Enumeration, conformation sampling and population of libraries of peptide macrocycles for the search of chemotherapeutic cardioprotection agents
- Authors: Sigauke, Lester Takunda
- Date: 2019
- Subjects: Peptides -- Synthesis , Macrocyclic compounds , Drug development , Drug discovery , Cardiovascular system -- Diseases -- Prevention , Proteins -- Synthesis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116056 , vital:34293
- Description: Peptides are uniquely endowed with features that allow them to perturb previously difficult to drug biomolecular targets. Peptide macrocycles in particular have seen a flurry of recent interest due to their enhanced bioavailability, tunability and specificity. Although these properties make them attractive hit-candidates in early stage drug discovery, knowing which peptides to pursue is non‐trivial due to the magnitude of the peptide sequence space. Computational screening approaches show promise in their ability to address the size of this search space but suffer from their inability to accurately interrogate the conformational landscape of peptide macrocycles. We developed an in‐silico compound enumerator that was tasked with populating a conformationally laden peptide virtual library. This library was then used in the search for cardio‐protective agents (that may be administered, reducing tissue damage during reperfusion after ischemia (heart attacks)). Our enumerator successfully generated a library of 15.2 billion compounds, requiring the use of compression algorithms, conformational sampling protocols and management of aggregated compute resources in the context of a local cluster. In the absence of experimental biophysical data, we performed biased sampling during alchemical molecular dynamics simulations in order to observe cyclophilin‐D perturbation by cyclosporine A and its mitochondrial targeted analogue. Reliable intermediate state averaging through a WHAM analysis of the biased dynamic pulling simulations confirmed that the cardio‐protective activity of cyclosporine A was due to its mitochondrial targeting. Paralleltempered solution molecular dynamics in combination with efficient clustering isolated the essential dynamics of a cyclic peptide scaffold. The rapid enumeration of skeletons from these essential dynamics gave rise to a conformation laden virtual library of all the 15.2 Billion unique cyclic peptides (given the limits on peptide sequence imposed). Analysis of this library showed the exact extent of physicochemical properties covered, relative to the bare scaffold precursor. Molecular docking of a subset of the virtual library against cyclophilin‐D showed significant improvements in affinity to the target (relative to cyclosporine A). The conformation laden virtual library, accessed by our methodology, provided derivatives that were able to make many interactions per peptide with the cyclophilin‐D target. Machine learning methods showed promise in the training of Support Vector Machines for synthetic feasibility prediction for this library. The synergy between enumeration and conformational sampling greatly improves the performance of this library during virtual screening, even when only a subset is used.
- Full Text:
- Date Issued: 2019
- Authors: Sigauke, Lester Takunda
- Date: 2019
- Subjects: Peptides -- Synthesis , Macrocyclic compounds , Drug development , Drug discovery , Cardiovascular system -- Diseases -- Prevention , Proteins -- Synthesis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116056 , vital:34293
- Description: Peptides are uniquely endowed with features that allow them to perturb previously difficult to drug biomolecular targets. Peptide macrocycles in particular have seen a flurry of recent interest due to their enhanced bioavailability, tunability and specificity. Although these properties make them attractive hit-candidates in early stage drug discovery, knowing which peptides to pursue is non‐trivial due to the magnitude of the peptide sequence space. Computational screening approaches show promise in their ability to address the size of this search space but suffer from their inability to accurately interrogate the conformational landscape of peptide macrocycles. We developed an in‐silico compound enumerator that was tasked with populating a conformationally laden peptide virtual library. This library was then used in the search for cardio‐protective agents (that may be administered, reducing tissue damage during reperfusion after ischemia (heart attacks)). Our enumerator successfully generated a library of 15.2 billion compounds, requiring the use of compression algorithms, conformational sampling protocols and management of aggregated compute resources in the context of a local cluster. In the absence of experimental biophysical data, we performed biased sampling during alchemical molecular dynamics simulations in order to observe cyclophilin‐D perturbation by cyclosporine A and its mitochondrial targeted analogue. Reliable intermediate state averaging through a WHAM analysis of the biased dynamic pulling simulations confirmed that the cardio‐protective activity of cyclosporine A was due to its mitochondrial targeting. Paralleltempered solution molecular dynamics in combination with efficient clustering isolated the essential dynamics of a cyclic peptide scaffold. The rapid enumeration of skeletons from these essential dynamics gave rise to a conformation laden virtual library of all the 15.2 Billion unique cyclic peptides (given the limits on peptide sequence imposed). Analysis of this library showed the exact extent of physicochemical properties covered, relative to the bare scaffold precursor. Molecular docking of a subset of the virtual library against cyclophilin‐D showed significant improvements in affinity to the target (relative to cyclosporine A). The conformation laden virtual library, accessed by our methodology, provided derivatives that were able to make many interactions per peptide with the cyclophilin‐D target. Machine learning methods showed promise in the training of Support Vector Machines for synthetic feasibility prediction for this library. The synergy between enumeration and conformational sampling greatly improves the performance of this library during virtual screening, even when only a subset is used.
- Full Text:
- Date Issued: 2019
Environmental conflict resolution: a critical analysis of the role of interests and value
- Authors: Mweshi, John
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55842 , vital:26740
- Description: This thesis intends to contribute to an enhanced understanding of environmental conflicts and their resolution. To accomplish this task the thesis will ascertain the role that value and interests play in environmental conflicts in order to establish an adequate basis upon which they can be resolved. In the process, the thesis will also examine three different approaches, namely, the Standard Approach; the Environmental Impact Assessment (EIA) framework; and the Structured Decision Making (SDM) approach. First, the standard approach is informed by the understanding that focusing on interests instead of human values makes the resolution of conflicts more tractable. In contrast, this thesis argues that an exclusive focus on interests, in the context of environmental conflict resolution, is inadequate in some important respects because there are other factors to be considered such as the environmental impacts at the root of the conflict. Second, the thesis examines the focus on impacts that characterises EIAs. It argues that this approach remedies the limitations of the standard approach insofar as impacts are understood in terms of object value. However, the EIA approach does not provide much guidance on how to deal with conflicting human values. Third, taking into account the fact that the standard approach does not address the question of object value, while the EIA addresses object value but does not deal directly with human values, the thesis examines the SDM approach to environmental risk decisions. The thesis argues that while the SDM approach claims to deal with conflicts involving human values head-on, it does not provide a viable alternative in terms of environmental conflict resolution. This is because it fails to recognise the key distinction between human values and object value despite acknowledging the presence of multiple value dimensions as a major obstacle to value trade-offs and therefore to the resolution of value conflicts. Finally, the thesis recommends an adequate basis upon which environmental conflicts can be resolved.
- Full Text:
- Date Issued: 2015
- Authors: Mweshi, John
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55842 , vital:26740
- Description: This thesis intends to contribute to an enhanced understanding of environmental conflicts and their resolution. To accomplish this task the thesis will ascertain the role that value and interests play in environmental conflicts in order to establish an adequate basis upon which they can be resolved. In the process, the thesis will also examine three different approaches, namely, the Standard Approach; the Environmental Impact Assessment (EIA) framework; and the Structured Decision Making (SDM) approach. First, the standard approach is informed by the understanding that focusing on interests instead of human values makes the resolution of conflicts more tractable. In contrast, this thesis argues that an exclusive focus on interests, in the context of environmental conflict resolution, is inadequate in some important respects because there are other factors to be considered such as the environmental impacts at the root of the conflict. Second, the thesis examines the focus on impacts that characterises EIAs. It argues that this approach remedies the limitations of the standard approach insofar as impacts are understood in terms of object value. However, the EIA approach does not provide much guidance on how to deal with conflicting human values. Third, taking into account the fact that the standard approach does not address the question of object value, while the EIA addresses object value but does not deal directly with human values, the thesis examines the SDM approach to environmental risk decisions. The thesis argues that while the SDM approach claims to deal with conflicts involving human values head-on, it does not provide a viable alternative in terms of environmental conflict resolution. This is because it fails to recognise the key distinction between human values and object value despite acknowledging the presence of multiple value dimensions as a major obstacle to value trade-offs and therefore to the resolution of value conflicts. Finally, the thesis recommends an adequate basis upon which environmental conflicts can be resolved.
- Full Text:
- Date Issued: 2015
Evaluation of metallophthalocyanine functionalized photocatalytic asymmetric polymer membranes for pollution control and antimicrobial activity
- Mafukidze, Donovan Musizvinoda Chidyamurimi
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
- Full Text:
- Date Issued: 2021
Evaluation of water quality, selected metals and endocrine-disrupting compounds in the rivers and municipal wastewaters of Eastern Cape province, South Africa
- Authors: Farounbi, Adebayo Ibikunle
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177327 , vital:42810
- Description: Thesis embargoed. Release date April 2022. , Thesis (PhD) -- Faculty of Science, Institute of Water Research, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Farounbi, Adebayo Ibikunle
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177327 , vital:42810
- Description: Thesis embargoed. Release date April 2022. , Thesis (PhD) -- Faculty of Science, Institute of Water Research, 2021
- Full Text:
- Date Issued: 2021-04
Examination of teacher mediation and its impact on foundational reading skills in Grade-R classrooms in Namibia
- Authors: Nzwala, Kenneth
- Date: 2019
- Subjects: Reading (Elementary) -- Namibia -- Case studies , Elementary school teachers -- Namibia -- Case studies , Early childhood education -- Curricula -- Namibia , Vygotskiĭ, L. S. (Lev Semenovich), 1896-1934
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92291 , vital:30700
- Description: Grounded in the Sociocultural Theory (SCT) of Lev Vygotsky, this study examined teacher mediation and its impact on development of foundational reading skills in six Grade-R classrooms in the Zambezi Region of Namibia. It was a multiple case study with a mixed methods approach. Six Grade R classes attached to primary schools were studied to facilitate following of the same learners to Grade One. A purposive sampling technique was used to draw a sample of six Grade-R and Grade-One teachers. Learners were selected using stratified random sampling. Data were collected by means of interviews, observation of Grade R lessons, and an emergent Early Grade Reading Assessment (eEGRA) test. eEGRA facilitated benchmarking teacher efficacy in mediating Grade R learners’ foundational reading skills. Nine Grade One learners per teacher per school took part in the test at the beginning of Grade One. Three 35-minute lessons, per Grade-R teacher, were observed. Data were analysed statistically using ANOVA with thematic qualitative analysis of interview data against document analysis of curricula, teacher planning and learner exercise books. The study established that teachers had no understanding of ‘emergent literacy’, did not promote a love of books, or promote learning through play. There was evidence of a language barrier during lessons, which potentially reduced the efficacy of teacher mediation. The curriculum was found to be inappropriate as it lacked guidance relevant to Grade R teachers. This point was particularly pertinent as all teachers in this study had not received Grade-R training and were therefore looking to the curriculum for support. The difference between what teachers said and what they did was revealed in their classroom practice. Lesson planning was found to be superficial and non-reflective, with a marked discrepancy between what was planned and what was done. The style of pedagogy was primarily transmissive and authoritarian. Finally, the socio-economic distribution of the schools did not demonstrate significant impact on learner performance in the benchmark test. This study concludes that the Grade-R curriculum needs to be revised to be culturally and age appropriate. Teachers should be trained to understand the speciality of Grade R, and support should be given to current teachers to adopt a child-centred, play-based approach to pedagogy.
