Synthesis, structure and in vitro anti-trypanosomal activity of non-toxic Arylpyrrole-Based Chalcone derivatives:
- Zulu, Ayanda I, Oderinlo, Ogunyemi O, Kruger, Cuan, Isaacs, Michelle, Hoppe, Heinrich C, Smith, Vincent J, Veale, Clinton G L, Khanye, Setshaba D
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- 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
Quality by Design Optimization of Cold Sonochemical Synthesis of Zidovudine-Lamivudine Nanosuspensions:
- Witika, Bwalya A, Smith, Vincent J, Walker, Roderick B
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148424 , vital:38738 , https://doi.org/10.3390/pharmaceutics12040367
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used to manage HIV/AIDS infection. The compounds require frequent dosing, exhibit unpredictable bioavailability and a side effect profile that includes hepato- and haema-toxicity. A novel pseudo one-solvent bottom-up approach and Design of Experiments using sodium dodecyl sulphate (SDS) and α-tocopheryl polyethylene glycol succinate 1000 (TPGS 1000) to electrosterically stablize the nano co-crystals was used to develop, produce and optimize 3TC and AZT nano co-crystals. Equimolar solutions of 3TC in surfactant dissolved in de-ionised water and AZT in methanol were rapidly injected into a vessel and sonicated at 4 °C.
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148424 , vital:38738 , https://doi.org/10.3390/pharmaceutics12040367
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used to manage HIV/AIDS infection. The compounds require frequent dosing, exhibit unpredictable bioavailability and a side effect profile that includes hepato- and haema-toxicity. A novel pseudo one-solvent bottom-up approach and Design of Experiments using sodium dodecyl sulphate (SDS) and α-tocopheryl polyethylene glycol succinate 1000 (TPGS 1000) to electrosterically stablize the nano co-crystals was used to develop, produce and optimize 3TC and AZT nano co-crystals. Equimolar solutions of 3TC in surfactant dissolved in de-ionised water and AZT in methanol were rapidly injected into a vessel and sonicated at 4 °C.
- Full Text:
- Date Issued: 2020
Nano-biomimetic drug delivery vehicles: Potential approaches for COVID-19 treatment
- Witika, Bwalya A, Makoni, Pedzisai A, Mweetwa, Larry L, Ntemi, Pascal V, Chikukwa, Mellisa T R, Matafwali, Scott K, Mwila, Chiluba, Mudenda, Steward, Katandula, Jonathan, Walker, Roderick B
- Authors: Witika, Bwalya A , Makoni, Pedzisai A , Mweetwa, Larry L , Ntemi, Pascal V , Chikukwa, Mellisa T R , Matafwali, Scott K , Mwila, Chiluba , Mudenda, Steward , Katandula, Jonathan , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183440 , vital:43991 , xlink:href="https://doi.org/10.3390/molecules25245952"
- Description: The current COVID-19 pandemic has tested the resolve of the global community with more than 35 million infections worldwide and numbers increasing with no cure or vaccine available to date. Nanomedicines have an advantage of providing enhanced permeability and retention and have been extensively studied as targeted drug delivery strategies for the treatment of different disease. The role of monocytes, erythrocytes, thrombocytes, and macrophages in diseases, including infectious and inflammatory diseases, cancer, and atherosclerosis, are better understood and have resulted in improved strategies for targeting and in some instances mimicking these cell types to improve therapeutic outcomes. Consequently, these primary cell types can be exploited for the purposes of serving as a "Trojan horse" for targeted delivery to identified organs and sites of inflammation. State of the art and potential utilization of nanocarriers such as nanospheres/nanocapsules, nanocrystals, liposomes, solid lipid nanoparticles/nano-structured lipid carriers, dendrimers, and nanosponges for biomimicry and/or targeted delivery of bioactives to cells are reported herein and their potential use in the treatment of COVID-19 infections discussed. Physicochemical properties, viz., hydrophilicity, particle shape, surface charge, composition, concentration, the use of different target-specific ligands on the surface of carriers, and the impact on carrier efficacy and specificity are also discussed.
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya A , Makoni, Pedzisai A , Mweetwa, Larry L , Ntemi, Pascal V , Chikukwa, Mellisa T R , Matafwali, Scott K , Mwila, Chiluba , Mudenda, Steward , Katandula, Jonathan , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183440 , vital:43991 , xlink:href="https://doi.org/10.3390/molecules25245952"
- Description: The current COVID-19 pandemic has tested the resolve of the global community with more than 35 million infections worldwide and numbers increasing with no cure or vaccine available to date. Nanomedicines have an advantage of providing enhanced permeability and retention and have been extensively studied as targeted drug delivery strategies for the treatment of different disease. The role of monocytes, erythrocytes, thrombocytes, and macrophages in diseases, including infectious and inflammatory diseases, cancer, and atherosclerosis, are better understood and have resulted in improved strategies for targeting and in some instances mimicking these cell types to improve therapeutic outcomes. Consequently, these primary cell types can be exploited for the purposes of serving as a "Trojan horse" for targeted delivery to identified organs and sites of inflammation. State of the art and potential utilization of nanocarriers such as nanospheres/nanocapsules, nanocrystals, liposomes, solid lipid nanoparticles/nano-structured lipid carriers, dendrimers, and nanosponges for biomimicry and/or targeted delivery of bioactives to cells are reported herein and their potential use in the treatment of COVID-19 infections discussed. Physicochemical properties, viz., hydrophilicity, particle shape, surface charge, composition, concentration, the use of different target-specific ligands on the surface of carriers, and the impact on carrier efficacy and specificity are also discussed.
