(Unused) potentials of educators’ covert language policies at public schools in Limpopo, South Africa:
- Kretzer, Michael M, Kaschula, Russell H
- Authors: Kretzer, Michael M , Kaschula, Russell H
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174679 , vital:42500 , DOI: 10.1039/D0PP00075B
- Description: Language policy is an influencing factor of the educational outcome for pupils in Africa. Colonial languages have been largely used and African Languages are neglected. Despite this, the South African Constitution (1996) declares eleven official languages. However, curricular developments favour Afrikaans and English. To analyse the implementation of the official language policy, we focus on Limpopo Province. Over 1000 questionnaires were answered by teachers. This approach aimed to analyse the language practices and language attitudes of teachers. Schools in Limpopo showed significant differences between the official language policy and the daily language practices. Some teachers implement the official language policy; others use one or more African languages in their oral communications during the lessons in the form of Code Switching.
- Full Text:
- Date Issued: 2020
- Authors: Kretzer, Michael M , Kaschula, Russell H
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174679 , vital:42500 , DOI: 10.1039/D0PP00075B
- Description: Language policy is an influencing factor of the educational outcome for pupils in Africa. Colonial languages have been largely used and African Languages are neglected. Despite this, the South African Constitution (1996) declares eleven official languages. However, curricular developments favour Afrikaans and English. To analyse the implementation of the official language policy, we focus on Limpopo Province. Over 1000 questionnaires were answered by teachers. This approach aimed to analyse the language practices and language attitudes of teachers. Schools in Limpopo showed significant differences between the official language policy and the daily language practices. Some teachers implement the official language policy; others use one or more African languages in their oral communications during the lessons in the form of Code Switching.
- Full Text:
- Date Issued: 2020
A search for enhanced photodynamic activity against Staphylococcus aureus planktonic cells and biofilms: the evaluation of phthalocyanine–detonation nanodiamond–Ag nanoconjugates
- Openda, Yolande Ikala, Matshitse, Refilwe, Nyokong, Tebello
- Authors: Openda, Yolande Ikala , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163825 , vital:41073 , DOI: 10.1039/D0PP00075B
- Description: The present work reports on the synthesis and characterization of novel zinc (2) and indium (3) 2-amino-4-bromophenoxy substituted phthalocyanines (Pcs) along with the self-assembled nanoconjugates formed via π–π stacking interaction onto detonation nanodiamonds (DNDs) to form 2@DNDs and 3@DNDs. 2@DNDs and 3@DNDs were covalently linked to chitosan–silver mediated nanoparticles (CSAg) to form 2@DNDs-CSAg and 3@DNDs-CSAg nanoconjugates. High singlet oxygen quantum yields in DMSO of 0.69 and 0.72 for Pcs alone and 0.90 and 0.92 for 2@DNDs-CSAg and 3@DNDs-CSAg, respectively, were obtained.
- Full Text:
- Date Issued: 2020
- Authors: Openda, Yolande Ikala , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163825 , vital:41073 , DOI: 10.1039/D0PP00075B
- Description: The present work reports on the synthesis and characterization of novel zinc (2) and indium (3) 2-amino-4-bromophenoxy substituted phthalocyanines (Pcs) along with the self-assembled nanoconjugates formed via π–π stacking interaction onto detonation nanodiamonds (DNDs) to form 2@DNDs and 3@DNDs. 2@DNDs and 3@DNDs were covalently linked to chitosan–silver mediated nanoparticles (CSAg) to form 2@DNDs-CSAg and 3@DNDs-CSAg nanoconjugates. High singlet oxygen quantum yields in DMSO of 0.69 and 0.72 for Pcs alone and 0.90 and 0.92 for 2@DNDs-CSAg and 3@DNDs-CSAg, respectively, were obtained.