- Full Text:
- Date Issued: 2019
- Authors: Nzwala, Kenneth
- Date: 2019
- Subjects: Reading (Elementary) -- Namibia -- Case studies , Elementary school teachers -- Namibia -- Case studies , Early childhood education -- Curricula -- Namibia , Vygotskiĭ, L. S. (Lev Semenovich), 1896-1934
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92291 , vital:30700
- Description: Grounded in the Sociocultural Theory (SCT) of Lev Vygotsky, this study examined teacher mediation and its impact on development of foundational reading skills in six Grade-R classrooms in the Zambezi Region of Namibia. It was a multiple case study with a mixed methods approach. Six Grade R classes attached to primary schools were studied to facilitate following of the same learners to Grade One. A purposive sampling technique was used to draw a sample of six Grade-R and Grade-One teachers. Learners were selected using stratified random sampling. Data were collected by means of interviews, observation of Grade R lessons, and an emergent Early Grade Reading Assessment (eEGRA) test. eEGRA facilitated benchmarking teacher efficacy in mediating Grade R learners’ foundational reading skills. Nine Grade One learners per teacher per school took part in the test at the beginning of Grade One. Three 35-minute lessons, per Grade-R teacher, were observed. Data were analysed statistically using ANOVA with thematic qualitative analysis of interview data against document analysis of curricula, teacher planning and learner exercise books. The study established that teachers had no understanding of ‘emergent literacy’, did not promote a love of books, or promote learning through play. There was evidence of a language barrier during lessons, which potentially reduced the efficacy of teacher mediation. The curriculum was found to be inappropriate as it lacked guidance relevant to Grade R teachers. This point was particularly pertinent as all teachers in this study had not received Grade-R training and were therefore looking to the curriculum for support. The difference between what teachers said and what they did was revealed in their classroom practice. Lesson planning was found to be superficial and non-reflective, with a marked discrepancy between what was planned and what was done. The style of pedagogy was primarily transmissive and authoritarian. Finally, the socio-economic distribution of the schools did not demonstrate significant impact on learner performance in the benchmark test. This study concludes that the Grade-R curriculum needs to be revised to be culturally and age appropriate. Teachers should be trained to understand the speciality of Grade R, and support should be given to current teachers to adopt a child-centred, play-based approach to pedagogy.
- Full Text:
- Date Issued: 2019
Examining mathematical reasoning through enacted visualisation
- Authors: Dongwi, Beata Lididimikeni
- Date: 2019
- Subjects: Visualization , Mathematics -- Study and teaching -- Namibia , Mathematics -- Study and teaching -- Audio-visual aids , Geometry -- Study and teaching , Reasoning , Mathematical ability
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68192 , vital:29217
- Description: This study sets out to analyse the co-emergence of visualisation and reasoning processes when selected learners engaged in solving word problems. The study argues that visualisation processes and mathematical reasoning processes are closely interlinked in the process of engaging in any mathematical activity. This qualitative research project adopted a case study methodology embedded within a broader interpretative orientation. The research participants were a cohort of 17 mixedgender and mixed-ability Grade 11 learners from a private school in southern Namibia. Data was collected in three phases and comprised of one-on-one task-based interviews in the first phase, focus group task-based interviews in the second, and semi-structured reflective interviews in the third. The analytical framework was informed by elements of enactivism and consisted of a hybrid of observable visualisation and mathematical reasoning indicators. The study was framed by an enactivist perspective that served as a linking mediator to bring visualisation and reasoning processes together, and as a lens through which the coemergence of these processes was observed and analysed. The key enactivist concepts of structural coupling and co-emergence were the two mediating ideas that enabled me to discuss the links between visualisation and reasoning that emerged whilst my participants solved the set word problems. The study argues that the visualisation processes enacted by the participants when solving these problems are inseparable from the reasoning processes that the participants brought to bear; that is, they co-emerged.
- Full Text:
- Date Issued: 2019
- Authors: Dongwi, Beata Lididimikeni
- Date: 2019
- Subjects: Visualization , Mathematics -- Study and teaching -- Namibia , Mathematics -- Study and teaching -- Audio-visual aids , Geometry -- Study and teaching , Reasoning , Mathematical ability
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68192 , vital:29217
- Description: This study sets out to analyse the co-emergence of visualisation and reasoning processes when selected learners engaged in solving word problems. The study argues that visualisation processes and mathematical reasoning processes are closely interlinked in the process of engaging in any mathematical activity. This qualitative research project adopted a case study methodology embedded within a broader interpretative orientation. The research participants were a cohort of 17 mixedgender and mixed-ability Grade 11 learners from a private school in southern Namibia. Data was collected in three phases and comprised of one-on-one task-based interviews in the first phase, focus group task-based interviews in the second, and semi-structured reflective interviews in the third. The analytical framework was informed by elements of enactivism and consisted of a hybrid of observable visualisation and mathematical reasoning indicators. The study was framed by an enactivist perspective that served as a linking mediator to bring visualisation and reasoning processes together, and as a lens through which the coemergence of these processes was observed and analysed. The key enactivist concepts of structural coupling and co-emergence were the two mediating ideas that enabled me to discuss the links between visualisation and reasoning that emerged whilst my participants solved the set word problems. The study argues that the visualisation processes enacted by the participants when solving these problems are inseparable from the reasoning processes that the participants brought to bear; that is, they co-emerged.
- Full Text:
- Date Issued: 2019
Expanding learning in clergy leadership formation in an Anglican Church Province in Southern Africa: a critical realist study
- Authors: Chinganga, Percy
- Date: 2019
- Subjects: Leadership -- Africa, Southern -- Religious aspects -- Christianity , Church management -- Africa, Southern , Critical realism , Educational leadership , Anglican Church of Southern Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92258 , vital:30704
- Description: The focus of this study was to investigate the kind of learning that happened when participants involved in clergy leadership formation programmes and activities in the Anglican Church of Southern Africa (ACSA) engaged in their responsibilities as a collective. Further, the research sought to explore collaborative and transforming practices in ACSA clergy leadership formation programmes and activities which could be expanded through learning. The study is premised on an investigation of the historical foundations of Christian leadership formation processes which sought to establish clergy leadership formation models relevant to ACSA (the context of the study) from inception (1848) to date (2017). This entailed investigating how the developments which have happened in the church from its inception in the New Testament times through the Medieval and Reformation periods, have contributed to the emergence of distinct Christian leadership formation models which have formed the basis of clergy leadership formation in ACSA. Accordingly, the study highlighted key issues relating to clergy leadership formation which are discernible in the different historical phases of the life and work of the church with the objective of establishing how ACSA, through expansive learning, could transform her current clergy leadership formation model(s) towards collaborative and transforming practices. The concept of expansive learning, drawn from Cultural Historical Activity Theory (CHAT), was used in the study as a methodological tool to create an environment where research participants (formators) from several dioceses would engage in collective work activities which would surface contradictions relating to how clergy leadership formation programmes and activities were understood and facilitated in ACSA. In response to the surfaced contradictions, the study engaged research participants in Change Laboratory Workshops whose goal was to transform the organisation (ACSA) in two particular ways: empowerment of participants (formators) with conceptual tools relevant to their responsibilities in clergy leadership formation programmes and activities in ACSA, and improvement of organisational cultural practices, that is, the manner in which ACSA ought to conceptualise, design, plan, facilitate and manage clergy leadership formation programmes and activities. The latter brought into the discourse the need for participants (formators) to select and employ methodologies, methods, approaches and resources relevant to the southern African context where ACSA is located even though the study also acknowledged the influence of other Anglican Church contexts on what happened at the local level. In order to decipher meaning out of investigated phenomena about clergy leadership formation in ACSA, the study employed the critical realist “underlabouring” philosophy advanced by theorists such as Bhaskar to surface underlying mechanisms that exist at the level of the “real” in order to understand the causes of particular events and experiences as they manifest in the “actual” and “empirical” domains of the world, ACSA in the case of the study. In particular, the study engaged critically the opinion deliberated by critical realists concerning the interplay between structure and agency in relation to the responsibilities of the research participants (formators) in ACSA clergy leadership formation programmes and activities. For instance, the study had an interest in investigating why bishops (principal formators in ACSA) exercised their episcopal authority in the manner they do and why individual formators were concerned about particular issues which relate to the facilitation of clergy leadership formation in ACSA (agential reflexivity/subjectivity). The study observed that, in the case of diocesan bishops, critical realists would argue that, by virtue of the authority which comes with their responsibilities (agency), they have the power to influence transformation of practices in clergy leadership formation in ACSA at any given point in time. The flip side of the discourse was also taken note of: that some bishops, for reasons known to themselves and their predecessors, are often reluctant to embrace new ideas relating to clergy leadership formation practices in their dioceses. Further, through critical realist lens, the study concluded that Canons, Vision and Mission statements, Acts, and structures such as Synod of Bishops, Provincial Synod, ABoTE, Cott, and TfM structurally shape ACSA, thus providing the organisation with a stable ontology which ought to direct, regulate and control the manner in which clergy leadership formation programmes and activities were conceptualised, designed, planned, facilitated and managed. As such, the study had an interest in establishing what would happen, in relation to clergy leadership formation practices in ACSA, when these structures would have been activated? Beyond that, in view of the goal of the study, it was enquired how expansive learning processes could be helpful in responding to the research findings towards exploring collaborative and transforming clergy leadership formation practices in ACSA. Drawing from the conceptual framework which was carved in the study on the basis of the theoretical tools (critical realism and educational leadership theory) and methodological tools (CHAT orientated concepts) undergirded by the Vygotskian theorisation of human consciousness development, the study concluded that clergy leadership formation is a collaborative activity which calls for the recognition, appreciation and utilisation of available expertise in ACSA and provision of a platform where participants (formators) could engage collectively on issues relating to their work with the objective of building each other up in knowledge and skills (expansive learning) towards realisation of the goals and objectives of the organisation. Diverse understandings (contradictions) of what needed to be prioritised in the facilitation of clergy leadership formation in ACSA would be considered as a positive rather than a negative. Ultimately, through the use of inductive, abductive and retroductive modes of inference, the study modelled a transforming, transformational, transformative, embodied and incarnational model of clergy leadership formation which ACSA could consider using in future deliberations on the object of study particularly in relation to the key research findings across the case studies which were used in the study.
- Full Text:
- Date Issued: 2019
- Authors: Chinganga, Percy
- Date: 2019
- Subjects: Leadership -- Africa, Southern -- Religious aspects -- Christianity , Church management -- Africa, Southern , Critical realism , Educational leadership , Anglican Church of Southern Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92258 , vital:30704
- Description: The focus of this study was to investigate the kind of learning that happened when participants involved in clergy leadership formation programmes and activities in the Anglican Church of Southern Africa (ACSA) engaged in their responsibilities as a collective. Further, the research sought to explore collaborative and transforming practices in ACSA clergy leadership formation programmes and activities which could be expanded through learning. The study is premised on an investigation of the historical foundations of Christian leadership formation processes which sought to establish clergy leadership formation models relevant to ACSA (the context of the study) from inception (1848) to date (2017). This entailed investigating how the developments which have happened in the church from its inception in the New Testament times through the Medieval and Reformation periods, have contributed to the emergence of distinct Christian leadership formation models which have formed the basis of clergy leadership formation in ACSA. Accordingly, the study highlighted key issues relating to clergy leadership formation which are discernible in the different historical phases of the life and work of the church with the objective of establishing how ACSA, through expansive learning, could transform her current clergy leadership formation model(s) towards collaborative and transforming practices. The concept of expansive learning, drawn from Cultural Historical Activity Theory (CHAT), was used in the study as a methodological tool to create an environment where research participants (formators) from several dioceses would engage in collective work activities which would surface contradictions relating to how clergy leadership formation programmes and activities were understood and facilitated in ACSA. In response to the surfaced contradictions, the study engaged research participants in Change Laboratory Workshops whose goal was to transform the organisation (ACSA) in two particular ways: empowerment of participants (formators) with conceptual tools relevant to their responsibilities in clergy leadership formation programmes and activities in ACSA, and improvement of organisational cultural practices, that is, the manner in which ACSA ought to conceptualise, design, plan, facilitate and manage clergy leadership formation programmes and activities. The latter brought into the discourse the need for participants (formators) to select and employ methodologies, methods, approaches and resources relevant to the southern African context where ACSA is located even though the study also acknowledged the influence of other Anglican Church contexts on what happened at the local level. In order to decipher meaning out of investigated phenomena about clergy leadership formation in ACSA, the study employed the critical realist “underlabouring” philosophy advanced by theorists such as Bhaskar to surface underlying mechanisms that exist at the level of the “real” in order to understand the causes of particular events and experiences as they manifest in the “actual” and “empirical” domains of the world, ACSA in the case of the study. In particular, the study engaged critically the opinion deliberated by critical realists concerning the interplay between structure and agency in relation to the responsibilities of the research participants (formators) in ACSA clergy leadership formation programmes and activities. For instance, the study had an interest in investigating why bishops (principal formators in ACSA) exercised their episcopal authority in the manner they do and why individual formators were concerned about particular issues which relate to the facilitation of clergy leadership formation in ACSA (agential reflexivity/subjectivity). The study observed that, in the case of diocesan bishops, critical realists would argue that, by virtue of the authority which comes with their responsibilities (agency), they have the power to influence transformation of practices in clergy leadership formation in ACSA at any given point in time. The flip side of the discourse was also taken note of: that some bishops, for reasons known to themselves and their predecessors, are often reluctant to embrace new ideas relating to clergy leadership formation practices in their dioceses. Further, through critical realist lens, the study concluded that Canons, Vision and Mission statements, Acts, and structures such as Synod of Bishops, Provincial Synod, ABoTE, Cott, and TfM structurally shape ACSA, thus providing the organisation with a stable ontology which ought to direct, regulate and control the manner in which clergy leadership formation programmes and activities were conceptualised, designed, planned, facilitated and managed. As such, the study had an interest in establishing what would happen, in relation to clergy leadership formation practices in ACSA, when these structures would have been activated? Beyond that, in view of the goal of the study, it was enquired how expansive learning processes could be helpful in responding to the research findings towards exploring collaborative and transforming clergy leadership formation practices in ACSA. Drawing from the conceptual framework which was carved in the study on the basis of the theoretical tools (critical realism and educational leadership theory) and methodological tools (CHAT orientated concepts) undergirded by the Vygotskian theorisation of human consciousness development, the study concluded that clergy leadership formation is a collaborative activity which calls for the recognition, appreciation and utilisation of available expertise in ACSA and provision of a platform where participants (formators) could engage collectively on issues relating to their work with the objective of building each other up in knowledge and skills (expansive learning) towards realisation of the goals and objectives of the organisation. Diverse understandings (contradictions) of what needed to be prioritised in the facilitation of clergy leadership formation in ACSA would be considered as a positive rather than a negative. Ultimately, through the use of inductive, abductive and retroductive modes of inference, the study modelled a transforming, transformational, transformative, embodied and incarnational model of clergy leadership formation which ACSA could consider using in future deliberations on the object of study particularly in relation to the key research findings across the case studies which were used in the study.