- Full Text:
- Date Issued: 2020
Biocompatibility of biomaterials for nanoencapsulation: Current approaches
- Witika, Bwalya A, Makoni, Pedzisai A, Matafwali, Scott K, Chabalenge, Billy, Mwila, Chiluba, Kalungia, Aubrey C, Nkanga, Christian I, Bapolisi, Alain M, Walker, Roderick B
- Authors: Witika, Bwalya A , Makoni, Pedzisai A , Matafwali, Scott K , Chabalenge, Billy , Mwila, Chiluba , Kalungia, Aubrey C , Nkanga, Christian I , Bapolisi, Alain M , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183289 , vital:43939 , xlink:href="https://doi.org/10.3390/nano10091649"
- Description: Nanoencapsulation is an approach to circumvent shortcomings such as reduced bioavailability, undesirable side effects, frequent dosing and unpleasant organoleptic properties of conventional drug delivery systems. The process of nanoencapsulation involves the use of biomaterials such as surfactants and/or polymers, often in combination with charge inducers and/or ligands for targeting. The biomaterials selected for nanoencapsulation processes must be as biocompatible as possible. The type(s) of biomaterials used for different nanoencapsulation approaches are highlighted and their use and applicability with regard to haemo- and, histocompatibility, cytotoxicity, genotoxicity and carcinogenesis are discussed.
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya A , Makoni, Pedzisai A , Matafwali, Scott K , Chabalenge, Billy , Mwila, Chiluba , Kalungia, Aubrey C , Nkanga, Christian I , Bapolisi, Alain M , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183289 , vital:43939 , xlink:href="https://doi.org/10.3390/nano10091649"
- Description: Nanoencapsulation is an approach to circumvent shortcomings such as reduced bioavailability, undesirable side effects, frequent dosing and unpleasant organoleptic properties of conventional drug delivery systems. The process of nanoencapsulation involves the use of biomaterials such as surfactants and/or polymers, often in combination with charge inducers and/or ligands for targeting. The biomaterials selected for nanoencapsulation processes must be as biocompatible as possible. The type(s) of biomaterials used for different nanoencapsulation approaches are highlighted and their use and applicability with regard to haemo- and, histocompatibility, cytotoxicity, genotoxicity and carcinogenesis are discussed.
- Full Text:
- Date Issued: 2020
Electricity use behaviour in a high-income neighbourhood in Johannesburg, South Africa:
- Williams, Stephanie P, Thondhlana, Gladman, Kua, Harn W
- Authors: Williams, Stephanie P , Thondhlana, Gladman , Kua, Harn W
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149725 , vital:38878 , https://doi.org/10.3390/su12114571
- Description: Worldwide, households’ consumption of electricity contributes to a substantial proportion of total national energy demand. Thus, the residential sector is a major entity in efforts to define and achieve global sustainability goals. Understanding electricity use behaviour and factors underlying behaviour is critical for designing behaviour change interventions, particularly in contexts characterised by fast-growing economies, burgeoning number of high-income households, and consumption growth. However, relative to developed economies, very little is known on this subject in South Africa. Using structured questionnaires, this study examines electricity use behaviour among high-income households in Johannesburg, South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Williams, Stephanie P , Thondhlana, Gladman , Kua, Harn W
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149725 , vital:38878 , https://doi.org/10.3390/su12114571
- Description: Worldwide, households’ consumption of electricity contributes to a substantial proportion of total national energy demand. Thus, the residential sector is a major entity in efforts to define and achieve global sustainability goals. Understanding electricity use behaviour and factors underlying behaviour is critical for designing behaviour change interventions, particularly in contexts characterised by fast-growing economies, burgeoning number of high-income households, and consumption growth. However, relative to developed economies, very little is known on this subject in South Africa. Using structured questionnaires, this study examines electricity use behaviour among high-income households in Johannesburg, South Africa.
- Full Text:
- Date Issued: 2020
Use of a non-hepatic cell line highlights limitations associated with cell-based assessment of metabolically induced toxicity:
- Weyers, Carli, Dingle, Laura M K, Wilhelmi, Brendan S, Edkins, Adrienne L, Veale, Clinton G
- Authors: Weyers, Carli , Dingle, Laura M K , Wilhelmi, Brendan S , Edkins, Adrienne L , Veale, Clinton G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160290 , vital:40431 , DOI: 10.1080/01480545.2019.1585869
- Description: Metabolically induced drug-toxicity is a major cause of drug failure late in drug optimization phases. Accordingly, in vitro metabolic profiling of compounds is being introduced at earlier stages of the drug discovery pipeline. An increasingly common method to obtain these profiles is through overexpression of key CYP450 metabolic enzymes in immortalized liver cells, to generate competent hepatocyte surrogates. Enhanced cytotoxicity is presumed to be due to toxic metabolite production via the overexpressed enzyme. However, metabolically induced toxicity is a complex multi-parameter phenomenon and the potential background contribution to metabolism arising from the use of liver cells which endogenously express CYP450 isoforms is consistently overlooked. In this study, we sought to reduce the potential background interference by applying this methodology in kidney-derived HEK293 cells which lack endogenous CYP450 expression.