- Full Text:
- Date Issued: 2020
An effort to study the influence of tides on the longitudinal variation of vertical E× B drift over the African sector:
- Habyarimana, Valence, Habarulema, John B, Mungufeni, Patrick, Uwamahoro, Jean C
- Authors: Habyarimana, Valence , Habarulema, John B , Mungufeni, Patrick , Uwamahoro, Jean C
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149026 , vital:38797 , https://doi.org/10.1016/j.jastp.2020.105338
- Description: Meteorological processes such as tides influence ionospheric variability through vertical coupling. For the first time, we have used data from Communication Navigation Outage and Forecasting System (C/NOFS) satellite from 2008–2015 to develop a Neural Network (NN) vertical E×B drift model over the African region, with inclusion of a proxy of tides as one of the inputs together with other physical and geophysical inputs. Two models (with and without tidal proxy input) were developed for both East and West African sectors. To derive the tidal proxy, we first calculate the 60-day running means per year which were subtracted from the actual vertical E×B drift measurements to obtain a set of residuals. The purpose of the subtraction was to remove long-term trends in vertical E×B drift that could potentially alias into tides.
- Full Text:
- Date Issued: 2020
- Authors: Habyarimana, Valence , Habarulema, John B , Mungufeni, Patrick , Uwamahoro, Jean C
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149026 , vital:38797 , https://doi.org/10.1016/j.jastp.2020.105338
- Description: Meteorological processes such as tides influence ionospheric variability through vertical coupling. For the first time, we have used data from Communication Navigation Outage and Forecasting System (C/NOFS) satellite from 2008–2015 to develop a Neural Network (NN) vertical E×B drift model over the African region, with inclusion of a proxy of tides as one of the inputs together with other physical and geophysical inputs. Two models (with and without tidal proxy input) were developed for both East and West African sectors. To derive the tidal proxy, we first calculate the 60-day running means per year which were subtracted from the actual vertical E×B drift measurements to obtain a set of residuals. The purpose of the subtraction was to remove long-term trends in vertical E×B drift that could potentially alias into tides.
- Full Text:
- Date Issued: 2020
An integrated analytical framework for analysing expansive learning in improved cook stove practice:
- Jalasi, Experencia Madalitso
- Authors: Jalasi, Experencia Madalitso
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149043 , vital:38798 , https://doi.org/10.1016/j.lcsi.2020.100414
- Description: This paper reveals relationships between four analytical frameworks, boundary interaction, reflexivity, transformative agency, and Sannino's reformulated Vygotskian double stimulation model in an Integrated Analytical Framework (IAF) used to analyse expansive learning processes via Boundary Crossing Change Laboratory Workshops in the development of will and volitional actions. I show how transformation emerges from expansive learning processes using two Transformative Pathways in Improved Cook Stove (ICS) practice in Chapita Village case study in Malawi. Introduction of ICSs in the traditional cooking practice generated conflict of motives within subjects of interacting activity systems. I used Cultural Historical Activity Theory (CHAT) to identify and analyse the conflict of motives using socio-cultural historical analysis and analysis of contradictions around learning, promotion, and utilisation of the ICS.
- Full Text:
- Date Issued: 2020
An integrated analytical framework for analysing expansive learning in improved cook stove practice:
- Authors: Jalasi, Experencia Madalitso
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149043 , vital:38798 , https://doi.org/10.1016/j.lcsi.2020.100414
- Description: This paper reveals relationships between four analytical frameworks, boundary interaction, reflexivity, transformative agency, and Sannino's reformulated Vygotskian double stimulation model in an Integrated Analytical Framework (IAF) used to analyse expansive learning processes via Boundary Crossing Change Laboratory Workshops in the development of will and volitional actions. I show how transformation emerges from expansive learning processes using two Transformative Pathways in Improved Cook Stove (ICS) practice in Chapita Village case study in Malawi. Introduction of ICSs in the traditional cooking practice generated conflict of motives within subjects of interacting activity systems. I used Cultural Historical Activity Theory (CHAT) to identify and analyse the conflict of motives using socio-cultural historical analysis and analysis of contradictions around learning, promotion, and utilisation of the ICS.
