Iodine nutrition status in Africa: Potentially high prevalence of iodine deficiency in pregnancy even in countries classified as iodine sufficient
- Charles Bitamazire Businge, Benjamin Longo-Mbenza, Andre Pascal Kengne
- Authors: Charles Bitamazire Businge , Benjamin Longo-Mbenza , Andre Pascal Kengne
- Date: 03-8-2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3377 , vital:43336 , https://www.cambridge.org/core/journals/public-health-nutrition/article/iodine-nutrition-status-in-africa-potentially-high-prevalence-of-iodine-deficiency-in-pregnancy-even-in-countries-classified-as-iodine-sufficient/B3DCB06E75CDDD8EAD410BE090198BA4
- Description: Objective: To assess the burden of iodine deficiency in pregnancy in Africa using estimated pregnancy median urinary iodine concentration (pMUIC). Design: pMUIC for each African country was estimated using a regression equation derived by correlating the school-age children (SAC) median UIC (mUIC) and pMUIC from countries around the globe, and the SAC mUIC data for African countries obtained from the Iodine Global Network (IGN) 2017 and 2019 Score cards. Setting: Iodine deficiency was endemic in many African countries before the introduction of iodine fortification, mainly through universal salt iodisation programmes about 25 years ago. There is a scarcity of data on the level of iodine nutrition in pregnancy in Africa. Women living in settings with pMUIC below 150 μg/l are at risk of iodine deficiency-related pregnancy complications. Participants: Fifty of the fifty-five African countries that had data on iodine nutrition status. Results: A cut-off school age mUIC ≤ 175 μg/l is correlated with insufficient iodine intake in pregnancy (pregnancy mUIC ≤ 150 μg/l). Twenty-two African countries had SAC mUIC less than 175 μg/l, which correlated with insufficient iodine intake during pregnancy (pMUIC less than 150 μg/l). However, nine of these twenty-two countries had adequate iodine intake based on SAC mUIC. Conclusions: There is likely a high prevalence of insufficient iodine intake in pregnancy, including in some African countries classified as having adequate iodine intake in the general population. A SAC mUIC ≤ 175 μ
- Full Text:
- Date Issued: 03-8-2020
- Authors: Charles Bitamazire Businge , Benjamin Longo-Mbenza , Andre Pascal Kengne
- Date: 03-8-2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3377 , vital:43336 , https://www.cambridge.org/core/journals/public-health-nutrition/article/iodine-nutrition-status-in-africa-potentially-high-prevalence-of-iodine-deficiency-in-pregnancy-even-in-countries-classified-as-iodine-sufficient/B3DCB06E75CDDD8EAD410BE090198BA4
- Description: Objective: To assess the burden of iodine deficiency in pregnancy in Africa using estimated pregnancy median urinary iodine concentration (pMUIC). Design: pMUIC for each African country was estimated using a regression equation derived by correlating the school-age children (SAC) median UIC (mUIC) and pMUIC from countries around the globe, and the SAC mUIC data for African countries obtained from the Iodine Global Network (IGN) 2017 and 2019 Score cards. Setting: Iodine deficiency was endemic in many African countries before the introduction of iodine fortification, mainly through universal salt iodisation programmes about 25 years ago. There is a scarcity of data on the level of iodine nutrition in pregnancy in Africa. Women living in settings with pMUIC below 150 μg/l are at risk of iodine deficiency-related pregnancy complications. Participants: Fifty of the fifty-five African countries that had data on iodine nutrition status. Results: A cut-off school age mUIC ≤ 175 μg/l is correlated with insufficient iodine intake in pregnancy (pregnancy mUIC ≤ 150 μg/l). Twenty-two African countries had SAC mUIC less than 175 μg/l, which correlated with insufficient iodine intake during pregnancy (pMUIC less than 150 μg/l). However, nine of these twenty-two countries had adequate iodine intake based on SAC mUIC. Conclusions: There is likely a high prevalence of insufficient iodine intake in pregnancy, including in some African countries classified as having adequate iodine intake in the general population. A SAC mUIC ≤ 175 μ
- Full Text:
- Date Issued: 03-8-2020
Exploring a systems approach to mainstreaming sustainability in universities: A case study of Rhodes University in South Africa
- Togo, Muchaiteyi, Lotz-Sisitka, Heila
- Authors: Togo, Muchaiteyi , Lotz-Sisitka, Heila
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182857 , vital:43886 , xlink:href="https://doi.org/10.1080/13504622.2012.749974"
- Description: This paper explores the use of systems theory to inform the mainstreaming of sustainability in a university’s functions as it responds to sustainable development challenges in its local context. Offering a case study of Rhodes University, the paper shows how the use of systems models and concepts, underpinned by a critical realist ontology and an understanding of morphogenetic change processes, have the potential to enable universities to mobilise their operations to respond to local sustainability challenges. In this instance, the success of such an approach is shown to depend on commitments from the university community and the availability of enabling inputs, such as financial and human resources. The paper concludes with reflections and recommendations to inform further development of a newly emerging systems approach in sustainability mainstreaming at Rhodes University, and other institutions pursuing similar approaches and goals.
