmetical learning, all four learners showed progress after spending four months in an afterschool maths club. This study also recommended Wright et al.’s (2006) LFIN framework to be used in assessing learners’ progress in mathematics, as it could inform the refinement of instructional design within the school curriculum and teachers’ education in the Namibian context.
- Full Text:
- Date Issued: 2017
- Authors: Pohamba, Penehafo K , Graven, Mellony , Stott, Deborah A , Ashipala, Daniel O
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70121 , vital:29623 , http://dx.doi.org/10.5430/irhe.v2n1p21
- Description: This study examined the nature of learning within an afterschool mathematics club established by the South African Numeracy Chair project. This study sought to establish what sort of progress in mathematical learning occurred in a grade 3 afterschool maths club, using assessment instruments associated with the Learning Framework in Number. The study also sought to understand the nature and effects of mentor mediation in the maths club, using Vygotsky’s notion of the Zone of Proximal Development (ZPD) together with the notion and practice of scaffolding. This study was interpretive in nature drawing on qualitative methods with some elements of quantification in relation to learners’ progression. The club consists of 10 learners of mixed ability (5 girls and 5 boys) at a township school in Graham’s town, South Africa. Learners in this case study were selected through purposive sampling. As part of the data collection strategies, the learners were interviewed twice in terms of their numeracy proficiency. The assessment interview results revealed that, in terms of proficiency in early arithmetical learning, all four learners showed progress after spending four months in an afterschool maths club. This study also recommended Wright et al.’s (2006) LFIN framework to be used in assessing learners’ progress in mathematics, as it could inform the refinement of instructional design within the school curriculum and teachers’ education in the Namibian context.
- Full Text:
- Date Issued: 2017
The development, manufacture and characterisation of niosomes intended to deliver nevirapine to the brain
- Authors: Witika, Bwalya Angel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65257 , vital:28715
- Description: Expected release date-May 2019
- Full Text:
- Date Issued: 2017
- Authors: Witika, Bwalya Angel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65257 , vital:28715
- Description: Expected release date-May 2019
- Full Text:
- Date Issued: 2017
Biological and geophysical feedbacks with fire in the Earth System
- Archibald, S, Lehmann, C E, Belcher, C, Bond, W J, Bradstock, R A, Daniau, A L, Dexter, K, Forrestel, E J, Greve, M, He, T, Higgins, Simon I, Ripley, Bradford S
- Authors: Archibald, S , Lehmann, C E , Belcher, C , Bond, W J , Bradstock, R A , Daniau, A L , Dexter, K , Forrestel, E J , Greve, M , He, T , Higgins, Simon I , Ripley, Bradford S
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61413 , vital:28024 , http://iopscience.iop.org/article/10.1088/1748-9326/aa9ead/meta
- Description: Roughly 3% of the Earth’s land surface burns annually, representing a critical exchange of energy and matter between the land and atmosphere via combustion. Fires range from slow smouldering peat fires, to low-intensity surface fires, to intense crown fires, depending on vegetation structure, fuel moisture, prevailing climate, and weather conditions. While the links between biogeochemistry, climate and fire are widely studied within Earth system science, these relationships are also mediated by fuels – namely plants and their litter – which are the product of evolutionary and ecological processes. Fire is a powerful selective force and, over their evolutionary history, plants across diverse clades have evolved numerous traits that either tolerate or promote fire. Here we outline a conceptual framework of how plant traits determine the flammability of ecosystems and interact with climate and weather to influence fire regimes. We explore how these evolutionary and ecological processes scale to impact biogeochemistry and Earth system processes. Finally, we outline several research challenges that, when resolved, will improve our understanding of the role of plant evolution in mediating the fire feedbacks driving Earth system processes. Understanding current patterns of fire and vegetation, as well as patterns of fire over geological time, requires research that incorporates evolutionary biology, ecology, biogeography, and the biogeosciences.
- Full Text:
- Date Issued: 2017
- Authors: Archibald, S , Lehmann, C E , Belcher, C , Bond, W J , Bradstock, R A , Daniau, A L , Dexter, K , Forrestel, E J , Greve, M , He, T , Higgins, Simon I , Ripley, Bradford S
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61413 , vital:28024 , http://iopscience.iop.org/article/10.1088/1748-9326/aa9ead/meta
- Description: Roughly 3% of the Earth’s land surface burns annually, representing a critical exchange of energy and matter between the land and atmosphere via combustion. Fires range from slow smouldering peat fires, to low-intensity surface fires, to intense crown fires, depending on vegetation structure, fuel moisture, prevailing climate, and weather conditions. While the links between biogeochemistry, climate and fire are widely studied within Earth system science, these relationships are also mediated by fuels – namely plants and their litter – which are the product of evolutionary and ecological processes. Fire is a powerful selective force and, over their evolutionary history, plants across diverse clades have evolved numerous traits that either tolerate or promote fire. Here we outline a conceptual framework of how plant traits determine the flammability of ecosystems and interact with climate and weather to influence fire regimes. We explore how these evolutionary and ecological processes scale to impact biogeochemistry and Earth system processes. Finally, we outline several research challenges that, when resolved, will improve our understanding of the role of plant evolution in mediating the fire feedbacks driving Earth system processes. Understanding current patterns of fire and vegetation, as well as patterns of fire over geological time, requires research that incorporates evolutionary biology, ecology, biogeography, and the biogeosciences.
- Full Text:
- Date Issued: 2017
Death of the PhD: when industry partners determine doctoral outcomes
- Frick, Liezel, McKenna, Sioux, Muthama, Evelyn
- Authors: Frick, Liezel , McKenna, Sioux , Muthama, Evelyn
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66680 , vital:28981 , ISSN 1469-8366 , https://doi.org/10.1080/07294360.2017.1263467
- Description: Pre-print , The PhD is the highest formal qualification and signifies a scholar’s rite of passage as a legitimate contributor of new knowledge in a field. Examiner reports make claims about what is legitimate in a thesis and what is not and thus articulate the organising principles through which participation in a field is measured. The authors analysed 39 examiners’ reports on 13 PhDs produced over a five-year period by scholars from the Higher Education Research doctoral studies programme at Rhodes University in South Africa. Drawing on aspects of Karl Maton’s Legitimation Code Theory (LCT), this study uses the dimensions of LCT:Specialisation and LCT:Semantics to explore what kinds of knowledge, skills and procedures and what kinds of knowers are validated in the field of Higher Education Research through the examination process. The study found that despite concerns in the literature about the a-theoretical nature of the Higher Education Studies field, examiners valued high-level theoretical and meta-theoretical engagement as well as methodological rigour. In addition, examiners prized the ability to demonstrate a strong ideological position, to use a clear doctoral voice, and to recognise the axiological drive of the field. The analysis showed that examiners were interested in strong contextualisation of the problem-spaces in higher education in South Africa but also commented positively on candidates’ ability to move from troubling an issue within its context to being able to abstract findings so as to contribute to the field as a whole.