- Full Text:
- Date Issued: 2020
Coastal engineers embrace nature: characterizing the metamorphosis in hydraulic engineering in terms of Four Continua
- Slinger, Jill H, Vreugdenhil, Heleen S I
- Authors: Slinger, Jill H , Vreugdenhil, Heleen S I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163846 , vital:41076 , https://doi.org/10.3390/w12092504
- Description: Hydraulic engineering infrastructures, such as reservoirs, dikes, breakwaters, and inlet closures, have significantly impacted ecosystem functioning over the last two centuries. Currently, nature-based solutions are receiving increasing attention in hydraulic engineering projects and research programs. However, there is a lack of reflection on the concomitant, fundamental changes occurring in the field of hydraulic engineering, and coastal engineering in particular, and what this could mean for sustainability. In this article, we signal the shift from conventional to ecosystem-based hydraulic engineering design and characterize this in terms of four continua: (i) the degree of inclusion of ecological knowledge, (ii) the extent to which the full infrastructural lifecycle is addressed, (iii) the complexity of the actor arena taken into account, and (iv) the resulting form of the infrastructural artefact. We support our arguments with two carefully selected, iconic examples from the Netherlands and indicate how the stretching ideals of ecosystem-based engineering could engender further shifts towards sustainability.
- Full Text:
- Date Issued: 2020
- Authors: Slinger, Jill H , Vreugdenhil, Heleen S I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163846 , vital:41076 , https://doi.org/10.3390/w12092504
- Description: Hydraulic engineering infrastructures, such as reservoirs, dikes, breakwaters, and inlet closures, have significantly impacted ecosystem functioning over the last two centuries. Currently, nature-based solutions are receiving increasing attention in hydraulic engineering projects and research programs. However, there is a lack of reflection on the concomitant, fundamental changes occurring in the field of hydraulic engineering, and coastal engineering in particular, and what this could mean for sustainability. In this article, we signal the shift from conventional to ecosystem-based hydraulic engineering design and characterize this in terms of four continua: (i) the degree of inclusion of ecological knowledge, (ii) the extent to which the full infrastructural lifecycle is addressed, (iii) the complexity of the actor arena taken into account, and (iv) the resulting form of the infrastructural artefact. We support our arguments with two carefully selected, iconic examples from the Netherlands and indicate how the stretching ideals of ecosystem-based engineering could engender further shifts towards sustainability.
- Full Text:
- Date Issued: 2020
Cytotoxicity of triterpenoids from Clerodendrum glabrum against triple negative breast cancer cells in vitro:
- Teclegeorgish, Zecarias W, Mokgalaka, Ntebogeng S, Vukea, Nyeleti, de la Mare, Jo-Anne, Tembu, Vuyelwa J
- Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
- Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
- Full Text:
- Date Issued: 2020
- Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
- Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
- Full Text:
- Date Issued: 2020
Effect of a low density dust shell on the propagation of gravitational waves:
- Bishop, Nigel T, van der Walt, Petrus J, Naidoo, Monos
- Authors: Bishop, Nigel T , van der Walt, Petrus J , Naidoo, Monos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159935 , vital:40357 , https://0-doi.org.wam.seals.ac.za/10.1007/s10714-020-02740-9
- Description: Using the Bondi-Sachs formalism, the problem of a gravitational wave source surrounded by a spherical dust shell is considered. Using linearized perturbation theory, the geometry is found in the regions: in the shell, exterior to the shell, and interior to the shell. It is found that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust.
- Full Text:
- Date Issued: 2020
- Authors: Bishop, Nigel T , van der Walt, Petrus J , Naidoo, Monos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159935 , vital:40357 , https://0-doi.org.wam.seals.ac.za/10.1007/s10714-020-02740-9
- Description: Using the Bondi-Sachs formalism, the problem of a gravitational wave source surrounded by a spherical dust shell is considered. Using linearized perturbation theory, the geometry is found in the regions: in the shell, exterior to the shell, and interior to the shell. It is found that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust.
