A study of the photophysicochemical and antimicrobial properties of two zinc phthalocyanine–silver nanoparticle conjugates
- Rapulenyane, Nomasonto, Antunes, Edith M, Nyokong, Tebello
- Authors: Rapulenyane, Nomasonto , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232522 , vital:49999 , xlink:href="https://doi.org/10.1039/C3NJ41107A"
- Description: This work reports conjugation of two mono carboxy substituted zinc phthalocyanines with glutathione capped silver nanoparticles (GSH-AgNPs). The photophysicochemical behaviour of the novel phthalocyanines–silver nanoparticle conjugates was investigated together with simple mixtures of the silver nanoparticles with low symmetry phthalocyanines (i.e. with no direct chemical bond formation). It was observed that upon conjugation of the phthalocyanines to the silver nanoparticles, a blue shifting of the Q band was induced. The triplet lifetimes and quantum yields improved upon conjugation as compared to the phthalocyanines alone. Fluorescence lifetimes and quantum yields decreased for conjugates compared to the phthalocyanines alone due to quenching caused by the silver nanoparticles. The low symmetry phthalocyanines and their conjugates showed antimicrobial activity against Escherichia coli in the presence and absence of light.
- Full Text:
- Date Issued: 2013
- Authors: Rapulenyane, Nomasonto , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232522 , vital:49999 , xlink:href="https://doi.org/10.1039/C3NJ41107A"
- Description: This work reports conjugation of two mono carboxy substituted zinc phthalocyanines with glutathione capped silver nanoparticles (GSH-AgNPs). The photophysicochemical behaviour of the novel phthalocyanines–silver nanoparticle conjugates was investigated together with simple mixtures of the silver nanoparticles with low symmetry phthalocyanines (i.e. with no direct chemical bond formation). It was observed that upon conjugation of the phthalocyanines to the silver nanoparticles, a blue shifting of the Q band was induced. The triplet lifetimes and quantum yields improved upon conjugation as compared to the phthalocyanines alone. Fluorescence lifetimes and quantum yields decreased for conjugates compared to the phthalocyanines alone due to quenching caused by the silver nanoparticles. The low symmetry phthalocyanines and their conjugates showed antimicrobial activity against Escherichia coli in the presence and absence of light.
- Full Text:
- Date Issued: 2013
A study on the morphology of thin copper films on para-aramid yarns and their influence on the yarn’s electro-conductive and mechanical properties
- Schwarz, Anne, Hakuzimana, Jean, Westbroek, Philippe, Mey, Gilbert De, Priniotakis, Georgios, Nyokong, Tebello, Langenhove, Lieva Van
- Authors: Schwarz, Anne , Hakuzimana, Jean , Westbroek, Philippe , Mey, Gilbert De , Priniotakis, Georgios , Nyokong, Tebello , Langenhove, Lieva Van
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243487 , vital:51157 , xlink:href="https://doi.org/10.1177/0040517511431291"
- Description: The latest technological advances in new materials and devices enabled wearable systems to be created by utilizing textile solutions. These solutions require electro-conductive yarns as a basic component. Although the production of electroconductive yarn is widely reported, research is still necessary to characterize them to advance their electro-conductive and mechanical properties. Hence, we served this need and characterized copper-coated para-aramid yarns produced by an in-house developed electroless deposition method. In this paper we present our investigation on the yarn’s copper layer characteristics after deposition. Furthermore, we looked, in depth, at the yarn’s electro-conductive properties before and after washing as well as their mechanical properties before and after copper deposition. We found a dependency of the copper layer morphology on its deposition time. This is directly correlated to the resulting layer thickness and hence to the yarn’s electro-conductive properties, demonstrating the autocatalytic nature of the coating process. Above that, the electro-conductive properties of the coated yarn linearly decrease with washing cycles. Furthermore, the copper coating impairs the yarn’s mechanical properties decreasing its specific stress at break by 30%.
- Full Text:
- Date Issued: 2012
- Authors: Schwarz, Anne , Hakuzimana, Jean , Westbroek, Philippe , Mey, Gilbert De , Priniotakis, Georgios , Nyokong, Tebello , Langenhove, Lieva Van
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243487 , vital:51157 , xlink:href="https://doi.org/10.1177/0040517511431291"
- Description: The latest technological advances in new materials and devices enabled wearable systems to be created by utilizing textile solutions. These solutions require electro-conductive yarns as a basic component. Although the production of electroconductive yarn is widely reported, research is still necessary to characterize them to advance their electro-conductive and mechanical properties. Hence, we served this need and characterized copper-coated para-aramid yarns produced by an in-house developed electroless deposition method. In this paper we present our investigation on the yarn’s copper layer characteristics after deposition. Furthermore, we looked, in depth, at the yarn’s electro-conductive properties before and after washing as well as their mechanical properties before and after copper deposition. We found a dependency of the copper layer morphology on its deposition time. This is directly correlated to the resulting layer thickness and hence to the yarn’s electro-conductive properties, demonstrating the autocatalytic nature of the coating process. Above that, the electro-conductive properties of the coated yarn linearly decrease with washing cycles. Furthermore, the copper coating impairs the yarn’s mechanical properties decreasing its specific stress at break by 30%.