- Full Text:
- Date Issued: 2013
- Authors: Togo, Muchaiteyi , Lotz-Sisitka, Heila
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182857 , vital:43886 , xlink:href="https://doi.org/10.1080/13504622.2012.749974"
- Description: This paper explores the use of systems theory to inform the mainstreaming of sustainability in a university’s functions as it responds to sustainable development challenges in its local context. Offering a case study of Rhodes University, the paper shows how the use of systems models and concepts, underpinned by a critical realist ontology and an understanding of morphogenetic change processes, have the potential to enable universities to mobilise their operations to respond to local sustainability challenges. In this instance, the success of such an approach is shown to depend on commitments from the university community and the availability of enabling inputs, such as financial and human resources. The paper concludes with reflections and recommendations to inform further development of a newly emerging systems approach in sustainability mainstreaming at Rhodes University, and other institutions pursuing similar approaches and goals.
- Full Text:
- Date Issued: 2013
Exploring learning networks for homestead food gardening and smallholder farming
- Authors: Lotz-Sisitka, Heila
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182775 , vital:43873 , xlink:href="https://hdl.handle.net/10520/EJC-f09c3866c "
- Description: The Water Research Commission (WRC) is well known for its high quality knowledge products. The Water Utilisation in Agriculture (WUA) section has, over the years, produced valuable knowledge to guide the harvesting and conservation of rainwater to improve agricultural productivity among smallholder crop farmers and household food producers. This knowledge is useful for especially the many women farmers around the country growing crops to feed their families, and whenever possible selling excess to generate some income. However, one of the problems experienced in the field is that this knowledge does not always reach the intended audience. This is the problem that the Amanzi [Water] for Food project was engaged with.
- Full Text:
- Date Issued: 2018
- Authors: Lotz-Sisitka, Heila
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182775 , vital:43873 , xlink:href="https://hdl.handle.net/10520/EJC-f09c3866c "
- Description: The Water Research Commission (WRC) is well known for its high quality knowledge products. The Water Utilisation in Agriculture (WUA) section has, over the years, produced valuable knowledge to guide the harvesting and conservation of rainwater to improve agricultural productivity among smallholder crop farmers and household food producers. This knowledge is useful for especially the many women farmers around the country growing crops to feed their families, and whenever possible selling excess to generate some income. However, one of the problems experienced in the field is that this knowledge does not always reach the intended audience. This is the problem that the Amanzi [Water] for Food project was engaged with.
- Full Text:
- Date Issued: 2018
Exploring the potential of developmental work research and change laboratory to support sustainability transformations: a case study of organic agriculture in Zimbabwe
- Mukute, Mutizwa, Mudokwani, Kuda, McAllistair, Georgina, Nyikahadzoi, Kefasi
- Authors: Mukute, Mutizwa , Mudokwani, Kuda , McAllistair, Georgina , Nyikahadzoi, Kefasi
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392119 , vital:68723 , xlink:href="https://doi.org/10.1080/10749039.2018.1451542"
- Description: This paper explores the emergence of transgressive learning in CHAT-informed development work research in a networked organic agriculture case study in Zimbabwe, based on intervention research involving district organic associations tackling interconnected issues of climate change, water, food security and solidarity. The study established that We change laboratories can be used to support transgressive learning through: confronting unproductive local norms; collective reframing of problematic issues; stimulating expansive learning and sustainability transformations in minds, relationships and landscapes across time. The study also confirms the need for fourth generation CHAT to address the complex social-ecological problems of today.
- Full Text:
- Date Issued: 2018
- Authors: Mukute, Mutizwa , Mudokwani, Kuda , McAllistair, Georgina , Nyikahadzoi, Kefasi
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392119 , vital:68723 , xlink:href="https://doi.org/10.1080/10749039.2018.1451542"
- Description: This paper explores the emergence of transgressive learning in CHAT-informed development work research in a networked organic agriculture case study in Zimbabwe, based on intervention research involving district organic associations tackling interconnected issues of climate change, water, food security and solidarity. The study established that We change laboratories can be used to support transgressive learning through: confronting unproductive local norms; collective reframing of problematic issues; stimulating expansive learning and sustainability transformations in minds, relationships and landscapes across time. The study also confirms the need for fourth generation CHAT to address the complex social-ecological problems of today.
