'Hayi, they don’t know Xhosa’: Comparative isiXhosa teaching challenges in the Eastern Cape and Gauteng
- Kaschula, Russell H, Kretzer, Michael M
- Authors: Kaschula, Russell H , Kretzer, Michael M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:42499 , https://doi.org/10.1080/02572117.2019.1672318
- Description: Language-in-education policy in South Africa is underpinned by the Constitution. The gap that this research addresses is the inconsistency of policy implementation and the actual teaching of isiXhosa in primary schools. It analyses the official and overt language policy and the (covert) language practices at schools. Semi-structured interviews were conducted with language teachers and principals. Data were also gathered from classroom observations and document analysis in the Eastern Cape and Gauteng. On the one hand, there are standard language policy documents that exist. These advocate for English as a language of learning and teaching and isiXhosa as a subject. On the other hand, the daily reality in classrooms partly reflects this policy implementation.
- Full Text:
- Date Issued: 2019
- Authors: Kaschula, Russell H , Kretzer, Michael M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:42499 , https://doi.org/10.1080/02572117.2019.1672318
- Description: Language-in-education policy in South Africa is underpinned by the Constitution. The gap that this research addresses is the inconsistency of policy implementation and the actual teaching of isiXhosa in primary schools. It analyses the official and overt language policy and the (covert) language practices at schools. Semi-structured interviews were conducted with language teachers and principals. Data were also gathered from classroom observations and document analysis in the Eastern Cape and Gauteng. On the one hand, there are standard language policy documents that exist. These advocate for English as a language of learning and teaching and isiXhosa as a subject. On the other hand, the daily reality in classrooms partly reflects this policy implementation.
- Full Text:
- Date Issued: 2019
'We throw away our books': Students’ reading practices and identities
- O'Shea, Cathy, McKenna, Sioux, Thomson, Carol I
- Authors: O'Shea, Cathy , McKenna, Sioux , Thomson, Carol I
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187128 , vital:44570 , xlink:href="https://doi.org/10.1016/j.linged.2018.11.001"
- Description: The aim of this research was to understand university students’ self-reported reading practices. The students attended the University of Fort Hare in South Africa, a historically black institution in a rural and under-resourced setting. A framework of New Literacy Studies (NLS) was used to understand students’ self-reported reading practices and the links between these and their identities. Tools provided by Gee, 2005, Gee, 2011 were applied to conduct a CDA of focus group discussions. In the ‘We Blacks’ Discourse, interviewees ‘othered’ the idea of reading as not being culturally valued. It was closely allied to the ‘Resistance to Reading’ Discourse, as participants explained that they tended to disregard books and did not enjoy leisure reading. The ‘Better Than Us’ discourse was drawn upon to suggest that reading was associated with attitudes of superiority. These discourses tended to homogenise class and other differences between black students and indicated the ways in which their experiences made adopting academic identities difficult. The analysis suggests that the racism of the past continues to impact students’ reading identities. The article concludes that the effects of these and related discourses require a response across the education sector, and transformative pedagogies might be needed in higher education.
- Full Text:
- Date Issued: 2019
- Authors: O'Shea, Cathy , McKenna, Sioux , Thomson, Carol I
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187128 , vital:44570 , xlink:href="https://doi.org/10.1016/j.linged.2018.11.001"
- Description: The aim of this research was to understand university students’ self-reported reading practices. The students attended the University of Fort Hare in South Africa, a historically black institution in a rural and under-resourced setting. A framework of New Literacy Studies (NLS) was used to understand students’ self-reported reading practices and the links between these and their identities. Tools provided by Gee, 2005, Gee, 2011 were applied to conduct a CDA of focus group discussions. In the ‘We Blacks’ Discourse, interviewees ‘othered’ the idea of reading as not being culturally valued. It was closely allied to the ‘Resistance to Reading’ Discourse, as participants explained that they tended to disregard books and did not enjoy leisure reading. The ‘Better Than Us’ discourse was drawn upon to suggest that reading was associated with attitudes of superiority. These discourses tended to homogenise class and other differences between black students and indicated the ways in which their experiences made adopting academic identities difficult. The analysis suggests that the racism of the past continues to impact students’ reading identities. The article concludes that the effects of these and related discourses require a response across the education sector, and transformative pedagogies might be needed in higher education.
- Full Text:
- Date Issued: 2019
[Post] Colonial Histories: Trauma, Memory and Reconciliation in the Context of the Angolan Civil War
- Authors: Baines, Gary F
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125752 , vital:35814 , https://doi.10.1080/03612759.2019.1587342
- Description: In 2007, a former South African Defence Force (SADF) paratrooper, Marius van Niekerk, embarked on a journey to confront his shameful memories relating to his role in the Angolan Civil War. From Sweden (where he had gone into exile), Van Niekerk returned to Angola, where he had been deployed during the mid-1980s, and recruited three other veterans of the war to join his party: Patrick Johannes, who had been coerced to fight for the Popular Armed Forces for the Liberation of Angola (FAPLA); Samuel Machado Amaru, who was forcefully enlisted by the National Union for the Total Independence of Angola (UNITA); and Mario Mahonga, who had fought for the Portuguese colonial army before he was recruited by the SADF to fight against the Popular Movement for the Liberation of Angola (MPLA) regime. Van Niekerk had been conscripted at the age of seventeen, and the others had been coerced into their respective militias at more tender ages. It is not clear how the three Angolans were induced to participate in the project, whose objectives they evidently did not share.