- Full Text:
- Date Issued: 2017
- Authors: Frick, Liezel , McKenna, Sioux , Muthama, Evelyn
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66680 , vital:28981 , ISSN 1469-8366 , https://doi.org/10.1080/07294360.2017.1263467
- Description: Pre-print , The PhD is the highest formal qualification and signifies a scholar’s rite of passage as a legitimate contributor of new knowledge in a field. Examiner reports make claims about what is legitimate in a thesis and what is not and thus articulate the organising principles through which participation in a field is measured. The authors analysed 39 examiners’ reports on 13 PhDs produced over a five-year period by scholars from the Higher Education Research doctoral studies programme at Rhodes University in South Africa. Drawing on aspects of Karl Maton’s Legitimation Code Theory (LCT), this study uses the dimensions of LCT:Specialisation and LCT:Semantics to explore what kinds of knowledge, skills and procedures and what kinds of knowers are validated in the field of Higher Education Research through the examination process. The study found that despite concerns in the literature about the a-theoretical nature of the Higher Education Studies field, examiners valued high-level theoretical and meta-theoretical engagement as well as methodological rigour. In addition, examiners prized the ability to demonstrate a strong ideological position, to use a clear doctoral voice, and to recognise the axiological drive of the field. The analysis showed that examiners were interested in strong contextualisation of the problem-spaces in higher education in South Africa but also commented positively on candidates’ ability to move from troubling an issue within its context to being able to abstract findings so as to contribute to the field as a whole.
- Full Text:
- Date Issued: 2017
Student-generated content: an approach to harnessing the power of diversity in higher education
- Snowball, Jeanette D, McKenna, Sioux
- Authors: Snowball, Jeanette D , McKenna, Sioux
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66763 , vital:28991 , ISSN 1470-1294 , https://doi.org/10.1080/13562517.2016.1273205
- Description: Publisher version , Internationally, classes in higher education institutions are becoming larger and more diverse. Support for ‘non-traditional’ students has often taken the form of additional remedial classes offered outside the main curriculum, which has met with limited success. Sociocultural theories of learning argue that the potential clash between the sociocultural context of disciplinary knowledge and the very different home contexts of many non-traditional students needs to be acknowledged. One way to achieve this is to use student-generated content, which allows teachers to bring student experiences and voices into the community of practice and acknowledges the importance of their prior experiences in knowledge production. Building on such sociocultural approaches to teaching and learning, this paper focuses on the use of student-generated podcasts as a means to harness the diversity of student experiences in a large (nearly 600 students) first-year Economics class at a South African University.
- Full Text: false
- Date Issued: 2017
- Authors: Snowball, Jeanette D , McKenna, Sioux
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66763 , vital:28991 , ISSN 1470-1294 , https://doi.org/10.1080/13562517.2016.1273205
- Description: Publisher version , Internationally, classes in higher education institutions are becoming larger and more diverse. Support for ‘non-traditional’ students has often taken the form of additional remedial classes offered outside the main curriculum, which has met with limited success. Sociocultural theories of learning argue that the potential clash between the sociocultural context of disciplinary knowledge and the very different home contexts of many non-traditional students needs to be acknowledged. One way to achieve this is to use student-generated content, which allows teachers to bring student experiences and voices into the community of practice and acknowledges the importance of their prior experiences in knowledge production. Building on such sociocultural approaches to teaching and learning, this paper focuses on the use of student-generated podcasts as a means to harness the diversity of student experiences in a large (nearly 600 students) first-year Economics class at a South African University.
- Full Text: false
- Date Issued: 2017
Undefined cellulase formulations hinder scientific reproducibility
- Himmel, Michael E, Abbas, Charles A, Baker, John O, Bayer, Edward A, Bomble, Yannick J, Brunecky, Roman, Chen, Xiaowen, Felby, Claus, Jeoh, Tina, Kumar, Rajeev, McCleary, Barry V, Pletschke, Brett I, Tucker, Melvin P, Wyman, Charles E, Decker, Stephen R
- Authors: Himmel, Michael E , Abbas, Charles A , Baker, John O , Bayer, Edward A , Bomble, Yannick J , Brunecky, Roman , Chen, Xiaowen , Felby, Claus , Jeoh, Tina , Kumar, Rajeev , McCleary, Barry V , Pletschke, Brett I , Tucker, Melvin P , Wyman, Charles E , Decker, Stephen R
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61402 , vital:28022 , https://doi.org/10.1186/s13068-017-0974-y
- Description: In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.
- Full Text:
- Date Issued: 2017
- Authors: Himmel, Michael E , Abbas, Charles A , Baker, John O , Bayer, Edward A , Bomble, Yannick J , Brunecky, Roman , Chen, Xiaowen , Felby, Claus , Jeoh, Tina , Kumar, Rajeev , McCleary, Barry V , Pletschke, Brett I , Tucker, Melvin P , Wyman, Charles E , Decker, Stephen R
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61402 , vital:28022 , https://doi.org/10.1186/s13068-017-0974-y
- Description: In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.
- Full Text:
- Date Issued: 2017
The effects of a lion (Panthera Leo) re-introduction on a resident cheetah (Acinonyx Jubatus) population In Mountain Zebra National Park, Eastern Cape, South Africa
- Authors: Van de Vyver, Daniel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7420 , vital:21259
- Description: The global decline of large (> 10 kg) carnivores has resulted in a variety of conservation measures being put into practice to prevent extinctions. The establishment of predator-proof fences around protected areas has been a successful tool for reducing human-predator conflict. Furthermore, the re-introduction of large carnivores into small (< 1 000 km²), enclosed reserves has aided in the conservation of many species. Cheetahs (Acinonyx jubatus) and lions (Panthera leo) have benefitted from such re-introductions. The re-introduction of cheetahs before lions into the Mountain Zebra National Park (MZNP) in the Eastern Cape Province of South Africa provided a unique opportunity to study the effects of lions on an already established cheetah population. Spatial data were downloaded remotely from GPS collared individuals (n=4) and cheetah kill data were collected using the GPS cluster method before (2012-2013) and after (2013-2014) the lion (n=3) re-introduction. The same methods were used for lion kill data collection once they had been re-introduced. In general, cheetah home range size did not change after the lion re-introduction. Cheetahs selected areas with a combination of open and closed vegetation covers, while lions selected either open or closed areas of vegetation covers. In addition, as vegetation cover became thicker, the presence of cheetahs decreased. The cheetahs preyed upon seven species before and 11 species after the lion re-introduction. Medium sized prey comprised the bulk of the cheetah diet with kudu (Tragelaphus strepsiceros) and springbok (Antidorcas marsupialis) being the preferred species both before and after the lion re-introduction. The lion diets consisted of medium to large sized prey, with the male lions selecting eland (Tragelaphus oryx) and buffalo (Syncerus caffer) and the lioness selecting red hartebeest (Alcelaphus buselaphus). The cheetahs had no significant dietary overlap with the lions and there was only one record of kleptoparasitism. The results of my study indicate that cheetahs are able to co-exist with lions when lions are at low densities in an enclosed reserve. The cheetahs did not experience landscape-level displacement because they made fine-scale adjustments to avoid lions within their environment. This adaptability may have important management implications for future re-introductions of cheetahs into enclosed game reserves.