- Full Text:
- Date Issued: 2018
An artificial neural network approach to predict the effects of formulation and process variables on prednisone release from a multipartite system
- Manda, Arthur, Walker, Roderick B, Khamanga, Sandile M
- Authors: Manda, Arthur , Walker, Roderick B , Khamanga, Sandile M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183237 , vital:43933 , xlink:href="https://doi.org/10.3390/pharmaceutics11030109"
- Description: The impact of formulation and process variables on the in-vitro release of prednisone from a multiple-unit pellet system was investigated. Box-Behnken Response Surface Methodology (RSM) was used to generate multivariate experiments. The extrusion-spheronization method was used to produce pellets and dissolution studies were performed using United States Pharmacopoeia (USP) Apparatus 2 as described in USP XXIV. Analysis of dissolution test samples was performed using a reversed-phase high-performance liquid chromatography (RP-HPLC) method. Four formulation and process variables viz., microcrystalline cellulose concentration, sodium starch glycolate concentration, spheronization time and extrusion speed were investigated and drug release, aspect ratio and yield were monitored for the trained artificial neural networks (ANN). To achieve accurate prediction, data generated from experimentation were used to train a multi-layer perceptron (MLP) using back propagation (BP) and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) 57 training algorithm until a satisfactory value of root mean square error (RMSE) was observed. The study revealed that the in-vitro release profile of prednisone was significantly impacted by microcrystalline cellulose concentration and sodium starch glycolate concentration. Increasing microcrystalline cellulose concentration retarded dissolution rate whereas increasing sodium starch glycolate concentration improved dissolution rate. Spheronization time and extrusion speed had minimal impact on prednisone release but had a significant impact on extrudate and pellet quality. This work demonstrated that RSM can be successfully used concurrently with ANN for dosage form manufacture to permit the exploration of experimental regions that are omitted when using RSM alone.
- Full Text:
- Date Issued: 2019
- Authors: Manda, Arthur , Walker, Roderick B , Khamanga, Sandile M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183237 , vital:43933 , xlink:href="https://doi.org/10.3390/pharmaceutics11030109"
- Description: The impact of formulation and process variables on the in-vitro release of prednisone from a multiple-unit pellet system was investigated. Box-Behnken Response Surface Methodology (RSM) was used to generate multivariate experiments. The extrusion-spheronization method was used to produce pellets and dissolution studies were performed using United States Pharmacopoeia (USP) Apparatus 2 as described in USP XXIV. Analysis of dissolution test samples was performed using a reversed-phase high-performance liquid chromatography (RP-HPLC) method. Four formulation and process variables viz., microcrystalline cellulose concentration, sodium starch glycolate concentration, spheronization time and extrusion speed were investigated and drug release, aspect ratio and yield were monitored for the trained artificial neural networks (ANN). To achieve accurate prediction, data generated from experimentation were used to train a multi-layer perceptron (MLP) using back propagation (BP) and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) 57 training algorithm until a satisfactory value of root mean square error (RMSE) was observed. The study revealed that the in-vitro release profile of prednisone was significantly impacted by microcrystalline cellulose concentration and sodium starch glycolate concentration. Increasing microcrystalline cellulose concentration retarded dissolution rate whereas increasing sodium starch glycolate concentration improved dissolution rate. Spheronization time and extrusion speed had minimal impact on prednisone release but had a significant impact on extrudate and pellet quality. This work demonstrated that RSM can be successfully used concurrently with ANN for dosage form manufacture to permit the exploration of experimental regions that are omitted when using RSM alone.
- Full Text:
- Date Issued: 2019
Making (non) sense of urban water flows: Qualities and processes for transformative and transgressive learning moments
- Authors: James, Anna
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390665 , vital:68572 , xlink:href="https://doi.org/10.3390/su11236817"
- Description: Urban sustainability and justice depend upon the flow of water across complex urban space. Yet, the characteristics of urban space produce a fragmented sense of our water resources. Cape Town, South Africa, the context of this research, is one such city whose water challenges have been exacerbated by climate change-induced drought, to the extent that the city nearly shut off the water running to residents’ taps. This context presents a particular challenge for the focus of this special issue, transformative and transgressive learning, an emerging arena of thought and practice concerned with learning processes that might foster more sustainable socio-ecological relations. The empirical material for this research draws from 12 arts-based inquiry workshops run with youth in an environmental organisation over four months, exploring a local water crisis. The data were generated through an engaged arts-based research process. The paper traces how transformative and transgressive learning in the context of urban water crisis might be characterised as making (non)sense by bringing the empirical material into dialogue with five entry points of transformative and transgressive learning literature rooted in Freirean educational praxis. This paper crafts and engages the concept of making (non)sense, a way of thinking about qualities and processes of learning praxis that responds to the wicked sustainability challenges we face today, particularly in terms of a Global South perspective. I argue such a praxis needs qualities and processes that disrupt and trouble the norm in the context of the socio-ecological challenge of urban water.
- Full Text:
- Date Issued: 2019
- Authors: James, Anna
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390665 , vital:68572 , xlink:href="https://doi.org/10.3390/su11236817"
- Description: Urban sustainability and justice depend upon the flow of water across complex urban space. Yet, the characteristics of urban space produce a fragmented sense of our water resources. Cape Town, South Africa, the context of this research, is one such city whose water challenges have been exacerbated by climate change-induced drought, to the extent that the city nearly shut off the water running to residents’ taps. This context presents a particular challenge for the focus of this special issue, transformative and transgressive learning, an emerging arena of thought and practice concerned with learning processes that might foster more sustainable socio-ecological relations. The empirical material for this research draws from 12 arts-based inquiry workshops run with youth in an environmental organisation over four months, exploring a local water crisis. The data were generated through an engaged arts-based research process. The paper traces how transformative and transgressive learning in the context of urban water crisis might be characterised as making (non)sense by bringing the empirical material into dialogue with five entry points of transformative and transgressive learning literature rooted in Freirean educational praxis. This paper crafts and engages the concept of making (non)sense, a way of thinking about qualities and processes of learning praxis that responds to the wicked sustainability challenges we face today, particularly in terms of a Global South perspective. I argue such a praxis needs qualities and processes that disrupt and trouble the norm in the context of the socio-ecological challenge of urban water.