- Full Text:
- Date Issued: 2019
[Post] Colonial Histories: Trauma, Memory and Reconciliation in the Context of the Angolan Civil War
- Authors: Baines, Gary F
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125752 , vital:35814 , https://doi.10.1080/03612759.2019.1587342
- Description: In 2007, a former South African Defence Force (SADF) paratrooper, Marius van Niekerk, embarked on a journey to confront his shameful memories relating to his role in the Angolan Civil War. From Sweden (where he had gone into exile), Van Niekerk returned to Angola, where he had been deployed during the mid-1980s, and recruited three other veterans of the war to join his party: Patrick Johannes, who had been coerced to fight for the Popular Armed Forces for the Liberation of Angola (FAPLA); Samuel Machado Amaru, who was forcefully enlisted by the National Union for the Total Independence of Angola (UNITA); and Mario Mahonga, who had fought for the Portuguese colonial army before he was recruited by the SADF to fight against the Popular Movement for the Liberation of Angola (MPLA) regime. Van Niekerk had been conscripted at the age of seventeen, and the others had been coerced into their respective militias at more tender ages. It is not clear how the three Angolans were induced to participate in the project, whose objectives they evidently did not share.
- Full Text:
- Date Issued: 2019
A 3, 5-DistyrylBODIPY Dye Functionalized with Boronic Acid Groups for Direct Electrochemical Glucose Sensing
- Ndebele, Nobuhle, Mack, John, Nyokong, Tebello
- Authors: Ndebele, Nobuhle , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187556 , vital:44671 , xlink:href="https://doi.org/10.1002/elan.201800651"
- Description: The synthesis and characterization of a novel BODIPY dye functionalized with bis-boronic acid groups to enable direct glucose sensing through selective recognition of carbohydrates is reported. Styrylation with boronic acid groups at the 3,5-positions of the BODIPY core results in an extension of the π-conjugation system of the dye and in a red-shift of the main absorption band from 500 to 637 nm. The functionalized BODIPY dye was adsorbed on a glassy carbon electrode using the drop and dry method. Modified and bare electrodes were characterized using cyclic voltammetry and scanning electrochemical microscopy, while glucose detection was carried out by using differential pulse voltammetry and chronoamperometry. The detection limit was determined to be 1.42 μM. The dye was found to be selective and sensitive towards glucose, since likely interferences have only minor effects on the glucose detection.
- Full Text:
- Date Issued: 2019
- Authors: Ndebele, Nobuhle , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187556 , vital:44671 , xlink:href="https://doi.org/10.1002/elan.201800651"
- Description: The synthesis and characterization of a novel BODIPY dye functionalized with bis-boronic acid groups to enable direct glucose sensing through selective recognition of carbohydrates is reported. Styrylation with boronic acid groups at the 3,5-positions of the BODIPY core results in an extension of the π-conjugation system of the dye and in a red-shift of the main absorption band from 500 to 637 nm. The functionalized BODIPY dye was adsorbed on a glassy carbon electrode using the drop and dry method. Modified and bare electrodes were characterized using cyclic voltammetry and scanning electrochemical microscopy, while glucose detection was carried out by using differential pulse voltammetry and chronoamperometry. The detection limit was determined to be 1.42 μM. The dye was found to be selective and sensitive towards glucose, since likely interferences have only minor effects on the glucose detection.
- Full Text:
- Date Issued: 2019
A case for the adoption of Swahili as a language of early school literacy instruction in Ekegusii-speaking areas of western Kenya:
- Mose, Peter, Kaschula, Russell H
- Authors: Mose, Peter , Kaschula, Russell H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174645 , vital:42497 , https://www.njas.fi/njas/article/view/433
- Description: Swahili, a national and official language in Kenya, is in wide use in the country as an inter-ethnic medium of communication and, generally, as a lingua franca. The operative language policy for lower primary–up to grade three–provides for the use of languages of the catchment as languages of instruction. The languages of the catchment refer to the more than 42 indigenous languages spoken in the country. The purpose of this study was to determine and discuss institutional and extra-institutional factors that might favour adoption of Swahili as the best medium–in the current sociolinguistic realities–in the ‘language-of-the-catchment-based’ literacy learning in Ekegusii-speaking areas of western Kenya. Data were obtained through classroom observations, teacher and church leaders’ interviews, observation and analysis of language trends at church worship services, and critical literature review.
- Full Text:
- Date Issued: 2019
- Authors: Mose, Peter , Kaschula, Russell H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174645 , vital:42497 , https://www.njas.fi/njas/article/view/433
- Description: Swahili, a national and official language in Kenya, is in wide use in the country as an inter-ethnic medium of communication and, generally, as a lingua franca. The operative language policy for lower primary–up to grade three–provides for the use of languages of the catchment as languages of instruction. The languages of the catchment refer to the more than 42 indigenous languages spoken in the country. The purpose of this study was to determine and discuss institutional and extra-institutional factors that might favour adoption of Swahili as the best medium–in the current sociolinguistic realities–in the ‘language-of-the-catchment-based’ literacy learning in Ekegusii-speaking areas of western Kenya. Data were obtained through classroom observations, teacher and church leaders’ interviews, observation and analysis of language trends at church worship services, and critical literature review.
- Full Text:
- Date Issued: 2019
A Century of South African Theatre
- Authors: Krueger, Anton
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229623 , vital:49694 , xlink:href="https://doi.org/10.1080/10137548.2020.1716515"
- Description: In many ways, this is an updated repackaging of Loren Kruger's seminal work of 20 years ago, Plays, Pageants and the Drama of South Africa (1999). The material has been extensively revised and reworked using similar categories as the first book, including: pageantry and representations of nationhood, neo-colonial theatre, urbanization and its consequences; the rise of Afrikaans theatre; theatres of resistance; black consciousness; and contemporary theatre. Some of these sections have been extended (such as a longer discussion of HIE Dhlomo) and there is also a completely new section which has not been published elsewhere on current theatre trends (cleverly titled “The Constitution of South African Theatre at the Present Time”).