- Full Text:
- Date Issued: 2017
- Authors: Van de Vyver, Daniel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7420 , vital:21259
- Description: The global decline of large (> 10 kg) carnivores has resulted in a variety of conservation measures being put into practice to prevent extinctions. The establishment of predator-proof fences around protected areas has been a successful tool for reducing human-predator conflict. Furthermore, the re-introduction of large carnivores into small (< 1 000 km²), enclosed reserves has aided in the conservation of many species. Cheetahs (Acinonyx jubatus) and lions (Panthera leo) have benefitted from such re-introductions. The re-introduction of cheetahs before lions into the Mountain Zebra National Park (MZNP) in the Eastern Cape Province of South Africa provided a unique opportunity to study the effects of lions on an already established cheetah population. Spatial data were downloaded remotely from GPS collared individuals (n=4) and cheetah kill data were collected using the GPS cluster method before (2012-2013) and after (2013-2014) the lion (n=3) re-introduction. The same methods were used for lion kill data collection once they had been re-introduced. In general, cheetah home range size did not change after the lion re-introduction. Cheetahs selected areas with a combination of open and closed vegetation covers, while lions selected either open or closed areas of vegetation covers. In addition, as vegetation cover became thicker, the presence of cheetahs decreased. The cheetahs preyed upon seven species before and 11 species after the lion re-introduction. Medium sized prey comprised the bulk of the cheetah diet with kudu (Tragelaphus strepsiceros) and springbok (Antidorcas marsupialis) being the preferred species both before and after the lion re-introduction. The lion diets consisted of medium to large sized prey, with the male lions selecting eland (Tragelaphus oryx) and buffalo (Syncerus caffer) and the lioness selecting red hartebeest (Alcelaphus buselaphus). The cheetahs had no significant dietary overlap with the lions and there was only one record of kleptoparasitism. The results of my study indicate that cheetahs are able to co-exist with lions when lions are at low densities in an enclosed reserve. The cheetahs did not experience landscape-level displacement because they made fine-scale adjustments to avoid lions within their environment. This adaptability may have important management implications for future re-introductions of cheetahs into enclosed game reserves.
- Full Text:
- Date Issued: 2017
Distributed leadership in South Africa
- Authors: Grant, Carolyn
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281024 , vital:55684 , xlink:href="https://doi.org/10.1080/13632434.2017.1360856"
- Description: Distributed leadership, while an established concept in the international literature on education leadership, is slowly gaining prominence in post-apartheid South Africa. This is primarily due to its normative and representational appeal. However, of concern is that the concept has become a catch-all phrase to describe any form of devolved or shared leadership and is being espoused as ‘the answer’ to the country’s educational leadership woes. Drawing on a South African publications-based doctoral study of distributed teacher leadership (Grant 2010. “Distributed Teacher Leadership: Troubling the Terrain.” Unpublished PhD diss., University of KwaZulu-Natal, Pietermaritzburg) for its evidence, this article argues for a theoretically robust form of distributed leadership conceptualised as socio-cultural practice and framed as a product of the joint interactions of school leaders, followers and aspects of their situation (Gronn 2000. “Distributed Properties: A New Architecture for Leadership.” Educational Management and Administration 28 (3): 317–338; Spillane, Halverson and Diamond 2004. “Towards a Theory of Leadership Practice: A Distributed Perspective.” Journal of Curriculum Studies 36 (1): 3–34; Spillane 2006. Distributed Leadership. San Francisco: Jossey-Bass). It endorses a sequential distributed leadership framing for the South African context and calls for further empirical studies which interrogate the complex practices of distributed school leadership. For without this theoretically robust work, the article argues, distributed leadership is likely to be relegated to the large pile of redundant leadership theories and become a passing fad.
- Full Text:
- Date Issued: 2017
- Authors: Grant, Carolyn
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281024 , vital:55684 , xlink:href="https://doi.org/10.1080/13632434.2017.1360856"
- Description: Distributed leadership, while an established concept in the international literature on education leadership, is slowly gaining prominence in post-apartheid South Africa. This is primarily due to its normative and representational appeal. However, of concern is that the concept has become a catch-all phrase to describe any form of devolved or shared leadership and is being espoused as ‘the answer’ to the country’s educational leadership woes. Drawing on a South African publications-based doctoral study of distributed teacher leadership (Grant 2010. “Distributed Teacher Leadership: Troubling the Terrain.” Unpublished PhD diss., University of KwaZulu-Natal, Pietermaritzburg) for its evidence, this article argues for a theoretically robust form of distributed leadership conceptualised as socio-cultural practice and framed as a product of the joint interactions of school leaders, followers and aspects of their situation (Gronn 2000. “Distributed Properties: A New Architecture for Leadership.” Educational Management and Administration 28 (3): 317–338; Spillane, Halverson and Diamond 2004. “Towards a Theory of Leadership Practice: A Distributed Perspective.” Journal of Curriculum Studies 36 (1): 3–34; Spillane 2006. Distributed Leadership. San Francisco: Jossey-Bass). It endorses a sequential distributed leadership framing for the South African context and calls for further empirical studies which interrogate the complex practices of distributed school leadership. For without this theoretically robust work, the article argues, distributed leadership is likely to be relegated to the large pile of redundant leadership theories and become a passing fad.
- Full Text:
- Date Issued: 2017
Counting on demographic equity to transform institutional cultures at historically white South African universities?:
- Booi, Masixole, Vincent, Louise, Liccardo, Sabrina
- Authors: Booi, Masixole , Vincent, Louise , Liccardo, Sabrina
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141946 , vital:38018 , DOI: 10.1080/07294360.2017.1289155
- Description: The post-apartheid higher education transformation project is faced with the challenge of recruiting and retaining black academics and other senior staff. But when we shift the focus from participation rates to equality–inequality within historically white universities (HWUs), then the discourse changes from demographic equity and redress to institutional culture and diversity. HWUs invoke the need to maintain their position as leading higher education institutions globally, and notions of ‘quality’ and ‘excellence’ have emerged as discursive practices, which serve to perpetuate exclusion. The question then arises as to which forms of capital comprise the Gold Standard at HWUs? Several South African universities have responded to the challenge of recruiting and retaining black academics by initiating programmes for the ‘accelerated development’ of these candidates.