- Full Text:
- Date Issued: 2019
Exploring and modelling the effects of agricultural land management and climate change on agroecosystem services in the Eastern Cape, South Africa
- Authors: Choruma, Dennis Junior
- Date: 2020
- Subjects: Agricultural ecology -- South Africa -- Eastern Cape , Agriculture -- Environmental aspects -- South Africa -- Eastern Cape , Crops and climate -- South Africa -- Eastern Cape , Corn -- Climatic factors -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146756 , vital:38554
- Description: The aims of this study were to evaluate the impacts of agricultural land management strategies and climate change on irrigated maize production in the Eastern Cape, South Africa. To achieve these aims, the study was guided by two overarching research questions, subsequently broken down into more specific questions. The first research question examined the reasons behind farmers’ current agricultural land management practices, the values they assigned to different agroecosystem services, their perceptions of climate change and the adaptation strategies they used to address challenges associated with agricultural crop production and climate change. To answer these questions, a survey of conventional farmers in the Eastern Cape was carried out. The survey targeted farmers who used fertilisers and irrigation water in their day to day farming. Results showed that farmers recognised the different benefits that agroecosystems provided even though they were not familiar with the term ‘ecosystem services.’ Farmers assigned a high value to food provisioning compared to other agroecosystem services and managed their farms for maximum crop yields or maximum crop quality. Fertiliser and irrigation water management decisions were based on multiple factors such as cost, availability of farming equipment and crop yield or crop quality considerations. Survey results showed that while most farmers were able to state the amount of fertiliser used per growing season, the majority of farmers did not know the amount of water they used per growing season. From the farmers’ survey it was recommended that extension services and agricultural education programmes be strengthened in the region to increase farmers’ knowledge on effective agricultural land management strategies that support sustainable intensification. The second research question investigated the effects of agricultural land management strategies and climate change on crop yields in the Eastern Cape. This investigation was done in three steps. First, a crop model, the Environmental Policy Integrated Climate (EPIC) model was calibrated and validated using limited field data from maize variety trials carried out at the Cradock Research Farm in the Eastern Cape. Calibration and validation results proved satisfactory with model efficiencies (Nash Sutcliffe, NSE) greater than 0.5 for both calibration and validation. It was concluded that limited data from field trials on maize that only included grain yield and agricultural land management dates can be used for the calibration of the EPIC model to simulate maize production under South African conditions. In the second step, the calibrated model was applied to simulate different irrigation and fertiliser management strategies for maize production in the Eastern Cape. Different irrigation and Nitrogen (N) fertiliser levels were compared to find optimal irrigation and N fertiliser management strategies that would increase maize yields while minimising environmental pollution (nitrate leaching). Model outputs were also compared to the average yields obtained in the field trials (baseline) and to maize yields reported by farmers in the farmers’ survey. Results showed that improved management of irrigation water and N fertiliser could improve farmers’ maize yields from approximately 7.2 t ha-1 to approximately 12.2 t ha-1, an increase of approximately 69%. Results also revealed a trade-off between food provision and nitrate leaching. Simulations showed that increasing N fertiliser application under sufficient irrigation water levels would increase maize yields, however, this would be accompanied by an increase in N leaching. Lastly, the EPIC model was then applied to simulate the effects of future climate change on irrigated maize production in the Eastern Cape. For these simulations, the model was driven by statistically downscaled climate data derived from three General Circulation Models (GCMs) for two future climate periods, (2040-2069) and (2070-2099), under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Future maize yields were compared to the baseline (1980-2010) maize yield average. All three climate models predicted a decline in maize yields, with yields declining by as much as 23.8% in RCP 8.5, 2070-2099. Simulations also predicted increases in average daily maximum and minimum temperatures for both the two future climate periods under both RCPs. Results also indicated a decrease in seasonal irrigation water requirements. Nitrate leaching was projected to significantly increase towards the end of the century, increasing by as much as 373.8% in RCP 8.5 2070-2099. Concerning farmers’ perceptions of climate change, results showed that farmers were aware of climate change and identified temperature and rainfall changes as the most important changes in climate that they had observed. To adapt to climate change, farmers used a variety of adaptation strategies such as crop rotations and intercropping. Apart from challenges posed by climate change, farmers also faced other challenges such as access to markets and access to financial credit lines, challenges that prevented them from effectively adapting to climate change. The study therefore recommended that appropriate and adequate strategies be designed to help farmers in the region offset the projected decrease in maize production and increase crop yields while minimising negative environmental impacts.
- Full Text:
- Date Issued: 2020
- Authors: Choruma, Dennis Junior
- Date: 2020
- Subjects: Agricultural ecology -- South Africa -- Eastern Cape , Agriculture -- Environmental aspects -- South Africa -- Eastern Cape , Crops and climate -- South Africa -- Eastern Cape , Corn -- Climatic factors -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146756 , vital:38554
- Description: The aims of this study were to evaluate the impacts of agricultural land management strategies and climate change on irrigated maize production in the Eastern Cape, South Africa. To achieve these aims, the study was guided by two overarching research questions, subsequently broken down into more specific questions. The first research question examined the reasons behind farmers’ current agricultural land management practices, the values they assigned to different agroecosystem services, their perceptions of climate change and the adaptation strategies they used to address challenges associated with agricultural crop production and climate change. To answer these questions, a survey of conventional farmers in the Eastern Cape was carried out. The survey targeted farmers who used fertilisers and irrigation water in their day to day farming. Results showed that farmers recognised the different benefits that agroecosystems provided even though they were not familiar with the term ‘ecosystem services.’ Farmers assigned a high value to food provisioning compared to other agroecosystem services and managed their farms for maximum crop yields or maximum crop quality. Fertiliser and irrigation water management decisions were based on multiple factors such as cost, availability of farming equipment and crop yield or crop quality considerations. Survey results showed that while most farmers were able to state the amount of fertiliser used per growing season, the majority of farmers did not know the amount of water they used per growing season. From the farmers’ survey it was recommended that extension services and agricultural education programmes be strengthened in the region to increase farmers’ knowledge on effective agricultural land management strategies that support sustainable intensification. The second research question investigated the effects of agricultural land management strategies and climate change on crop yields in the Eastern Cape. This investigation was done in three steps. First, a crop model, the Environmental Policy Integrated Climate (EPIC) model was calibrated and validated using limited field data from maize variety trials carried out at the Cradock Research Farm in the Eastern Cape. Calibration and validation results proved satisfactory with model efficiencies (Nash Sutcliffe, NSE) greater than 0.5 for both calibration and validation. It was concluded that limited data from field trials on maize that only included grain yield and agricultural land management dates can be used for the calibration of the EPIC model to simulate maize production under South African conditions. In the second step, the calibrated model was applied to simulate different irrigation and fertiliser management strategies for maize production in the Eastern Cape. Different irrigation and Nitrogen (N) fertiliser levels were compared to find optimal irrigation and N fertiliser management strategies that would increase maize yields while minimising environmental pollution (nitrate leaching). Model outputs were also compared to the average yields obtained in the field trials (baseline) and to maize yields reported by farmers in the farmers’ survey. Results showed that improved management of irrigation water and N fertiliser could improve farmers’ maize yields from approximately 7.2 t ha-1 to approximately 12.2 t ha-1, an increase of approximately 69%. Results also revealed a trade-off between food provision and nitrate leaching. Simulations showed that increasing N fertiliser application under sufficient irrigation water levels would increase maize yields, however, this would be accompanied by an increase in N leaching. Lastly, the EPIC model was then applied to simulate the effects of future climate change on irrigated maize production in the Eastern Cape. For these simulations, the model was driven by statistically downscaled climate data derived from three General Circulation Models (GCMs) for two future climate periods, (2040-2069) and (2070-2099), under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Future maize yields were compared to the baseline (1980-2010) maize yield average. All three climate models predicted a decline in maize yields, with yields declining by as much as 23.8% in RCP 8.5, 2070-2099. Simulations also predicted increases in average daily maximum and minimum temperatures for both the two future climate periods under both RCPs. Results also indicated a decrease in seasonal irrigation water requirements. Nitrate leaching was projected to significantly increase towards the end of the century, increasing by as much as 373.8% in RCP 8.5 2070-2099. Concerning farmers’ perceptions of climate change, results showed that farmers were aware of climate change and identified temperature and rainfall changes as the most important changes in climate that they had observed. To adapt to climate change, farmers used a variety of adaptation strategies such as crop rotations and intercropping. Apart from challenges posed by climate change, farmers also faced other challenges such as access to markets and access to financial credit lines, challenges that prevented them from effectively adapting to climate change. The study therefore recommended that appropriate and adequate strategies be designed to help farmers in the region offset the projected decrease in maize production and increase crop yields while minimising negative environmental impacts.