- Full Text:
- Date Issued: 2019
- Authors: Krueger, Anton
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229623 , vital:49694 , xlink:href="https://doi.org/10.1080/10137548.2020.1716515"
- Description: In many ways, this is an updated repackaging of Loren Kruger's seminal work of 20 years ago, Plays, Pageants and the Drama of South Africa (1999). The material has been extensively revised and reworked using similar categories as the first book, including: pageantry and representations of nationhood, neo-colonial theatre, urbanization and its consequences; the rise of Afrikaans theatre; theatres of resistance; black consciousness; and contemporary theatre. Some of these sections have been extended (such as a longer discussion of HIE Dhlomo) and there is also a completely new section which has not been published elsewhere on current theatre trends (cleverly titled “The Constitution of South African Theatre at the Present Time”).
- Full Text:
- Date Issued: 2019
A comparative study of the singlet oxygen generation capability of a zinc phthalocyanine linked to graphene quantum dots through π-π stacking and covalent conjugation when embedded in asymmetric polymer membranes
- Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187461 , vital:44655 , xlink:href="https://doi.org/10.1016/j.molstruc.2018.11.096"
- Description: Following the establishment of graphene quantum dots as potential phthalocyanine supports in photoactive membrane preparation for phthalocyanines lacking linkage functional groups, the practical efficiency of p-p stacking versus covalent linkage was investigated. Synthesized materials were characterized using FT-IR, Raman, powder X-ray diffraction, and UVeVis spectroscopies and also by transmission electron and scanning electron microscopies. Phthalocyanine loadings onto graphene quantum dots of 0.40 mg/mg and 0.14 mg/mg (Pc mass/conjugate mass) for the p-p stacked and covalent linked conjugates respectively were observed. Covalent linkage to graphene quantum dots proved to be functionally superior to p-p linkage, where singlet oxygen quantum yield value of the phthalocyanine in the membrane for the covalent linked conjugate was approximately twice that of the p-p stacked membrane.
- Full Text:
- Date Issued: 2019
- Authors: Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187461 , vital:44655 , xlink:href="https://doi.org/10.1016/j.molstruc.2018.11.096"
- Description: Following the establishment of graphene quantum dots as potential phthalocyanine supports in photoactive membrane preparation for phthalocyanines lacking linkage functional groups, the practical efficiency of p-p stacking versus covalent linkage was investigated. Synthesized materials were characterized using FT-IR, Raman, powder X-ray diffraction, and UVeVis spectroscopies and also by transmission electron and scanning electron microscopies. Phthalocyanine loadings onto graphene quantum dots of 0.40 mg/mg and 0.14 mg/mg (Pc mass/conjugate mass) for the p-p stacked and covalent linked conjugates respectively were observed. Covalent linkage to graphene quantum dots proved to be functionally superior to p-p linkage, where singlet oxygen quantum yield value of the phthalocyanine in the membrane for the covalent linked conjugate was approximately twice that of the p-p stacked membrane.
- Full Text:
- Date Issued: 2019
A continental-scale validation of ecosystem service models
- Willcock, Simon, Hooftman, Danny A P, Balbi, Stefano, Blanchard, Ryan, Dawson, Terence P, O’Farrell, Patrick J, Hickler, Thomas, Hudson, Malcolm D, Lindeskog, Mats, Martinez-Lopez, Javier, Mulligan, Mark, Reyers, Belinda, Shackleton, Charlie M, Sitas, Nadia, Villa, Ferdinando, Watts, Sophie M, Eigenbrod, Felix, Bullock, James M
- Authors: Willcock, Simon , Hooftman, Danny A P , Balbi, Stefano , Blanchard, Ryan , Dawson, Terence P , O’Farrell, Patrick J , Hickler, Thomas , Hudson, Malcolm D , Lindeskog, Mats , Martinez-Lopez, Javier , Mulligan, Mark , Reyers, Belinda , Shackleton, Charlie M , Sitas, Nadia , Villa, Ferdinando , Watts, Sophie M , Eigenbrod, Felix , Bullock, James M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177476 , vital:42825 , https://doi.org/10.1007/s10021-019-00380-y
- Description: Faced with environmental degradation, governments worldwide are developing policies to safeguard ecosystem services (ES). Many ES models exist to support these policies, but they are generally poorly validated, especially at large scales, which undermines their credibility. To address this gap, we describe a study of multiple models of five ES, which we validate at an unprecedented scale against 1675 data points across sub-Saharan Africa.
- Full Text:
- Date Issued: 2019
- Authors: Willcock, Simon , Hooftman, Danny A P , Balbi, Stefano , Blanchard, Ryan , Dawson, Terence P , O’Farrell, Patrick J , Hickler, Thomas , Hudson, Malcolm D , Lindeskog, Mats , Martinez-Lopez, Javier , Mulligan, Mark , Reyers, Belinda , Shackleton, Charlie M , Sitas, Nadia , Villa, Ferdinando , Watts, Sophie M , Eigenbrod, Felix , Bullock, James M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177476 , vital:42825 , https://doi.org/10.1007/s10021-019-00380-y
- Description: Faced with environmental degradation, governments worldwide are developing policies to safeguard ecosystem services (ES). Many ES models exist to support these policies, but they are generally poorly validated, especially at large scales, which undermines their credibility. To address this gap, we describe a study of multiple models of five ES, which we validate at an unprecedented scale against 1675 data points across sub-Saharan Africa.