- Full Text:
- Date Issued: 2012
A survey of fruit-feeding insects and their parasitoids occurring on wild olives, Olea europaea ssp. cuspidata, in the Eastern Cape of South Africa
- Mkize, Nolwazi, Hoelmer, Kim A, Villet, Martin H
- Authors: Mkize, Nolwazi , Hoelmer, Kim A , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441694 , vital:73907 , https://doi.org/10.1080/09583150802450154
- Description: Fruits of wild olives, Olea europaea ssp. cuspidata (Wall. ex G. Don) Cif., were collected in the Eastern Cape, South Africa, during 2003–2005 to quantify levels of fruit-infesting pests and their parasitoids. Two species of Tephritidae, Bactrocera oleae (Rossi) and B. biguttula (Bezzi), were the most abundant insects recovered and were reared from most samples. Fruit infestation rates by the Bactrocera spp. were generally below 8% and over half of the infestations were under 1%. When parasitism occurred in samples with flies, levels ranged from 7 to 83%. Several species of opiine braconid wasps, Psyttalia concolor (Szépligeti), Psyttalia lounsburyi (Silvestri), and Utetes africanus (Szépligeti) and one braconine wasp, Bracon celer Szépligeti, were reared from fruits containing B. oleae and/or B. biguttula. Chalcidoid parasitoids and seed wasps included seven species of Eurytomidae (Eurytoma oleae, Eurytoma sp., and Sycophila sp.), Ormyridae (Ormyrus sp.), Torymidae (Megastigmus sp.), and Eupelmidae (Eupelmus afer and E. spermophilus). One species of moth, Palpita unionalis (Hübner) (Crambidae), was recovered in very low numbers and without parasitoids. The survey results indicate that fruit flies might not become economic pests of the nascent commercial olive industry in the Eastern Cape, and the small numbers present may be controlled to a considerable level by natural enemies.
- Full Text:
- Date Issued: 2008
- Authors: Mkize, Nolwazi , Hoelmer, Kim A , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441694 , vital:73907 , https://doi.org/10.1080/09583150802450154
- Description: Fruits of wild olives, Olea europaea ssp. cuspidata (Wall. ex G. Don) Cif., were collected in the Eastern Cape, South Africa, during 2003–2005 to quantify levels of fruit-infesting pests and their parasitoids. Two species of Tephritidae, Bactrocera oleae (Rossi) and B. biguttula (Bezzi), were the most abundant insects recovered and were reared from most samples. Fruit infestation rates by the Bactrocera spp. were generally below 8% and over half of the infestations were under 1%. When parasitism occurred in samples with flies, levels ranged from 7 to 83%. Several species of opiine braconid wasps, Psyttalia concolor (Szépligeti), Psyttalia lounsburyi (Silvestri), and Utetes africanus (Szépligeti) and one braconine wasp, Bracon celer Szépligeti, were reared from fruits containing B. oleae and/or B. biguttula. Chalcidoid parasitoids and seed wasps included seven species of Eurytomidae (Eurytoma oleae, Eurytoma sp., and Sycophila sp.), Ormyridae (Ormyrus sp.), Torymidae (Megastigmus sp.), and Eupelmidae (Eupelmus afer and E. spermophilus). One species of moth, Palpita unionalis (Hübner) (Crambidae), was recovered in very low numbers and without parasitoids. The survey results indicate that fruit flies might not become economic pests of the nascent commercial olive industry in the Eastern Cape, and the small numbers present may be controlled to a considerable level by natural enemies.
- Full Text:
- Date Issued: 2008
A systematic analysis of doctoral publication trends in South Africa
- Van Schalkwyk, Susan, Mouton, Johann, Redelinghuys, Herman, McKenna, Sioux
- Authors: Van Schalkwyk, Susan , Mouton, Johann , Redelinghuys, Herman , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185826 , vital:44438 , xlink:href="http://dx.doi.org/10.17159/sajs.2020/7926"
- Description: It is incumbent upon doctoral students that their work makes a substantive contribution to the field within which it is conducted. Dissemination of this work beyond the dissertation, whether whilst studying or after graduation, is necessary to ensure that the contribution does not remain largely dormant. While dissemination can take many forms, peer-reviewed journal articles are the key medium by which knowledge is shared. We aimed to establish the proportion of doctoral theses that results in journal publications by linking South African doctoral thesis metadata to journal articles authored by doctoral candidates. To effect this matching, a customised data set was created that comprised two large databases: the South African Theses Database (SATD), which documented all doctoral degrees awarded in South Africa (2005-2014), and the South African Knowledgebase (SAK), which listed all publications submitted for subsidy to the South African Department of Higher Education and Training (2005-2017). The process followed several iterations of matching and verification, including manual inspection of the data, in order to isolate only those records for which the link was established beyond doubt. Over the period under review, 47.6% of graduates, representing 22 of the 26 higher education institutions, published at least one journal article. Results further indicate increasingly higher publication rates over time. To explore whether the journal article identified was a direct product of the study, a similarity index was developed. Over 75% of records demonstrated high similarity. While the trend towards increasing publications by graduates is promising, work in this area should be ongoing. In spite of increasing trends in publications by graduates, many are not disseminating their work, suggesting that significant bodies of research are potentially not being shared with the academic community and are therefore not contributing to the relevant discipline or field. •This study provides baseline data from which a number of further investigations can be launched, such as exploring the extent to which doctoral candidates who are also academics are publishing their work; the factors that enable or constrain publication; the other avenues of dissemination used; and whether publishing or not publishing can serve as a proxy for the quality of the doctoral work.
- Full Text:
- Date Issued: 2020
- Authors: Van Schalkwyk, Susan , Mouton, Johann , Redelinghuys, Herman , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185826 , vital:44438 , xlink:href="http://dx.doi.org/10.17159/sajs.2020/7926"
- Description: It is incumbent upon doctoral students that their work makes a substantive contribution to the field within which it is conducted. Dissemination of this work beyond the dissertation, whether whilst studying or after graduation, is necessary to ensure that the contribution does not remain largely dormant. While dissemination can take many forms, peer-reviewed journal articles are the key medium by which knowledge is shared. We aimed to establish the proportion of doctoral theses that results in journal publications by linking South African doctoral thesis metadata to journal articles authored by doctoral candidates. To effect this matching, a customised data set was created that comprised two large databases: the South African Theses Database (SATD), which documented all doctoral degrees awarded in South Africa (2005-2014), and the South African Knowledgebase (SAK), which listed all publications submitted for subsidy to the South African Department of Higher Education and Training (2005-2017). The process followed several iterations of matching and verification, including manual inspection of the data, in order to isolate only those records for which the link was established beyond doubt. Over the period under review, 47.6% of graduates, representing 22 of the 26 higher education institutions, published at least one journal article. Results further indicate increasingly higher publication rates over time. To explore whether the journal article identified was a direct product of the study, a similarity index was developed. Over 75% of records demonstrated high similarity. While the trend towards increasing publications by graduates is promising, work in this area should be ongoing. In spite of increasing trends in publications by graduates, many are not disseminating their work, suggesting that significant bodies of research are potentially not being shared with the academic community and are therefore not contributing to the relevant discipline or field. •This study provides baseline data from which a number of further investigations can be launched, such as exploring the extent to which doctoral candidates who are also academics are publishing their work; the factors that enable or constrain publication; the other avenues of dissemination used; and whether publishing or not publishing can serve as a proxy for the quality of the doctoral work.