- Full Text:
- Date Issued: 2020
From the Booth to the Dock: 2018 elections in Zimbabwe and the elusive search for electoral integrity
- Mwonzora, Gift, Xaba, Mzingaye Brilliant
- Authors: Mwonzora, Gift , Xaba, Mzingaye Brilliant
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159946 , vital:40358 , https://doi.org/10.1080/14662043.2020.1813457
- Description: The issue of presidential election petitions seems to be repeating itself with regularity in much of Africa, thus warranting the need for thorough analysis. Utilising the 2018 presidential election petition in Zimbabwe, the article examines whether electoral integrity and legitimacy can be derived from court-based action. Data for this article was gleaned from case law analysis, review of expert analysis from constitutional lawyers and election experts, video evidence, in-depth and critical reading of grey material. The article concludes that there are limitations in relying on litigation in seeking to realise electoral justice in much of Africa, including in Zimbabwe.
- Full Text:
- Date Issued: 2020
- Authors: Mwonzora, Gift , Xaba, Mzingaye Brilliant
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159946 , vital:40358 , https://doi.org/10.1080/14662043.2020.1813457
- Description: The issue of presidential election petitions seems to be repeating itself with regularity in much of Africa, thus warranting the need for thorough analysis. Utilising the 2018 presidential election petition in Zimbabwe, the article examines whether electoral integrity and legitimacy can be derived from court-based action. Data for this article was gleaned from case law analysis, review of expert analysis from constitutional lawyers and election experts, video evidence, in-depth and critical reading of grey material. The article concludes that there are limitations in relying on litigation in seeking to realise electoral justice in much of Africa, including in Zimbabwe.
- Full Text:
- Date Issued: 2020
High genetic diversity and limited spatial structure in an endangered, endemic South African sparid, the red steenbras Petrus rupestris:
- Gouws, Gavin, Kerwath, S E, Potts, Warren M, James, Nicola C, Vine, Niall G, Cowley, Paul D
- Authors: Gouws, Gavin , Kerwath, S E , Potts, Warren M , James, Nicola C , Vine, Niall G , Cowley, Paul D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160379 , vital:40440 , DOI: 10.2989/1814232X.2020.1788640
- Description: The red steenbras Petrus rupestris is endemic to South Africa, occurring from False Bay in the Western Cape Province to St Lucia in the province of KwaZulu-Natal. This species, the largest member of the family Sparidae, has undergone a substantial stock decline as a result of overfishing and is considered to be collapsed. Various aspects of its life history, including high residency, predictable migrations, late maturity and longevity, have made it vulnerable to overexploitation. This study analysed the diversity and genetic structure of red steenbras across seven sampling regions, using mitochondrial (control region) and nuclear (S7 intron 1) DNA markers.
- Full Text:
- Date Issued: 2020
- Authors: Gouws, Gavin , Kerwath, S E , Potts, Warren M , James, Nicola C , Vine, Niall G , Cowley, Paul D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160379 , vital:40440 , DOI: 10.2989/1814232X.2020.1788640
- Description: The red steenbras Petrus rupestris is endemic to South Africa, occurring from False Bay in the Western Cape Province to St Lucia in the province of KwaZulu-Natal. This species, the largest member of the family Sparidae, has undergone a substantial stock decline as a result of overfishing and is considered to be collapsed. Various aspects of its life history, including high residency, predictable migrations, late maturity and longevity, have made it vulnerable to overexploitation. This study analysed the diversity and genetic structure of red steenbras across seven sampling regions, using mitochondrial (control region) and nuclear (S7 intron 1) DNA markers.