- Full Text:
- Date Issued: 2019
A functional ontology for information systems
- Motara, Yusuf, M, Van der Schyff, Karl
- Authors: Motara, Yusuf, M , Van der Schyff, Karl
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428936 , vital:72547 , https://hdl.handle.net/10520/EJC-1d75ba3e4a
- Description: The ontology of information systems — the way in which knowledge claims, and thus theories, are conceptualised and represented — is of particular importance in the information systems field, due to its reliance on relations between entities. This work proposes, demonstrates, and evaluates an alternative ontology for theory description which is arguably more powerful and more expressive than the dominant ontological model.
- Full Text:
- Date Issued: 2019
- Authors: Motara, Yusuf, M , Van der Schyff, Karl
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428936 , vital:72547 , https://hdl.handle.net/10520/EJC-1d75ba3e4a
- Description: The ontology of information systems — the way in which knowledge claims, and thus theories, are conceptualised and represented — is of particular importance in the information systems field, due to its reliance on relations between entities. This work proposes, demonstrates, and evaluates an alternative ontology for theory description which is arguably more powerful and more expressive than the dominant ontological model.
- Full Text:
- Date Issued: 2019
A novel axially palladium (II)-Schiff base complex substituted silicon (IV) phthalocyanine
- Sen, Pinar, Nyokong, Tebello
- Authors: Sen, Pinar , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186813 , vital:44536 , xlink:href="https://doi.org/10.1016/j.poly.2019.114135"
- Description: In this study, a novel silicon(IV) phthalocyanine is reported for the first time as a phthalocyanine derivative bearing axially a palladium(II)-Schiff base complex. The photophysical and photochemical properties of the new Si(IV)Pc, such as absorption, fluorescence, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were measured in DMSO. The new silicon phthalocyanine displayed very low fluorescence, showing efficient intersystem crossing resulting in high triplet and high singlet oxygen quantum yields in DMSO. When compared with the unsubstituted SiPcCl2, the singlet oxygen quantum yield value (UD = 0.47) in relation to the triplet quantum yield (UT = 0.82), which is an important determinant for PDT applications, increased. The photodynamic antimicrobial chemotherapy activity (PACT) of new Si(IV)Pc towards Staphylococcus aureus was determined in comparison to the unsubstituted SiPcCl2. The results of the photodynamic antimicrobial effect study demonstrated that the Pd(II) complex substituted SiPc (5) possesses excellent photodynamic activity with a reduction percentage value of 99.94% and a log red value of 3.26.
- Full Text:
- Date Issued: 2019
- Authors: Sen, Pinar , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186813 , vital:44536 , xlink:href="https://doi.org/10.1016/j.poly.2019.114135"
- Description: In this study, a novel silicon(IV) phthalocyanine is reported for the first time as a phthalocyanine derivative bearing axially a palladium(II)-Schiff base complex. The photophysical and photochemical properties of the new Si(IV)Pc, such as absorption, fluorescence, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were measured in DMSO. The new silicon phthalocyanine displayed very low fluorescence, showing efficient intersystem crossing resulting in high triplet and high singlet oxygen quantum yields in DMSO. When compared with the unsubstituted SiPcCl2, the singlet oxygen quantum yield value (UD = 0.47) in relation to the triplet quantum yield (UT = 0.82), which is an important determinant for PDT applications, increased. The photodynamic antimicrobial chemotherapy activity (PACT) of new Si(IV)Pc towards Staphylococcus aureus was determined in comparison to the unsubstituted SiPcCl2. The results of the photodynamic antimicrobial effect study demonstrated that the Pd(II) complex substituted SiPc (5) possesses excellent photodynamic activity with a reduction percentage value of 99.94% and a log red value of 3.26.
- Full Text:
- Date Issued: 2019
A novel technique for artificial pack formation in African wild dogs using odour familiarity:
- Marneweck, Courtney J, Marchal, Antoine F J, Marneweck, David G, Beverley, Grant, Davies-Mostert, Harriet T, Parker, Daniel M
- Authors: Marneweck, Courtney J , Marchal, Antoine F J , Marneweck, David G , Beverley, Grant , Davies-Mostert, Harriet T , Parker, Daniel M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150060 , vital:38935 , https://doi.org/10.3957/056.049.0116
- Description: Reintroductions are recognized tools for species recovery. However, operations are costly, difficult to implement, and failures are common and not always understood. Their success for group-living species depends on the mimicry of natural processes that promote social integration. Due to fragmented landscapes, human mediated (i.e. artificial) group formation is often required.
- Full Text:
- Date Issued: 2019
- Authors: Marneweck, Courtney J , Marchal, Antoine F J , Marneweck, David G , Beverley, Grant , Davies-Mostert, Harriet T , Parker, Daniel M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150060 , vital:38935 , https://doi.org/10.3957/056.049.0116
- Description: Reintroductions are recognized tools for species recovery. However, operations are costly, difficult to implement, and failures are common and not always understood. Their success for group-living species depends on the mimicry of natural processes that promote social integration. Due to fragmented landscapes, human mediated (i.e. artificial) group formation is often required.
- Full Text:
- Date Issued: 2019
A return to common-sense: why ecology needs transcendental realism
- Authors: Price, Leigh
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390324 , vital:68538 , xlink:href="https://doi.org/10.1080/14767430.2019.1580178"
- Description: Empirical realist ecologists, such as C. S. Holling, face significant methodological contradictions; for instance, they must cope with the problem that ecological models and theories of climate change, resilience and succession cannot make predictions in open systems. Generally, they respond to this problem by supplementing their empirical realism with transcendental idealism: they therefore say that their models are simply metaphorical or heuristic, that is, 'not true' in that they are not empirical. Thus, they explicitly deny an ontology for what their models are about. Nevertheless, in their practice, ecologists act as if their theories do have an ontology and thus tell us something truthful about the real world. This discrepancy leaves ecology vulnerable to unnecessary critique, such as that climate science is not real science. Transcendental realism offers a solution because it releases ecologists from the requirement to make predictions; but it does so without denying ontology. This provides several advantages to ecologists.