- Full Text:
- Date Issued: 2020
A tropical/subtropical biogeographic disjunction in southeastern Africa separates two evolutionarily significant units of an estuarine prawn
- Teske, Peter R, Winker, A Henning, McQuaid, Christopher D, Barker, Nigel P
- Authors: Teske, Peter R , Winker, A Henning , McQuaid, Christopher D , Barker, Nigel P
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445407 , vital:74383 , https://doi.org/10.1007/s00227-009-1168-3
- Description: Recent phylogeographic research has indicated that biodiversity in the sea may be considerably greater than previously thought. However, the majority of phylogeographic studies on marine invertebrates have exclusively used a single locus (mitochondrial DNA), and it is questionable whether the phylogroups identified can be considered distinct species. We tested whether the mtDNA phylogroups of the southern African sandprawn Callianassa kraussi Stebbing (Decapoda: Thalassinidea) are also recovered using nuclear sequence data. Four mtDNA phylogroups were recovered that were each associated with one of South Africa’s four major biogeographic provinces. Three of these were poorly differentiated, but the fourth (tropical) group was highly distinct. The nuclear phylogeny recovered two major clades, one present in the tropical region and the other in the remainder of South Africa. Congruence between mitochondrial and nuclear DNA indicates that the species comprises two Evolutionarily Significant Units sensu Moritz (1994). In conjunction with physiological data from C. kraussi and morphological, ecological and physiological data from other species, this result supports the notion that at least some of the mtDNA phylogroups of coastal invertebrates whose distributions are limited.
- Full Text:
- Date Issued: 2009
- Authors: Teske, Peter R , Winker, A Henning , McQuaid, Christopher D , Barker, Nigel P
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445407 , vital:74383 , https://doi.org/10.1007/s00227-009-1168-3
- Description: Recent phylogeographic research has indicated that biodiversity in the sea may be considerably greater than previously thought. However, the majority of phylogeographic studies on marine invertebrates have exclusively used a single locus (mitochondrial DNA), and it is questionable whether the phylogroups identified can be considered distinct species. We tested whether the mtDNA phylogroups of the southern African sandprawn Callianassa kraussi Stebbing (Decapoda: Thalassinidea) are also recovered using nuclear sequence data. Four mtDNA phylogroups were recovered that were each associated with one of South Africa’s four major biogeographic provinces. Three of these were poorly differentiated, but the fourth (tropical) group was highly distinct. The nuclear phylogeny recovered two major clades, one present in the tropical region and the other in the remainder of South Africa. Congruence between mitochondrial and nuclear DNA indicates that the species comprises two Evolutionarily Significant Units sensu Moritz (1994). In conjunction with physiological data from C. kraussi and morphological, ecological and physiological data from other species, this result supports the notion that at least some of the mtDNA phylogroups of coastal invertebrates whose distributions are limited.
- Full Text:
- Date Issued: 2009
A tuple space web service for distributed programming-Simplifying distributed web services applications
- Wells, George C, Mueller, Barbara, Schulé, Lo¨ıc
- Authors: Wells, George C , Mueller, Barbara , Schulé, Lo¨ıc
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430437 , vital:72691 , https://www.scitepress.org/PublishedPapers/2008/15170/15170.pdf
- Description: This paper describes a new tuple space web service for coordination and communication in distributed web applications. This web service is based on the Linda programming model. Linda is a coordination lan-guage for parallel and distributed processing, providing a communica-tion mechanism based on a logically shared memory space. The origi-nal Linda model has been extended through the provision of a pro-grammable mechanism, providing additional flexibility and improved performance. The implementation of the web service is discussed, to-gether with the details of the programmable matching mechanism. Some results from the implementation of a location-based mobile appli-cation, using the tuple space web service are presented, demonstrating the benefits of our system.
- Full Text:
- Date Issued: 2008
- Authors: Wells, George C , Mueller, Barbara , Schulé, Lo¨ıc
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430437 , vital:72691 , https://www.scitepress.org/PublishedPapers/2008/15170/15170.pdf
- Description: This paper describes a new tuple space web service for coordination and communication in distributed web applications. This web service is based on the Linda programming model. Linda is a coordination lan-guage for parallel and distributed processing, providing a communica-tion mechanism based on a logically shared memory space. The origi-nal Linda model has been extended through the provision of a pro-grammable mechanism, providing additional flexibility and improved performance. The implementation of the web service is discussed, to-gether with the details of the programmable matching mechanism. Some results from the implementation of a location-based mobile appli-cation, using the tuple space web service are presented, demonstrating the benefits of our system.