- Full Text:
- Date Issued: 2020
Exploring learners’ proficiency in stoichiometry and attitudes towards science through Process Oriented Guided Inquiry Learning (POGIL) intervention
- Authors: Agunbiade, Arinola Esther
- Date: 2021-04
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Nigeria , Chemistry -- Study and teaching (Secondary) -- Nigeria , Process-oriented guided inquiry learning , Student-centered learning -- Nigeria , Science students -- Attitudes
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174402 , vital:42474
- Description: Stoichiometry is one of the difficult topics in the senior secondary school chemistry curriculum. It is usually taught through the traditional lecture method of presentation that is non-engaging for learners. Consequently, there is poor understanding, achievement, and negative perceptions of stoichiometry and chemistry in general. The goal of this study was to explore learners’ evolving proficiency in stoichiometry and attitudes towards science as a result of their participation in Process Oriented Guided Inquiry Learning (POGIL) activities. That is, POGIL which incorporates guided-inquiry and collaborative learning was introduced as an intervention strategy in learning stoichiometry. This was assessed by examining learners’ experiences with learning stoichiometry before and after the POGIL intervention. The study further investigated possible contributing factors to learners’ evolving proficiency in stoichiometry and attitudes towards science. This study employed the socio-cultural learning theory as proposed by Vygotsky (1978). The role of socio-cultural features such as ‘social interaction’, ‘cultural tools’, ‘self-regulation’ and ‘zone of proximal development’ (ZPD) were explored with regards to learners’ stoichiometry proficiency and attitudes towards science progression as they participated in POGIL activities. The work of Kilpatrick, Swafford and Findell (2001) on proficiency and Fraser (1981) on attitudes towards science were used as analytical lenses to understand learners’ proficiency in stoichiometry and attitudes towards science, respectively. This study was underpinned by the pragmatic research paradigm. Thus, a Quant + Qual concurrent mixed-methods approach which involves generating, analysing, and integrating both qualitative and quantitative data to provide answers to research questions was adopted. It was an intervention study carried out in two senior secondary schools in the Ilorin metropolis of Kwara State, Nigeria. A sample of 53 senior secondary school year two learners participated. Questionnaires and journal entries were completed by the 53 learners, while seven learners were interviewed. Data were collected using both qualitative and quantitative data generating tools including pre-and post-tests. The stoichiometry learning questionnaire (SLQ), test of science related attitude (TOSRA) questionnaire, and stoichiometry achievement tool (SAT) were used to generate quantitative data while the SLQ, semi-structured interviews, and journal entries were the qualitative data tools. Data were generated in three phases. Phase one was baseline data through SLQ, TOSRA and SAT pre-tests. The second phase was the intervention phase where the POGIL approach was implemented in the classrooms and learners were engaged in journal entries. Post-intervention was the last phase where TOSRA and SAT post-tests were administered and semi-structured interviews were conducted with participants. Thus, data were analysed quantitatively and qualitatively. Before the POGIL intervention, the findings of this study revealed that most of the learners perceived stoichiometry as difficult because of the instructional characteristics, the nature of stoichiometry concepts, and learners’ attributes. After the POGIL intervention, however, learners showed increased proficiency in stoichiometry and attitudes towards science. Findings also indicate that learners’ proficiency in stoichiometry and attitude towards science were associated with the facilitators or learning environment features, the nature of instructional characteristics, learners’ perceptions of stoichiometry or science, and the extent to which learners could comprehend or master science concepts. Notably, these features are intertwined and cohere with the socio-cultural theory and POGIL principles. This study offered insights into how proficiency in stoichiometry and attitudes towards science may develop among senior secondary school learners in Nigeria. The findings point to POGIL as an example of an instructional approach that provides enabling characteristics and useful information for planning instructional activities for the development and nurturing of proficiency and attitudes towards science. The results suggest that the POGIL strategy could alleviate some of the factors perceived as contributors to difficulty in learning stoichiometry. As such, the study makes contributions to the field of science education in Nigeria particularly regarding how both the tenets of the socio-cultural framework (social interaction, cultural tools, self-regulation, and ZPD) and POGIL (guided-inquiry and collaborative learning) could be aligned to facilitate the development of proficiency and attitudes towards science. The study, therefore, recommends that POGIL should be used as an inquiry-based approach in science classrooms to promote the development of learners’ proficiency and attitudes towards science. The study could also be utilised as a resource to guide or set a base for further investigation into the implementation of POGIL in other areas of chemistry or science as well as creating professional development spaces that promote community of practice among science teachers as observed in this study.
- Full Text:
- Date Issued: 2021-04
- Authors: Agunbiade, Arinola Esther
- Date: 2021-04
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Nigeria , Chemistry -- Study and teaching (Secondary) -- Nigeria , Process-oriented guided inquiry learning , Student-centered learning -- Nigeria , Science students -- Attitudes
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174402 , vital:42474
- Description: Stoichiometry is one of the difficult topics in the senior secondary school chemistry curriculum. It is usually taught through the traditional lecture method of presentation that is non-engaging for learners. Consequently, there is poor understanding, achievement, and negative perceptions of stoichiometry and chemistry in general. The goal of this study was to explore learners’ evolving proficiency in stoichiometry and attitudes towards science as a result of their participation in Process Oriented Guided Inquiry Learning (POGIL) activities. That is, POGIL which incorporates guided-inquiry and collaborative learning was introduced as an intervention strategy in learning stoichiometry. This was assessed by examining learners’ experiences with learning stoichiometry before and after the POGIL intervention. The study further investigated possible contributing factors to learners’ evolving proficiency in stoichiometry and attitudes towards science. This study employed the socio-cultural learning theory as proposed by Vygotsky (1978). The role of socio-cultural features such as ‘social interaction’, ‘cultural tools’, ‘self-regulation’ and ‘zone of proximal development’ (ZPD) were explored with regards to learners’ stoichiometry proficiency and attitudes towards science progression as they participated in POGIL activities. The work of Kilpatrick, Swafford and Findell (2001) on proficiency and Fraser (1981) on attitudes towards science were used as analytical lenses to understand learners’ proficiency in stoichiometry and attitudes towards science, respectively. This study was underpinned by the pragmatic research paradigm. Thus, a Quant + Qual concurrent mixed-methods approach which involves generating, analysing, and integrating both qualitative and quantitative data to provide answers to research questions was adopted. It was an intervention study carried out in two senior secondary schools in the Ilorin metropolis of Kwara State, Nigeria. A sample of 53 senior secondary school year two learners participated. Questionnaires and journal entries were completed by the 53 learners, while seven learners were interviewed. Data were collected using both qualitative and quantitative data generating tools including pre-and post-tests. The stoichiometry learning questionnaire (SLQ), test of science related attitude (TOSRA) questionnaire, and stoichiometry achievement tool (SAT) were used to generate quantitative data while the SLQ, semi-structured interviews, and journal entries were the qualitative data tools. Data were generated in three phases. Phase one was baseline data through SLQ, TOSRA and SAT pre-tests. The second phase was the intervention phase where the POGIL approach was implemented in the classrooms and learners were engaged in journal entries. Post-intervention was the last phase where TOSRA and SAT post-tests were administered and semi-structured interviews were conducted with participants. Thus, data were analysed quantitatively and qualitatively. Before the POGIL intervention, the findings of this study revealed that most of the learners perceived stoichiometry as difficult because of the instructional characteristics, the nature of stoichiometry concepts, and learners’ attributes. After the POGIL intervention, however, learners showed increased proficiency in stoichiometry and attitudes towards science. Findings also indicate that learners’ proficiency in stoichiometry and attitude towards science were associated with the facilitators or learning environment features, the nature of instructional characteristics, learners’ perceptions of stoichiometry or science, and the extent to which learners could comprehend or master science concepts. Notably, these features are intertwined and cohere with the socio-cultural theory and POGIL principles. This study offered insights into how proficiency in stoichiometry and attitudes towards science may develop among senior secondary school learners in Nigeria. The findings point to POGIL as an example of an instructional approach that provides enabling characteristics and useful information for planning instructional activities for the development and nurturing of proficiency and attitudes towards science. The results suggest that the POGIL strategy could alleviate some of the factors perceived as contributors to difficulty in learning stoichiometry. As such, the study makes contributions to the field of science education in Nigeria particularly regarding how both the tenets of the socio-cultural framework (social interaction, cultural tools, self-regulation, and ZPD) and POGIL (guided-inquiry and collaborative learning) could be aligned to facilitate the development of proficiency and attitudes towards science. The study, therefore, recommends that POGIL should be used as an inquiry-based approach in science classrooms to promote the development of learners’ proficiency and attitudes towards science. The study could also be utilised as a resource to guide or set a base for further investigation into the implementation of POGIL in other areas of chemistry or science as well as creating professional development spaces that promote community of practice among science teachers as observed in this study.
- Full Text:
- Date Issued: 2021-04
Exploring Social Learning within the Context of Community-Based Farming : Implications for Farmers’ Agency and Capabilities
- Authors: Dirwai, Crispen
- Date: 2021-04
- Subjects: Crops and climate -- Zimbabwe -- Mutasa District , Livestock -- Climatic factors -- Zimbabwe -- Mutasa District , Social learning -- Zimbabwe -- Mutasa District , Community-supported agriculture -- Zimbabwe -- Mutasa District , Environmental education -- Zimbabwe -- Mutasa District , Climatic changes -- Social aspects -- Zimbabwe -- Mutasa District , Critical realism
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174526 , vital:42485 , https://doi.org/10.21504/10962/174526
- Description: This thesis, ‘Exploring social learning within the context of community-based farming: Implications for farmers’ agency and capabilities’, provided an opportunity to investigate how community-based farmers engaged a social learning process in adjusting their practices to the observed climate change and variability risks and vulnerabilities. The social learning and pedagogic trajectory towards climate change adaptation, involved a multi-sectoral approach in a community of practice that was inclusive of extension service, developmental agencies, a university, climate change activists, a primary school, a university, the agro-industrial community, the urban open market and the local standards association. Social learning, in this community of practice, took place during field days, field tours, focus groups and observations in a multi-case study approach. The main research question addressed in this thesis was ‘How can and does social learning facilitate or constrain the conversion of resources into functionings and new adaptation capabilities of communal farmers in Muchena village in the face of increasing climate change and associated climate variability related socio-ecological risks and vulnerabilities?’ In order to address this main research question and its corresponding sub-questions, two main categories of climate change adaptive agricultural practices, crop and non-crop, were studied in the context of social learning and collective and individual capabilities and agency. The research ontology and epistemology were grounded in critical realism, with the epistemic work in the multiple case study being drawing on a constructivist approach where eleven Farmers’ Case Stories [FCS] from crop and non-crop community-based farmers were purposively followed throughout this thesis journey, while the ontological dynamics were pursued through critical realist depth ontological enquiry. The theoretical framework for this thesis encompassed Bhaskar’s (1998; 2016) dialectical critical realist MELD schema, which underlabours conversion factors from Sen’s (1993; 2005) capabilities theory mobilised via the six sequential moments of the pedagogic practice of social learning as articulated by Wals (2007). This gave the theoretical framework a multi-dimensional facet. In this multi-dimensional theoretical framework, the ontologically influential generative mechanisms identified at 1M, were droughts, food insecurity, economic poverty, poor farming methods, floods, pests, socio-political stress, socio-cultural and intergenerational knowledge transfer, government policies and market forces. Effort was made to absent these ills at 2E, through knowledge co-creation within the communities of practice, through individual and collective reflexivity and was guided by the six sequential moments of Wals’ (2007) social learning pedagogic trajectory and by the three capabilities conversion factors; personal, environmental and social. At 3L’s totalities (laminated) and false totalities and compromises, the community-based farmers came to realise, appreciate and utilised the benefits of individual and collective agency as knowledge generation. In the theoretical framework, the social learning process was a product of collective and individual agency, a product of co-creation, co-sharing and co-monitoring and mentoring of each other’s work in a non-linear process towards transformation at 4D. The thesis identified the following capability sets and their corresponding functionings: education with the new achieved functionings of knowledge on market oriented economy with more functionings such as apiary, dendrology, aqua-culture and horticultural practices, partnerships including contract farming and company registration; health as a capability set had the new functionings of improved people’s and soil’s health from organic and conservation production practices; nutrition as a capability set with new functionings of organic and conservation farming as well as, through testing of products and soils to ascertain nutritional parameters, nutritional functionings. These identified capability sets as valued beings and doings all attempted to absent climate change induced droughts, food insecurity and economic poverty through the social learning process. The new achieved functionings of knowledge on related market oriented economy, were used for food security as farmers were able to buy maize, the staple food, which has been constrained by climate change induced droughts and pests. The new capability sets and achieved functionings in alternatives to maize crop farming could be viewed in this thesis as a positive emancipatory cyclic movement in the community-based farmers from non-being to agency [1M to 4D]. The thesis found that for the social learning process to be transformative, the community-based farmers had to reflect as individuals and collectively as a community from T1 [social learning layer 1] to T00 [social learning as multi-layered and infinite]. Learning starts from T1 by engaging the ontological and epistemological question ‘what?’ and the pedagogical question, ‘how?’, in order to understand existing ills and how best to absent them. Tensions existed as the community still take maize meal as their staple food and yet maize production is less resilient to droughts in the absence of water harvesting for irrigation. Despite realising the nutritional value of small grains, the research findings claimed that small grains were difficult to process into a mealie-meal and so, could not replace maize as a staple food. Theoretical contributions from this thesis entailed both epistemological and ontological implications as the community-based farmers started to question positivism as the only benchmark for organic standards by sending what they self-perceived as ‘organic’ products and soils, for verification from observed laboratory tests. This might have indicated a recognised shift in the epistemology of the poor community-based farmer, who are widely viewed in