- Full Text:
- Date Issued: 2020
Integrative taxonomy reveals hidden diversity in the southern African darters genus Nannocharax Günther 1867 (Characiformes: Distichodontidae):
- Bragança, Pedro H N, Smith, Timothy G, Vreven, Emmanuel J W M N, Chakona, Albert
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163510 , vital:41044 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163510 , vital:41044 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
Integrative taxonomy reveals hidden diversity in the southern African darters genus Nannocharax Günther 1867 (Characiformes: Distichodontidae):
- Bragança, Pedro H N, Smith, Timothy G, Vreven, Emmanuel J W M N, Chakona, Albert
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163543 , vital:41047 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163543 , vital:41047 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
Movement patterns of the epizoic limpet Lottia tenuisculpta on two host snails Omphalius nigerrimus and Reishia clavigera:
- Nakano, Tomoyuki, Okumura, Yousuke, Nakayama, Ryo, Seuront, Laurent
- Authors: Nakano, Tomoyuki , Okumura, Yousuke , Nakayama, Ryo , Seuront, Laurent
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160268 , vital:40429 , DOI: 10.1080/13235818.2020.1808280
- Description: The tiny epizoic limpet Lottia tenuisculpta lives on rocky surfaces and shells of the snails Omphalius nigerrimus and Reishia clavigera. The movement patterns of the limpet on host snails was observed during 24 h under controlled laboratory conditions. A specific behaviour, referred to as returning behaviour and reminiscent of homing behaviour, was observed in seven out of 20 individuals, and two out of 15 individuals on O. nigerrimus and R. clavigera, respectively.
- Full Text:
- Date Issued: 2020
- Authors: Nakano, Tomoyuki , Okumura, Yousuke , Nakayama, Ryo , Seuront, Laurent
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160268 , vital:40429 , DOI: 10.1080/13235818.2020.1808280
- Description: The tiny epizoic limpet Lottia tenuisculpta lives on rocky surfaces and shells of the snails Omphalius nigerrimus and Reishia clavigera. The movement patterns of the limpet on host snails was observed during 24 h under controlled laboratory conditions. A specific behaviour, referred to as returning behaviour and reminiscent of homing behaviour, was observed in seven out of 20 individuals, and two out of 15 individuals on O. nigerrimus and R. clavigera, respectively.
- Full Text:
- Date Issued: 2020
Natural hair chronicles of black female vloggers: influences on their psychological well-being
- Jacobs, Liezille, Kelemi, Anelisa
- Authors: Jacobs, Liezille , Kelemi, Anelisa
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158354 , vital:40177 , https://doi.org/10.1080/14330237.2020.1796046
- Description: This study explored how hair texture chronicles in a post-colonial country is influenced by psychological well-being and a sense of self in women. Our informants were 10 female, black, South African YouTube vloggers, with Afro-textured, frizzy, natural hair. The participants completed qualitative descriptions of their hair chronicles with vlogging. Thematic analysis of the data yielded the following themes: (i) untangling the politics of hair, identity, and race through transitioning hair stories; (ii) hair chronicles for psychological well-being; and (iii) empowerment from wearing natural hair.
- Full Text:
- Date Issued: 2020
- Authors: Jacobs, Liezille , Kelemi, Anelisa
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158354 , vital:40177 , https://doi.org/10.1080/14330237.2020.1796046
- Description: This study explored how hair texture chronicles in a post-colonial country is influenced by psychological well-being and a sense of self in women. Our informants were 10 female, black, South African YouTube vloggers, with Afro-textured, frizzy, natural hair. The participants completed qualitative descriptions of their hair chronicles with vlogging. Thematic analysis of the data yielded the following themes: (i) untangling the politics of hair, identity, and race through transitioning hair stories; (ii) hair chronicles for psychological well-being; and (iii) empowerment from wearing natural hair.
- Full Text:
- Date Issued: 2020
Occurrence of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of South Africa using photographic identification:
- Caputo, Michelle, Bouveroux, Thibaut, Froneman, P William, Shaanika, Titus, Plön, Stephanie
- Authors: Caputo, Michelle , Bouveroux, Thibaut , Froneman, P William , Shaanika, Titus , Plön, Stephanie
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160367 , vital:40439 , https://0-doi.org.wam.seals.ac.za/10.1111/mms.12740
- Description: The present study represents the first reported boat‐based photographic identification study of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of southeast South Africa. This area is known for the annual sardine run, which attracts apex predators to the region during the austral winter. Dedicated photo‐identification surveys were conducted along this coast at three different study sites in February, June, and November of each year from 2014 to 2016.