- Full Text:
- Date Issued: 2008
A wake-up call: Equity, inequality and Covid-19 emergency remote teaching and learning
- Czerniewicz, Laura, Agherdien, Najma, Badenhorst, Johan, Belluigi, Dina Z, Chambers, Tracey, Chili, Muntuwenkosi, De Villiers, Magriet, Felix, Alan, Gachago, Daniela, Gokhale, Craig, Ivala, Eunice, Kramm, Neil, Madiba, Matete, Mistri, Gitanjali, Mgqwashu, Emmanuel M, Pallitt, Nicola, Prinsloo, Paul, Solomon, Kelly, Strydom, Sonja, Swanepoel, Mike, Waghid, Faiq, Wissing, Gerrit
- Authors: Czerniewicz, Laura , Agherdien, Najma , Badenhorst, Johan , Belluigi, Dina Z , Chambers, Tracey , Chili, Muntuwenkosi , De Villiers, Magriet , Felix, Alan , Gachago, Daniela , Gokhale, Craig , Ivala, Eunice , Kramm, Neil , Madiba, Matete , Mistri, Gitanjali , Mgqwashu, Emmanuel M , Pallitt, Nicola , Prinsloo, Paul , Solomon, Kelly , Strydom, Sonja , Swanepoel, Mike , Waghid, Faiq , Wissing, Gerrit
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439449 , vital:73598 , https://doi.org/10.1007/s42438-020-00187-4
- Description: Produced from experiences at the outset of the intense times when Covid-19 lockdown restrictions began in March 2020, this collaborative paper offers the collective reflections and analysis of a group of teaching and learning and Higher Education (HE) scholars from a diverse 15 of the 26 South African public universities. In the form of a theorised narrative insistent on foregrounding personal voices, it presents a snapshot of the pandemic addressing the following question: what does the ‘pivot online’to Emergency Remote Teaching and Learning (ERTL), forced into urgent existence by the Covid-19 pandemic, mean for equity considerations in teaching and learning in HE? Drawing on the work of Therborn (2009: 20–32; 2012: 579–589; 2013; 2020) the reflections consider the forms of inequality-vital, resource and existential-exposed in higher education. Drawing on the work of Tronto (1993; 2015; White and Tronto 2004) the paper shows the networks of care which were formed as a counter to the systemic failures of the sector at the onset of the pandemic.
- Full Text:
- Date Issued: 2020
- Authors: Czerniewicz, Laura , Agherdien, Najma , Badenhorst, Johan , Belluigi, Dina Z , Chambers, Tracey , Chili, Muntuwenkosi , De Villiers, Magriet , Felix, Alan , Gachago, Daniela , Gokhale, Craig , Ivala, Eunice , Kramm, Neil , Madiba, Matete , Mistri, Gitanjali , Mgqwashu, Emmanuel M , Pallitt, Nicola , Prinsloo, Paul , Solomon, Kelly , Strydom, Sonja , Swanepoel, Mike , Waghid, Faiq , Wissing, Gerrit
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439449 , vital:73598 , https://doi.org/10.1007/s42438-020-00187-4
- Description: Produced from experiences at the outset of the intense times when Covid-19 lockdown restrictions began in March 2020, this collaborative paper offers the collective reflections and analysis of a group of teaching and learning and Higher Education (HE) scholars from a diverse 15 of the 26 South African public universities. In the form of a theorised narrative insistent on foregrounding personal voices, it presents a snapshot of the pandemic addressing the following question: what does the ‘pivot online’to Emergency Remote Teaching and Learning (ERTL), forced into urgent existence by the Covid-19 pandemic, mean for equity considerations in teaching and learning in HE? Drawing on the work of Therborn (2009: 20–32; 2012: 579–589; 2013; 2020) the reflections consider the forms of inequality-vital, resource and existential-exposed in higher education. Drawing on the work of Tronto (1993; 2015; White and Tronto 2004) the paper shows the networks of care which were formed as a counter to the systemic failures of the sector at the onset of the pandemic.
- Full Text:
- Date Issued: 2020
A watershed study on genetic diversity phylogenetic analysis of the Platypleura plumosa (Hemiptera Cicadidae) complex reveals catchment-specific lineages
- Price, Benjamin W, Barker, Nigel P, Villet, Martin H
- Authors: Price, Benjamin W , Barker, Nigel P , Villet, Martin H
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441711 , vital:73909 , https://doi.org/10.1016/j.ympev.2009.10.011
- Description: Historical biogeography studies have at their disposal a small suite of vicariance models to explain genetic differentiation within and between species. One of these processes involves the role of river catchments and their associated watersheds, in driving diversification and is applicable to both aquatic and terrestrial organisms. Although the idea of catchments structuring the genetic history of aquatic organisms is reasonably well understood, their effect on terrestrial organisms has largely been overlooked, with relevant studies being limited in scope. South Africa presents a perfect test-bed for elucidating this mechanism of diversification due to its rich biodiversity, range of climatic environments and many large river catchments. Here we use the cicadas of the Platypleura plumosa complex to highlight the importance of catchments and their associated watersheds in driving diversification of terrestrial invertebrates that lack an aquatic life-stage. Population structure was found to correspond to primary and in some cases secondary catchments; highlighting the need to include information on catchment structure when formulating hypotheses of population diversification. Recognizing that climate change in the near future is likely to alter the environment, and particularly precipitation patterns, insight into recent patterns of population change related to catchments may be useful in a conservation context.
- Full Text:
- Date Issued: 2010
- Authors: Price, Benjamin W , Barker, Nigel P , Villet, Martin H
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441711 , vital:73909 , https://doi.org/10.1016/j.ympev.2009.10.011
- Description: Historical biogeography studies have at their disposal a small suite of vicariance models to explain genetic differentiation within and between species. One of these processes involves the role of river catchments and their associated watersheds, in driving diversification and is applicable to both aquatic and terrestrial organisms. Although the idea of catchments structuring the genetic history of aquatic organisms is reasonably well understood, their effect on terrestrial organisms has largely been overlooked, with relevant studies being limited in scope. South Africa presents a perfect test-bed for elucidating this mechanism of diversification due to its rich biodiversity, range of climatic environments and many large river catchments. Here we use the cicadas of the Platypleura plumosa complex to highlight the importance of catchments and their associated watersheds in driving diversification of terrestrial invertebrates that lack an aquatic life-stage. Population structure was found to correspond to primary and in some cases secondary catchments; highlighting the need to include information on catchment structure when formulating hypotheses of population diversification. Recognizing that climate change in the near future is likely to alter the environment, and particularly precipitation patterns, insight into recent patterns of population change related to catchments may be useful in a conservation context.
