Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/13809
K. Ahmed, M. Malahleha, T. E. Mbatsane, Dineo Thindisa, V. Bailey, I. Seocharan, A. Dilraj
In clinical trials, a vital protocol requirement for participants is adherence to scheduled visits. A substantial number of missed visits and the resultant missing data could affect generalisability of the findings and undermine the scientific conclusions. We aimed to investigate the extent of and reasons for missed visits in the Evidence for Contraceptive Options and HIV Outcomes (ECHO) trial in order to optimise recruitment and retention practices. Despite being a multi-country study, we investigated missed visits only at Setshaba Research Centre in Soshanguve, Tshwane, South Africa. Of 810 participants enrolled at Setshaba Research Centre, 94 (11.6%) participants missed visits and 231 missed visits were recorded. Of the 94 participants who missed visits, 53 (56.4%) missed at least two visits; 37 (39.4%) missed three or more visits, and of these, 32 (86.5%) missed at least two visits for the same reason. Overall, the main reasons for missed visits were: participant had to work (60; 26.0%), unable to contact participant (60; 26.0%), participant relocated (32; 13.9%), and participant travelled out of area (23; 10%). The large proportion of participants who missed two or more visits indicates that participants who miss a single visit are likely to miss even more, often for the same reason. Site staff need to be vigilant to detect any trends in missed visits early and innovative in developing personalised strategies to minimise missed visits and retain participants until completion of their scheduled visits.
{"title":"Addressing missed visits to improve retention of young South African women in clinical trials","authors":"K. Ahmed, M. Malahleha, T. E. Mbatsane, Dineo Thindisa, V. Bailey, I. Seocharan, A. Dilraj","doi":"10.17159/sajs.2023/13809","DOIUrl":"https://doi.org/10.17159/sajs.2023/13809","url":null,"abstract":"In clinical trials, a vital protocol requirement for participants is adherence to scheduled visits. A substantial number of missed visits and the resultant missing data could affect generalisability of the findings and undermine the scientific conclusions. We aimed to investigate the extent of and reasons for missed visits in the Evidence for Contraceptive Options and HIV Outcomes (ECHO) trial in order to optimise recruitment and retention practices. Despite being a multi-country study, we investigated missed visits only at Setshaba Research Centre in Soshanguve, Tshwane, South Africa. Of 810 participants enrolled at Setshaba Research Centre, 94 (11.6%) participants missed visits and 231 missed visits were recorded. Of the 94 participants who missed visits, 53 (56.4%) missed at least two visits; 37 (39.4%) missed three or more visits, and of these, 32 (86.5%) missed at least two visits for the same reason. Overall, the main reasons for missed visits were: participant had to work (60; 26.0%), unable to contact participant (60; 26.0%), participant relocated (32; 13.9%), and participant travelled out of area (23; 10%). The large proportion of participants who missed two or more visits indicates that participants who miss a single visit are likely to miss even more, often for the same reason. Site staff need to be vigilant to detect any trends in missed visits early and innovative in developing personalised strategies to minimise missed visits and retain participants until completion of their scheduled visits.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45455679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/16073
N. Madondo
{"title":"A timely, deeper, and complex analysis of dysfunctionality in South African public universities","authors":"N. Madondo","doi":"10.17159/sajs.2023/16073","DOIUrl":"https://doi.org/10.17159/sajs.2023/16073","url":null,"abstract":"","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47312986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/14914
J. Holmes, J. Fitchett
Oxygen- and hydrogen-isotope ratios in rainfall provide important hydroclimatic information, yet despite a global network of rainfall isotope measurements, significant geographical gaps exist in data coverage, with only three long-term stations spanning the southern African region. Project-based, ad hoc collections of rainfall for isotope analysis can improve this coverage. However, all rainfall samples that are destined for stable isotope analysis must be collected in such a way to avoid evaporation and resultant isotope fractionation. While such rainwater collectors are available commercially, both the product and shipping are prohibitively costly. We describe the construction of a simple rainfall collector using a design from the literature and materials that are readily available in South African hardware stores. Our rainwater collector can be constructed for the much lower cost of just under ZAR820 in comparison with the cost of ZAR9300 inclusive of shipping from commercial outlets (2022 prices). Our design modifications have the added advantage of portability, with the rainwater collector housed in a bucket with a handle. The device was tested by comparing its performance, in terms of evaporative water loss and isotopic fractionation, with that of an open bottle, using tap water in both cases. Testing confirmed that the collector prevented evaporation over a one-week period, indicating that it is suitable for weekly or more frequent sampling of rainfall. Although the design described was based on materials procured in South Africa, it could easily be adapted for construction elsewhere.