- Full Text:
- Date Issued: 2020
- Authors: Weyers, Carli , Dingle, Laura M K , Wilhelmi, Brendan S , Edkins, Adrienne L , Veale, Clinton G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160290 , vital:40431 , DOI: 10.1080/01480545.2019.1585869
- Description: Metabolically induced drug-toxicity is a major cause of drug failure late in drug optimization phases. Accordingly, in vitro metabolic profiling of compounds is being introduced at earlier stages of the drug discovery pipeline. An increasingly common method to obtain these profiles is through overexpression of key CYP450 metabolic enzymes in immortalized liver cells, to generate competent hepatocyte surrogates. Enhanced cytotoxicity is presumed to be due to toxic metabolite production via the overexpressed enzyme. However, metabolically induced toxicity is a complex multi-parameter phenomenon and the potential background contribution to metabolism arising from the use of liver cells which endogenously express CYP450 isoforms is consistently overlooked. In this study, we sought to reduce the potential background interference by applying this methodology in kidney-derived HEK293 cells which lack endogenous CYP450 expression.
- Full Text:
- Date Issued: 2020
Bat species richness and community composition along a mega-transect in the Okavango river basin:
- Weier, Sina M, Keith, Mark, Neef, Götz G, Parker, Daniel M, Taylor, Peter
- Authors: Weier, Sina M , Keith, Mark , Neef, Götz G , Parker, Daniel M , Taylor, Peter
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149264 , vital:38820 , https://doi.org/10.3390/d12050188
- Description: The Okavango River Basin is a hotspot of bat diversity that requires urgent and adequate protection. To advise future conservation strategies, we investigated the relative importance of a range of potential environmental drivers of bat species richness and functional community composition in the Okavango River Basin. During annual canoe transects along the major rivers, originating in the central Angolan highlands, we recorded more than 25,000 bat echolocation calls from 2015 to 2018. We corrected for possible biases in sampling design and effort.
- Full Text:
- Date Issued: 2020
- Authors: Weier, Sina M , Keith, Mark , Neef, Götz G , Parker, Daniel M , Taylor, Peter
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149264 , vital:38820 , https://doi.org/10.3390/d12050188
- Description: The Okavango River Basin is a hotspot of bat diversity that requires urgent and adequate protection. To advise future conservation strategies, we investigated the relative importance of a range of potential environmental drivers of bat species richness and functional community composition in the Okavango River Basin. During annual canoe transects along the major rivers, originating in the central Angolan highlands, we recorded more than 25,000 bat echolocation calls from 2015 to 2018. We corrected for possible biases in sampling design and effort.
- Full Text:
- Date Issued: 2020
Mapping subtidal estuarine habitats with a remotely operated underwater vehicle (ROV):
- Wasserman, J, Claassens, L, Adams, J B
- Authors: Wasserman, J , Claassens, L , Adams, J B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150163 , vital:38945 , DOI: 10.2989/1814232X.2020.1731598
- Description: Subtidal habitats have not yet been accounted for in habitat maps of South African estuaries. In this study, a novel method for mapping subtidal estuarine habitats, using a remotely operated underwater vehicle (ROV) piloted from a boat, was developed and tested in the Knysna Estuary. Video footage was recorded along 48 transects across the width of the estuary, and then reviewed to identify, classify and map habitats. Using the method developed in this study, 21 hours of footage was recorded over 15 days of sampling, and about 30 hours of post-processing was carried out to map an area exceeding 850 ha. This study has produced the first baseline dataset of subtidal habitats for a South African estuary. Additionally, the study revealed the previously unknown distribution of the invasive red seaweed Asparagopsis taxiformis, and the underestimation in previous studies of the estuary of area cover of eelgrass Zostera capensis by 130 ha.
- Full Text:
- Date Issued: 2020
- Authors: Wasserman, J , Claassens, L , Adams, J B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150163 , vital:38945 , DOI: 10.2989/1814232X.2020.1731598
- Description: Subtidal habitats have not yet been accounted for in habitat maps of South African estuaries. In this study, a novel method for mapping subtidal estuarine habitats, using a remotely operated underwater vehicle (ROV) piloted from a boat, was developed and tested in the Knysna Estuary. Video footage was recorded along 48 transects across the width of the estuary, and then reviewed to identify, classify and map habitats. Using the method developed in this study, 21 hours of footage was recorded over 15 days of sampling, and about 30 hours of post-processing was carried out to map an area exceeding 850 ha. This study has produced the first baseline dataset of subtidal habitats for a South African estuary. Additionally, the study revealed the previously unknown distribution of the invasive red seaweed Asparagopsis taxiformis, and the underestimation in previous studies of the estuary of area cover of eelgrass Zostera capensis by 130 ha.