- Full Text:
- Date Issued: 2020
- Authors: Caputo, Michelle , Bouveroux, Thibaut , Froneman, P William , Shaanika, Titus , Plön, Stephanie
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160367 , vital:40439 , https://0-doi.org.wam.seals.ac.za/10.1111/mms.12740
- Description: The present study represents the first reported boat‐based photographic identification study of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of southeast South Africa. This area is known for the annual sardine run, which attracts apex predators to the region during the austral winter. Dedicated photo‐identification surveys were conducted along this coast at three different study sites in February, June, and November of each year from 2014 to 2016.
- Full Text:
- Date Issued: 2020
Passphrase and Keystroke Dynamics Authentication: Usable Security
- Bhana, Bhaveer, Flowerday, Stephen
- Authors: Bhana, Bhaveer , Flowerday, Stephen
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158372 , vital:40178 , https://doi.org/10.1016/j.cose.2020.101925
- Description: It was found that employees spend a total of 2.25 days within 60 days on password-related activities. The time consumed by this is unproductive and has a negative impact on usability. The problem is caused by current text-based user authentication policies in use. This study aims to address this research problem by assessing the effectiveness of a proposed two-tier user authentication solution involving passphrases and keystroke dynamics.
- Full Text:
- Date Issued: 2020
- Authors: Bhana, Bhaveer , Flowerday, Stephen
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158372 , vital:40178 , https://doi.org/10.1016/j.cose.2020.101925
- Description: It was found that employees spend a total of 2.25 days within 60 days on password-related activities. The time consumed by this is unproductive and has a negative impact on usability. The problem is caused by current text-based user authentication policies in use. This study aims to address this research problem by assessing the effectiveness of a proposed two-tier user authentication solution involving passphrases and keystroke dynamics.
- Full Text:
- Date Issued: 2020
Photodynamic antimicrobial chemotherapy of a dimethylamino-functionalized asymmetric zinc (II) phthalocyanine and its quaternized derivative against Staphylococcus aureus when supported on asymmetric polystyrene polymer membranes:
- Mafukidze, Donovan Musizvinoda Chidyamurimi, Nyokong, Tebello
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148595 , vital:38753 , https://doi.org/10.1016/j.reactfunctpolym.2020.104634
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148595 , vital:38753 , https://doi.org/10.1016/j.reactfunctpolym.2020.104634
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
Privacy risk and the use of Facebook Apps: a gender-focused vulnerability assessment
- van der Schyff, Karl, Flowerday, Stephen, Furnell, Steven
- Authors: van der Schyff, Karl , Flowerday, Stephen , Furnell, Steven
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149054 , vital:38800 , https://doi.org/10.1016/j.cose.2020.101866
- Description: The surveillance and subsequent privacy risks (i.e., misuse of personal information) of Facebook App data constitute a persistent problem that affects millions of users. However, despite Facebook App research on specifics such as privacy concerns, value of information, and demographics, none of them has conducted vulnerability assessments on the use of Facebook Apps as influenced by specific factors such as age, gender, and information privacy attitudes. As such, the purpose of this study was to predict the extent to which these factors influence an individual's intention to continue using Facebook Apps as part of a gender-focused vulnerability assessment. We evaluate two hypotheses by way of ordinal logistic regression using data gathered from 621 respondents. The results are indicative of the following: First, females are particularly vulnerable to privacy risks as a function of continued use of Facebook Apps. More specifically, those risks related to Facebook's access to personal information. Second, results indicate that a user's age is nonsignificant in relation to the continued use of Facebook Apps. We conclude with several theoretical and practice-oriented information privacy recommendations.