literature, as non-being and subsistence, towards an organised transformative market oriented practice. In this regard, transformative social learning catalysed by the thesis, contributed towards an organic practice characterised by absenting synthetic fertilisers and certain heavy elements from the soils and from the products, thereby adapting and mitigating to global climate change at a micro-scale. The study, though small scale, might be viewed as having global policy implications. For SGD:2 FCS 1, VS absented hunger by transforming from zero tonnage in 2012 to an estimated harvest of four tonnes in 2017. For SDG:3, FCS 3, LN produced close to a tonne of organic peas that passed through laboratory testing for nutritional parameters and testing against heavy metals during the 2018 and 2019 farming season. SDG: 1 could be assessed and reflected through improved livelihoods from income raised under market gardening as shown in FCS 3, LN; FCS, 4 SM2; FCS 5 SS and FCS 6 JM2. Also from SDG 1, were alternatives to maize crop farming and climate change adaptation market oriented apiary practiced by FCS 7, LM2 & FCS 8, LM3 and market oriented dendrology from FCS, 10, VC & FCS 11, JC. FCS 10, VC, managed to register a small company while FCS 11, JC managed to get contracts from reputable tobacco companies in the country and he also managed to access bank loans to purchase a small truck to absent the transport ills that constrained the youths who finally moved out of the achieved functioning of dendrology. FCS, 3, LN and the group of youths valued sending their products and soils for laboratory tests, an indicator of the quality of education that they attained through Social learning process’ communities of practice engagement. By supplying part of their products as raw materials to an agro-industry, the newly achieved functioning of market oriented agriculture from FCS 3, LN and FCS 4, SM2 could be viewed as a move towards SDG: 9. In terms of SDG: 12, the farming practices studied in this thesis were deemed environmentally friendly, green and so were adaptations to climate change which could be read along with SDG: 13. The thesis findings thus could be viewed as those that could open up some ways of assessing and providing practical implementation pathways for some of the sustainable development goals as well as providing a platform to interrogate other ways of understanding critical realism’s underlying generative mechanisms as enablers and constrainers to shaping social learning and people’s measurable functionings in the context of education for sustainable development and the global action programme (GAP) and its immanent successor, the ESD Agenda 2030 framework. The research is therefore well poised to inform this agenda. The study concludes that in order to enhance community-based farmers’ social learning and agency towards climate change adaptation, extension service, the standards association institution, agro-industry, the university as well as the media, might need to engage pro-actively with the farmers’ capabilities and agency. The thesis also attempted to inform the university institution’s community engagement, thereby giving practical meaning to the whole institution approaches to ESD as promoted in the UNESCO ESD Global Action Programme, and the emerging ESD 2030 Agenda. The thesis therefore has potential to inform pedagogic practices at the formal, non-formal and the informal learning sectors. The thesis concludes that the social learning process, when coupled with critical realism and the capabilities theories, could facilitate the conversion of resources into new adaptive functionings. The social learning process is transformative, reflexive and recursive, but might have to start from 1M to 4D and from T1 to T00. Moreover, the thesis concludes that poverty remained one of the major disablers of the farmers’ capabilities and agency in this thesis. , Thesis (PhD)--Rhodes University, Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Dirwai, Crispen
- Date: 2021-04
- Subjects: Crops and climate -- Zimbabwe -- Mutasa District , Livestock -- Climatic factors -- Zimbabwe -- Mutasa District , Social learning -- Zimbabwe -- Mutasa District , Community-supported agriculture -- Zimbabwe -- Mutasa District , Environmental education -- Zimbabwe -- Mutasa District , Climatic changes -- Social aspects -- Zimbabwe -- Mutasa District , Critical realism
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174526 , vital:42485 , https://doi.org/10.21504/10962/174526
- Description: This thesis, ‘Exploring social learning within the context of community-based farming: Implications for farmers’ agency and capabilities’, provided an opportunity to investigate how community-based farmers engaged a social learning process in adjusting their practices to the observed climate change and variability risks and vulnerabilities. The social learning and pedagogic trajectory towards climate change adaptation, involved a multi-sectoral approach in a community of practice that was inclusive of extension service, developmental agencies, a university, climate change activists, a primary school, a university, the agro-industrial community, the urban open market and the local standards association. Social learning, in this community of practice, took place during field days, field tours, focus groups and observations in a multi-case study approach. The main research question addressed in this thesis was ‘How can and does social learning facilitate or constrain the conversion of resources into functionings and new adaptation capabilities of communal farmers in Muchena village in the face of increasing climate change and associated climate variability related socio-ecological risks and vulnerabilities?’ In order to address this main research question and its corresponding sub-questions, two main categories of climate change adaptive agricultural practices, crop and non-crop, were studied in the context of social learning and collective and individual capabilities and agency. The research ontology and epistemology were grounded in critical realism, with the epistemic work in the multiple case study being drawing on a constructivist approach where eleven Farmers’ Case Stories [FCS] from crop and non-crop community-based farmers were purposively followed throughout this thesis journey, while the ontological dynamics were pursued through critical realist depth ontological enquiry. The theoretical framework for this thesis encompassed Bhaskar’s (1998; 2016) dialectical critical realist MELD schema, which underlabours conversion factors from Sen’s (1993; 2005) capabilities theory mobilised via the six sequential moments of the pedagogic practice of social learning as articulated by Wals (2007). This gave the theoretical framework a multi-dimensional facet. In this multi-dimensional theoretical framework, the ontologically influential generative mechanisms identified at 1M, were droughts, food insecurity, economic poverty, poor farming methods, floods, pests, socio-political stress, socio-cultural and intergenerational knowledge transfer, government policies and market forces. Effort was made to absent these ills at 2E, through knowledge co-creation within the communities of practice, through individual and collective reflexivity and was guided by the six sequential moments of Wals’ (2007) social learning pedagogic trajectory and by the three capabilities conversion factors; personal, environmental and social. At 3L’s totalities (laminated) and false totalities and compromises, the community-based farmers came to realise, appreciate and utilised the benefits of individual and collective agency as knowledge generation. In the theoretical framework, the social learning process was a product of collective and individual agency, a product of co-creation, co-sharing and co-monitoring and mentoring of each other’s work in a non-linear process towards transformation at 4D. The thesis identified the following capability sets and their corresponding functionings: education with the new achieved functionings of knowledge on market oriented economy with more functionings such as apiary, dendrology, aqua-culture and horticultural practices, partnerships including contract farming and company registration; health as a capability set had the new functionings of improved people’s and soil’s health from organic and conservation production practices; nutrition as a capability set with new functionings of organic and conservation farming as well as, through testing of products and soils to ascertain nutritional parameters, nutritional functionings. These identified capability sets as valued beings and doings all attempted to absent climate change induced droughts, food insecurity and economic poverty through the social learning process. The new achieved functionings of knowledge on related market oriented economy, were used for food security as farmers were able to buy maize, the staple food, which has been constrained by climate change induced droughts and pests. The new capability sets and achieved functionings in alternatives to maize crop farming could be viewed in this thesis as a positive emancipatory cyclic movement in the community-based farmers from non-being to agency [1M to 4D]. The thesis found that for the social learning process to be transformative, the community-based farmers had to reflect as individuals and collectively as a community from T1 [social learning layer 1] to T00 [social learning as multi-layered and infinite]. Learning starts from T1 by engaging the ontological and epistemological question ‘what?’ and the pedagogical question, ‘how?’, in order to understand existing ills and how best to absent them. Tensions existed as the community still take maize meal as their staple food and yet maize production is less resilient to droughts in the absence of water harvesting for irrigation. Despite realising the nutritional value of small grains, the research findings claimed that small grains were difficult to process into a mealie-meal and so, could not replace maize as a staple food. Theoretical contributions from this thesis entailed both epistemological and ontological implications as the community-based farmers started to question positivism as the only benchmark for organic standards by sending what they self-perceived as ‘organic’ products and soils, for verification from observed laboratory tests. This might have indicated a recognised shift in the epistemology of the poor community-based farmer, who are widely viewed in literature, as non-being and subsistence, towards an organised transformative market oriented practice. In this regard, transformative social learning catalysed by the thesis, contributed towards an organic practice characterised by absenting synthetic fertilisers and certain heavy elements from the soils and from the products, thereby adapting and mitigating to global climate change at a micro-scale. The study, though small scale, might be viewed as having global policy implications. For SGD:2 FCS 1, VS absented hunger by transforming from zero tonnage in 2012 to an estimated harvest of four tonnes in 2017. For SDG:3, FCS 3, LN produced close to a tonne of organic peas that passed through laboratory testing for nutritional parameters and testing against heavy metals during the 2018 and 2019 farming season. SDG: 1 could be assessed and reflected through improved livelihoods from income raised under market gardening as shown in FCS 3, LN; FCS, 4 SM2; FCS 5 SS and FCS 6 JM2. Also from SDG 1, were alternatives to maize crop farming and climate change adaptation market oriented apiary practiced by FCS 7, LM2 & FCS 8, LM3 and market oriented dendrology from FCS, 10, VC & FCS 11, JC. FCS 10, VC, managed to register a small company while FCS 11, JC managed to get contracts from reputable tobacco companies in the country and he also managed to access bank loans to purchase a small truck to absent the transport ills that constrained the youths who finally moved out of the achieved functioning of dendrology. FCS, 3, LN and the group of youths valued sending their products and soils for laboratory tests, an indicator of the quality of education that they attained through Social learning process’ communities of practice engagement. By supplying part of their products as raw materials to an agro-industry, the newly achieved functioning of market oriented agriculture from FCS 3, LN and FCS 4, SM2 could be viewed as a move towards SDG: 9. In terms of SDG: 12, the farming practices studied in this thesis were deemed environmentally friendly, green and so were adaptations to climate change which could be read along with SDG: 13. The thesis findings thus could be viewed as those that could open up some ways of assessing and providing practical implementation pathways for some of the sustainable development goals as well as providing a platform to interrogate other ways of understanding critical realism’s underlying generative mechanisms as enablers and constrainers to shaping social learning and people’s measurable functionings in the context of education for sustainable development and the global action programme (GAP) and its immanent successor, the ESD Agenda 2030 framework. The research is therefore well poised to inform this agenda. The study concludes that in order to enhance community-based farmers’ social learning and agency towards climate change adaptation, extension service, the standards association institution, agro-industry, the university as well as the media, might need to engage pro-actively with the farmers’ capabilities and agency. The thesis also attempted to inform the university institution’s community engagement, thereby giving practical meaning to the whole institution approaches to ESD as promoted in the UNESCO ESD Global Action Programme, and the emerging ESD 2030 Agenda. The thesis therefore has potential to inform pedagogic practices at the formal, non-formal and the informal learning sectors. The thesis concludes that the social learning process, when coupled with critical realism and the capabilities theories, could facilitate the conversion of resources into new adaptive functionings. The social learning process is transformative, reflexive and recursive, but might have to start from 1M to 4D and from T1 to T00. Moreover, the thesis concludes that poverty remained one of the major disablers of the farmers’ capabilities and agency in this thesis. , Thesis (PhD)--Rhodes University, Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
Exploring teaching and learning German as a foreign language at a South African institution of higher education: blended learning and collocations
- Authors: Ortner, Gwyndolen Jeanie
- Date: 2020
- Subjects: German language -- Study and teaching (Higher) -- South Africa , German language -- Study and teaching (Higher) -- Foreign speakers -- South Africa , German language -- Study and teaching (Higher) -- English speakers -- South Africa , Rhodes University -- Students , Rhodes University. German Studies
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167295 , vital:41465
- Description: German Studies students at Rhodes University have normally never studied the German language before enrolling for the first-year course and face the challenge of a fairly rapid linguistic advancement, in a context with very limited exposure to the foreign language outside the classroom. Free writing is an area which students find particularly challenging as it requires students to syndissertatione grammatical and vocabulary knowledge. Furthermore, South African students are often underprepared for the challenges they face at university regarding language, technology and finance, as they try to to assimilate to the academic environment and gain epistemological access to their various subjects, in this case, language acquisition and the attendant modules of translation, literature and cultural studies. The use of technology in teaching and learning, known as blended learning, is said to produce better results than face-to face teaching alone, through creating opportunities for more autonomous student learning. Scholars of instructed second-language acquisition also suggest using technology to improve language instruction. One particular area which is gaining ground is teaching students collocational structures through exploring large language corpora, to improve students’ language competencies such as writing fluency. However, both blended learning practices and corpus-based teaching practices suggested by scholars are often not reported on in a particular teaching and learning context, taking into account factors such as institutional infrastructure, student and staff backgrounds and preparedness, and larger socio-political factors. Thus, it remains unclear how these practices (blended learning and corpus-based teaching of collocations) may be integrated into standard urricula, particularly for languages other than English, which have been severely under-researched. The purpose of this research is to take a context-based approach to language teaching and thereby investigate current blended learning practices for German Studies at Rhodes University in South Africa and explore through an action research approach how to integrate collocational awareness into the curriculum, within the blended learning model. Insights from corpus linguistics guide an adaptation of teaching practice, helping students develop skills to aid with writing fluency, seeking to make the patterned nature of language salient to our students. This is undertaken in a scaffolded way, within the curriculum, making use firstly of the texts to which students are exposed in the textbook (comprehensible input) as a source of collocational examples, and following this by making use of reallife language data from an online German corpus, DWDS. Findings from the study reveal a number of best practices related to the use of blended learning and teaching collocations in context of the German foreign language curriculum at a South African institution of higher education.