- Full Text:
- Date Issued: 2020
Perceived benefits of nature-based experiences as mediators of connectedness with nature: The case of Mystic Mountain
- Ward-Smith, Chesney, Naidoo, Tony, Olvitt, Lausanne L, Olvitt, Lausanne, Akhurst, Jacqueline
- Authors: Ward-Smith, Chesney , Naidoo, Tony , Olvitt, Lausanne L , Olvitt, Lausanne , Akhurst, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372782 , vital:66622 , xlink:href="https://doi.org/10.1177/00812463209470"
- Description: Perceived nature disconnection lies at the heart of the world’s socio-ecological crisis. Finding ways to reconnect with nature is fundamental towards reducing the adverse psychological–social– ecological consequences of this disconnection. Understanding the psychological and social benefits of nature-based experiences is important towards actualising reconnection. This article discusses such benefits for child and adult participants from the Eastern Cape, South Africa. This work stems from Ecopsychology research with an outdoor education centre, Mystic Mountain. The experiences of two groups of children (n=25, aged 10–14years) and adult instructors (n=12, aged 18–50years) were explored using interpretive case-study methodology. Through semi-structured interviews and focus groups, participant observation, and reflexive journaling, data were collected and analysed thematically. This article centralises participants’ perceived psychological and social benefits of nature-based experiences as mediators of deeper self and nature connectedness. Integrating these benefits into nature-based pedagogy-design processes could contribute towards more effective enhancements of nature connectedness, and in turn, foster Earth’s larger flourishment.
- Full Text:
- Date Issued: 2020
- Authors: Ward-Smith, Chesney , Naidoo, Tony , Olvitt, Lausanne L , Olvitt, Lausanne , Akhurst, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372782 , vital:66622 , xlink:href="https://doi.org/10.1177/00812463209470"
- Description: Perceived nature disconnection lies at the heart of the world’s socio-ecological crisis. Finding ways to reconnect with nature is fundamental towards reducing the adverse psychological–social– ecological consequences of this disconnection. Understanding the psychological and social benefits of nature-based experiences is important towards actualising reconnection. This article discusses such benefits for child and adult participants from the Eastern Cape, South Africa. This work stems from Ecopsychology research with an outdoor education centre, Mystic Mountain. The experiences of two groups of children (n=25, aged 10–14years) and adult instructors (n=12, aged 18–50years) were explored using interpretive case-study methodology. Through semi-structured interviews and focus groups, participant observation, and reflexive journaling, data were collected and analysed thematically. This article centralises participants’ perceived psychological and social benefits of nature-based experiences as mediators of deeper self and nature connectedness. Integrating these benefits into nature-based pedagogy-design processes could contribute towards more effective enhancements of nature connectedness, and in turn, foster Earth’s larger flourishment.
- Full Text:
- Date Issued: 2020
UN Decade on Ecosystem Restoration 2021–2030: what chance for success in restoring coastal ecosystems?
- Waltham, Nathan J, Elliott, Michael, Lee, Shing Yip, Lovelock, Catherine, Duarte, Carlos M, Buelow, Christina, Simenstad, Charles, Nagelkerken, Ivan, Claassens, Louw, Wen, Colin K-C, Barletta, Mario, Connolly, Rod M, Gillies, Chris, Mitsch, William J, Ogburn, Matthew B, Purandare, Jemma, Possingham, Hugh, Sheaves, Marcus
- Authors: Waltham, Nathan J , Elliott, Michael , Lee, Shing Yip , Lovelock, Catherine , Duarte, Carlos M , Buelow, Christina , Simenstad, Charles , Nagelkerken, Ivan , Claassens, Louw , Wen, Colin K-C , Barletta, Mario , Connolly, Rod M , Gillies, Chris , Mitsch, William J , Ogburn, Matthew B , Purandare, Jemma , Possingham, Hugh , Sheaves, Marcus
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149836 , vital:38887 , https://doi.org/10.3389/fmars.2020.00071
- Description: On 1 March 2019, the United Nations (UN) General Assembly (New York) declared 2021–2030 the “UN Decade on Ecosystem Restoration.” This call to action has the purpose of recognizing the need to massively accelerate global restoration of degraded ecosystems, to fight the climate heating crisis, enhance food security, provide clean water and protect biodiversity on the planet. The scale of restoration will be key; for example, the Bonn Challenge has the goal to restore 350 million km2 (almost the size of India) of degraded terrestrial ecosystems by 2030. However, international support for restoration of “blue” coastal ecosystems, which provide an impressive array of benefits to people, has lagged. Only the Global Mangrove Alliance (https://mangrovealliance.org/) comes close to the Bonn Challenge, with the aim of increasing the global area of mangroves by 20% by 2030. However, mangrove scientists have reservations about this target, voicing concerns that it is unrealistic and may prompt inappropriate practices in attempting to reach this target (Lee et al., 2019). The decade of ecosystem restoration declaration also coincides with the UN Decade of Ocean Science for Sustainable Development, which aims to reverse deterioration in ocean health. If executed in a holistic and coordinated manner, signatory nations could stand to deliver on both these UN calls to action.