- Full Text:
- Date Issued: 2019
- Authors: Price, Leigh
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390324 , vital:68538 , xlink:href="https://doi.org/10.1080/14767430.2019.1580178"
- Description: Empirical realist ecologists, such as C. S. Holling, face significant methodological contradictions; for instance, they must cope with the problem that ecological models and theories of climate change, resilience and succession cannot make predictions in open systems. Generally, they respond to this problem by supplementing their empirical realism with transcendental idealism: they therefore say that their models are simply metaphorical or heuristic, that is, 'not true' in that they are not empirical. Thus, they explicitly deny an ontology for what their models are about. Nevertheless, in their practice, ecologists act as if their theories do have an ontology and thus tell us something truthful about the real world. This discrepancy leaves ecology vulnerable to unnecessary critique, such as that climate science is not real science. Transcendental realism offers a solution because it releases ecologists from the requirement to make predictions; but it does so without denying ontology. This provides several advantages to ecologists.
- Full Text:
- Date Issued: 2019
A spatio-temporal, landscape perspective on Acacia dealbata invasions and broader land use and cover changes in the northern Eastern Cape, South Africa
- Gouws, Aidan J, Prof.Shackleton, Charlie M
- Authors: Gouws, Aidan J , Prof.Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179670 , vital:43156 , xlink:href="https://doi.org/10.1007/s10661-019-7204-y"
- Description: Biological invasions and human land use both have the potential to drastically alter the patterns and processes of landscapes, driving habitat fragmentation and altering natural disturbance regimes. The proliferation of an invasive species depends on composition and configuration of the landscape, as well as the invasiveness of the species. To effectively manage a highly invasive species, such as Acacia dealbata, it is crucial to understand the historical progression of the invasion within the landscape. This study sought to examine the landscape dynamics of biological invasions by tracking the historical spread of A. dealbata and broader land use/land cover (LULC) changes at different spatiotemporal scales in the northern Eastern Cape. A timeseries of aerial photographs were systematically classified according to designated A. dealbata and LULC categories in ArcGIS to track the changes in the extent and rate of spread of A. dealbata. Markedly dynamic, multi-directional, and spatio-temporally variable LULC transitions were observed across the northern Eastern Cape over the last six decades. A. dealbata frequently retained a high proportion of cover over time, and despite the loss of cover to other LULC classes, a net increase in A. dealbata cover occurred as it spread at an overall annual rate of 0.11–0.21%, occupying approximately 8–18% of land cover across all sampled sites by 2013.
- Full Text:
- Date Issued: 2019
- Authors: Gouws, Aidan J , Prof.Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179670 , vital:43156 , xlink:href="https://doi.org/10.1007/s10661-019-7204-y"
- Description: Biological invasions and human land use both have the potential to drastically alter the patterns and processes of landscapes, driving habitat fragmentation and altering natural disturbance regimes. The proliferation of an invasive species depends on composition and configuration of the landscape, as well as the invasiveness of the species. To effectively manage a highly invasive species, such as Acacia dealbata, it is crucial to understand the historical progression of the invasion within the landscape. This study sought to examine the landscape dynamics of biological invasions by tracking the historical spread of A. dealbata and broader land use/land cover (LULC) changes at different spatiotemporal scales in the northern Eastern Cape. A timeseries of aerial photographs were systematically classified according to designated A. dealbata and LULC categories in ArcGIS to track the changes in the extent and rate of spread of A. dealbata. Markedly dynamic, multi-directional, and spatio-temporally variable LULC transitions were observed across the northern Eastern Cape over the last six decades. A. dealbata frequently retained a high proportion of cover over time, and despite the loss of cover to other LULC classes, a net increase in A. dealbata cover occurred as it spread at an overall annual rate of 0.11–0.21%, occupying approximately 8–18% of land cover across all sampled sites by 2013.
- Full Text:
- Date Issued: 2019
A tree cannot make a forest: looking inward, reaching out in African Art Studies
- Authors: Fọlárànmí, Stephen
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146090 , vital:38494 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00453
- Description: These proverbs from the Yorùbá of southwestern Nigeria and the Bemba of Zambia are a few examples that can be found in many Africa languages. While these proverbs are rich in philosophical sayings and muses, many are being forgotten because fewer and fewer people possess deep knowledge of languages, and in the arts, Africans tend to look to the Global North for theoretical frameworks to examine their art and other cultural properties. The title of this piece is therefore an identification with the potency of the proverbs because of the trends of collaboration that I have noticed in the last few years in African Art Studies. It could also be said to be a call to look into what could be shared within Global Souths in terms of an available knowledge base that could be used to forge ahead rather than subjecting thoughts and knowledge to the Global North.
- Full Text:
- Date Issued: 2019
- Authors: Fọlárànmí, Stephen
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146090 , vital:38494 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00453
- Description: These proverbs from the Yorùbá of southwestern Nigeria and the Bemba of Zambia are a few examples that can be found in many Africa languages. While these proverbs are rich in philosophical sayings and muses, many are being forgotten because fewer and fewer people possess deep knowledge of languages, and in the arts, Africans tend to look to the Global North for theoretical frameworks to examine their art and other cultural properties. The title of this piece is therefore an identification with the potency of the proverbs because of the trends of collaboration that I have noticed in the last few years in African Art Studies. It could also be said to be a call to look into what could be shared within Global Souths in terms of an available knowledge base that could be used to forge ahead rather than subjecting thoughts and knowledge to the Global North.