- Full Text:
- Date Issued: 2010
A white man in exile
- Authors: Krueger, Anton
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229459 , vital:49677 , xlink:href="https://doi.org/10.1080/10137548.2011.636974"
- Description: This article explores intersections between understandings of masculinity and nationalism. Etymologically, ‘patriotism’ refers to a love for a fatherland and a patriarchal order; it includes notions of loyalty, honour and a range of qualities often associated with conceptions of masculinity. But if gender remains fixed to these normative constructions, what happens to one’s sense of masculine identity when the national state changes? My interest lies in exploring how white South African men have been repositioned in terms of a shift in their gendered identification, with a reflection on the possibly tragic consequences of maintaining an overly rigid gender role identification. As long as masculinity is embedded within nationalism, it will be caught up within a defensive reactive mode which can turn self-destructive. In order to explore these ideas the article employs as its central metaphor the character of Dawid Olivier, who is the protagonist of Athol Fugard’s Sorrows and Rejoicings (2002).
- Full Text:
- Date Issued: 2011
- Authors: Krueger, Anton
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229459 , vital:49677 , xlink:href="https://doi.org/10.1080/10137548.2011.636974"
- Description: This article explores intersections between understandings of masculinity and nationalism. Etymologically, ‘patriotism’ refers to a love for a fatherland and a patriarchal order; it includes notions of loyalty, honour and a range of qualities often associated with conceptions of masculinity. But if gender remains fixed to these normative constructions, what happens to one’s sense of masculine identity when the national state changes? My interest lies in exploring how white South African men have been repositioned in terms of a shift in their gendered identification, with a reflection on the possibly tragic consequences of maintaining an overly rigid gender role identification. As long as masculinity is embedded within nationalism, it will be caught up within a defensive reactive mode which can turn self-destructive. In order to explore these ideas the article employs as its central metaphor the character of Dawid Olivier, who is the protagonist of Athol Fugard’s Sorrows and Rejoicings (2002).
- Full Text:
- Date Issued: 2011
A2B type copper (III) corroles containing zero-to-five fluorine atoms
- Li, Minzhi, Niu, Yingjie, Zhu, Weihua, Mack, John, Fomo, Gertrude, Nyokong, Tebello, Liang, Xu
- Authors: Li, Minzhi , Niu, Yingjie , Zhu, Weihua , Mack, John , Fomo, Gertrude , Nyokong, Tebello , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/238275 , vital:50604 , xlink:href="https://doi.org/10.1016/j.dyepig.2016.10.044"
- Description: Four low symmetric A2B meso-substituted Cu(III)corroles with electron withdrawing meso-aryl rings have been synthesized and characterized. A detailed analysis of the optical and redox properties has been carried out by comparing their optical spectroscopy, electrochemistry and spectroelectrochemistry to a series of DFT and TD-DFT calculations. A series of experiments demonstrate that these Cu(III)corroles can be used as highly effective catalysts for hydrogen evolution reactions (HERs). Moreover, when the number of fluorine atoms at B meso-position is increased, there is a marked enhancement in the catalytic ability of the corrole complexes, which demonstrates that modification to the structures of low symmetry corroles is a useful strategy for developing new HER catalysts.
- Full Text:
- Date Issued: 2017
- Authors: Li, Minzhi , Niu, Yingjie , Zhu, Weihua , Mack, John , Fomo, Gertrude , Nyokong, Tebello , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/238275 , vital:50604 , xlink:href="https://doi.org/10.1016/j.dyepig.2016.10.044"
- Description: Four low symmetric A2B meso-substituted Cu(III)corroles with electron withdrawing meso-aryl rings have been synthesized and characterized. A detailed analysis of the optical and redox properties has been carried out by comparing their optical spectroscopy, electrochemistry and spectroelectrochemistry to a series of DFT and TD-DFT calculations. A series of experiments demonstrate that these Cu(III)corroles can be used as highly effective catalysts for hydrogen evolution reactions (HERs). Moreover, when the number of fluorine atoms at B meso-position is increased, there is a marked enhancement in the catalytic ability of the corrole complexes, which demonstrates that modification to the structures of low symmetry corroles is a useful strategy for developing new HER catalysts.
- Full Text:
- Date Issued: 2017
Aardvark burrows: a potential resource for animals in arid and semi-arid environments
- Whittington-Jones, Gareth M, Bernard, Ric T F, Parker, Daniel M
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443852 , vital:74166 , https://doi.org/10.1080/15627020.2011.11407509
- Description: Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.
- Full Text:
- Date Issued: 2011
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443852 , vital:74166 , https://doi.org/10.1080/15627020.2011.11407509
- Description: Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.
- Full Text:
- Date Issued: 2011
Abortion embedded and embodied in social relations: Challenges for feminist psychology
- Marecek, Jeanne, Macleod, Catriona I, Hoggart, Lesley
- Authors: Marecek, Jeanne , Macleod, Catriona I , Hoggart, Lesley
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444223 , vital:74208 , xlink:href="https://doi.org/10.1177/0959353517704877"
- Description: Public health and rights-based approaches to abortion advocacy are well established. Feminists are, however, increasingly using a broader framework of ‘reproductive justice’, which considers the intersecting conditions that serve to enhance or hinder women’s reproductive freedoms, including their capacities to decide about the outcome of their pregnancies. Nonetheless, reproductive justice approaches to abortion are, conceptually, relatively under-developed. We introduce a reparative justice approach as a method of further articulating the concept of reproductive justice. We first explain how this approach can be used to conceptualise safe, accessible and supportive abortion as a key element of reproductive justice in relation to the injustice of unwanted or unsupportable pregnancies. Using Ernesto Verdeja’s critical theory of reparative justice and case studies of two countries (South Africa and Great Britain) where abortion is legal, we show how such an approach enables an analysis of reproductive justice within the specificities of particular contexts. We argue that both the rights-based legal framework adopted in South Africa and the medicalised approach of British law have, in practice, limited reparative justice in these contexts. We discuss the implications of reparative justice for abortion advocacy.