- Full Text:
- Date Issued: 2020
- Authors: Waltham, Nathan J , Elliott, Michael , Lee, Shing Yip , Lovelock, Catherine , Duarte, Carlos M , Buelow, Christina , Simenstad, Charles , Nagelkerken, Ivan , Claassens, Louw , Wen, Colin K-C , Barletta, Mario , Connolly, Rod M , Gillies, Chris , Mitsch, William J , Ogburn, Matthew B , Purandare, Jemma , Possingham, Hugh , Sheaves, Marcus
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149836 , vital:38887 , https://doi.org/10.3389/fmars.2020.00071
- Description: On 1 March 2019, the United Nations (UN) General Assembly (New York) declared 2021–2030 the “UN Decade on Ecosystem Restoration.” This call to action has the purpose of recognizing the need to massively accelerate global restoration of degraded ecosystems, to fight the climate heating crisis, enhance food security, provide clean water and protect biodiversity on the planet. The scale of restoration will be key; for example, the Bonn Challenge has the goal to restore 350 million km2 (almost the size of India) of degraded terrestrial ecosystems by 2030. However, international support for restoration of “blue” coastal ecosystems, which provide an impressive array of benefits to people, has lagged. Only the Global Mangrove Alliance (https://mangrovealliance.org/) comes close to the Bonn Challenge, with the aim of increasing the global area of mangroves by 20% by 2030. However, mangrove scientists have reservations about this target, voicing concerns that it is unrealistic and may prompt inappropriate practices in attempting to reach this target (Lee et al., 2019). The decade of ecosystem restoration declaration also coincides with the UN Decade of Ocean Science for Sustainable Development, which aims to reverse deterioration in ocean health. If executed in a holistic and coordinated manner, signatory nations could stand to deliver on both these UN calls to action.
- Full Text:
- Date Issued: 2020
Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives
- Waleguele, Christine C, Mba'ning, Brice M, Awantu, Angelbert F, Bankeu, Jean J, Fongang, Yannick S F, Ngouela, Augustin S, Tsamo, Etienne, Sewald, Norbert, Lenta, Bruno N, Krause, Rui W M
- Authors: Waleguele, Christine C , Mba'ning, Brice M , Awantu, Angelbert F , Bankeu, Jean J , Fongang, Yannick S F , Ngouela, Augustin S , Tsamo, Etienne , Sewald, Norbert , Lenta, Bruno N , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193364 , vital:45325 , xlink:href="https://doi.org/10.3390/molecules25122862"
- Description: The MeOH/CH2Cl2 (1:1) extracts of the roots and leaves of Beilschmiedia louisii and B. obscura showed potent antitrypanosomal activity during preliminary screening on Trypanosoma brucei brucei. Phytochemical investigation of these extracts led to the isolation of a mixture of two new endiandric acid derivatives beilschmiedol B (1) and beilschmiedol C (2), and one new phenylalkene obscurene A (3) together with twelve known compounds (4–15). In addition, four new derivatives (11a–11d) were synthesized from compound 11. Their structures were elucidated based on their NMR and MS data. Compounds 5, 6, and 7 were isolated for the first time from the Beilschmiedia genus. Additionally, the NMR data of compound 4 are given here for the first time. The isolates were evaluated for their antitrypanosomal and antimalarial activities against Tb brucei and the Plasmodium falciparum chloroquine-resistant strain Pf3D7 in vitro, respectively. From the tested compounds, the mixture of new compounds 1 and 2 exhibited the most potent antitrypanosomal activity in vitro with IC50 value of 4.91 μM.
- Full Text:
- Date Issued: 2020
- Authors: Waleguele, Christine C , Mba'ning, Brice M , Awantu, Angelbert F , Bankeu, Jean J , Fongang, Yannick S F , Ngouela, Augustin S , Tsamo, Etienne , Sewald, Norbert , Lenta, Bruno N , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193364 , vital:45325 , xlink:href="https://doi.org/10.3390/molecules25122862"
- Description: The MeOH/CH2Cl2 (1:1) extracts of the roots and leaves of Beilschmiedia louisii and B. obscura showed potent antitrypanosomal activity during preliminary screening on Trypanosoma brucei brucei. Phytochemical investigation of these extracts led to the isolation of a mixture of two new endiandric acid derivatives beilschmiedol B (1) and beilschmiedol C (2), and one new phenylalkene obscurene A (3) together with twelve known compounds (4–15). In addition, four new derivatives (11a–11d) were synthesized from compound 11. Their structures were elucidated based on their NMR and MS data. Compounds 5, 6, and 7 were isolated for the first time from the Beilschmiedia genus. Additionally, the NMR data of compound 4 are given here for the first time. The isolates were evaluated for their antitrypanosomal and antimalarial activities against Tb brucei and the Plasmodium falciparum chloroquine-resistant strain Pf3D7 in vitro, respectively. From the tested compounds, the mixture of new compounds 1 and 2 exhibited the most potent antitrypanosomal activity in vitro with IC50 value of 4.91 μM.
- Full Text:
- Date Issued: 2020
Detection of pharmaceutical residues in surface waters of the Eastern Cape Province:
- Vumazonke, Sesethu, Khamanga, Sandile M, Ngqwala, Nosiphiwe P
- Authors: Vumazonke, Sesethu , Khamanga, Sandile M , Ngqwala, Nosiphiwe P
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149819 , vital:38886 , https://doi.org/10.3390/ijerph17114067
- Description: Pharmaceuticals are emerging contaminants in the aquatic environments. Their presence poses toxicological effects in humans and animals even at trace concentrations. This study investigated the presence of antibiotics, anti-epilepsy and anti-inflammatory drugs in river water of selected rivers in the Eastern Cape Province in South Africa. Enzyme-linked immunosorbent assay was used for screening of sulfamethoxazole and fluoroquinolones antibiotics. The samples were collected in upper-stream, middle-stream and lower-stream regions of the rivers and effluent of selected wastewater treatment plants. Pre-concentration of the samples was conducted using lyophilisation and extraction was conducted using solid phase extraction (SPE) on Waters Oasis hydrophilic-lipophilic-balanced cartridge.