- Full Text:
- Date Issued: 2019
But is it publishable? Mastering the MMed message
- Authors: A G Parrish , E S Grossman,
- Date: 202
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3353 , vital:43318 , http://www.samj.org.za/index.php/samj/article/view/13033
- Description: The research requirement for South African specialist registration offers opportunities and challenges. For some clinicians it may spark a lifelong interest in clinical investigation, while for many others it may provide a potential publication opportunity. Integrating the specific requirements of an MMed mini-dissertation with those of standard medical publications can be difficult for first-time authors and their supervisors; published guidance caters to full-length laboratory Master’s or doctoral research. We suggest that research is more likely to be publishable if it is locally relevant, has a clear clinical message and is coherently presented.
- Full Text:
- Date Issued: 202
- Authors: A G Parrish , E S Grossman,
- Date: 202
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3353 , vital:43318 , http://www.samj.org.za/index.php/samj/article/view/13033
- Description: The research requirement for South African specialist registration offers opportunities and challenges. For some clinicians it may spark a lifelong interest in clinical investigation, while for many others it may provide a potential publication opportunity. Integrating the specific requirements of an MMed mini-dissertation with those of standard medical publications can be difficult for first-time authors and their supervisors; published guidance caters to full-length laboratory Master’s or doctoral research. We suggest that research is more likely to be publishable if it is locally relevant, has a clear clinical message and is coherently presented.
- Full Text:
- Date Issued: 202
"Knowing With": New Rhodes Board Navigates Collaboration, Intimacy, and Solidarity
- Baasch, Rachel M, Fọlárànmí, Stephen, Koide, Emi, Kakande, Angelo, Simbao, Ruth K
- Authors: Baasch, Rachel M , Fọlárànmí, Stephen , Koide, Emi , Kakande, Angelo , Simbao, Ruth K
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147514 , vital:38645 , https://doi.org/10.1162/afar_a_00523
- Description: Rhodes University (or UCKAR), based in Makhanda, South Africa, joined the African Arts editorial consortium in 2016 and its first journal issue—vol. 50, no. 2—was published in 2017. Initially the board was run by Ruth Simbao, with the aim of developing collaborations with other scholars, particularly those based on the African continent and within the global south (Simbao 2017: 1). For the second Rhodes issue (Summer 2018), Simbao worked with Guest Board Member Amanda Tumusiime from Makerere University, and for the third Rhodes issue (Summer 2019) she collaborated with Stephen Folárànmí from Obáfémi Awólówò University, Ilé-Ifè, Nigeria, who at the time was a Postdoctoral Fellow at Rhodes.
- Full Text:
- Date Issued: 2020
- Authors: Baasch, Rachel M , Fọlárànmí, Stephen , Koide, Emi , Kakande, Angelo , Simbao, Ruth K
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147514 , vital:38645 , https://doi.org/10.1162/afar_a_00523
- Description: Rhodes University (or UCKAR), based in Makhanda, South Africa, joined the African Arts editorial consortium in 2016 and its first journal issue—vol. 50, no. 2—was published in 2017. Initially the board was run by Ruth Simbao, with the aim of developing collaborations with other scholars, particularly those based on the African continent and within the global south (Simbao 2017: 1). For the second Rhodes issue (Summer 2018), Simbao worked with Guest Board Member Amanda Tumusiime from Makerere University, and for the third Rhodes issue (Summer 2019) she collaborated with Stephen Folárànmí from Obáfémi Awólówò University, Ilé-Ifè, Nigeria, who at the time was a Postdoctoral Fellow at Rhodes.
- Full Text:
- Date Issued: 2020
(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 career in photophysicochemical and electrochemical properties of phthalocyanine: A Linstead Career Award paper
- Authors: Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186045 , vital:44458 , xlink:href="https://doi.org/10.1142/S1088424620300037"
- Description: This manuscript highlights the author’s contributions to phthalocyanine chemistry, especially the applications based on their electrochemistry and photophysicochemistry. In particular, the use of phthalocyanines as electrocatalysts and photocatalysts is presented. For photocatalysis, photodynamic antimicrobial chemotherapy and pollution control using green technologies are highlighted. For electrocatalysis the phthalocyanines are employed for the detection of pollutants and environmentally important molecules. Phthalocyanines are combined with nanomaterials for improved photocatalysis and electrocatalysis.
- Full Text:
- Date Issued: 2020
- Authors: Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186045 , vital:44458 , xlink:href="https://doi.org/10.1142/S1088424620300037"
- Description: This manuscript highlights the author’s contributions to phthalocyanine chemistry, especially the applications based on their electrochemistry and photophysicochemistry. In particular, the use of phthalocyanines as electrocatalysts and photocatalysts is presented. For photocatalysis, photodynamic antimicrobial chemotherapy and pollution control using green technologies are highlighted. For electrocatalysis the phthalocyanines are employed for the detection of pollutants and environmentally important molecules. Phthalocyanines are combined with nanomaterials for improved photocatalysis and electrocatalysis.