- Full Text:
- Date Issued: 2019
Abundance and correlates of the Acacia dealbata invasion in the northern Eastern Cape, South Africa
- Gouws, Aidan J, Shackleton, Charlie M
- Authors: Gouws, Aidan J , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179735 , vital:43165 , xlink:href="https://doi.org/10.1016/j.foreco.2018.09.048"
- Description: An increase in the density and biomass of woody invasive plants contributes to the intensification of ecological impacts and can often be met with dissatisfaction by local communities. Despite their reliance on Acacia dealbata as a source of livelihood, villagers in the northern Eastern Cape have expressed concerns about the high densities of the species. This study sought to quantify the current abundance and growth of A. dealbata in selected landscapes in the northern Eastern Cape, around nine villages in rural Matatiele, Mount Fletcher and Maclear. Standard vegetation survey techniques were adopted to quantify the density, biomass and growth rate of A. dealbata. Overall, the average density, biomass and productivity of A. dealbata were estimated at approximately 7000 stems ha−1, 12 Mg ha−1 and 4 Mg ha−1 year−1, respectively. However, the abundance and productivity of A. dealbata were spatially variable between study areas. Acacia dealbata stems experienced significant growth over the period of a single year, contributing to substantial biomass production at the landscape level, despite continued harvest. Furthermore, relatively few biophysical variables were significantly influential correlates with the abundance of A. dealbata. Indeed, the degree of biological invasion can be highly variable across the landscape, shaped by the interaction of local-scale biophysical conditions.
- Full Text:
- Date Issued: 2019
- Authors: Gouws, Aidan J , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179735 , vital:43165 , xlink:href="https://doi.org/10.1016/j.foreco.2018.09.048"
- Description: An increase in the density and biomass of woody invasive plants contributes to the intensification of ecological impacts and can often be met with dissatisfaction by local communities. Despite their reliance on Acacia dealbata as a source of livelihood, villagers in the northern Eastern Cape have expressed concerns about the high densities of the species. This study sought to quantify the current abundance and growth of A. dealbata in selected landscapes in the northern Eastern Cape, around nine villages in rural Matatiele, Mount Fletcher and Maclear. Standard vegetation survey techniques were adopted to quantify the density, biomass and growth rate of A. dealbata. Overall, the average density, biomass and productivity of A. dealbata were estimated at approximately 7000 stems ha−1, 12 Mg ha−1 and 4 Mg ha−1 year−1, respectively. However, the abundance and productivity of A. dealbata were spatially variable between study areas. Acacia dealbata stems experienced significant growth over the period of a single year, contributing to substantial biomass production at the landscape level, despite continued harvest. Furthermore, relatively few biophysical variables were significantly influential correlates with the abundance of A. dealbata. Indeed, the degree of biological invasion can be highly variable across the landscape, shaped by the interaction of local-scale biophysical conditions.
- Full Text:
- Date Issued: 2019
Addressing geographical bias: A review of Robinia pseudoacacia (black locust) in the Southern Hemisphere
- Authors: Martin, Grant D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423937 , vital:72107 , xlink:href="https://doi.org/10.1016/j.sajb.2019.08.01"
- Description: Robinia pseudoacacia (black locust) is a medium-sized deciduous tree, native to the Southeastern United States. Due to a number of beneficial attributes, it has been widely planted and become naturalised in several countries. It has one of the largest distributions in Europe of any introduced plant and has increased its distribution into a number of Southern Hemisphere countries. In its introduced range, the species exhibits a number of invasive tendencies, which result in negative environmental and economic impacts. This review presents information on aspects of the plant's biology and ecology with emphasis on its status in the Southern Hemisphere. Topics covered include taxonomy, morphological attributes, distributions, habitats, relationships with other species, growth and development, reproduction, hybridisation, population dynamics, uses, toxicity and the invasive status of the plant in Southern Hemisphere countries This manuscript also provides insights into management options including biological control, which has never been intentionally implemented against this species.
- Full Text:
- Date Issued: 2019
- Authors: Martin, Grant D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423937 , vital:72107 , xlink:href="https://doi.org/10.1016/j.sajb.2019.08.01"
- Description: Robinia pseudoacacia (black locust) is a medium-sized deciduous tree, native to the Southeastern United States. Due to a number of beneficial attributes, it has been widely planted and become naturalised in several countries. It has one of the largest distributions in Europe of any introduced plant and has increased its distribution into a number of Southern Hemisphere countries. In its introduced range, the species exhibits a number of invasive tendencies, which result in negative environmental and economic impacts. This review presents information on aspects of the plant's biology and ecology with emphasis on its status in the Southern Hemisphere. Topics covered include taxonomy, morphological attributes, distributions, habitats, relationships with other species, growth and development, reproduction, hybridisation, population dynamics, uses, toxicity and the invasive status of the plant in Southern Hemisphere countries This manuscript also provides insights into management options including biological control, which has never been intentionally implemented against this species.