- Full Text:
- Date Issued: 2017
- Authors: Booi, Masixole , Vincent, Louise , Liccardo, Sabrina
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141946 , vital:38018 , DOI: 10.1080/07294360.2017.1289155
- Description: The post-apartheid higher education transformation project is faced with the challenge of recruiting and retaining black academics and other senior staff. But when we shift the focus from participation rates to equality–inequality within historically white universities (HWUs), then the discourse changes from demographic equity and redress to institutional culture and diversity. HWUs invoke the need to maintain their position as leading higher education institutions globally, and notions of ‘quality’ and ‘excellence’ have emerged as discursive practices, which serve to perpetuate exclusion. The question then arises as to which forms of capital comprise the Gold Standard at HWUs? Several South African universities have responded to the challenge of recruiting and retaining black academics by initiating programmes for the ‘accelerated development’ of these candidates.
- Full Text:
- Date Issued: 2017
Effects of charge on the photophysicochemical properties of zinc phthalocyanine derivatives doped onto silica nanoparticles
- Peteni, Siwaphiwe, Sekhosana, Kutloano E, Britton, Jonathan, Nyokong, Tebello
- Authors: Peteni, Siwaphiwe , Sekhosana, Kutloano E , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188159 , vital:44728 , xlink:href="https://doi.org/10.1016/j.poly.2017.09.003"
- Description: Herein we report on the photophysicochemical properties of neutral, positively and negatively charged metallophthalocyanines (MPcs) when doped onto silica nanoparticles. The MPcs are: unsubstituted ZnPc (complex 1, neutral), Zn tetraaminophenoxy phthalocyanine (ZnTAPhPc, complex 2, neutral), tetrakis[4-(iodo-N-methylpyridinium)thio] phthalocyanine (ZnTMPyPc, complex 3, cationic), and Zn tetra sulfophenoxy phthalocyanine (ZnTSPhPc, complex 4, anionic). Following doping onto SiNPs, the triplet quantum yields increased for neutral complex 1 and positively charged complex 3. However, singlet oxygen quantum yields increased for positively charged 3 (in 3-SiNPs) and the negatively charge 4 (in 4-SiNPs) and not for complex 1 (in 1-SiNPs), compared to Pcs alone, due to the screening effect.
- Full Text:
- Date Issued: 2017
- Authors: Peteni, Siwaphiwe , Sekhosana, Kutloano E , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188159 , vital:44728 , xlink:href="https://doi.org/10.1016/j.poly.2017.09.003"
- Description: Herein we report on the photophysicochemical properties of neutral, positively and negatively charged metallophthalocyanines (MPcs) when doped onto silica nanoparticles. The MPcs are: unsubstituted ZnPc (complex 1, neutral), Zn tetraaminophenoxy phthalocyanine (ZnTAPhPc, complex 2, neutral), tetrakis[4-(iodo-N-methylpyridinium)thio] phthalocyanine (ZnTMPyPc, complex 3, cationic), and Zn tetra sulfophenoxy phthalocyanine (ZnTSPhPc, complex 4, anionic). Following doping onto SiNPs, the triplet quantum yields increased for neutral complex 1 and positively charged complex 3. However, singlet oxygen quantum yields increased for positively charged 3 (in 3-SiNPs) and the negatively charge 4 (in 4-SiNPs) and not for complex 1 (in 1-SiNPs), compared to Pcs alone, due to the screening effect.
- Full Text:
- Date Issued: 2017
The effects of rhizobium inoculation on growth performance, forage production, nutrient and anti-nutrient content of lablab purpureus cultivars
- Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Authors: Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Date: 2017
- Subjects: Livestock productivity , Rhizobium japonicum
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22864 , vital:53011
- Description: Declining soil fertility and inadequate low quality feed resources limit smallholder livestock production in the semi-arid regions of Eastern Cape in South Africa. Smallholder farmers are facing problems of high cost of artificial fertilisers limiting them in production of cereal crops and also fodder for their livestock. This leads to poor nutrition, particularly in the dry season, it affects livestock production. Planting Lablab purpureus and inoculating with Rhizobium would limit the necessity for buying expensive protein supplements and nitrogen fertilisers. Lablab purpureus can provide feed in the dry season for the improvement of livestock production. The objective of this study was to investigate the effect of Bradyrhizobium japonicum inoculation on growth performance, biomass production, nutrient and anti-nutrient content of the two Lablab purpureus cultivars (Rongai and Highworth). The experiment was conducted at Fort Hare Research Farm in Alice, South Africa. Data was collected on plant seedling emergence, plant height, stem diameter, plant vigour, chlorophyll content, nodule numbers as well as dry matter content, biomass yield, nutrient and anti-nutrient contents at 30, 60 and 90 DAP. Samples of Lablab purpureus were harvested at flowering stage and analysed for dry matter content, biomass yield, chemical, mineral and anti-ntrient composition. The results showed that Rhizobium inoculation significantly increased (p<0.05) seedling emergence, plant height and stem diameter of both Lablab purpureus cultivars. Rhizobium inoculation had no significant effect (p>0.05) on chlorophyll content for both cultivars. Highworth had significantly higher (p<0.05) plant vigour than Rongai on both inoculated and uninoculated. Varieties and inoculation effects were significant (p<0.05) for number of nodules, nodulation rate, active nodules and nodule dry yield. Rhizobium inoculation significantly (p<0.05) increased fresh matter yield, dry matter yied and dry matter content on both cultivars. There were no significant differences (p>0.05) in NDF, ADIN, ADL, ADF, and Na between inoculated and uninoculated plants for both cultivars. The inoculation of Rhizobium improved CP (15.65%) in Highworth cultivar. The inoculation of Rhizobium significantly increased Ca (1.76-1.84%), Zn (191.91-2 8.33ppm) and Cu (3.50-6.16ppm) compared to un-inoculated plants. Varieties and Rhizobium had no interaction (p>0.05) with condensed tannin, hydrolysable tannin, total polyphenols and saponins . Therefore, the Rhizobium inoculation assisted in improving quality in terms of nutrient composition and decreasing anti-nutrients. It is recommended to use both cultivars of Lablab purpureus. Based on the results of this study it is concluded that Rhizobium inoculation increases yield and forage quality of Lablab purpureus. It is recommended that Highworth cultivar can be used by communal farmers in the Eastern Cape. This cultivar showed that it needs Rhizobium inoculation inorder to produce high quality that can increase livestock production. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017
- Authors: Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Date: 2017
- Subjects: Livestock productivity , Rhizobium japonicum
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22864 , vital:53011