- Full Text:
- Date Issued: 2020
- Authors: Vumazonke, Sesethu , Khamanga, Sandile M , Ngqwala, Nosiphiwe P
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149819 , vital:38886 , https://doi.org/10.3390/ijerph17114067
- Description: Pharmaceuticals are emerging contaminants in the aquatic environments. Their presence poses toxicological effects in humans and animals even at trace concentrations. This study investigated the presence of antibiotics, anti-epilepsy and anti-inflammatory drugs in river water of selected rivers in the Eastern Cape Province in South Africa. Enzyme-linked immunosorbent assay was used for screening of sulfamethoxazole and fluoroquinolones antibiotics. The samples were collected in upper-stream, middle-stream and lower-stream regions of the rivers and effluent of selected wastewater treatment plants. Pre-concentration of the samples was conducted using lyophilisation and extraction was conducted using solid phase extraction (SPE) on Waters Oasis hydrophilic-lipophilic-balanced cartridge.
- Full Text:
- Date Issued: 2020
Detection of pharmaceutical residues in surface waters of the Eastern Cape Province:
- Vumazonke, Sesethu, Khamanga, Sandile M, Ngqwala, Nosiphiwe P
- Authors: Vumazonke, Sesethu , Khamanga, Sandile M , Ngqwala, Nosiphiwe P
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149693 , vital:38875 , https://doi.org/10.3390/ijerph17114067
- Description: Pharmaceuticals are emerging contaminants in the aquatic environments. Their presence poses toxicological effects in humans and animals even at trace concentrations. This study investigated the presence of antibiotics, anti-epilepsy and anti-inflammatory drugs in river water of selected rivers in the Eastern Cape Province in South Africa. Enzyme-linked immunosorbent assay was used for screening of sulfamethoxazole and fluoroquinolones antibiotics. The samples were collected in upper-stream, middle-stream and lower-stream regions of the rivers and effluent of selected wastewater treatment plants. Pre-concentration of the samples was conducted using lyophilisation and extraction was conducted using solid phase extraction (SPE) on Waters Oasis hydrophilic-lipophilic-balanced cartridge.
- Full Text:
- Date Issued: 2020
- Authors: Vumazonke, Sesethu , Khamanga, Sandile M , Ngqwala, Nosiphiwe P
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149693 , vital:38875 , https://doi.org/10.3390/ijerph17114067
- Description: Pharmaceuticals are emerging contaminants in the aquatic environments. Their presence poses toxicological effects in humans and animals even at trace concentrations. This study investigated the presence of antibiotics, anti-epilepsy and anti-inflammatory drugs in river water of selected rivers in the Eastern Cape Province in South Africa. Enzyme-linked immunosorbent assay was used for screening of sulfamethoxazole and fluoroquinolones antibiotics. The samples were collected in upper-stream, middle-stream and lower-stream regions of the rivers and effluent of selected wastewater treatment plants. Pre-concentration of the samples was conducted using lyophilisation and extraction was conducted using solid phase extraction (SPE) on Waters Oasis hydrophilic-lipophilic-balanced cartridge.
- Full Text:
- Date Issued: 2020
Effect of drought on communal livestock farmers in KwaZulu-Natal, South Africa:
- Vetter, S, Goodall, V L, Alcock, R
- Authors: Vetter, S , Goodall, V L , Alcock, R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179006 , vital:40105 , https://doi.org/10.2989/10220119.2020.1738552
- Description: Despite the size of the informal small-scale farming sector and its livestock holdings in South Africa, there has been little detailed work to assess how livestock populations are affected by drought. South Africa experienced a major drought in 2015–2016. We analysed goat and cattle census data from the Msinga area in KwaZulu-Natal, which represent the livestock of some 3 000 households. Cattle farmers in the study area lost 43% of the herd, compared with 29% for goats, in 2015–2016. Three years after the drought, cattle numbers remained depressed, whereas goat numbers had recovered. Larger herds suffered lower mortality rates, suggesting that owners of larger herds had better means to support their herds. Support to reduce drought losses and aid recovery should take into consideration the different capabilities and requirements of small and large herd owners. Effects of high stocking rates and resource condition on mortality and herd growth were apparent during the drought year of 2016, but not the other years. Most die-offs appear to have been concentrated in a short period once forage and water resources became too scarce and far to reach. Recognising when this threshold is imminent would be useful for targeting strategic interventions.
- Full Text:
- Date Issued: 2020
- Authors: Vetter, S , Goodall, V L , Alcock, R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179006 , vital:40105 , https://doi.org/10.2989/10220119.2020.1738552
- Description: Despite the size of the informal small-scale farming sector and its livestock holdings in South Africa, there has been little detailed work to assess how livestock populations are affected by drought. South Africa experienced a major drought in 2015–2016. We analysed goat and cattle census data from the Msinga area in KwaZulu-Natal, which represent the livestock of some 3 000 households. Cattle farmers in the study area lost 43% of the herd, compared with 29% for goats, in 2015–2016. Three years after the drought, cattle numbers remained depressed, whereas goat numbers had recovered. Larger herds suffered lower mortality rates, suggesting that owners of larger herds had better means to support their herds. Support to reduce drought losses and aid recovery should take into consideration the different capabilities and requirements of small and large herd owners. Effects of high stocking rates and resource condition on mortality and herd growth were apparent during the drought year of 2016, but not the other years. Most die-offs appear to have been concentrated in a short period once forage and water resources became too scarce and far to reach. Recognising when this threshold is imminent would be useful for targeting strategic interventions.