- Full Text:
- Date Issued: 2019
Allosteric site modulators: a case study for falcipains as malarial drug targets
- Musyoka, Thommas, Tastan Bishop, Özlem
- Authors: Musyoka, Thommas , Tastan Bishop, Özlem
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/162699 , vital:40974 , https://doi.org/10.21955/gatesopenres.1116459.1
- Description: Fighting against malaria is a never-ending battle. Plasmodium parasites continuously develop resistance to the drugs used against them including the artemisinin-based combination therapies as observed recently in Southeast Asia. The main concern now is whether the resistant parasite strains spread to Africa, where most malaria cases are located. To prevent this, we need to think outside the box. To date, there is no allosteric drug for malaria. Hence, allosteric drug targeting sites and modulators might be a new hope for malarial treatment. In Plasmodium falciparum two cysteine proteases, falcipain-2 (FP-2) and falcipain-3 (FP-3), have been identified as the main hemoglobinases, and are considered as attractive drug targets.
- Full Text:
- Date Issued: 2019
- Authors: Musyoka, Thommas , Tastan Bishop, Özlem
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/162699 , vital:40974 , https://doi.org/10.21955/gatesopenres.1116459.1
- Description: Fighting against malaria is a never-ending battle. Plasmodium parasites continuously develop resistance to the drugs used against them including the artemisinin-based combination therapies as observed recently in Southeast Asia. The main concern now is whether the resistant parasite strains spread to Africa, where most malaria cases are located. To prevent this, we need to think outside the box. To date, there is no allosteric drug for malaria. Hence, allosteric drug targeting sites and modulators might be a new hope for malarial treatment. In Plasmodium falciparum two cysteine proteases, falcipain-2 (FP-2) and falcipain-3 (FP-3), have been identified as the main hemoglobinases, and are considered as attractive drug targets.
- Full Text:
- Date Issued: 2019
An analysis of the fruit-sucking and fruit-piercing moth complex in citrus orchards in South Africa
- Goddard, M, Hill, Martin P, Moore, Sean D
- Authors: Goddard, M , Hill, Martin P , Moore, Sean D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407000 , vital:70329 , xlink:href="https://hdl.handle.net/10520/EJC-15072d6de5"
- Description: Fruit-piercing moths are a sporadic pest of citrus, especially in the Eastern Cape Province of South Africa, where the adults can cause significant damage in outbreak years. However, growers confuse fruit-piercing moths with fruit-sucking moths that do not cause primary damage. In this study we trapped these moths during the 2013–2015 growing seasons. A large number of diverse fruit-feeding moths were collected through weekly sampling in citrus orchards in the Eastern Cape and northern Limpopo provinces. Twenty-three species of fruit-feeding moth were trapped. However, only two were fruit-piercing species, capable of causing primary damage, namely Serrodes partita (Fabricius) (Erebidae) and Eudocima divitiosa (Walker) (Erebidae). Surprisingly S. partita, which has been reported as the main fruit-piercing moth pest of citrus in South Africa, comprised only 6.9 % of trap catches. The categorisation of moths as fruit-piercing or fruit-sucking (causing secondary damage) was confirmed by examining the morphological structures (tearing hooks and erectile barbs) of these moths’ proboscides. This study has shown that in non-outbreak seasons, S. partita comprised only a small percentage of fruit-feeding moths in citrus orchards. However, growers may misidentify the harmless fruit-sucking species as fruit-piercing species, and thus overestimate the density of fruit-piercing moths.
- Full Text:
- Date Issued: 2019
- Authors: Goddard, M , Hill, Martin P , Moore, Sean D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407000 , vital:70329 , xlink:href="https://hdl.handle.net/10520/EJC-15072d6de5"
- Description: Fruit-piercing moths are a sporadic pest of citrus, especially in the Eastern Cape Province of South Africa, where the adults can cause significant damage in outbreak years. However, growers confuse fruit-piercing moths with fruit-sucking moths that do not cause primary damage. In this study we trapped these moths during the 2013–2015 growing seasons. A large number of diverse fruit-feeding moths were collected through weekly sampling in citrus orchards in the Eastern Cape and northern Limpopo provinces. Twenty-three species of fruit-feeding moth were trapped. However, only two were fruit-piercing species, capable of causing primary damage, namely Serrodes partita (Fabricius) (Erebidae) and Eudocima divitiosa (Walker) (Erebidae). Surprisingly S. partita, which has been reported as the main fruit-piercing moth pest of citrus in South Africa, comprised only 6.9 % of trap catches. The categorisation of moths as fruit-piercing or fruit-sucking (causing secondary damage) was confirmed by examining the morphological structures (tearing hooks and erectile barbs) of these moths’ proboscides. This study has shown that in non-outbreak seasons, S. partita comprised only a small percentage of fruit-feeding moths in citrus orchards. However, growers may misidentify the harmless fruit-sucking species as fruit-piercing species, and thus overestimate the density of fruit-piercing moths.
- Full Text:
- Date Issued: 2019
An artificial neural network approach to predict the effects of formulation and process variables on prednisone release from a multipartite system
- Manda, Arthur, Walker, Roderick B, Khamanga, Sandile M
- Authors: Manda, Arthur , Walker, Roderick B , Khamanga, Sandile M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183237 , vital:43933 , xlink:href="https://doi.org/10.3390/pharmaceutics11030109"
- Description: The impact of formulation and process variables on the in-vitro release of prednisone from a multiple-unit pellet system was investigated. Box-Behnken Response Surface Methodology (RSM) was used to generate multivariate experiments. The extrusion-spheronization method was used to produce pellets and dissolution studies were performed using United States Pharmacopoeia (USP) Apparatus 2 as described in USP XXIV. Analysis of dissolution test samples was performed using a reversed-phase high-performance liquid chromatography (RP-HPLC) method. Four formulation and process variables viz., microcrystalline cellulose concentration, sodium starch glycolate concentration, spheronization time and extrusion speed were investigated and drug release, aspect ratio and yield were monitored for the trained artificial neural networks (ANN). To achieve accurate prediction, data generated from experimentation were used to train a multi-layer perceptron (MLP) using back propagation (BP) and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) 57 training algorithm until a satisfactory value of root mean square error (RMSE) was observed. The study revealed that the in-vitro release profile of prednisone was significantly impacted by microcrystalline cellulose concentration and sodium starch glycolate concentration. Increasing microcrystalline cellulose concentration retarded dissolution rate whereas increasing sodium starch glycolate concentration improved dissolution rate. Spheronization time and extrusion speed had minimal impact on prednisone release but had a significant impact on extrudate and pellet quality. This work demonstrated that RSM can be successfully used concurrently with ANN for dosage form manufacture to permit the exploration of experimental regions that are omitted when using RSM alone.