- Description: Declining soil fertility and inadequate low quality feed resources limit smallholder livestock production in the semi-arid regions of Eastern Cape in South Africa. Smallholder farmers are facing problems of high cost of artificial fertilisers limiting them in production of cereal crops and also fodder for their livestock. This leads to poor nutrition, particularly in the dry season, it affects livestock production. Planting Lablab purpureus and inoculating with Rhizobium would limit the necessity for buying expensive protein supplements and nitrogen fertilisers. Lablab purpureus can provide feed in the dry season for the improvement of livestock production. The objective of this study was to investigate the effect of Bradyrhizobium japonicum inoculation on growth performance, biomass production, nutrient and anti-nutrient content of the two Lablab purpureus cultivars (Rongai and Highworth). The experiment was conducted at Fort Hare Research Farm in Alice, South Africa. Data was collected on plant seedling emergence, plant height, stem diameter, plant vigour, chlorophyll content, nodule numbers as well as dry matter content, biomass yield, nutrient and anti-nutrient contents at 30, 60 and 90 DAP. Samples of Lablab purpureus were harvested at flowering stage and analysed for dry matter content, biomass yield, chemical, mineral and anti-ntrient composition. The results showed that Rhizobium inoculation significantly increased (p<0.05) seedling emergence, plant height and stem diameter of both Lablab purpureus cultivars. Rhizobium inoculation had no significant effect (p>0.05) on chlorophyll content for both cultivars. Highworth had significantly higher (p<0.05) plant vigour than Rongai on both inoculated and uninoculated. Varieties and inoculation effects were significant (p<0.05) for number of nodules, nodulation rate, active nodules and nodule dry yield. Rhizobium inoculation significantly (p<0.05) increased fresh matter yield, dry matter yied and dry matter content on both cultivars. There were no significant differences (p>0.05) in NDF, ADIN, ADL, ADF, and Na between inoculated and uninoculated plants for both cultivars. The inoculation of Rhizobium improved CP (15.65%) in Highworth cultivar. The inoculation of Rhizobium significantly increased Ca (1.76-1.84%), Zn (191.91-2 8.33ppm) and Cu (3.50-6.16ppm) compared to un-inoculated plants. Varieties and Rhizobium had no interaction (p>0.05) with condensed tannin, hydrolysable tannin, total polyphenols and saponins . Therefore, the Rhizobium inoculation assisted in improving quality in terms of nutrient composition and decreasing anti-nutrients. It is recommended to use both cultivars of Lablab purpureus. Based on the results of this study it is concluded that Rhizobium inoculation increases yield and forage quality of Lablab purpureus. It is recommended that Highworth cultivar can be used by communal farmers in the Eastern Cape. This cultivar showed that it needs Rhizobium inoculation inorder to produce high quality that can increase livestock production. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017
Development and assessment of gastric-retentive sustained release metronidazole microcapsules
- Authors: Makan, Anjana
- Date: 2017
- Subjects: Metronidazole , Drug delivery systems , Helicobacter pylori , High performance liquid chromatography , Gas chromatography , Drugs , Drugs Controlled release
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59240 , vital:27491
- Description: Helicobacter pylori is one of the most common pathogenic bacterial infections and is the leading cause of gastritis, gastroduodenal ulcer disease and gastric cancers. Studies have revealed the prevalence of Helicobacter pylori is high in many countries around the globe. Although Helicobacter pylori is highly sensitive to antimicrobial agents in vitro the clinical eradication rate of the disease is still low. The instability of API at gastric pH, low concentration of API in the gastric mucosa and short gastric residence times are the main reasons for poor eradication rates. The high prevalence rate of this disease necessitates the design and development of gastric-retentive site specific oral dosage forms for the optimized delivery of existing therapeutic molecules and may be an approach to improving the eradication rate of Helicobacter pylori. Metronidazole (MTZ) is a 5-nitroimidazole derivative that exhibits antibiotic and antiprotozoal activity. MTZ is used in combination with other compounds for the treatment of Helicobacter pylori in peptic ulcer disease. MTZ is a potential candidate for inclusion in a sustained release gastric-retentive delivery system that acts in the stomach and since it is unstable in the intestinal/colonic environment enhancing gastric residence time would be a therapeutic advantage. MTZ is a cost-effective therapy that exhibits good anti-microbial activity and has a favourable pharmacokinetic profile. A sustained release gastric-retentive formulation is therefore proposed as an approach to enhance the local delivery of MTZ and improve treatment outcomes for patients infected with Helicobacter pylori. A stability indicating Reversed-Phase High Performance Liquid Chromatography (RP- HPLC) method for the quantitation of MTZ in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. The RP-HPLC method was found to be linear, accurate, precise, sensitive, selective, and was applied to the analysis of MTZ in commercially available medicines. Preformulation studies were conducted as preparative work prior to manufacture gastric- retentive sustained release MTZ microcapsules. The experiments conducted were tailored for the development of sustained release MTZ microcapsules using a solvent evaporation method. The particle size and shape of the microcapsules was investigated using Scanning Electron Microscopy (SEM). MTZ- excipient compatibility studies were performed using Fourier Transform Infra-red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). The results revealed that no definite interaction between MTZ and intended excipients to be used for manufacture of MTZ formulations occurred. A solvent evaporation procedure was used for the manufacture of MTZ microcapsules. Preliminary formulations were manufactured using two different grades of Methocel® at various levels. In addition the impact of processing parameters on performance was also investigated. The formulations were assessed in terms of in vitro release, buoyancy, yield, encapsulation efficiency and microcapsule size. Formulation optimisation was undertaken using a CCD approach and numerical optimisation was used to predict an optimised formulation composition that would produce minimal initial MTZ release, maximum MTZ release at 12 hours and maximum buoyancy, encapsulation efficiency and yield. The kinetics of MTZ release from microcapsules was established by fitting in vitro release data to different mathematical models. Higuchi model and first-order model appeared to best fit the data as majority of the formulation batches had highest R2 values for these models. Short-term stability assessment of the optimised formulation was established by undertaking stability studies at 25°C/60% RH and 40°C/75%RH. No significant changes in any of the CQA were observed over 30 days of stability testing. A gas chromatographic (GC) method was developed and validated for the quantitation of residual acetone and n-hexane. The optimised formulation contained 213.60 ppm/g acetone and 25.23 ppm/g n-hexane which are well below the limits set for residual solvents. In conclusion, gastric-retentive sustained release MTZ microcapsules with potential for further development and optimisation have been successfully developed and assessed in these studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
- Authors: Makan, Anjana
- Date: 2017