{"title":"Construction and testing of a low-cost device for the collection of rainfall samples destined for stable isotope analysis","authors":"J. Holmes, J. Fitchett","doi":"10.17159/sajs.2023/14914","DOIUrl":"https://doi.org/10.17159/sajs.2023/14914","url":null,"abstract":"Oxygen- and hydrogen-isotope ratios in rainfall provide important hydroclimatic information, yet despite a global network of rainfall isotope measurements, significant geographical gaps exist in data coverage, with only three long-term stations spanning the southern African region. Project-based, ad hoc collections of rainfall for isotope analysis can improve this coverage. However, all rainfall samples that are destined for stable isotope analysis must be collected in such a way to avoid evaporation and resultant isotope fractionation. While such rainwater collectors are available commercially, both the product and shipping are prohibitively costly. We describe the construction of a simple rainfall collector using a design from the literature and materials that are readily available in South African hardware stores. Our rainwater collector can be constructed for the much lower cost of just under ZAR820 in comparison with the cost of ZAR9300 inclusive of shipping from commercial outlets (2022 prices). Our design modifications have the added advantage of portability, with the rainwater collector housed in a bucket with a handle. The device was tested by comparing its performance, in terms of evaporative water loss and isotopic fractionation, with that of an open bottle, using tap water in both cases. Testing confirmed that the collector prevented evaporation over a one-week period, indicating that it is suitable for weekly or more frequent sampling of rainfall. Although the design described was based on materials procured in South Africa, it could easily be adapted for construction elsewhere.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46165667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/10709
Buster Mogonong, J. Fisher, D. Furniss, Debbie Jewitt
Rural landscapes in South Africa experience high conversion rates due to intense land use; however, the changes are site specific and depend on the socio-economic and political history of the area. Land cover change (LCC) was assessed in response to socio-economic and political factors in uThukela Municipal District, KwaZulu-Natal, using Landsat imagery from 1984 to 2014, while making comparisons to other studies in South Africa. Socio-economic/political data were used to gain insights into the observed LCC patterns. Land cover was classified using a random forest classifier, and accuracies ranging from 87% to 92% were achieved. Systematic and intensity analysis methods were used to describe patterns, rates, and transitions of LCC in Imbabazane (ILM) and Okhahlamba (OLM) local municipalities. The results showed a reduced rate of change intensity from 3.4% to 0.9% in ILM and from 3.1% to 1.1% in OLM between 1984 and 2014. Grassland was persistent, covering over 70% in both local municipalities between 1984 and 2014. Although persistent, grassland experienced respective losses of 3.7% and 14.3% in both observation periods in ILM and of 10.2% and 13.3% in OLM. During the analysis period, settlements and cropland gained actively in both local municipalities. The changes represent a degree of population, local authority, and people’s perception as influencers of land use and LCC. It is therefore argued that socio-economic and political changes can potentially influence land use and LCC; however, natural ecosystems can persist under those conditions, and this requires more research efforts.