- Full Text:
- Date Issued: 2020
A comparative study of the effect of different stabilizers on the critical quality attributes of self-assembling nano co-crystals
- Witika, Bwalya A, Smith, Vincent J, Walker, Roderick B
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183224 , vital:43931 , xlink:href=" https://doi.org/10.3390/pharmaceutics12020182"
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used orally to manage HIV/AIDS infection. A pseudo one-solvent bottom-up approach was used to develop and produce nano co-crystals of 3TC and AZT. Equimolar amounts of 3TC dissolved in de-ionized water and AZT in methanol were rapidly injected into a pre-cooled vessel and sonicated at 4 °C. The resultant suspensions were characterized using a Zetasizer. The particle size, polydispersity index and Zeta potential were elucidated. Further characterization was undertaken using powder X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and energy dispersive X-ray spectroscopy scanning electron microscopy. Different surfactants were assessed for their ability to stabilize the nano co-crystals and for their ability to produce nano co-crystals with specific and desirable critical quality attributes (CQA) including particle size (PS) less than 1000 nm, polydispersity index (PDI) less than 0.500 and Zeta potential (ZP) less than −30 mV. All surfactants produced co-crystals in the nanometer range. The PDI and PS are concentration-dependent for all nano co-crystals manufactured while only ZP was within specification when sodium dodecyl sulfate was used in the process.
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183224 , vital:43931 , xlink:href=" https://doi.org/10.3390/pharmaceutics12020182"
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used orally to manage HIV/AIDS infection. A pseudo one-solvent bottom-up approach was used to develop and produce nano co-crystals of 3TC and AZT. Equimolar amounts of 3TC dissolved in de-ionized water and AZT in methanol were rapidly injected into a pre-cooled vessel and sonicated at 4 °C. The resultant suspensions were characterized using a Zetasizer. The particle size, polydispersity index and Zeta potential were elucidated. Further characterization was undertaken using powder X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and energy dispersive X-ray spectroscopy scanning electron microscopy. Different surfactants were assessed for their ability to stabilize the nano co-crystals and for their ability to produce nano co-crystals with specific and desirable critical quality attributes (CQA) including particle size (PS) less than 1000 nm, polydispersity index (PDI) less than 0.500 and Zeta potential (ZP) less than −30 mV. All surfactants produced co-crystals in the nanometer range. The PDI and PS are concentration-dependent for all nano co-crystals manufactured while only ZP was within specification when sodium dodecyl sulfate was used in the process.
- Full Text:
- Date Issued: 2020
A comparative study of the photophysicochemical and photodynamic activity properties of meso-4-methylthiophenyl functionalized Sn (IV) tetraarylporphyrins and triarylcorroles
- Dingiswayo, Somila, Babu, Balaji, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Dingiswayo, Somila , Babu, Balaji , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186157 , vital:44469 , xlink:href="https://doi.org/10.1142/S1088424620500273"
- Description: Tin(IV) complexes of a 4-methylthiophenyl functionalized porphyrin (1-Sn) and its corrole analogue (2-Sn) were synthesized so that their photophysicochemical properties and photodynamic activities against MCF-7 breast cancer cells could be compared. Singlet oxygen luminescence studies revealed that 1-Sn and 2-Sn have comparable ΦΔΦΔ values in DMF of 0.59 and 0.60, respectively, while the IC5050 values after irradiation of MCF-7 cells for 30 min with a Thorlabs 625 nm LED (432 J · cm−2)−2) were determined to be 12.4 and 8.9 μμM. The results demonstrate that the cellular uptake of 2-Sn and its molar absorptivity at the irradiation wavelength play a crucial role during in vitro cytotoxicity studies.
- Full Text:
- Date Issued: 2020
- Authors: Dingiswayo, Somila , Babu, Balaji , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186157 , vital:44469 , xlink:href="https://doi.org/10.1142/S1088424620500273"
- Description: Tin(IV) complexes of a 4-methylthiophenyl functionalized porphyrin (1-Sn) and its corrole analogue (2-Sn) were synthesized so that their photophysicochemical properties and photodynamic activities against MCF-7 breast cancer cells could be compared. Singlet oxygen luminescence studies revealed that 1-Sn and 2-Sn have comparable ΦΔΦΔ values in DMF of 0.59 and 0.60, respectively, while the IC5050 values after irradiation of MCF-7 cells for 30 min with a Thorlabs 625 nm LED (432 J · cm−2)−2) were determined to be 12.4 and 8.9 μμM. The results demonstrate that the cellular uptake of 2-Sn and its molar absorptivity at the irradiation wavelength play a crucial role during in vitro cytotoxicity studies.