- Subjects: Metronidazole , Drug delivery systems , Helicobacter pylori , High performance liquid chromatography , Gas chromatography , Drugs , Drugs Controlled release
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59240 , vital:27491
- Description: Helicobacter pylori is one of the most common pathogenic bacterial infections and is the leading cause of gastritis, gastroduodenal ulcer disease and gastric cancers. Studies have revealed the prevalence of Helicobacter pylori is high in many countries around the globe. Although Helicobacter pylori is highly sensitive to antimicrobial agents in vitro the clinical eradication rate of the disease is still low. The instability of API at gastric pH, low concentration of API in the gastric mucosa and short gastric residence times are the main reasons for poor eradication rates. The high prevalence rate of this disease necessitates the design and development of gastric-retentive site specific oral dosage forms for the optimized delivery of existing therapeutic molecules and may be an approach to improving the eradication rate of Helicobacter pylori. Metronidazole (MTZ) is a 5-nitroimidazole derivative that exhibits antibiotic and antiprotozoal activity. MTZ is used in combination with other compounds for the treatment of Helicobacter pylori in peptic ulcer disease. MTZ is a potential candidate for inclusion in a sustained release gastric-retentive delivery system that acts in the stomach and since it is unstable in the intestinal/colonic environment enhancing gastric residence time would be a therapeutic advantage. MTZ is a cost-effective therapy that exhibits good anti-microbial activity and has a favourable pharmacokinetic profile. A sustained release gastric-retentive formulation is therefore proposed as an approach to enhance the local delivery of MTZ and improve treatment outcomes for patients infected with Helicobacter pylori. A stability indicating Reversed-Phase High Performance Liquid Chromatography (RP- HPLC) method for the quantitation of MTZ in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. The RP-HPLC method was found to be linear, accurate, precise, sensitive, selective, and was applied to the analysis of MTZ in commercially available medicines. Preformulation studies were conducted as preparative work prior to manufacture gastric- retentive sustained release MTZ microcapsules. The experiments conducted were tailored for the development of sustained release MTZ microcapsules using a solvent evaporation method. The particle size and shape of the microcapsules was investigated using Scanning Electron Microscopy (SEM). MTZ- excipient compatibility studies were performed using Fourier Transform Infra-red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). The results revealed that no definite interaction between MTZ and intended excipients to be used for manufacture of MTZ formulations occurred. A solvent evaporation procedure was used for the manufacture of MTZ microcapsules. Preliminary formulations were manufactured using two different grades of Methocel® at various levels. In addition the impact of processing parameters on performance was also investigated. The formulations were assessed in terms of in vitro release, buoyancy, yield, encapsulation efficiency and microcapsule size. Formulation optimisation was undertaken using a CCD approach and numerical optimisation was used to predict an optimised formulation composition that would produce minimal initial MTZ release, maximum MTZ release at 12 hours and maximum buoyancy, encapsulation efficiency and yield. The kinetics of MTZ release from microcapsules was established by fitting in vitro release data to different mathematical models. Higuchi model and first-order model appeared to best fit the data as majority of the formulation batches had highest R2 values for these models. Short-term stability assessment of the optimised formulation was established by undertaking stability studies at 25°C/60% RH and 40°C/75%RH. No significant changes in any of the CQA were observed over 30 days of stability testing. A gas chromatographic (GC) method was developed and validated for the quantitation of residual acetone and n-hexane. The optimised formulation contained 213.60 ppm/g acetone and 25.23 ppm/g n-hexane which are well below the limits set for residual solvents. In conclusion, gastric-retentive sustained release MTZ microcapsules with potential for further development and optimisation have been successfully developed and assessed in these studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
Disclaiming/denigrating/dodging: white South African academics’ everyday racetalk
- Vincent, Louise, Idahosa, Grace E, Msomi, Zuziwe
- Authors: Vincent, Louise , Idahosa, Grace E , Msomi, Zuziwe
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141900 , vital:38014 , DOI: 10.1080/14725843.2017.1292119
- Description: The call for the ‘transformation’ of higher education in South Africa is one instance of a wider effort, since the country’s first democratic election in 1994, to surmount an apartheid and colonial legacy of institutionalised racism. In 2015 and 2016 nationwide protests led to universities being shut down as students and staff expressed frustration institutions that continue to be experienced as racist and ‘untransformed’. In this study we report on interviews conducted with senior white academics at one South African university shortly before these protests began. Given that our participants are people of influence in their respective university departments, we asked, in in-depth open-ended interviews, what contribution they saw themselves making to ‘transformation’. We argue that the talk of these participants could be described as what authors in the field call 'racetalk', Talk is understood here as a form of social practice, the analysis of which helps us to understand how racism is reproduced in mundane ways which, taken together, account for the persistence of pervasive institutionalised racism in South African higher education that appears impervious to policy and regime change.
- Full Text:
- Date Issued: 2017
- Authors: Vincent, Louise , Idahosa, Grace E , Msomi, Zuziwe
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141900 , vital:38014 , DOI: 10.1080/14725843.2017.1292119
- Description: The call for the ‘transformation’ of higher education in South Africa is one instance of a wider effort, since the country’s first democratic election in 1994, to surmount an apartheid and colonial legacy of institutionalised racism. In 2015 and 2016 nationwide protests led to universities being shut down as students and staff expressed frustration institutions that continue to be experienced as racist and ‘untransformed’. In this study we report on interviews conducted with senior white academics at one South African university shortly before these protests began. Given that our participants are people of influence in their respective university departments, we asked, in in-depth open-ended interviews, what contribution they saw themselves making to ‘transformation’. We argue that the talk of these participants could be described as what authors in the field call 'racetalk', Talk is understood here as a form of social practice, the analysis of which helps us to understand how racism is reproduced in mundane ways which, taken together, account for the persistence of pervasive institutionalised racism in South African higher education that appears impervious to policy and regime change.