- Full Text:
- Date Issued: 2020
- Authors: Ortner, Gwyndolen Jeanie
- Date: 2020
- Subjects: German language -- Study and teaching (Higher) -- South Africa , German language -- Study and teaching (Higher) -- Foreign speakers -- South Africa , German language -- Study and teaching (Higher) -- English speakers -- South Africa , Rhodes University -- Students , Rhodes University. German Studies
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167295 , vital:41465
- Description: German Studies students at Rhodes University have normally never studied the German language before enrolling for the first-year course and face the challenge of a fairly rapid linguistic advancement, in a context with very limited exposure to the foreign language outside the classroom. Free writing is an area which students find particularly challenging as it requires students to syndissertatione grammatical and vocabulary knowledge. Furthermore, South African students are often underprepared for the challenges they face at university regarding language, technology and finance, as they try to to assimilate to the academic environment and gain epistemological access to their various subjects, in this case, language acquisition and the attendant modules of translation, literature and cultural studies. The use of technology in teaching and learning, known as blended learning, is said to produce better results than face-to face teaching alone, through creating opportunities for more autonomous student learning. Scholars of instructed second-language acquisition also suggest using technology to improve language instruction. One particular area which is gaining ground is teaching students collocational structures through exploring large language corpora, to improve students’ language competencies such as writing fluency. However, both blended learning practices and corpus-based teaching practices suggested by scholars are often not reported on in a particular teaching and learning context, taking into account factors such as institutional infrastructure, student and staff backgrounds and preparedness, and larger socio-political factors. Thus, it remains unclear how these practices (blended learning and corpus-based teaching of collocations) may be integrated into standard urricula, particularly for languages other than English, which have been severely under-researched. The purpose of this research is to take a context-based approach to language teaching and thereby investigate current blended learning practices for German Studies at Rhodes University in South Africa and explore through an action research approach how to integrate collocational awareness into the curriculum, within the blended learning model. Insights from corpus linguistics guide an adaptation of teaching practice, helping students develop skills to aid with writing fluency, seeking to make the patterned nature of language salient to our students. This is undertaken in a scaffolded way, within the curriculum, making use firstly of the texts to which students are exposed in the textbook (comprehensible input) as a source of collocational examples, and following this by making use of reallife language data from an online German corpus, DWDS. Findings from the study reveal a number of best practices related to the use of blended learning and teaching collocations in context of the German foreign language curriculum at a South African institution of higher education.
- Full Text:
- Date Issued: 2020
Factors that shape learner achievement in socially disadvantaged and rural contexts: a social realist study in two rural senior secondary schools in Omusati region, Namibia
- Authors: Shilongo, Erica
- Date: 2018
- Subjects: Academic achievement Namibia Omusati , High school students Namibia Omusati Social conditions , Rural schools Namibia Omusati , Education, Rural Namibia Omusati , Social realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62240 , vital:28146
- Description: Learners’ performance and the reasons for either achievement or failure in school has lo ng been a topic of debate. In early research on academic achievement, theorists, educators, biologists and psychologists traditionally focused on the learners from socially disadvantaged family backgrounds who underachieve. Much of the debate internationally centred on whether learner academic achievement / underachievement is a product of hereditary traits or the social context. In particular, arguments for and against whether the reasons for the achievement / underachievement of children from socially disadvantaged families are genetic or the social context in which they find themselves continue unabated. Such explanations do not provide insight into why it is that despite familial (genetic) and social circumstances (social disadvantage), some children succeed and/or are able to act outside expectations of failure. Little research has focused on those in the same or similar contexts who are achieving academic success despite their limiting circumstances and the reasons for their success. This study used a social realist lens to investigate the factors that shape the academic achievement of 12 learners in two rural senior secondary schools in Omusati region, Namibia. All 12 learners are from low socioeconomic family backgrounds. The data was collected through survey, interviews with learners, parents and teachers, field notes and document analysis. The main finding of the study show that contrary to research that portrayed learners’ achievement as determined either by heredity or social contexts, the 12 learners constantly used their agentic possibilities to navigate constraining structural and cultural conditions at regional, familial and school levels to achieve academic success. Their agency was shaped by the socioeconomic conditions in their lives, namely, socioeconomic deprivation; large extended families in rural households, lack of amenities and utilities in their families, participation in household chores, experience of family tragedies and of changes when they were young.
- Full Text:
- Date Issued: 2018
- Authors: Shilongo, Erica
- Date: 2018
- Subjects: Academic achievement Namibia Omusati , High school students Namibia Omusati Social conditions , Rural schools Namibia Omusati , Education, Rural Namibia Omusati , Social realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62240 , vital:28146
- Description: Learners’ performance and the reasons for either achievement or failure in school has lo ng been a topic of debate. In early research on academic achievement, theorists, educators, biologists and psychologists traditionally focused on the learners from socially disadvantaged family backgrounds who underachieve. Much of the debate internationally centred on whether learner academic achievement / underachievement is a product of hereditary traits or the social context. In particular, arguments for and against whether the reasons for the achievement / underachievement of children from socially disadvantaged families are genetic or the social context in which they find themselves continue unabated. Such explanations do not provide insight into why it is that despite familial (genetic) and social circumstances (social disadvantage), some children succeed and/or are able to act outside expectations of failure. Little research has focused on those in the same or similar contexts who are achieving academic success despite their limiting circumstances and the reasons for their success. This study used a social realist lens to investigate the factors that shape the academic achievement of 12 learners in two rural senior secondary schools in Omusati region, Namibia. All 12 learners are from low socioeconomic family backgrounds. The data was collected through survey, interviews with learners, parents and teachers, field notes and document analysis. The main finding of the study show that contrary to research that portrayed learners’ achievement as determined either by heredity or social contexts, the 12 learners constantly used their agentic possibilities to navigate constraining structural and cultural conditions at regional, familial and school levels to achieve academic success. Their agency was shaped by the socioeconomic conditions in their lives, namely, socioeconomic deprivation; large extended families in rural households, lack of amenities and utilities in their families, participation in household chores, experience of family tragedies and of changes when they were young.
- Full Text:
- Date Issued: 2018
Former farm workers of foreign descent in communal areas in post-fast track Zimbabwe : the case of Shamva District
- Authors: Chadambuka, Patience
- Date: 2021-10-29
- Subjects: Migrant agricultural laborers -- Zimbabwe -- Shamva District , Agricultural laborers, Foreign -- Zimbabwe -- Shamva District , Land reform -- Zimbabwe , Belonging (Social psychology) -- Zimbabwe -- Shamva District , Social integration-- Zimbabwe -- Shamva District , Fast Track Land Reform Programme (FTLRP)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178420 , vital:42938 , 10.21504/10962/178420
- Description: Land and ethnicity continue to condition contestations in relation to belonging amongst rural Zimbabweans. The colonial era defined Zimbabwe’s land politics in a highly racialised and ethnicised manner. Racially, the colonial era gave birth to white-owned fertile farm lands, while blacks (or Africans) were resettled in agriculturally-unproductive Reserves, later referred to as communal areas in the post-colonial era. Though they were initially created with a segregatory and oppressive intent bent on disenfranchising native Africans, the Reserves became a definitive landscape embedded in ethnic and ancestral belonging for the autochthonous Natives. The Reserves were created exclusively for autochthonous Africans, and the colonial administration ensured that foreign migrant Africans recruited mainly as covenanted labour from nearby colonies would not be accommodated and consequently belong in Reserves. Migrant Africans were instead domiciled in white commercial farms, mines and urban areas, and deprived of land rights accorded to the autochthones. In the case of white farms specifically, the labourers experienced a conditional belonging (to the farm). This overall exclusionary system was later inherited and maintained by the post-colonial Zimbabwean government, up until the year 2000. Zimbabwe’s highly documented Fast Track Land Reform Programme (FTLRP) from the year 2000 did away with the entrenched racial bifurcations of land, as white commercial farms became fast track farms. However, it did not undercut the existence of communal areas. The FTLRP had a profound effect on the lives of commercial farm workers, particularly those of foreign origin who had no other home or source of livelihood to fall back on after fast track displacements. Some though sought to move into communal areas, from which they had been excluded previously. Within this context, most scholarly studies of the post fast track period ignore the plight of former farm workers especially those that moved to, and into, communal areas. This ethnographic study, specifically of former farm workers of foreign origin in Shamva communal areas, therefore seeks to contribute to Zimbabwean studies in this regard. It documents and examines the perceptions, practices and lived experiences of former farm workers of foreign origin now residing in the Bushu communal areas of Shamva, and how they interface with Bushu autochthones in seeking to belong to Bushu. This is pursued by way of qualitative research methods (including lengthy stays in the study sites) as well as through the use of a theoretical framing focusing on lifeworlds, interfaces, belonging, othering and strangerhood. Key findings reveal that belonging by the former farm workers in Bushu entails a non-linear and convoluted process characterised by a series of contestations around for instance land shortages, limited livelihood strategies and cultural difference. This project of belonging does not entail assimilation on the part of the former farm workers, as they continue to uphold certain historical practices, leading to a form of co-existence between the autochthones and allochthones in Bushu. In this way, the former farm workers seem to develop a conditional belonging in (and to) Bushu, albeit different than the one experienced on white farms in the past. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Chadambuka, Patience
- Date: 2021-10-29
- Subjects: Migrant agricultural laborers -- Zimbabwe -- Shamva District , Agricultural laborers, Foreign -- Zimbabwe -- Shamva District , Land reform -- Zimbabwe , Belonging (Social psychology) -- Zimbabwe -- Shamva District , Social integration-- Zimbabwe -- Shamva District , Fast Track Land Reform Programme (FTLRP)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178420 , vital:42938 , 10.21504/10962/178420
- Description: Land and ethnicity continue to condition contestations in relation to belonging amongst rural Zimbabweans. The colonial era defined Zimbabwe’s land politics in a highly racialised and ethnicised manner. Racially, the colonial era gave birth to white-owned fertile farm lands, while blacks (or Africans) were resettled in agriculturally-unproductive Reserves, later referred to as communal areas in the post-colonial era. Though they were initially created with a segregatory and oppressive intent bent on disenfranchising native Africans, the Reserves became a definitive landscape embedded in ethnic and ancestral belonging for the autochthonous Natives. The Reserves were created exclusively for autochthonous Africans, and the colonial administration ensured that foreign migrant Africans recruited mainly as covenanted labour from nearby colonies would not be accommodated and consequently belong in Reserves. Migrant Africans were instead domiciled in white commercial farms, mines and urban areas, and deprived of land rights accorded to the autochthones. In the case of white farms specifically, the labourers experienced a conditional belonging (to the farm). This overall exclusionary system was later inherited and maintained by the post-colonial Zimbabwean government, up until the year 2000. Zimbabwe’s highly documented Fast Track Land Reform Programme (FTLRP) from the year 2000 did away with the entrenched racial bifurcations of land, as white commercial farms became fast track farms. However, it did not undercut the existence of communal areas. The FTLRP had a profound effect on the lives of commercial farm workers, particularly those of foreign origin who had no other home or source of livelihood to fall back on after fast track displacements. Some though sought to move into communal areas, from which they had been excluded previously. Within this context, most scholarly studies of the post fast track period ignore the plight of former farm workers especially those that moved to, and into, communal areas. This ethnographic study, specifically of former farm workers of foreign origin in Shamva communal areas, therefore seeks to contribute to Zimbabwean studies in this regard. It documents and examines the perceptions, practices and lived experiences of former farm workers of foreign origin now residing in the Bushu communal areas of Shamva, and how they interface with Bushu autochthones in seeking to belong to Bushu. This is pursued by way of qualitative research methods (including lengthy stays in the study sites) as well as through the use of a theoretical framing focusing on lifeworlds, interfaces, belonging, othering and strangerhood. Key findings reveal that belonging by the former farm workers in Bushu entails a non-linear and convoluted process characterised by a series of contestations around for instance land shortages, limited livelihood strategies and cultural difference. This project of belonging does not entail assimilation on the part of the former farm workers, as they continue to uphold certain historical practices, leading to a form of co-existence between the autochthones and allochthones in Bushu. In this way, the former farm workers seem to develop a conditional belonging in (and to) Bushu, albeit different than the one experienced on white farms in the past. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