- Full Text:
- Date Issued: 2020
- Authors: van der Schyff, Karl , Flowerday, Stephen , Furnell, Steven
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149054 , vital:38800 , https://doi.org/10.1016/j.cose.2020.101866
- Description: The surveillance and subsequent privacy risks (i.e., misuse of personal information) of Facebook App data constitute a persistent problem that affects millions of users. However, despite Facebook App research on specifics such as privacy concerns, value of information, and demographics, none of them has conducted vulnerability assessments on the use of Facebook Apps as influenced by specific factors such as age, gender, and information privacy attitudes. As such, the purpose of this study was to predict the extent to which these factors influence an individual's intention to continue using Facebook Apps as part of a gender-focused vulnerability assessment. We evaluate two hypotheses by way of ordinal logistic regression using data gathered from 621 respondents. The results are indicative of the following: First, females are particularly vulnerable to privacy risks as a function of continued use of Facebook Apps. More specifically, those risks related to Facebook's access to personal information. Second, results indicate that a user's age is nonsignificant in relation to the continued use of Facebook Apps. We conclude with several theoretical and practice-oriented information privacy recommendations.
- Full Text:
- Date Issued: 2020
Probing the structural dynamics of the Plasmodium falciparum tunneling-fold enzyme 6-pyruvoyl tetrahydropterin synthase to reveal allosteric drug targeting sites:
- Khairallah, Afrah, Ross, Caroline J, Tastan Bishop, Özlem
- Authors: Khairallah, Afrah , Ross, Caroline J , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163057 , vital:41008 , https://doi.org/10.3389/fmolb.2020.575196
- Description: The de novo folate synthesis pathway is a well-established drug target in the treatment of many infectious diseases. Antimalarial antifolate drugs have proven to be effective against malaria, however, rapid drug resistance has emerged on the two primary targeted enzymes: dihydrofolate reductase and dihydroptoreate synthase. The need to identify alternative antifolate drugs and novel metabolic targets is of imminent importance. The 6-pyruvol tetrahydropterin synthase (PTPS) enzyme belongs to the tunneling fold protein superfamily which is characterized by a distinct central tunnel/cavity. The enzyme catalyzes the second reaction step of the parasite’s de novo folate synthesis pathway and is responsible for the conversion of 7,8-dihydroneopterin to 6-pyruvoyl-tetrahydropterin. In this study, we examine the structural dynamics of Plasmodium falciparum PTPS using the anisotropic network model, to elucidate the collective motions that drive the function of the enzyme and identify potential sites for allosteric modulation of its binding properties.
- Full Text:
- Date Issued: 2020
- Authors: Khairallah, Afrah , Ross, Caroline J , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163057 , vital:41008 , https://doi.org/10.3389/fmolb.2020.575196
- Description: The de novo folate synthesis pathway is a well-established drug target in the treatment of many infectious diseases. Antimalarial antifolate drugs have proven to be effective against malaria, however, rapid drug resistance has emerged on the two primary targeted enzymes: dihydrofolate reductase and dihydroptoreate synthase. The need to identify alternative antifolate drugs and novel metabolic targets is of imminent importance. The 6-pyruvol tetrahydropterin synthase (PTPS) enzyme belongs to the tunneling fold protein superfamily which is characterized by a distinct central tunnel/cavity. The enzyme catalyzes the second reaction step of the parasite’s de novo folate synthesis pathway and is responsible for the conversion of 7,8-dihydroneopterin to 6-pyruvoyl-tetrahydropterin. In this study, we examine the structural dynamics of Plasmodium falciparum PTPS using the anisotropic network model, to elucidate the collective motions that drive the function of the enzyme and identify potential sites for allosteric modulation of its binding properties.