- Full Text:
- Date Issued: 2017
- Authors: Marecek, Jeanne , Macleod, Catriona I , Hoggart, Lesley
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444223 , vital:74208 , xlink:href="https://doi.org/10.1177/0959353517704877"
- Description: Public health and rights-based approaches to abortion advocacy are well established. Feminists are, however, increasingly using a broader framework of ‘reproductive justice’, which considers the intersecting conditions that serve to enhance or hinder women’s reproductive freedoms, including their capacities to decide about the outcome of their pregnancies. Nonetheless, reproductive justice approaches to abortion are, conceptually, relatively under-developed. We introduce a reparative justice approach as a method of further articulating the concept of reproductive justice. We first explain how this approach can be used to conceptualise safe, accessible and supportive abortion as a key element of reproductive justice in relation to the injustice of unwanted or unsupportable pregnancies. Using Ernesto Verdeja’s critical theory of reparative justice and case studies of two countries (South Africa and Great Britain) where abortion is legal, we show how such an approach enables an analysis of reproductive justice within the specificities of particular contexts. We argue that both the rights-based legal framework adopted in South Africa and the medicalised approach of British law have, in practice, limited reparative justice in these contexts. We discuss the implications of reparative justice for abortion advocacy.
- Full Text:
- Date Issued: 2017
Abortion Services and Reproductive Justice in Rural South Africa
- du Plessis, Ulandi, Macleod, Catriona I
- Authors: du Plessis, Ulandi , Macleod, Catriona I
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/434081 , vital:73030 , ISBN 9781776148738 , https://www.witspress.co.za/page/detail/Abortion-Services-and-Reproductive-Justice-in-Rural-South-Africa/?K=9781776148776
- Description: Despite progressive legislation, abortion service implementa-tion and access in South Africa’s rural areas is challenging and directly affects low-income communities. This book urges an intervention for safe and accessible abortion services that does not compromise costs or confidentiality within a repara-tive reproductive justice framework. South Africa’s progressive abortion legislation was hailed as transformative in terms of reproductive health and rights. Despite this promise, many challenges persist resulting in a lack of services, especially in rural areas where distances and transport costs are a factor.
- Full Text:
- Date Issued: 2023
- Authors: du Plessis, Ulandi , Macleod, Catriona I
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/434081 , vital:73030 , ISBN 9781776148738 , https://www.witspress.co.za/page/detail/Abortion-Services-and-Reproductive-Justice-in-Rural-South-Africa/?K=9781776148776
- Description: Despite progressive legislation, abortion service implementa-tion and access in South Africa’s rural areas is challenging and directly affects low-income communities. This book urges an intervention for safe and accessible abortion services that does not compromise costs or confidentiality within a repara-tive reproductive justice framework. South Africa’s progressive abortion legislation was hailed as transformative in terms of reproductive health and rights. Despite this promise, many challenges persist resulting in a lack of services, especially in rural areas where distances and transport costs are a factor.
- Full Text:
- Date Issued: 2023
Absenting absence: Expanding zones of proximal development in environmental learning processes
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436939 , vital:73318 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: In this chapter I demonstrate that indigenous knowledge practice is com mensurate with critical realist scientific practice. Critical realism under labours for Western scien-tific knowledge, helping to bring its practice in line with its theory. In this paper I similarly underlabour for indigenous knowledge. I use examples from the Eastern Coast of Tan-zania to suggest that the kind of knowledge that is gener-ated through indigenous pro cesses is based on retroduc-tive and retrodictive reasoning (as well as induc tive and deductive reasoning) and is thus grounded in the theory development principles of DREI(C)/RRREI(C) which, ac-cording to Bhaskar (1993), is the basis for all scientific knowledge. The chapter therefore creates a basis for indi-viduals, groups, organiza tions, and institutions that are involved in the field of environment and sustainability edu-cation and have an indigenous knowledge component, to use the DREI(C)/RRREI(C) for learning and research pur-poses. In this way, they can assume the commensurablity of both Western scientific knowledge and indigenous knowledge. This work substantiates the signifi cance of indigenous knowledge as science in its own right, which pursues specified scientific principles and procedures to inform practice or praxis in the coastal learning environ-ment in a manner that may enhance social learning. There already exists a body of literature that regards indigenous knowledge as ‘local science’ (Sillitoe, 2007). However, I hope to expand this view by more closely aligning this ‘lo-cal science’ with the same prac tices used by science in general, where this science is defined according to critical realist principles.
- Full Text:
- Date Issued: 2015
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436939 , vital:73318 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: In this chapter I demonstrate that indigenous knowledge practice is com mensurate with critical realist scientific practice. Critical realism under labours for Western scien-tific knowledge, helping to bring its practice in line with its theory. In this paper I similarly underlabour for indigenous knowledge. I use examples from the Eastern Coast of Tan-zania to suggest that the kind of knowledge that is gener-ated through indigenous pro cesses is based on retroduc-tive and retrodictive reasoning (as well as induc tive and deductive reasoning) and is thus grounded in the theory development principles of DREI(C)/RRREI(C) which, ac-cording to Bhaskar (1993), is the basis for all scientific knowledge. The chapter therefore creates a basis for indi-viduals, groups, organiza tions, and institutions that are involved in the field of environment and sustainability edu-cation and have an indigenous knowledge component, to use the DREI(C)/RRREI(C) for learning and research pur-poses. In this way, they can assume the commensurablity of both Western scientific knowledge and indigenous knowledge. This work substantiates the signifi cance of indigenous knowledge as science in its own right, which pursues specified scientific principles and procedures to inform practice or praxis in the coastal learning environ-ment in a manner that may enhance social learning. There already exists a body of literature that regards indigenous knowledge as ‘local science’ (Sillitoe, 2007). However, I hope to expand this view by more closely aligning this ‘lo-cal science’ with the same prac tices used by science in general, where this science is defined according to critical realist principles.