- Full Text:
- Date Issued: 2020
A comparison of three models used to determine water fluxes over the Albany Thicket, Eastern Cape, South Africa:
- Palmer, Anthony R, Ezenne, G I, Choruma, D J, Gwate, O, Mantel, Sukhmani M, Tanner, Jane L
- Authors: Palmer, Anthony R , Ezenne, G I , Choruma, D J , Gwate, O , Mantel, Sukhmani M , Tanner, Jane L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150047 , vital:38934 , https://doi.org/10.1016/j.agrformet.2020.107984
- Description: The Albany Thicket (AT) biome contains outstanding global biodiversity as well as the potential to achieve carbon credits associated with water-efficient Crasslucean acid metabolism (CAM). Understanding the water fluxes in the AT is crucial to determining carbon (C) sequestration rates and water-use efficiency. Despite large variation in water fluxes across the AT, only a few studies have been conducted in this region with their results validated against short periods of observed data. This study aims to evaluate three models of water fluxes over AT against data from an eddy covariance (EC) system active from October 2015 to May 2018. ET was modelled using the BioGeoChemistry Management (BGC-MAN) model, a biophysical model (Penman-Monteith-Leuning (PML)) and a remotely-sensed product (MOD16), and their results compared with that from the EC system.
- Full Text:
- Date Issued: 2020
- Authors: Palmer, Anthony R , Ezenne, G I , Choruma, D J , Gwate, O , Mantel, Sukhmani M , Tanner, Jane L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150047 , vital:38934 , https://doi.org/10.1016/j.agrformet.2020.107984
- Description: The Albany Thicket (AT) biome contains outstanding global biodiversity as well as the potential to achieve carbon credits associated with water-efficient Crasslucean acid metabolism (CAM). Understanding the water fluxes in the AT is crucial to determining carbon (C) sequestration rates and water-use efficiency. Despite large variation in water fluxes across the AT, only a few studies have been conducted in this region with their results validated against short periods of observed data. This study aims to evaluate three models of water fluxes over AT against data from an eddy covariance (EC) system active from October 2015 to May 2018. ET was modelled using the BioGeoChemistry Management (BGC-MAN) model, a biophysical model (Penman-Monteith-Leuning (PML)) and a remotely-sensed product (MOD16), and their results compared with that from the EC system.
- Full Text:
- Date Issued: 2020
A leopard's favourite spots: habitat preference and population density of leopards in a semi-arid biodiversity hotspot
- Mann, Gareth K H, O'Riain, M Justin, Parker, Daniel M
- Authors: Mann, Gareth K H , O'Riain, M Justin , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148584 , vital:38752 , https://doi.org/10.1016/j.jaridenv.2020.104218
- Description: Leopards (Panthera pardus) are the only free-ranging large predators to still occur naturally throughout much of Africa, but are vulnerable to habitat loss, ecosystem degradation and persecution. We used a systematic camera trap survey covering an area of ∼3100 km2 in the Little Karoo, a semi-arid biodiversity hotspot in South Africa, to assess the impacts of land use and habitat type on leopard density. Camera data were supplemented by opportunistic scat collection to produce a habitat suitability model. We used a habitat suitability model to inform spatially explicit capture-recapture models used to estimate population density. We recorded 152 independent photographs of 27 individually recognizable leopards at 54 camera stations and collected scats from a further 76 locations. Our habitat suitability model showed that primary productivity and vegetation type were the best predictors of leopard habitat suitability. Our best performing population density model allowed for detection and movement of individuals to vary according to sex, and estimated population density at 1.26 (SE ± 0.25) leopards/100 km2.
- Full Text:
- Date Issued: 2020
- Authors: Mann, Gareth K H , O'Riain, M Justin , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148584 , vital:38752 , https://doi.org/10.1016/j.jaridenv.2020.104218
- Description: Leopards (Panthera pardus) are the only free-ranging large predators to still occur naturally throughout much of Africa, but are vulnerable to habitat loss, ecosystem degradation and persecution. We used a systematic camera trap survey covering an area of ∼3100 km2 in the Little Karoo, a semi-arid biodiversity hotspot in South Africa, to assess the impacts of land use and habitat type on leopard density. Camera data were supplemented by opportunistic scat collection to produce a habitat suitability model. We used a habitat suitability model to inform spatially explicit capture-recapture models used to estimate population density. We recorded 152 independent photographs of 27 individually recognizable leopards at 54 camera stations and collected scats from a further 76 locations. Our habitat suitability model showed that primary productivity and vegetation type were the best predictors of leopard habitat suitability. Our best performing population density model allowed for detection and movement of individuals to vary according to sex, and estimated population density at 1.26 (SE ± 0.25) leopards/100 km2.
- Full Text:
- Date Issued: 2020
A mathematics teacher's response to a dilemma: 'I'm supposed to teach them in English but they don't understand'
- Robertson, Sally-Ann, Graven, Mellony
- Authors: Robertson, Sally-Ann , Graven, Mellony
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148889 , vital:38783 , https://doi.org/10.4102/sajce.v10i1.800
- Description: English is the dominant language in South African schools although it is the home language for less than 10% of the population. Many schools have yet to embrace the Language in Education Policy’s advocacy of additive bilingualism. This has led to a majority of the country’s children learning and being assessed through a language in which they lack proficiency. This article draws on second language teaching and learning theory to make a case for more systematic support for learners’ second language development and for legitimation of use of home language in mathematics classrooms where a different language is the official medium. The article shares empirical data from a South African Grade 4 mathematics teacher’s classroom to illuminate arguments in favour of additive bilingualism.