- Full Text:
- Date Issued: 2020
Green Apartheid: Urban green infrastructure remains unequally distributed across income and race geographies in South Africa
- Venter, Zander S, Shackleton, Charlie M, Van Staden, Francini, Selomane, Odirilwe, Masterson, Vanessa A
- Authors: Venter, Zander S , Shackleton, Charlie M , Van Staden, Francini , Selomane, Odirilwe , Masterson, Vanessa A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160323 , vital:40435 , https://doi.org/10.1016/j.landurbplan.2020.103889 , https://researchdata.ru.ac.za/search?q=:keyword: "Environmental justice"
- Description: Urban green infrastructure provides ecosystem services that are essential to human wellbeing. A dearth of national-scale assessments in the Global South has precluded the ability to explore how political regimes, such as the forced racial segregation in South Africa during and after Apartheid, have influenced the extent of and access to green infrastructure over time. We investigate whether there are disparities in green infrastructure distributions across race and income geographies in urban South Africa. Using open-source satellite imagery and geographic information, along with national census statistics, we find that public and private green infrastructure is more abundant, accessible, greener and more treed in high-income relative to low-income areas, and in areas where previously advantaged racial groups (i.e. White citizens) reside.
- Full Text:
- Date Issued: 2020
- Authors: Venter, Zander S , Shackleton, Charlie M , Van Staden, Francini , Selomane, Odirilwe , Masterson, Vanessa A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160323 , vital:40435 , https://doi.org/10.1016/j.landurbplan.2020.103889 , https://researchdata.ru.ac.za/search?q=:keyword: "Environmental justice"
- Description: Urban green infrastructure provides ecosystem services that are essential to human wellbeing. A dearth of national-scale assessments in the Global South has precluded the ability to explore how political regimes, such as the forced racial segregation in South Africa during and after Apartheid, have influenced the extent of and access to green infrastructure over time. We investigate whether there are disparities in green infrastructure distributions across race and income geographies in urban South Africa. Using open-source satellite imagery and geographic information, along with national census statistics, we find that public and private green infrastructure is more abundant, accessible, greener and more treed in high-income relative to low-income areas, and in areas where previously advantaged racial groups (i.e. White citizens) reside.
- Full Text:
- Date Issued: 2020
Small scale habitat effects on anthropogenic litter material and sources in a coastal lagoon system:
- Velez, Nadja, Nicastro, Katy R, McQuaid, Christopher D, Zardi, Gerardi I
- Authors: Velez, Nadja , Nicastro, Katy R , McQuaid, Christopher D , Zardi, Gerardi I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160489 , vital:40450 , https://doi.org/10.1016/j.marpolbul.2020.111689
- Description: Anthropogenic litter is ubiquitous throughout marine ecosystems, but its abundance and distribution are driven by complex interactions of distinct environmental factors and thus can be extremely heterogeneous. Here we compare the extent of anthropogenic litter pollution at a sheltered lagoon habitat and nearby open coast sites. Monthly surveys over a period of five months showed that both the types and sources of litter always differed significantly between lagoon and open coast sites.
- Full Text:
- Date Issued: 2020
Small scale habitat effects on anthropogenic litter material and sources in a coastal lagoon system:
- Authors: Velez, Nadja , Nicastro, Katy R , McQuaid, Christopher D , Zardi, Gerardi I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160489 , vital:40450 , https://doi.org/10.1016/j.marpolbul.2020.111689
- Description: Anthropogenic litter is ubiquitous throughout marine ecosystems, but its abundance and distribution are driven by complex interactions of distinct environmental factors and thus can be extremely heterogeneous. Here we compare the extent of anthropogenic litter pollution at a sheltered lagoon habitat and nearby open coast sites. Monthly surveys over a period of five months showed that both the types and sources of litter always differed significantly between lagoon and open coast sites.
- Full Text:
- Date Issued: 2020
Application of quality by design principles for optimizing process variables of Extrusion and Spheronization of a Captopril Pellet Formulation:
- Veerubhotla, Krishna, Walker, Roderick B
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
Climate responsive innovation within the agricultural curriculum and learning system
- Authors: van Staden, Wilma
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389744 , vital:68479 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/186598"
- Description: The purpose of this paper is to outline the climate responsive innovation process within the agricultural innovation system of the North West Province, South Africa. The focus was on the embedded curriculum and learning activity system and its responses to social-ecological and earth system changes influenced by climate change. It outlines the barriers and processes hampering curriculum and learning innovations towards climate-smart responsiveness, and also examines the processes required to initiate micro and macro innovations. This paper focusses on how actors within the system can initiate curriculum innovation and climate responsiveness through micro innovations when supported and how this can lead to macro innovations. The system experienced various barriers during the innovation process and overcame many challenges during the journey towards climate-smart responsiveness through the identification of contradictions within the system, developing tools to assist in the transitioning process and expansion in the social-spatial dimension by establishing a learning network within the surrounding communities. The research indicated that the catalysing of the curriculum and learning system required specific tools, time and the understanding of the importance of micro-level innovation.