- Full Text:
- Date Issued: 2015
Absenting the absence of parallel learning pathways for intermediate skills: The ‘missing middle' in the environmental sector in South Africa
- Authors: Ramsarup, Presha
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436964 , vital:73320 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: Environment and sustainable development are recognized for: their significance for the future of South Africa’s well-being; their complex, transversal nature; and their associated ‘new-ness’ within South African education and training systems. In a sector with relatively new occupations without clear learning pathways into jobs and where occupational contexts are rapid-ly changing with evolving skill needs, the chapter explores a critical realist dialectical view of learning pathways across sys-tems of work and learning. It highlights the need to develop more sophisticated understandings of learning pathways, and the way in which work, education and training systems inter-face to support the transitions needed for particular forms of work and learning. The chapter also explores how critical real-ist dialectics can help to explain more fully the absence of in-termediate pathways in the environment and sustainable de-velopment ‘sector’ in South Africa. It highlights the absences within the post-school provisioning system and through this analysis raises the patterns of emergence that characterize environmental learning pathways. This then advances an edu-cational critique that assists in the development of deeper knowledge of the object of the study (elements constituting learning pathways) in order to understand possibilities for change and to present opportunities for creating more seam-less environmental learning pathways into green jobs, enhanc-ing social justice potential and public good concerns.
- Full Text:
- Date Issued: 2015
- Authors: Ramsarup, Presha
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436964 , vital:73320 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: Environment and sustainable development are recognized for: their significance for the future of South Africa’s well-being; their complex, transversal nature; and their associated ‘new-ness’ within South African education and training systems. In a sector with relatively new occupations without clear learning pathways into jobs and where occupational contexts are rapid-ly changing with evolving skill needs, the chapter explores a critical realist dialectical view of learning pathways across sys-tems of work and learning. It highlights the need to develop more sophisticated understandings of learning pathways, and the way in which work, education and training systems inter-face to support the transitions needed for particular forms of work and learning. The chapter also explores how critical real-ist dialectics can help to explain more fully the absence of in-termediate pathways in the environment and sustainable de-velopment ‘sector’ in South Africa. It highlights the absences within the post-school provisioning system and through this analysis raises the patterns of emergence that characterize environmental learning pathways. This then advances an edu-cational critique that assists in the development of deeper knowledge of the object of the study (elements constituting learning pathways) in order to understand possibilities for change and to present opportunities for creating more seam-less environmental learning pathways into green jobs, enhanc-ing social justice potential and public good concerns.
- Full Text:
- Date Issued: 2015
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
Abundance and trophodynamics of Euphausia crystallorophias in the shelf region of the Lazarev Sea during austral spring and summer
- Pakhomov, Evgeny A, Perissinotto, Renzo, Froneman, P William
- Authors: Pakhomov, Evgeny A , Perissinotto, Renzo , Froneman, P William
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/480895 , vital:78491 , https://doi.org/10.1016/S0924-7963(98)00046-3
- Description: An investigation to estimate the seasonal changes in feeding habits in relation to the energy budget of Euphausia crystallorophias was carried out during austral spring and summer 1994/95 in the shelf region of the Lazarev Sea.
- Full Text:
- Date Issued: 1998
- Authors: Pakhomov, Evgeny A , Perissinotto, Renzo , Froneman, P William
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/480895 , vital:78491 , https://doi.org/10.1016/S0924-7963(98)00046-3
- Description: An investigation to estimate the seasonal changes in feeding habits in relation to the energy budget of Euphausia crystallorophias was carried out during austral spring and summer 1994/95 in the shelf region of the Lazarev Sea.
- Full Text:
- Date Issued: 1998
Abundance, population structure and harvesting selection of two palm species (Hyphaene coriacea and Phoenix reclinata) in Zitundo area, southern Mozambique
- Martins, Angelina R O, Shackleton, Charlie M
- Authors: Martins, Angelina R O , Shackleton, Charlie M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182003 , vital:43789 , xlink:href="https://doi.org/10.1016/j.foreco.2017.05.005"
- Description: In southern Mozambique, the sap and leaves of the palms Hyphaene coriacea and Phoenix reclinata are harvested by local people as sources of traditional beverages, weaving, roofing, fencing and furniture material. The harvesting of these palm products may affect palm population structure, dynamics and viability. This work evaluates the abundance, population structure and harvesting selection of these two heavily harvested palm species. Hyphaene coriacea was more abundant, with a mean density of 601.5 ± 455.9 stems ha−1 against the 251.9 ± 527.3 stems ha−1 of Phoenix reclinata. Both species exhibited steeper negative slopes in the regression analyses of the size class distribution, indicating the presence of more individuals in smaller size classes. Although there was a dominance of shorter over taller size classes, limited recruitment was observed through low densities of seedling and juvenile size classes compared to the size class 1–50 cm. The Simpson index of dominance, the permutation index, and the fluctuating quotients between the consecutive size classes showed a degree of instability in both populations. Hyphaene coriacea appears to be more resilient to tapping than Phoenix reclinata, evident in the higher rate of stem survival after tapping. Hyphaene coriacea is favored for tapping compared to Phoenix reclinata. Tappers exhibited positive selection for five out of the six Hyphaene coriacea size classes, against only one Phoenix reclinata size class. The most preferred size class to tap for both species was between 101 cm and 150 cm tall. The instability detected by the indices of population stability, the coincidence between the size classes with high numbers of dead stems and the most preferred and the low level of the sexual reproduction encountered in both population emphasizes the need for long-term monitoring as well as management measures that integrate the resource users, to ensure the long-term sustainability of these populations.