Formulation and characterisation of a combination captopril and hydrochlorothiazide microparticulate dosage form for paediatric use
- Chikukwa, Mellisa Tafadzwa Ruramai
- Authors: Chikukwa, Mellisa Tafadzwa Ruramai
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163216 , vital:41019 , doi:10.21504/10962/163216
- Description: Thesis (PhD)--Rhodes University, Pharmacy Faculty, Department of Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
- Authors: Chikukwa, Mellisa Tafadzwa Ruramai
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163216 , vital:41019 , doi:10.21504/10962/163216
- Description: Thesis (PhD)--Rhodes University, Pharmacy Faculty, Department of Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
Formulation development, manufacture and evaluation of a lamivudine-zidovudine nano co-crystal thermo-responsive suspension
- Authors: Witika, Bwalya Angel
- Date: 2020
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140546 , vital:37897 , http://dx.doi.org/10.21504/10962/140546
- Description: Expected release date-April 2021
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya Angel
- Date: 2020
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140546 , vital:37897 , http://dx.doi.org/10.21504/10962/140546
- Description: Expected release date-April 2021
- Full Text:
- Date Issued: 2020
Formulation, development and assessment of devil’s claw loaded phyto-elastosomes in thermo-responsive hydrogels
- Authors: Ntemi, Pascal Vitalis
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164568 , vital:41139 , doi:10.21504/10962/164568
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
- Authors: Ntemi, Pascal Vitalis
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164568 , vital:41139 , doi:10.21504/10962/164568
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
From ‘cleanliness is next to Godliness’ to ‘without perfect health, there is nothing’: discourses of healthy lifestyle in the construction of young adult identities in urban South Africa
- Authors: De Jong, Michelle
- Date: 2019
- Subjects: Health , Cleanliness , Social structure -- Health aspects , Health behavior , Social medicine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64940 , vital:28638
- Description: This research explores popular constructions of “healthiness” as individual lifestyle choices in the context of contemporary South African consumer culture, and how these constructions relate to formations of subjectivity. This is a qualitative study conducted within a social constructionist, theoretical framework. Data was collected using in-depth, semi structured interviews and are analysed using a Foucauldian inspired version of discourse analysis. A critical stance is taken towards the assumption in these discourses that their version of healthiness is always and unquestionably positive. Special attention is paid to the lifestyle and marketing media discourses appropriated in understandings of personal health through self-management, and of the optimization of health in the pursuit of well-being. The ways in which different discourses of healthiness facilitate the construction of specific identities are considered in order to untangle some of the problems created by the moralism underpinning popular consumer health discourse. How constructions of healthiness and aspirant healthy lifestyles support, and are supported by, the ideologies and practices of neoliberal capitalism are also explored. From this perspective, healthiness as lifestyle consumption choices can be seen as an ideological apparatus that produces the subjects necessary to reproduce the social order (Althusser, 2001), functioning not only positively amongst the social classes with the leisure and economic resources to pursue these options, but also negatively as victim-blaming of those who are excluded. The argument here is not that health is bad or that people should not be bothered with activities aimed at promoting good health, but that in a context where the concept of health is idealised as always positive and beneficial, the potentially harmful consequences of some of the health discourses we make use of may be occluded. This idealisation of health or ‘healthism’ may also function to divert attention away from some of the challenges to health that are not the direct result of personal behaviours and are unlikely to be remedied through individually focussed interventions, for example, inequality and inadequate access to basic resources. Six discourses which were used to construct understandings of health are analysed. These include Happiness, Freedom, Control, Care, Balance and Goodness. The ways in which these discourses played a role in constructing the kinds of subject positions which were made available to participants, and the possible implications this has, are explored in depth.
- Full Text:
- Date Issued: 2019
- Authors: De Jong, Michelle
- Date: 2019
- Subjects: Health , Cleanliness , Social structure -- Health aspects , Health behavior , Social medicine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64940 , vital:28638
- Description: This research explores popular constructions of “healthiness” as individual lifestyle choices in the context of contemporary South African consumer culture, and how these constructions relate to formations of subjectivity. This is a qualitative study conducted within a social constructionist, theoretical framework. Data was collected using in-depth, semi structured interviews and are analysed using a Foucauldian inspired version of discourse analysis. A critical stance is taken towards the assumption in these discourses that their version of healthiness is always and unquestionably positive. Special attention is paid to the lifestyle and marketing media discourses appropriated in understandings of personal health through self-management, and of the optimization of health in the pursuit of well-being. The ways in which different discourses of healthiness facilitate the construction of specific identities are considered in order to untangle some of the problems created by the moralism underpinning popular consumer health discourse. How constructions of healthiness and aspirant healthy lifestyles support, and are supported by, the ideologies and practices of neoliberal capitalism are also explored. From this perspective, healthiness as lifestyle consumption choices can be seen as an ideological apparatus that produces the subjects necessary to reproduce the social order (Althusser, 2001), functioning not only positively amongst the social classes with the leisure and economic resources to pursue these options, but also negatively as victim-blaming of those who are excluded. The argument here is not that health is bad or that people should not be bothered with activities aimed at promoting good health, but that in a context where the concept of health is idealised as always positive and beneficial, the potentially harmful consequences of some of the health discourses we make use of may be occluded. This idealisation of health or ‘healthism’ may also function to divert attention away from some of the challenges to health that are not the direct result of personal behaviours and are unlikely to be remedied through individually focussed interventions, for example, inequality and inadequate access to basic resources. Six discourses which were used to construct understandings of health are analysed. These include Happiness, Freedom, Control, Care, Balance and Goodness. The ways in which these discourses played a role in constructing the kinds of subject positions which were made available to participants, and the possible implications this has, are explored in depth.
- Full Text:
- Date Issued: 2019
Genetic characterisation of a range of geographically distinct Helicoverpa armigera nucleopolyhedrovirus (HearNPV) isolates and evaluation of biological activity against South African populations of the African bollworm, Helicoverpa armigera (Hu bner) (Lepidoptera: Noctuidae)
- Mtambanengwe, Kudzai Tapiwanashe Esau
- Authors: Mtambanengwe, Kudzai Tapiwanashe Esau
- Date: 2019
- Subjects: Helicoverpa armigera -- Biological control -- South Africa , Baculoviruses -- Genetics , Agricultural pests -- Biological control -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/97334 , vital:31426
- Description: The African bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a pest of economic and agricultural importance globally. It is a polyphagous pest that feeds on a wide range of host plants including economically important crops. The impact it has on agricultural systems makes its control a priority. The most common method of control is using chemical pesticides; however, continuous application of the pesticides has resulted in the development of resistance. The use of biological control has been investigated and established as an effective method of control as a standalone or part of an integrated pest management (IPM) system. The use of the baculovirus Helicoverpa armigera nucleopolyhedrovirus (HearNPV), has shown promise in the control of H. armigera. Commercial formulations based on the virus are available in many global markets. However, the identification of novel HearNPV isolates will aid in the control of H. armigera as well as provide alternative isolates that may have better virulence. Three new HearNPV isolates were purified and identified from three distinct geographical South African locations H. armigera cadavers and named HearNPV-Albany, HearNPV-KZN and HearNPV-Haygrove. The genomes of two of the HearNPV isolates, namely HearNPV-Albany and HearNPV-KZN were genetically characterised and compared to other geographically distinct HearNPV isolates. Virulence studies were performed comparing the new HearNPV isolates against established commercial HearNPV formulations, Helicovir™ and Helicovex® and other geographically distinct isolated HearNPV, HearNPV-G4 and HearNPV-SP1. Two laboratory colonies were established using H. armigera collected from South African fields in the Belmont Valley near Grahamstown labelled as Albany colony and a colony provided from Haygrove Eden farm near George labelled as Haygrove colony. Biological studies were carried out using the Albany H. armigera colony comparing the rate of development, survival and fertility on bell green peppers, cabbage leaves and on artificial diet. From the biological studies, it was recorded that development and survivorship was best on artificial diet. Regular quality control was required for the maintenance of the colony and continuous generations of healthy larvae were eventually established. Diseased cadavers with signs of baculovirus infection were collected after bioprospecting from the Kwa-Zulu Natal Province in South Africa and were labelled KZN isolate; Belmont Valley near Grahamstown and were labelled Albany isolate; and Haygrove Eden farm near George and were labelled Haygrove isolate for the study. A fourth isolate made up of a crude extract of occlusion bodies (OBs) first described by Whitlock was also analysed and labelled Whitlock isolate. Occlusion bodies were extracted, purified and morphologically identified from the KZN, Albany, Haygrove and Whitlock isolates using TEM. Genomic DNA, which was extracted from the purified OBs. Using PCR, the identity of the OBs as HearNPV was confirmed. Genomic analyses were performed on HearNPV-Albany and HearNPV-KZN through genetic characterisation and comparison with other geographically distinct HearNPV genomes to confirm novelty and establish potential genetic relationships between the isolates through evolutionary distances. Full genomic sequencing of the isolated HearNPV and comparison with other geographically distinct HearNPV isolates identified genomic differences that showed that the HearNPV isolates were novel. HearNPV-Albany and HearNPV-KZN were successfully sequenced and identified as novel isolates with unique fragment patterns and unique gene sequences through deletions or insertions when compared to other geographically distinct HearNPV. This raised the potential for differences in biological activity against H. armigera larvae when tested through biological assays. HearNPV-Whit genome assembly had low quality data which resulted in many gaps and failed assembly. The biological activity of HearNPV isolates from Spain, China, South Africa and two commercial formulations were studied against the laboratory established H. armigera South African colony. The LC50 values of the different South African HearNPV isolates were established to be between 7.7 × 101 OBs.ml-1 for the most effective and 3.2 × 102 OBs.ml-1 for the least effective. The Spanish and Chinese HearNPV isolates resulted in LC50 values of 2.0 × 102 OBs.ml-1 and 1.2 × 101 OBs.ml-1 respectively. The commercial formulations resulted in the least virulence observed with an LC50 of 5.84× 102 OBs.ml-1 and 9.0 × 102 OBs.ml-1 for Helicovex® and Helicovir™ respectively. In this study, novel South African HearNPV isolates were isolated and identified. Through characterisation and bioassays against South African H. armigera populations the HearNPV isolates were shown to have different virulence in comparison to geographically distinct isolates. From this research, there is potential for development of new H. armigera biopesticides based on the novel isolates after field trial testing.