{"title":"Land cover change in marginalised landscapes of South Africa (1984–2014): Insights into the influence of socio-economic and political factors","authors":"Buster Mogonong, J. Fisher, D. Furniss, Debbie Jewitt","doi":"10.17159/sajs.2023/10709","DOIUrl":"https://doi.org/10.17159/sajs.2023/10709","url":null,"abstract":"Rural landscapes in South Africa experience high conversion rates due to intense land use; however, the changes are site specific and depend on the socio-economic and political history of the area. Land cover change (LCC) was assessed in response to socio-economic and political factors in uThukela Municipal District, KwaZulu-Natal, using Landsat imagery from 1984 to 2014, while making comparisons to other studies in South Africa. Socio-economic/political data were used to gain insights into the observed LCC patterns. Land cover was classified using a random forest classifier, and accuracies ranging from 87% to 92% were achieved. Systematic and intensity analysis methods were used to describe patterns, rates, and transitions of LCC in Imbabazane (ILM) and Okhahlamba (OLM) local municipalities. The results showed a reduced rate of change intensity from 3.4% to 0.9% in ILM and from 3.1% to 1.1% in OLM between 1984 and 2014. Grassland was persistent, covering over 70% in both local municipalities between 1984 and 2014. Although persistent, grassland experienced respective losses of 3.7% and 14.3% in both observation periods in ILM and of 10.2% and 13.3% in OLM. During the analysis period, settlements and cropland gained actively in both local municipalities. The changes represent a degree of population, local authority, and people’s perception as influencers of land use and LCC. It is therefore argued that socio-economic and political changes can potentially influence land use and LCC; however, natural ecosystems can persist under those conditions, and this requires more research efforts.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44236255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/13745
R. Beesoo, R. Bhagooli, T. Bahorun, V. Neergheen
Marine sponges belonging to the genus Neopetrosia represent a quasi-inexhaustible source of novel cytotoxic compounds. Yet studies delineating their molecular mechanisms of action in cancer cells remain scarce. We investigated the cytotoxic and apoptosis inducing potential of the Mauritian marine sponge Neopetrosia exigua derived crude extract, hexane and ethyl acetate fraction. Their cytotoxic activity was screened against four cancer cell lines and two non-malignant cell lines via the Alamar Blue metabolic assay. The level of intracellular reactive oxygen species (ROS) production, endogenous antioxidant enzyme activity (catalase and superoxide dismutase) and mitochondrial membrane potential were determined. The ability of the active extract to induce apoptosis in cancer cells and modulate the expression levels of apoptotic markers (caspases and polyADP-ribose polymerase (PARP)) was further evaluated via western blot. The ethyl acetate fraction (NEEAF) displayed the highest inhibitory effect with an IC50 of 6.87 μg/mL against the liver hepatocellular carcinoma cell line (HepG2). Mechanistically, NEEAF induced morphological hallmarks characteristic of apoptosis, increased ROS production, decreased catalase and superoxide dismutase activity and mitochondrial membrane depolarisation in a concentration-dependent manner compared to the control (p<0.05). In addition, NEEAF induced the activation of caspase-9, -7, -3 and cleavage of PARP. Overall, this study provides biochemical evidence for oxidative stress-mediated cytotoxicity and apoptosis in HepG2 cells by NEEAF. Further in-depth investigations are needed to isolate the active constituents, which may potentially lead to the development of novel anticancer therapeutics.
{"title":"In vitro cytotoxic and apoptotic activity of the Mauritian marine sponge Neopetrosia exigua","authors":"R. Beesoo, R. Bhagooli, T. Bahorun, V. Neergheen","doi":"10.17159/sajs.2023/13745","DOIUrl":"https://doi.org/10.17159/sajs.2023/13745","url":null,"abstract":"Marine sponges belonging to the genus Neopetrosia represent a quasi-inexhaustible source of novel cytotoxic compounds. Yet studies delineating their molecular mechanisms of action in cancer cells remain scarce. We investigated the cytotoxic and apoptosis inducing potential of the Mauritian marine sponge Neopetrosia exigua derived crude extract, hexane and ethyl acetate fraction. Their cytotoxic activity was screened against four cancer cell lines and two non-malignant cell lines via the Alamar Blue metabolic assay. The level of intracellular reactive oxygen species (ROS) production, endogenous antioxidant enzyme activity (catalase and superoxide dismutase) and mitochondrial membrane potential were determined. The ability of the active extract to induce apoptosis in cancer cells and modulate the expression levels of apoptotic markers (caspases and polyADP-ribose polymerase (PARP)) was further evaluated via western blot. The ethyl acetate fraction (NEEAF) displayed the highest inhibitory effect with an IC50 of 6.87 μg/mL against the liver hepatocellular carcinoma cell line (HepG2). Mechanistically, NEEAF induced morphological hallmarks characteristic of apoptosis, increased ROS production, decreased catalase and superoxide dismutase activity and mitochondrial membrane depolarisation in a concentration-dependent manner compared to the control (p<0.05). In addition, NEEAF induced the activation of caspase-9, -7, -3 and cleavage of PARP. Overall, this study provides biochemical evidence for oxidative stress-mediated cytotoxicity and apoptosis in HepG2 cells by NEEAF. Further in-depth investigations are needed to isolate the active constituents, which may potentially lead to the development of novel anticancer therapeutics.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43180136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/15840