- Full Text:
- Date Issued: 2017
- Authors: Martins, Angelina R O , Shackleton, Charlie M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182003 , vital:43789 , xlink:href="https://doi.org/10.1016/j.foreco.2017.05.005"
- Description: In southern Mozambique, the sap and leaves of the palms Hyphaene coriacea and Phoenix reclinata are harvested by local people as sources of traditional beverages, weaving, roofing, fencing and furniture material. The harvesting of these palm products may affect palm population structure, dynamics and viability. This work evaluates the abundance, population structure and harvesting selection of these two heavily harvested palm species. Hyphaene coriacea was more abundant, with a mean density of 601.5 ± 455.9 stems ha−1 against the 251.9 ± 527.3 stems ha−1 of Phoenix reclinata. Both species exhibited steeper negative slopes in the regression analyses of the size class distribution, indicating the presence of more individuals in smaller size classes. Although there was a dominance of shorter over taller size classes, limited recruitment was observed through low densities of seedling and juvenile size classes compared to the size class 1–50 cm. The Simpson index of dominance, the permutation index, and the fluctuating quotients between the consecutive size classes showed a degree of instability in both populations. Hyphaene coriacea appears to be more resilient to tapping than Phoenix reclinata, evident in the higher rate of stem survival after tapping. Hyphaene coriacea is favored for tapping compared to Phoenix reclinata. Tappers exhibited positive selection for five out of the six Hyphaene coriacea size classes, against only one Phoenix reclinata size class. The most preferred size class to tap for both species was between 101 cm and 150 cm tall. The instability detected by the indices of population stability, the coincidence between the size classes with high numbers of dead stems and the most preferred and the low level of the sexual reproduction encountered in both population emphasizes the need for long-term monitoring as well as management measures that integrate the resource users, to ensure the long-term sustainability of these populations.
- Full Text:
- Date Issued: 2017
Academic development: Autonomy pathways towards gaining legitimacy
- Authors: Vorster, Jo-Anne E
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/445759 , vital:74427 , ISBN 9781003028215 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781003028215-16/academic-development-jo-anne-vorster
- Description: Despite playing a critical role in universities grappling with change, practitioners working in the field of academic staff development often struggle with legitimacy. Being a relatively young field in higher education, the challenges faced by these actors are largely un-theorized and under-researched. This chapter explores how academic staff development practitioners at eight universities seek (and gain) legitimacy amongst disciplinary academic peers. Drawing on LCT concepts of ‘autonomy codes’, it analyses practices in terms of the fields from which they come and the purpose to which they are directed. Data include publications by academic developers and interviews with academic developers, academics and senior managers of the eight institutions. The chapter demonstrates how academic developers often struggle to gain legitimacy as they occupy a liminal position between academic or administrative positions in relation to the disciplinary experts they work with. Furthermore, it demonstrates that the most successful academic development work occurs when disciplinary staff view academic development as enabling them to become better teachers. The chapter reveals how legitimacy may be more successfully enabled in the field of academic staff development.
- Full Text:
- Date Issued: 2020
- Authors: Vorster, Jo-Anne E
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/445759 , vital:74427 , ISBN 9781003028215 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781003028215-16/academic-development-jo-anne-vorster
- Description: Despite playing a critical role in universities grappling with change, practitioners working in the field of academic staff development often struggle with legitimacy. Being a relatively young field in higher education, the challenges faced by these actors are largely un-theorized and under-researched. This chapter explores how academic staff development practitioners at eight universities seek (and gain) legitimacy amongst disciplinary academic peers. Drawing on LCT concepts of ‘autonomy codes’, it analyses practices in terms of the fields from which they come and the purpose to which they are directed. Data include publications by academic developers and interviews with academic developers, academics and senior managers of the eight institutions. The chapter demonstrates how academic developers often struggle to gain legitimacy as they occupy a liminal position between academic or administrative positions in relation to the disciplinary experts they work with. Furthermore, it demonstrates that the most successful academic development work occurs when disciplinary staff view academic development as enabling them to become better teachers. The chapter reveals how legitimacy may be more successfully enabled in the field of academic staff development.
- Full Text:
- Date Issued: 2020
Academic discourse: An inter-disciplinary dialogue
- Martin, J R, Maton, Karl, Doran, Y JR
- Authors: Martin, J R , Maton, Karl , Doran, Y JR
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/445880 , vital:74439 , ISBN 9780429280726 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429280726-1/academic-discourse-martin-karl-maton-doran
- Description: This volume has been designed to showcase the cutting-edge of the ever-growing dialogue between systemic functional linguistics (SFL) and Legitimation Code Theory (LCT) and the insights into academic discourse this brings. This opening chapter reviews the foundations of this dialogue and positions the work presented throughout the book within this context. First it steps through the development of SFL work in education, focusing on the register-variable field and how it has been impinged upon by successive developments in Bernstein’s code theory and subsequently LCT. It then introduces how LCT extends and integrates Bernstein’s work to embrace a greater range of phenomena within a more systematic framework. It does this by introducing the dimensions of Specialization and Semantics, and showing the insights these conceptual tools can bring to academic knowledge and academic discourse. Finally, it introduces the chapters that make up the volume and positions them in relation to the ways the LCT–SFL dialogue has driven their understandings. This opening chapter lays the foundations for what is to follow and gives a flavour of energy and explanatory power this dialogue generates.
- Full Text:
- Date Issued: 2019
- Authors: Martin, J R , Maton, Karl , Doran, Y JR
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/445880 , vital:74439 , ISBN 9780429280726 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429280726-1/academic-discourse-martin-karl-maton-doran
- Description: This volume has been designed to showcase the cutting-edge of the ever-growing dialogue between systemic functional linguistics (SFL) and Legitimation Code Theory (LCT) and the insights into academic discourse this brings. This opening chapter reviews the foundations of this dialogue and positions the work presented throughout the book within this context. First it steps through the development of SFL work in education, focusing on the register-variable field and how it has been impinged upon by successive developments in Bernstein’s code theory and subsequently LCT. It then introduces how LCT extends and integrates Bernstein’s work to embrace a greater range of phenomena within a more systematic framework. It does this by introducing the dimensions of Specialization and Semantics, and showing the insights these conceptual tools can bring to academic knowledge and academic discourse. Finally, it introduces the chapters that make up the volume and positions them in relation to the ways the LCT–SFL dialogue has driven their understandings. This opening chapter lays the foundations for what is to follow and gives a flavour of energy and explanatory power this dialogue generates.
- Full Text:
- Date Issued: 2019