- Full Text:
- Date Issued: 2019
- Authors: Mtambanengwe, Kudzai Tapiwanashe Esau
- Date: 2019
- Subjects: Helicoverpa armigera -- Biological control -- South Africa , Baculoviruses -- Genetics , Agricultural pests -- Biological control -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/97334 , vital:31426
- Description: The African bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a pest of economic and agricultural importance globally. It is a polyphagous pest that feeds on a wide range of host plants including economically important crops. The impact it has on agricultural systems makes its control a priority. The most common method of control is using chemical pesticides; however, continuous application of the pesticides has resulted in the development of resistance. The use of biological control has been investigated and established as an effective method of control as a standalone or part of an integrated pest management (IPM) system. The use of the baculovirus Helicoverpa armigera nucleopolyhedrovirus (HearNPV), has shown promise in the control of H. armigera. Commercial formulations based on the virus are available in many global markets. However, the identification of novel HearNPV isolates will aid in the control of H. armigera as well as provide alternative isolates that may have better virulence. Three new HearNPV isolates were purified and identified from three distinct geographical South African locations H. armigera cadavers and named HearNPV-Albany, HearNPV-KZN and HearNPV-Haygrove. The genomes of two of the HearNPV isolates, namely HearNPV-Albany and HearNPV-KZN were genetically characterised and compared to other geographically distinct HearNPV isolates. Virulence studies were performed comparing the new HearNPV isolates against established commercial HearNPV formulations, Helicovir™ and Helicovex® and other geographically distinct isolated HearNPV, HearNPV-G4 and HearNPV-SP1. Two laboratory colonies were established using H. armigera collected from South African fields in the Belmont Valley near Grahamstown labelled as Albany colony and a colony provided from Haygrove Eden farm near George labelled as Haygrove colony. Biological studies were carried out using the Albany H. armigera colony comparing the rate of development, survival and fertility on bell green peppers, cabbage leaves and on artificial diet. From the biological studies, it was recorded that development and survivorship was best on artificial diet. Regular quality control was required for the maintenance of the colony and continuous generations of healthy larvae were eventually established. Diseased cadavers with signs of baculovirus infection were collected after bioprospecting from the Kwa-Zulu Natal Province in South Africa and were labelled KZN isolate; Belmont Valley near Grahamstown and were labelled Albany isolate; and Haygrove Eden farm near George and were labelled Haygrove isolate for the study. A fourth isolate made up of a crude extract of occlusion bodies (OBs) first described by Whitlock was also analysed and labelled Whitlock isolate. Occlusion bodies were extracted, purified and morphologically identified from the KZN, Albany, Haygrove and Whitlock isolates using TEM. Genomic DNA, which was extracted from the purified OBs. Using PCR, the identity of the OBs as HearNPV was confirmed. Genomic analyses were performed on HearNPV-Albany and HearNPV-KZN through genetic characterisation and comparison with other geographically distinct HearNPV genomes to confirm novelty and establish potential genetic relationships between the isolates through evolutionary distances. Full genomic sequencing of the isolated HearNPV and comparison with other geographically distinct HearNPV isolates identified genomic differences that showed that the HearNPV isolates were novel. HearNPV-Albany and HearNPV-KZN were successfully sequenced and identified as novel isolates with unique fragment patterns and unique gene sequences through deletions or insertions when compared to other geographically distinct HearNPV. This raised the potential for differences in biological activity against H. armigera larvae when tested through biological assays. HearNPV-Whit genome assembly had low quality data which resulted in many gaps and failed assembly. The biological activity of HearNPV isolates from Spain, China, South Africa and two commercial formulations were studied against the laboratory established H. armigera South African colony. The LC50 values of the different South African HearNPV isolates were established to be between 7.7 × 101 OBs.ml-1 for the most effective and 3.2 × 102 OBs.ml-1 for the least effective. The Spanish and Chinese HearNPV isolates resulted in LC50 values of 2.0 × 102 OBs.ml-1 and 1.2 × 101 OBs.ml-1 respectively. The commercial formulations resulted in the least virulence observed with an LC50 of 5.84× 102 OBs.ml-1 and 9.0 × 102 OBs.ml-1 for Helicovex® and Helicovir™ respectively. In this study, novel South African HearNPV isolates were isolated and identified. Through characterisation and bioassays against South African H. armigera populations the HearNPV isolates were shown to have different virulence in comparison to geographically distinct isolates. From this research, there is potential for development of new H. armigera biopesticides based on the novel isolates after field trial testing.
- Full Text:
- Date Issued: 2019
Geomorphological connectivity and sensitivity examined in a recently degraded gravel-bed stream: implications for river-floodplain rehabilitation
- Authors: Powell, Rebecca
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/53722 , vital:26313
- Description: The study of river complexity and sensitivity to future human land-use activities and climate change is a fast growing field within the discipline of fluvial geomorphology. Associated with this is a need to improve river rehabilitation and catchment management approach, design and effectiveness. This study aimed to investigate drivers of the recent geomorphological sensitivity of the Baviaanskloof River-floodplain, an upland system in South Africa, by integrating the concepts of geomorphological connectivity and Panarchy. The understanding generated was used to evaluate the approach of the State agency, Working for Wetlands (WfWet), to river-floodplain rehabilitation in the catchment.The concepts of geomorphological connectivity and Panarchy provide useful frameworks for understanding interactions between geomorphological processes and structure across scales of space and time. Geomorphological connectivity explains the degree to which water and sediment is linked in a river landscape, determined by the distribution of erosional and depositional landforms (Brierley et al. 2006; Fryirs et al. 2007a; Fryirs et al. 2007b). Panarchy attempts to explain lagged response to disturbances, non-linear interactions, and sudden shifts in system state, and has been applied largely to ecological systems. Panarchy theory, when combined with the concept of geomorphological connectivity, provides a guiding framework for understanding river complexity in greater depth. The first results chapter of this study investigated river long-term and recent geomorphological history, towards understanding the nature and timing of river geomorphological cycling between erosion and deposition. Optically Stimulated Luminescence dating of alluvial fan and floodplain sedimentary units was conducted, for analysis of river-floodplain long-term history (100s to 1 000s of years). Interviews with 11 local landowners, combined with analysis of historic aerial imagery and river-floodplain topographic surveys, provided a means of describing recent (last few decades) geomorphological dynamics. The results indicated that the Baviaanskloof is naturally a cut- and-fill landscape over scales of several hundred to thousands of years, characterized by the alternation between phases of high fluvial energy and alluvial fan expansion, and low energy conditions associated with floodplain accretion. Recent and widespread river-floodplain degradation was compressed into a short period of approximately 30 years, suggesting that one or more drivers have pushed the system beyond a threshold, resulting in increased water and sediment connectivity. The second results chapter investigated the role of human land-use activities and flooding frequency and magnitude, as drivers of recent river-floodplain degradation. Human impacts were investigated by describing land-use activities for the preceding 80 years, and relating these activities to changes in river-floodplain form and behavior. Temporal trends in flood events of different frequency and magnitude were investigated by analyzing rainfall data, integrated with landowner reports of flood-inducing rainfall magnitudes. The findings indicated that human land-use activities have been an important driver of recent river- floodplain degradation, through the enhancement of water and sediment connectivity across spatial scales of the catchment. Episodic and high magnitude floods synergized with human driven increased connectivity, precipitating stream power and geomorphological threshold breaches, resulting in a shift in river behaviour. The third results chapter investigated the influence of tributary-junction streams and fans on the geomorphological form, behavior and sensitivity of the Baviaanskloof River. Local- scale topographic impacts of tributary fans and streams were described using topographic surveys and geomorphological mapping techniques. Tributary streams form a major control on the behaviour of the river, by influencing the degree of coarse sediment connectivity with the main channel. Although tributary fans buffer the river from disturbances occurring in the wider catchment, they initiate topographic variations along the floodplain, influencing local-scale patterns of deposition and erosion along the river. The main river responds to water and sediment inputs from tributary junction streams by locally adjusting longitudinal slope, maintaining an overall constant slope of 0.0066 m/m. The response of the Baviaanskloof River to tributary junction fans and streams is however variable, and is fashioned by complex interactions between geomorphological and anthropogenic factors. The final two chapters of the thesis evaluate the findings of the study within the context of river-floodplain rehabilitation approaches in South Africa, and within the theoretical, philosophical and methodological context of the research. The first of these two chapters evaluates the approach of the WfWet programme to river-floodplain rehabilitation in the Baviaanskloof. The chapter indicates that the present practice of WfWet is to reinstate a pre-degradation state, which is not suited to the Baviaanskloof River-floodplain, since the river-floodplain has passed a geomorphological threshold, resulting in a new set of interacting processes and landforms. The author presents a conceptual model illustrating the existence of geomorphological adaptive cycles interacting across spatial and temporal scales, thereby attempting to explain a river Panarchy specific to the Baviaanskloof. From this conceptual model, a hierarchical rehabilitation framework, targeting geomorphological processes and structure situated at different spatial and temporal scales of the landscape is suggested. The final chapter discusses the implications of integrating the concepts of geomorphological connectivity and river Panarchy theory in studies of river complexity and sensitivity to geomorphological change. The author suggests that there is scope for further investigation of the application of the two concepts within the discipline of fluvial geomorphology, particularly with regard to developing quantitative approaches to measuring and describing connectivity and Panarchy.
- Full Text:
- Date Issued: 2017
- Authors: Powell, Rebecca
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/53722 , vital:26313
- Description: The study of river complexity and sensitivity to future human land-use activities and climate change is a fast growing field within the discipline of fluvial geomorphology. Associated with this is a need to improve river rehabilitation and catchment management approach, design and effectiveness. This study aimed to investigate drivers of the recent geomorphological sensitivity of the Baviaanskloof River-floodplain, an upland system in South Africa, by integrating the concepts of geomorphological connectivity and Panarchy. The understanding generated was used to evaluate the approach of the State agency, Working for Wetlands (WfWet), to river-floodplain rehabilitation in the catchment.The concepts of geomorphological connectivity and Panarchy provide useful frameworks for understanding interactions between geomorphological processes and structure across scales of space and time. Geomorphological connectivity explains the degree to which water and sediment is linked in a river landscape, determined by the distribution of erosional and depositional landforms (Brierley et al. 2006; Fryirs et al. 2007a; Fryirs et al. 2007b). Panarchy attempts to explain lagged response to disturbances, non-linear interactions, and sudden shifts in system state, and has been applied largely to ecological systems. Panarchy theory, when combined with the concept of geomorphological connectivity, provides a guiding framework for understanding river complexity in greater depth. The first results chapter of this study investigated river long-term and recent geomorphological history, towards understanding the nature and timing of river geomorphological cycling between erosion and deposition. Optically Stimulated Luminescence dating of alluvial fan and floodplain sedimentary units was conducted, for analysis of river-floodplain long-term history (100s to 1 000s of years). Interviews with 11 local landowners, combined with analysis of historic aerial imagery and river-floodplain topographic surveys, provided a means of describing recent (last few decades) geomorphological dynamics. The results indicated that the Baviaanskloof is naturally a cut- and-fill landscape over scales of several hundred to thousands of years, characterized by the alternation between phases of high fluvial energy and alluvial fan expansion, and low energy conditions associated with floodplain accretion. Recent and widespread river-floodplain degradation was compressed into a short period of approximately 30 years, suggesting that one or more drivers have pushed the system beyond a threshold, resulting in increased water and sediment connectivity. The second results chapter investigated the role of human land-use activities and flooding frequency and magnitude, as drivers of recent river-floodplain degradation. Human impacts were investigated by describing land-use activities for the preceding 80 years, and relating these activities to changes in river-floodplain form and behavior. Temporal trends in flood events of different frequency and magnitude were investigated by analyzing rainfall data, integrated with landowner reports of flood-inducing rainfall magnitudes. The findings indicated that human land-use activities have been an important driver of recent river- floodplain degradation, through the enhancement of water and sediment connectivity across spatial scales of the catchment. Episodic and high magnitude floods synergized with human driven increased connectivity, precipitating stream power and geomorphological threshold breaches, resulting in a shift in river behaviour. The third results chapter investigated the influence of tributary-junction streams and fans on the geomorphological form, behavior and sensitivity of the Baviaanskloof River. Local- scale topographic impacts of tributary fans and streams were described using topographic surveys and geomorphological mapping techniques. Tributary streams form a major control on the behaviour of the river, by influencing the degree of coarse sediment connectivity with the main channel. Although tributary fans buffer the river from disturbances occurring in the wider catchment, they initiate topographic variations along the floodplain, influencing local-scale patterns of deposition and erosion along the river. The main river responds to water and sediment inputs from tributary junction streams by locally adjusting longitudinal slope, maintaining an overall constant slope of 0.0066 m/m. The response of the Baviaanskloof River to tributary junction fans and streams is however variable, and is fashioned by complex interactions between geomorphological and anthropogenic factors. The final two chapters of the thesis evaluate the findings of the study within the context of river-floodplain rehabilitation approaches in South Africa, and within the theoretical, philosophical and methodological context of the research. The first of these two chapters evaluates the approach of the WfWet programme to river-floodplain rehabilitation in the Baviaanskloof. The chapter indicates that the present practice of WfWet is to reinstate a pre-degradation state, which is not suited to the Baviaanskloof River-floodplain, since the river-floodplain has passed a geomorphological threshold, resulting in a new set of interacting processes and landforms. The author presents a conceptual model illustrating the existence of geomorphological adaptive cycles interacting across spatial and temporal scales, thereby attempting to explain a river Panarchy specific to the Baviaanskloof. From this conceptual model, a hierarchical rehabilitation framework, targeting geomorphological processes and structure situated at different spatial and temporal scales of the landscape is suggested. The final chapter discusses the implications of integrating the concepts of geomorphological connectivity and river Panarchy theory in studies of river complexity and sensitivity to geomorphological change. The author suggests that there is scope for further investigation of the application of the two concepts within the discipline of fluvial geomorphology, particularly with regard to developing quantitative approaches to measuring and describing connectivity and Panarchy.
- Full Text:
- Date Issued: 2017
Governing pregnancy in South Africa: political and health debate, policy and procedures
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
- Full Text:
- Date Issued: 2019
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
- Full Text:
- Date Issued: 2019