- Full Text:
- Date Issued: 2020
- Authors: Robertson, Sally-Ann , Graven, Mellony
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148889 , vital:38783 , https://doi.org/10.4102/sajce.v10i1.800
- Description: English is the dominant language in South African schools although it is the home language for less than 10% of the population. Many schools have yet to embrace the Language in Education Policy’s advocacy of additive bilingualism. This has led to a majority of the country’s children learning and being assessed through a language in which they lack proficiency. This article draws on second language teaching and learning theory to make a case for more systematic support for learners’ second language development and for legitimation of use of home language in mathematics classrooms where a different language is the official medium. The article shares empirical data from a South African Grade 4 mathematics teacher’s classroom to illuminate arguments in favour of additive bilingualism.
- Full Text:
- Date Issued: 2020
A multinational study of authors’ perceptions of and practical approaches to writing geography textbooks:
- Lee, Jongwon, Catling, Simon, Kidman, Gillian, Bednarz, Robert, Krause, Uwe, Martija, Andoni A, Ohnishi, Koji, Wilmot, P Dianne, Zecha, Stefane
- Authors: Lee, Jongwon , Catling, Simon , Kidman, Gillian , Bednarz, Robert , Krause, Uwe , Martija, Andoni A , Ohnishi, Koji , Wilmot, P Dianne , Zecha, Stefane
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158269 , vital:40168 , https://doi.org/10.1080/10382046.2020.1743931
- Description: Like all school textbooks, geography textbooks are authored. Almost all textbook research in and beyond geography has neglected their authors. This questionnaire-based multinational research project investigated the perceptions of 71 primary and secondary school geography textbook authors from seven countries in five continents. Though not intended as a definitive study, the findings identified several values and areas of expertise which many textbook authors in different countries held to be important for their work.
- Full Text:
- Date Issued: 2020
- Authors: Lee, Jongwon , Catling, Simon , Kidman, Gillian , Bednarz, Robert , Krause, Uwe , Martija, Andoni A , Ohnishi, Koji , Wilmot, P Dianne , Zecha, Stefane
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158269 , vital:40168 , https://doi.org/10.1080/10382046.2020.1743931
- Description: Like all school textbooks, geography textbooks are authored. Almost all textbook research in and beyond geography has neglected their authors. This questionnaire-based multinational research project investigated the perceptions of 71 primary and secondary school geography textbook authors from seven countries in five continents. Though not intended as a definitive study, the findings identified several values and areas of expertise which many textbook authors in different countries held to be important for their work.
- Full Text:
- Date Issued: 2020
A novel dimeric exoglucanase (GH5_38): Biochemical and Structural Characterisation towards its Application in Alkyl Cellobioside Synthesis
- Mafa, Mpho S, Dirr, Heinrich, Malgas, Samkelo, Krause, Rui W M, Pletschke, Brett I
- Authors: Mafa, Mpho S , Dirr, Heinrich , Malgas, Samkelo , Krause, Rui W M , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193976 , vital:45412 , xlink:href="https://doi.org/10.3390/molecules25030746"
- Description: An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.7 U/mg protein, respectively) and lichenin (24.5 and 23.7 U/mg protein, respectively). They displayed a broad optimum pH range from 5.5 to 7 and a temperature optimum from 40 to 60 °C. Kinetic studies demonstrated that Exg-D had a higher affinity towards β-glucan, with a Km of 7.9 mg/mL and a kcat of 117.2 s−1, compared to lichenin which had a Km of 21.5 mg/mL and a kcat of 70.0 s−1. The circular dichroism profile of Exg-D showed that its secondary structure consisted of 11% α-helices, 36% β-strands and 53% coils. Exg-D performed transglycosylation using p-nitrophenyl cellobioside as a glycosyl donor and several primary alcohols as acceptors to produce methyl-, ethyl- and propyl-cellobiosides. These products were identified and quantified via thin-layer chromatography (TLC) and liquid chromatography–mass spectrometry (LC-MS). We concluded that Exg-D is a novel and promising oligomeric glycoside hydrolase for the one-step synthesis of alkyl glycosides with more than one monosaccharide unit.
- Full Text:
- Date Issued: 2020
- Authors: Mafa, Mpho S , Dirr, Heinrich , Malgas, Samkelo , Krause, Rui W M , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193976 , vital:45412 , xlink:href="https://doi.org/10.3390/molecules25030746"
- Description: An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.7 U/mg protein, respectively) and lichenin (24.5 and 23.7 U/mg protein, respectively). They displayed a broad optimum pH range from 5.5 to 7 and a temperature optimum from 40 to 60 °C. Kinetic studies demonstrated that Exg-D had a higher affinity towards β-glucan, with a Km of 7.9 mg/mL and a kcat of 117.2 s−1, compared to lichenin which had a Km of 21.5 mg/mL and a kcat of 70.0 s−1. The circular dichroism profile of Exg-D showed that its secondary structure consisted of 11% α-helices, 36% β-strands and 53% coils. Exg-D performed transglycosylation using p-nitrophenyl cellobioside as a glycosyl donor and several primary alcohols as acceptors to produce methyl-, ethyl- and propyl-cellobiosides. These products were identified and quantified via thin-layer chromatography (TLC) and liquid chromatography–mass spectrometry (LC-MS). We concluded that Exg-D is a novel and promising oligomeric glycoside hydrolase for the one-step synthesis of alkyl glycosides with more than one monosaccharide unit.