- Full Text:
- Date Issued: 2019
- Authors: Manda, Arthur , Walker, Roderick B , Khamanga, Sandile M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183237 , vital:43933 , xlink:href="https://doi.org/10.3390/pharmaceutics11030109"
- Description: The impact of formulation and process variables on the in-vitro release of prednisone from a multiple-unit pellet system was investigated. Box-Behnken Response Surface Methodology (RSM) was used to generate multivariate experiments. The extrusion-spheronization method was used to produce pellets and dissolution studies were performed using United States Pharmacopoeia (USP) Apparatus 2 as described in USP XXIV. Analysis of dissolution test samples was performed using a reversed-phase high-performance liquid chromatography (RP-HPLC) method. Four formulation and process variables viz., microcrystalline cellulose concentration, sodium starch glycolate concentration, spheronization time and extrusion speed were investigated and drug release, aspect ratio and yield were monitored for the trained artificial neural networks (ANN). To achieve accurate prediction, data generated from experimentation were used to train a multi-layer perceptron (MLP) using back propagation (BP) and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) 57 training algorithm until a satisfactory value of root mean square error (RMSE) was observed. The study revealed that the in-vitro release profile of prednisone was significantly impacted by microcrystalline cellulose concentration and sodium starch glycolate concentration. Increasing microcrystalline cellulose concentration retarded dissolution rate whereas increasing sodium starch glycolate concentration improved dissolution rate. Spheronization time and extrusion speed had minimal impact on prednisone release but had a significant impact on extrudate and pellet quality. This work demonstrated that RSM can be successfully used concurrently with ANN for dosage form manufacture to permit the exploration of experimental regions that are omitted when using RSM alone.
- Full Text:
- Date Issued: 2019
An Evaluation of Text Mining Techniques in Sampling of Network Ports from IBR Traffic
- Chindipha, Stones D, Irwin, Barry V W, Herbert, Alan
- Authors: Chindipha, Stones D , Irwin, Barry V W , Herbert, Alan
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427630 , vital:72452 , https://www.researchgate.net/profile/Stones-Chindi-pha/publication/335910179_An_Evaluation_of_Text_Mining_Techniques_in_Sampling_of_Network_Ports_from_IBR_Traffic/links/5d833084458515cbd1985a38/An-Evaluation-of-Text-Mining-Techniques-in-Sampling-of-Network-Ports-from-IBR-Traffic.pdf
- Description: Information retrieval (IR) has had techniques that have been used to gauge the extent to which certain keywords can be retrieved from a document. These techniques have been used to measure similarities in duplicated images, native language identification, optimize algorithms, among others. With this notion, this study proposes the use of four of the Information Retrieval Techniques (IRT/IR) to gauge the implications of sampling a/24 IPv4 ports into smaller subnet equivalents. Using IR, this paper shows how the ports found in a/24 IPv4 net-block relate to those found in the smaller subnet equivalents. Using Internet Background Radiation (IBR) data that was collected from Rhodes University, the study found compelling evidence of the viability of using such techniques in sampling datasets. Essentially, being able to identify the variation that comes with sampling the baseline dataset. It shows how the various samples are similar to the baseline dataset. The correlation observed in the scores proves how viable these techniques are to quantifying variations in the sampling of IBR data. In this way, one can identify which subnet equivalent best represents the unique ports found in the baseline dataset (IPv4 net-block dataset).
- Full Text:
- Date Issued: 2019
- Authors: Chindipha, Stones D , Irwin, Barry V W , Herbert, Alan
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427630 , vital:72452 , https://www.researchgate.net/profile/Stones-Chindi-pha/publication/335910179_An_Evaluation_of_Text_Mining_Techniques_in_Sampling_of_Network_Ports_from_IBR_Traffic/links/5d833084458515cbd1985a38/An-Evaluation-of-Text-Mining-Techniques-in-Sampling-of-Network-Ports-from-IBR-Traffic.pdf
- Description: Information retrieval (IR) has had techniques that have been used to gauge the extent to which certain keywords can be retrieved from a document. These techniques have been used to measure similarities in duplicated images, native language identification, optimize algorithms, among others. With this notion, this study proposes the use of four of the Information Retrieval Techniques (IRT/IR) to gauge the implications of sampling a/24 IPv4 ports into smaller subnet equivalents. Using IR, this paper shows how the ports found in a/24 IPv4 net-block relate to those found in the smaller subnet equivalents. Using Internet Background Radiation (IBR) data that was collected from Rhodes University, the study found compelling evidence of the viability of using such techniques in sampling datasets. Essentially, being able to identify the variation that comes with sampling the baseline dataset. It shows how the various samples are similar to the baseline dataset. The correlation observed in the scores proves how viable these techniques are to quantifying variations in the sampling of IBR data. In this way, one can identify which subnet equivalent best represents the unique ports found in the baseline dataset (IPv4 net-block dataset).
- Full Text:
- Date Issued: 2019