- Full Text:
- Date Issued: 2017
Application of graphene quantum dots functionalized with thymine and thymine-appended zinc phthalocyanine as novel photoluminescent nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
The isolation and genetic characterisation of a novel alphabaculovirus for the microbial control of Cryptophlebia peltastica and closely related tortricid pests
- Authors: Marsberg, Tamryn
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/59292 , vital:27543
- Description: Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae) is an economically damaging pest of litchis and macadamias in South Africa. Cryptophlebia peltastica causes both pre- and post-harvest damage to litchis, reducing overall yields and thus classifying the pest as a phytosanitary risk. Various control methods have been implemented against C. peltastica in an integrated pest management programme. These control methods include chemical control, cultural control and biological control. However, these methods have not yet provided satisfactory control as of yet. As a result, an alternative control option needs to be identified and implemented into the IPM programme. An alternative method of control that has proved successful in other agricultural sectors and not yet implemented in the control of C. peltastica is that of microbial control, specifically the use of baculovirus biopesticides. This study aimed to isolate and characterise a novel baculovirus from a laboratory culture of C. peltastica that could be used as a commercially available baculovirus biopesticide. In order to isolate a baculovirus a laboratory culture of C. peltastica was successfully established at Rhodes University, Grahamstown, South Africa. This is the first time a laboratory culture of C. peltastica has been established. This allowed for various biological aspects of the pest to be determined, which included: length of the life cycle, fecundity and time to oviposition, egg and larval development and percentage hatch. The results obtained from these studies found that the biology of C. peltastica was similar to that of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). Once the laboratory culture had reached high densities, larvae showing symptoms of baculovirus infection were observed. Symptomatic larvae were collected and examined for the presence of a baculovirus. An alphabaculovirus (NPV) was successfully isolated and morphologically identified using purified OBs that were sectioned and observed by transmission electron microscopy. This was then confirmed by amplifying the polyhedrin gene region using degenerate primers. A BLAST analysis found a 93% similarity to a partial polyhedrin gene sequence to be that of Epinotia granitalis (Butler) (Lepidoptera: Tortricidae). The alphabaculovirus was then genetically characterised by generating restriction profiles and sequencing the whole genome. Due to the novelty of the virus, no comparison could be made. The biological activity of the alphabaculovirus was then tested against C. peltastica and two closely related Tortricidae pests: T. leucotreta and Cydiapomonella (Linnaeous) (Lepidoptera: Tortricidae). The alphabaculovirus was highly virulent against all three species. The lethal concentrations (LC50 and LC90) for the virus against C. peltastica was 8.19 x 103 and 3.33 x 105 OBs/ml. The LC50 and LC90 for T. leucotreta was 2.29 x 103 and 9.97 x 104 OBs/ml, respectively and C. pomonella had a LC50 of 1.43 x 103 OBs/ml and LC90 1.26 x 104 OBs/ml. The virus was particularly virulent against T. leucotreta and C. pomonella as compared to C. peltastica. The biological activity of the alphabaculovirus was also tested against CpGV resistant European C. pomonella. From the results it was observed that the virus had the ability to overcome the resistance in C. pomonella and could potentially be used in the resistance management of C. pomonella. With the successful biological activity results obtained from this study, preliminary investigation were made into the mass production of the alphabaculovirus using both the in vivo and in vitro production methods. For in vivo production both the homologous host (C. peltastica) and a heterologous host (T leucotreta) were investigated. Preliminary studies focused on determining the biological activity in fifth instars of both hosts. Fifth instar LC50 and LC90 values for C. peltastica were 3.43 x 103 and 1.11 x 107 OBs/ml and for T. leucotreta the LC50 and LC90 values were 2.53 x 103 and 8.82 x 106 OBs/ml, respectively. The average yield of virus produced in each species was also determined. Cryptophlebia peltastica had the highest viral yield of 5.37 x 1010 OBs/larva and 2.93 x 1010 OBs/larva for T. leucotreta. The results obtained, from the preliminary investigation concluded that the virus could be produced in vivo in both C. peltastica and T. leucotreta, however further research is required into the mass production in both hosts. The in vitro production of the virus was also considered and the susceptibility of the virus was tested against the C. pomonella cell line, Cp14R. After infection of the Cp14R cells with budded virus collected from fifth instar C. peltastica larvae, OBs could be observed after three days. Thus, the alphabaculovirus is susceptible to the Cp14R cell line, thus has the potential to be produced in vitro and further characterised. This study is the first to report of the identification and characterisation of a novel alphabaculovirus isolated from a laboratory reared culture of C. peltastica and the potential for it to be commercially developed into a bipoesticide and used against Tortricidae pests.
- Full Text:
- Date Issued: 2017
- Authors: Marsberg, Tamryn
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/59292 , vital:27543
- Description: Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae) is an economically damaging pest of litchis and macadamias in South Africa. Cryptophlebia peltastica causes both pre- and post-harvest damage to litchis, reducing overall yields and thus classifying the pest as a phytosanitary risk. Various control methods have been implemented against C. peltastica in an integrated pest management programme. These control methods include chemical control, cultural control and biological control. However, these methods have not yet provided satisfactory control as of yet. As a result, an alternative control option needs to be identified and implemented into the IPM programme. An alternative method of control that has proved successful in other agricultural sectors and not yet implemented in the control of C. peltastica is that of microbial control, specifically the use of baculovirus biopesticides. This study aimed to isolate and characterise a novel baculovirus from a laboratory culture of C. peltastica that could be used as a commercially available baculovirus biopesticide. In order to isolate a baculovirus a laboratory culture of C. peltastica was successfully established at Rhodes University, Grahamstown, South Africa. This is the first time a laboratory culture of C. peltastica has been established. This allowed for various biological aspects of the pest to be determined, which included: length of the life cycle, fecundity and time to oviposition, egg and larval development and percentage hatch. The results obtained from these studies found that the biology of C. peltastica was similar to that of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). Once the laboratory culture had reached high densities, larvae showing symptoms of baculovirus infection were observed. Symptomatic larvae were collected and examined for the presence of a baculovirus. An alphabaculovirus (NPV) was successfully isolated and morphologically identified using purified OBs that were sectioned and observed by transmission electron microscopy. This was then confirmed by amplifying the polyhedrin gene region using degenerate primers. A BLAST analysis found a 93% similarity to a partial polyhedrin gene sequence to be that of Epinotia granitalis (Butler) (Lepidoptera: Tortricidae). The alphabaculovirus was then genetically characterised by generating restriction profiles and sequencing the whole genome. Due to the novelty of the virus, no comparison could be made. The biological activity of the alphabaculovirus was then tested against C. peltastica and two closely related Tortricidae pests: T. leucotreta and Cydiapomonella (Linnaeous) (Lepidoptera: Tortricidae). The alphabaculovirus was highly virulent against all three species. The lethal concentrations (LC50 and LC90) for the virus against C. peltastica was 8.19 x 103 and 3.33 x 105 OBs/ml. The LC50 and LC90 for T. leucotreta was 2.29 x 103 and 9.97 x 104 OBs/ml, respectively and C. pomonella had a LC50 of 1.43 x 103 OBs/ml and LC90 1.26 x 104 OBs/ml. The virus was particularly virulent against T. leucotreta and C. pomonella as compared to C. peltastica. The biological activity of the alphabaculovirus was also tested against CpGV resistant European C. pomonella. From the results it was observed that the virus had the ability to overcome the resistance in C. pomonella and could potentially be used in the resistance management of C. pomonella. With the successful biological activity results obtained from this study, preliminary investigation were made into the mass production of the alphabaculovirus using both the in vivo and in vitro production methods. For in vivo production both the homologous host (C. peltastica) and a heterologous host (T leucotreta) were investigated. Preliminary studies focused on determining the biological activity in fifth instars of both hosts. Fifth instar LC50 and LC90 values for C. peltastica were 3.43 x 103 and 1.11 x 107 OBs/ml and for T. leucotreta the LC50 and LC90 values were 2.53 x 103 and 8.82 x 106 OBs/ml, respectively. The average yield of virus produced in each species was also determined. Cryptophlebia peltastica had the highest viral yield of 5.37 x 1010 OBs/larva and 2.93 x 1010 OBs/larva for T. leucotreta. The results obtained, from the preliminary investigation concluded that the virus could be produced in vivo in both C. peltastica and T. leucotreta, however further research is required into the mass production in both hosts. The in vitro production of the virus was also considered and the susceptibility of the virus was tested against the C. pomonella cell line, Cp14R. After infection of the Cp14R cells with budded virus collected from fifth instar C. peltastica larvae, OBs could be observed after three days. Thus, the alphabaculovirus is susceptible to the Cp14R cell line, thus has the potential to be produced in vitro and further characterised. This study is the first to report of the identification and characterisation of a novel alphabaculovirus isolated from a laboratory reared culture of C. peltastica and the potential for it to be commercially developed into a bipoesticide and used against Tortricidae pests.