- Full Text:
- Date Issued: 2020
- Authors: van Staden, Wilma
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389744 , vital:68479 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/186598"
- Description: The purpose of this paper is to outline the climate responsive innovation process within the agricultural innovation system of the North West Province, South Africa. The focus was on the embedded curriculum and learning activity system and its responses to social-ecological and earth system changes influenced by climate change. It outlines the barriers and processes hampering curriculum and learning innovations towards climate-smart responsiveness, and also examines the processes required to initiate micro and macro innovations. This paper focusses on how actors within the system can initiate curriculum innovation and climate responsiveness through micro innovations when supported and how this can lead to macro innovations. The system experienced various barriers during the innovation process and overcame many challenges during the journey towards climate-smart responsiveness through the identification of contradictions within the system, developing tools to assist in the transitioning process and expansion in the social-spatial dimension by establishing a learning network within the surrounding communities. The research indicated that the catalysing of the curriculum and learning system required specific tools, time and the understanding of the importance of micro-level innovation.
- Full Text:
- Date Issued: 2020
A systematic analysis of doctoral publication trends in South Africa
- van Schalkwyk, Susan, Mouton, Johann, Redlinghuys, Herman, McKenna, Sioux
- Authors: van Schalkwyk, Susan , Mouton, Johann , Redlinghuys, Herman , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185826 , vital:44438 , xlink:href="http://dx.doi.org/10.17159/sajs.2020/7926"
- Description: It is incumbent upon doctoral students that their work makes a substantive contribution to the field within which it is conducted. Dissemination of this work beyond the dissertation, whether whilst studying or after graduation, is necessary to ensure that the contribution does not remain largely dormant. While dissemination can take many forms, peer-reviewed journal articles are the key medium by which knowledge is shared. We aimed to establish the proportion of doctoral theses that results in journal publications by linking South African doctoral thesis metadata to journal articles authored by doctoral candidates. To effect this matching, a customised data set was created that comprised two large databases: the South African Theses Database (SATD), which documented all doctoral degrees awarded in South Africa (2005-2014), and the South African Knowledgebase (SAK), which listed all publications submitted for subsidy to the South African Department of Higher Education and Training (2005-2017). The process followed several iterations of matching and verification, including manual inspection of the data, in order to isolate only those records for which the link was established beyond doubt. Over the period under review, 47.6% of graduates, representing 22 of the 26 higher education institutions, published at least one journal article. Results further indicate increasingly higher publication rates over time. To explore whether the journal article identified was a direct product of the study, a similarity index was developed. Over 75% of records demonstrated high similarity. While the trend towards increasing publications by graduates is promising, work in this area should be ongoing. In spite of increasing trends in publications by graduates, many are not disseminating their work, suggesting that significant bodies of research are potentially not being shared with the academic community and are therefore not contributing to the relevant discipline or field. •This study provides baseline data from which a number of further investigations can be launched, such as exploring the extent to which doctoral candidates who are also academics are publishing their work; the factors that enable or constrain publication; the other avenues of dissemination used; and whether publishing or not publishing can serve as a proxy for the quality of the doctoral work.
- Full Text:
- Date Issued: 2020
- Authors: van Schalkwyk, Susan , Mouton, Johann , Redlinghuys, Herman , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185826 , vital:44438 , xlink:href="http://dx.doi.org/10.17159/sajs.2020/7926"
- Description: It is incumbent upon doctoral students that their work makes a substantive contribution to the field within which it is conducted. Dissemination of this work beyond the dissertation, whether whilst studying or after graduation, is necessary to ensure that the contribution does not remain largely dormant. While dissemination can take many forms, peer-reviewed journal articles are the key medium by which knowledge is shared. We aimed to establish the proportion of doctoral theses that results in journal publications by linking South African doctoral thesis metadata to journal articles authored by doctoral candidates. To effect this matching, a customised data set was created that comprised two large databases: the South African Theses Database (SATD), which documented all doctoral degrees awarded in South Africa (2005-2014), and the South African Knowledgebase (SAK), which listed all publications submitted for subsidy to the South African Department of Higher Education and Training (2005-2017). The process followed several iterations of matching and verification, including manual inspection of the data, in order to isolate only those records for which the link was established beyond doubt. Over the period under review, 47.6% of graduates, representing 22 of the 26 higher education institutions, published at least one journal article. Results further indicate increasingly higher publication rates over time. To explore whether the journal article identified was a direct product of the study, a similarity index was developed. Over 75% of records demonstrated high similarity. While the trend towards increasing publications by graduates is promising, work in this area should be ongoing. In spite of increasing trends in publications by graduates, many are not disseminating their work, suggesting that significant bodies of research are potentially not being shared with the academic community and are therefore not contributing to the relevant discipline or field. •This study provides baseline data from which a number of further investigations can be launched, such as exploring the extent to which doctoral candidates who are also academics are publishing their work; the factors that enable or constrain publication; the other avenues of dissemination used; and whether publishing or not publishing can serve as a proxy for the quality of the doctoral work.
- Full Text:
- Date Issued: 2020