- Full Text:
- Date Issued: 2020
A relational approach to landscape stewardship: Towards a new perspective for multi-actor collaboration
- Cockburn, Jessica J, Rosenberg, Eureta, Copteros, Athina, Cornelius, Susanna F, Libala, Notiswa, Metcalfe, Liz, van der Waal, Benjamin
- Authors: Cockburn, Jessica J , Rosenberg, Eureta , Copteros, Athina , Cornelius, Susanna F , Libala, Notiswa , Metcalfe, Liz , van der Waal, Benjamin
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370098 , vital:66297 , xlink:href="https://doi.org/10.3390/land9070224"
- Description: Landscape stewardship is increasingly understood within the framing of complex social-ecological systems. To consider the implications of this, we focus on one of the key characteristics of complex social-ecological systems: they are relationally constituted, meaning that system characteristics emerge out of dynamic relations between system components. We focus on multi-actor collaboration as a key form of relationality in landscapes, seeking a more textured understanding of the social relations between landscape actors. We draw on a set of ‘gardening tools’ to analyse the boundary-crossing work of multi-actor collaboration. These tools comprise three key concepts: relational expertise, common knowledge, and relational agency. We apply the tools to two cases of landscape stewardship in South Africa: the Langkloof Region and the Tsitsa River catchment. These landscapes are characterised by economically, socio-culturally, and politically diverse groups of actors. Our analysis reveals that history and context strongly influence relational processes, that boundary-crossing work is indeed difficult, and that doing boundary-crossing work in smaller pockets within a landscape is helpful. The tools also helped to identify three key social-relational practices which lend a new perspective on boundary-crossing work: 1. belonging while differing, 2. growing together by interacting regularly and building common knowledge, and 3. learning and adapting together with humility and empathy.
- Full Text:
- Date Issued: 2020
- Authors: Cockburn, Jessica J , Rosenberg, Eureta , Copteros, Athina , Cornelius, Susanna F , Libala, Notiswa , Metcalfe, Liz , van der Waal, Benjamin
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370098 , vital:66297 , xlink:href="https://doi.org/10.3390/land9070224"
- Description: Landscape stewardship is increasingly understood within the framing of complex social-ecological systems. To consider the implications of this, we focus on one of the key characteristics of complex social-ecological systems: they are relationally constituted, meaning that system characteristics emerge out of dynamic relations between system components. We focus on multi-actor collaboration as a key form of relationality in landscapes, seeking a more textured understanding of the social relations between landscape actors. We draw on a set of ‘gardening tools’ to analyse the boundary-crossing work of multi-actor collaboration. These tools comprise three key concepts: relational expertise, common knowledge, and relational agency. We apply the tools to two cases of landscape stewardship in South Africa: the Langkloof Region and the Tsitsa River catchment. These landscapes are characterised by economically, socio-culturally, and politically diverse groups of actors. Our analysis reveals that history and context strongly influence relational processes, that boundary-crossing work is indeed difficult, and that doing boundary-crossing work in smaller pockets within a landscape is helpful. The tools also helped to identify three key social-relational practices which lend a new perspective on boundary-crossing work: 1. belonging while differing, 2. growing together by interacting regularly and building common knowledge, and 3. learning and adapting together with humility and empathy.
- 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
A snapshot of early childhood care and education in South Africa: institutional offerings, challenges and recommendations
- Authors: Harrison, Giulietta D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160312 , vital:40433 , https://doi.org/10.4102/sajce.v10i1.797
- Description: This article draws from a research report on the Project for Inclusive Early Childhood Care and Education (PIECCE), which surveyed attitudes, training strategies, materials and entrance requirements across most relevant higher education institutions (HEIs), non-governmental organisations (NGOs) and technical and vocational education and training colleges (TVETs). The aim of this study was to identify what institutions were offering in terms of training teachers in the birth-to-four age group, to identify the challenges and provide recommendations based on the findings.
- Full Text:
- Date Issued: 2020
- Authors: Harrison, Giulietta D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160312 , vital:40433 , https://doi.org/10.4102/sajce.v10i1.797
- Description: This article draws from a research report on the Project for Inclusive Early Childhood Care and Education (PIECCE), which surveyed attitudes, training strategies, materials and entrance requirements across most relevant higher education institutions (HEIs), non-governmental organisations (NGOs) and technical and vocational education and training colleges (TVETs). The aim of this study was to identify what institutions were offering in terms of training teachers in the birth-to-four age group, to identify the challenges and provide recommendations based on the findings.
- Full Text:
- Date Issued: 2020