- Full Text:
- Date Issued: 2017
The Role of HOP in Emerin-Mediated Nuclear Structure
- Authors: Kituyi, Sarah Naulikha
- Date: 2017
- Subjects: Heat shock proteins , Nuclear structure , Nuclear membranes , Cancer Treatment , Molecular chaperones , Cytoskeleton , Cytoplasm
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/59230 , vital:27485 , DOI 10.21504/10962/59230
- Description: A vital component of the integral nuclear membrane is emerin, a Lamin Emerin and Man1 (LEM) domain protein whose concentration determines the levels of partner proteins that together constitute the structure of the nuclear envelope. Deficiencies in any of these proteins causes the failure of the structure and assembly and disassembly of the nuclear envelope, which disrupts chromosome segregation and nuclear compartmentalization that are both associated with disease. Emerin also localizes in the cytoplasm where it is implicated in the structure of the cytoskeleton via interaction with tubulin and actin and thus its deficiency may equally contribute to the collapse of the cytoskeleton. The Hsp70-Hsp90 organising protein (Hop) functions as a cochaperone for entry of client proteins into the Hsp90 folding cycle. Hop is upregulated in cancer and regulates a number of cell biology processes via interactions with proteins independently of Hsp90. In a previous study using global whole cell mass spectrometry, emerin was shown to be the most significantly down regulated protein in Hop depleted cell lysates. In this current study, it was postulated that emerin interacts with Hop, and this interaction regulates the stability, and level of emerin in the nucleus which impacts on the structure of the nuclear envelope. We used HEK293T cell lines stably expressing shRNA against Hop, emerin and a non-targeting control alongside the over expression of Hop in HEK293 cells to determine the effect of Hop levels on emerin expression and vice versa via Western blotting. The effect of Hop on the localization of emerin was assessed via subcellullar fractionation and confocal microscopy, while the impact on the structure of the nucleus was determined by transmission electron microscopy (TEM). We established that the depletion of Hop using shRNA and the over expression of Hop both result in the proteasomal and lysosomal degradation of emerin. Co-immunoprecipitation assays confirmed that Hop and emerin are in a common complex, which was not dependent on the presence of Hsp90. Loss of Hop or emerin led to a deformation of nuclear structure and a statistically significant decrease in nuclear size compared to control cells and was associated with an increase in the levels of nuclear protein, lamin A-C. Loss of emerin and Hop resulted in increased long term cell survival, but only after restriction of the nucleus when the cells had migrated across a transwell membrane. Taken together, the results obtained suggest that Hop acts as a scaffold for the stabilization of emerin and that the effects of Hop depletion on the structure of the nucleus and long term survival are mediated via the depletion of emerin. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2017
- Full Text:
- Date Issued: 2017
- Authors: Kituyi, Sarah Naulikha
- Date: 2017
- Subjects: Heat shock proteins , Nuclear structure , Nuclear membranes , Cancer Treatment , Molecular chaperones , Cytoskeleton , Cytoplasm
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/59230 , vital:27485 , DOI 10.21504/10962/59230
- Description: A vital component of the integral nuclear membrane is emerin, a Lamin Emerin and Man1 (LEM) domain protein whose concentration determines the levels of partner proteins that together constitute the structure of the nuclear envelope. Deficiencies in any of these proteins causes the failure of the structure and assembly and disassembly of the nuclear envelope, which disrupts chromosome segregation and nuclear compartmentalization that are both associated with disease. Emerin also localizes in the cytoplasm where it is implicated in the structure of the cytoskeleton via interaction with tubulin and actin and thus its deficiency may equally contribute to the collapse of the cytoskeleton. The Hsp70-Hsp90 organising protein (Hop) functions as a cochaperone for entry of client proteins into the Hsp90 folding cycle. Hop is upregulated in cancer and regulates a number of cell biology processes via interactions with proteins independently of Hsp90. In a previous study using global whole cell mass spectrometry, emerin was shown to be the most significantly down regulated protein in Hop depleted cell lysates. In this current study, it was postulated that emerin interacts with Hop, and this interaction regulates the stability, and level of emerin in the nucleus which impacts on the structure of the nuclear envelope. We used HEK293T cell lines stably expressing shRNA against Hop, emerin and a non-targeting control alongside the over expression of Hop in HEK293 cells to determine the effect of Hop levels on emerin expression and vice versa via Western blotting. The effect of Hop on the localization of emerin was assessed via subcellullar fractionation and confocal microscopy, while the impact on the structure of the nucleus was determined by transmission electron microscopy (TEM). We established that the depletion of Hop using shRNA and the over expression of Hop both result in the proteasomal and lysosomal degradation of emerin. Co-immunoprecipitation assays confirmed that Hop and emerin are in a common complex, which was not dependent on the presence of Hsp90. Loss of Hop or emerin led to a deformation of nuclear structure and a statistically significant decrease in nuclear size compared to control cells and was associated with an increase in the levels of nuclear protein, lamin A-C. Loss of emerin and Hop resulted in increased long term cell survival, but only after restriction of the nucleus when the cells had migrated across a transwell membrane. Taken together, the results obtained suggest that Hop acts as a scaffold for the stabilization of emerin and that the effects of Hop depletion on the structure of the nucleus and long term survival are mediated via the depletion of emerin. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2017
- Full Text:
- Date Issued: 2017