Bárbara Direito
{"title":"Exploring the dynamics of the relationship between South Africa and southern Mozambique","authors":"Bárbara Direito","doi":"10.17159/sajs.2023/15840","DOIUrl":"https://doi.org/10.17159/sajs.2023/15840","url":null,"abstract":"","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41662882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.17159/sajs.2023/13733
Houraa Daher, B. Kirtman
South African climate variability has been linked to changes in both the Agulhas system and external forcing (i.e. CO2 and ozone). We analysed future climate change in the Agulhas system volume transport and its associated impacts on South Africa’s precipitation using the Community Climate System Model version 4 as part of the Coupled Model Intercomparison Project, phase 5. Output from one historical and three future greenhouse gas emission scenarios were examined to project various climate storylines. We found that the Agulhas Current volume transport decreases across all three scenarios and that the current displays a strong baroclinic component with an increase in transport at the surface and decrease at intermediate depths. Agulhas leakage was found to increase with historical emissions. Additionally, an east-west dipole pattern for convective precipitation was found over South Africa, with an increase over the eastern region related to an increase in greenhouse gas emissions and a decrease in the western region linked to the location of Hadley cell edge latitude. Moving into the 21st century, future predictions in regional climate variability are shown to be dependent on the intensity of greenhouse gas emissions and are extremely important for South Africa, a region prone to drought and flooding and home to a large population dependent on rain-fed agriculture.
{"title":"Future climate change in the Agulhas system and its associated impact on South African rainfall","authors":"Houraa Daher, B. Kirtman","doi":"10.17159/sajs.2023/13733","DOIUrl":"https://doi.org/10.17159/sajs.2023/13733","url":null,"abstract":"South African climate variability has been linked to changes in both the Agulhas system and external forcing (i.e. CO2 and ozone). We analysed future climate change in the Agulhas system volume transport and its associated impacts on South Africa’s precipitation using the Community Climate System Model version 4 as part of the Coupled Model Intercomparison Project, phase 5. Output from one historical and three future greenhouse gas emission scenarios were examined to project various climate storylines. We found that the Agulhas Current volume transport decreases across all three scenarios and that the current displays a strong baroclinic component with an increase in transport at the surface and decrease at intermediate depths. Agulhas leakage was found to increase with historical emissions. Additionally, an east-west dipole pattern for convective precipitation was found over South Africa, with an increase over the eastern region related to an increase in greenhouse gas emissions and a decrease in the western region linked to the location of Hadley cell edge latitude. Moving into the 21st century, future predictions in regional climate variability are shown to be dependent on the intensity of greenhouse gas emissions and are extremely important for South Africa, a region prone to drought and flooding and home to a large population dependent on rain-fed agriculture.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44117571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-31DOI: 10.17159/sajs.2023/13844c
Craig D. Morris, Kevin P. Kirkman, Pete J.K. Zacharias
Original article: https://doi.org/10.17159/sajs.2022/13844 An error appears in the key (but not the data points) in Figure 3: the square symbol representing Sourveld should be depicted in orange, while the circle symbol representing Sweetveld should be depicted in green.
{"title":"Corrigendum: Will the grass be greener on the other side of climate change?","authors":"Craig D. Morris, Kevin P. Kirkman, Pete J.K. Zacharias","doi":"10.17159/sajs.2023/13844c","DOIUrl":"https://doi.org/10.17159/sajs.2023/13844c","url":null,"abstract":"Original article: https://doi.org/10.17159/sajs.2022/13844 An error appears in the key (but not the data points) in Figure 3: the square symbol representing Sourveld should be depicted in orange, while the circle symbol representing Sweetveld should be depicted in green.","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135100247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Repurposing research data for commercial use: POPIA, a foil or a facilitator?","authors":"Beverley Townsend, Amy Gooden, Marietjie Botes, Donrich Thaldar","doi":"10.17159/sajs.2023/15075","DOIUrl":"10.17159/sajs.2023/15075","url":null,"abstract":"","PeriodicalId":21928,"journal":{"name":"South African Journal of Science","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12520580/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48819046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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