- Full Text:
- Date Issued: 2020
Quantifying the impacts of abrasion and bacterial transfer when fish are exposed to sand during a catch-and-release event:
- Foster, Ryan M, Childs, Amber-Robyn, Brooks, Margot, Farthing, Matthew W, Butler, Edward C, Potts, Warren M
- Authors: Foster, Ryan M , Childs, Amber-Robyn , Brooks, Margot , Farthing, Matthew W , Butler, Edward C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160427 , vital:40445 , https://doi.org/10.2989/1814232X.2020.1792982
- Description: Best-practice guidelines to improve recreational fishers’ handling during catch-and-release (CandR) events are critical to improve the conservation and management of fish stocks worldwide. While best-practice research is growing, there are knowledge gaps, with the effects of sand exposure on fish mucous membranes understudied. This study aimed to determine the effects of exposing a fish to sand during a CandR event. A total of 360 juvenile (48–137 mm TL) Cape stumpnose Rhabdosargus holubi were subjected to a simulated CandR event during which they were either held: (i) with wet hands, or (ii) dry hands; or with wet hands and then placed on either (iii) wet sterilised sand, (iv) dry sterilised sand, (v) wet unsterilised sand, or (vi) dry unsterilised sand. Fish were maintained in a recirculating system for two weeks, euthanised and subjected to an examination of their mucous layer (bacterial counts, abrasion counts and percentage of abrasion area) and an internal biological assessment. Bacteria fro m fish mucous layers were cultivated on agar plates to count bacterial colonies.
- Full Text:
- Date Issued: 2020
- Authors: Foster, Ryan M , Childs, Amber-Robyn , Brooks, Margot , Farthing, Matthew W , Butler, Edward C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160427 , vital:40445 , https://doi.org/10.2989/1814232X.2020.1792982
- Description: Best-practice guidelines to improve recreational fishers’ handling during catch-and-release (CandR) events are critical to improve the conservation and management of fish stocks worldwide. While best-practice research is growing, there are knowledge gaps, with the effects of sand exposure on fish mucous membranes understudied. This study aimed to determine the effects of exposing a fish to sand during a CandR event. A total of 360 juvenile (48–137 mm TL) Cape stumpnose Rhabdosargus holubi were subjected to a simulated CandR event during which they were either held: (i) with wet hands, or (ii) dry hands; or with wet hands and then placed on either (iii) wet sterilised sand, (iv) dry sterilised sand, (v) wet unsterilised sand, or (vi) dry unsterilised sand. Fish were maintained in a recirculating system for two weeks, euthanised and subjected to an examination of their mucous layer (bacterial counts, abrasion counts and percentage of abrasion area) and an internal biological assessment. Bacteria fro m fish mucous layers were cultivated on agar plates to count bacterial colonies.
- Full Text:
- Date Issued: 2020
Researching mobile phones in the everyday life of the “less connected”: the development of a New Diary Method
- de Lanerolle, Indra, Schoon, Alette, Walton, Marion
- Authors: de Lanerolle, Indra , Schoon, Alette , Walton, Marion
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160413 , vital:40443 , DOI: 10.1080/23743670.2020.1813785
- Description: This article introduces our mobile diary method, a qualitative method for the study of mobile phone practices. Adapted from the diary methods of psychology and media studies audience research, it is designed to foreground tacit and mundane data about everyday mobile phone practices. The diary interview reconstructs details of the social practices of everyday life that make up each participant’s “yesterday” and situates mobile practices within this account. To illustrate the method, we provide examples from our study, Izolo, that spanned three distinct South African neighbourhoods in different parts of the country and focused on less-connected people.
- Full Text:
- Date Issued: 2020
- Authors: de Lanerolle, Indra , Schoon, Alette , Walton, Marion
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160413 , vital:40443 , DOI: 10.1080/23743670.2020.1813785
- Description: This article introduces our mobile diary method, a qualitative method for the study of mobile phone practices. Adapted from the diary methods of psychology and media studies audience research, it is designed to foreground tacit and mundane data about everyday mobile phone practices. The diary interview reconstructs details of the social practices of everyday life that make up each participant’s “yesterday” and situates mobile practices within this account. To illustrate the method, we provide examples from our study, Izolo, that spanned three distinct South African neighbourhoods in different parts of the country and focused on less-connected people.
- Full Text:
- Date Issued: 2020