Antibacterial effects of Alchornea cordifolia (Schumach. and Thonn.) Müll. Arg extracts and compounds on gastrointestinal, skin, respiratory and urinary tract pathogens
- Siwe-Noundou, Xavier, Krause, Rui W M, van Vuuren, Sandy, Tantoh Ndinteh, Derek, Olivier, D K
- Authors: Siwe-Noundou, Xavier , Krause, Rui W M , van Vuuren, Sandy , Tantoh Ndinteh, Derek , Olivier, D K
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195418 , vital:45563 , xlink:href="https://doi.org/10.1016/j.jep.2015.12.043"
- Description: Ethnopharmacological relevance:The leaves, stems and roots ofAlchornea cordifolia(Schumach. andThonn.) Müll. Arg. are used as traditional medicine in many African countries for the management ofgastrointestinal, respiratory and urinary tract infections as well as for the treatment of wounds.Aim of the study:To determine the in vitro antibacterial activity of the crude extracts of leaves and stemsofA. cordifoliaon gastrointestinal, skin, respiratory and urinary tract pathogens and to identify thecompounds in the extracts that may be responsible for this activity.Materials and methods:The antibacterial activities of crude extracts [hexane, chloroform (CHCl3), ethylacetate (EtOAc), ethanol (EtOH), methanol (MeOH) and water (H2O)] as well as pure compounds isolatedfrom these extracts were evaluated by means of the micro-dilution assay against four Gram-positivebacteria, i.e.Bacillus cereusATCC 11778,Enterococcus faecalisATCC 29212, Staphylococcus aureusATCC25923 andS. saprophyticusATCC 15305,as well as four Gram-negative bacterial strains, i.e.EscherichiacoliATCC 25922, Klebsiella pneumoniaeATCC 13883, Moraxella catarrhalisATCC 23246 andProteus mir-abilisATCC 43071. The isolation of the active constituents was undertaken by bio-autographic assays inconjunction with chromatographic techniques. The identification and characterisation of the isolatedcompounds were done using mass spectrometry (MS) and Fourier transformed infrared spectrometry(FTIR) as well as 1D- and 2D- nuclear magnetic resonance (NMR) analyses.Results:The leaves and stems ofA. cordifoliaexhibited varied antibacterial activity against all eight pa-thogens. Most of the MIC values ranged between 63 and 2000mg/ml. The highest activities for the crudeextracts (63mg/ml) were observed againstS. saprophyticus[stem (EtOAc, CHCl3and hexane), leaves(MeOH, EtOH, EtOAc and CHCl3)],E. coli[stem (MeOH and EtOH), leaves (MeOH, EtOH, EtOAc andCHCl3)],M. catarrhalis[leaves (EtOAc and CHCl3)],K. pneumoniae[stem (CHCl3), leaves (CHCl3)] andS.aureus[leaves (CHCl3)]. Seven constituents [stigmasterol (1), stigmasta-4,22-dien-3-one (2), friedelin (3),friedelane-3-one-28-al (4), 3-O-acetyl-aleuritolic acid (5), 3-O-acetyl-erythrodiol (6) and methyl-3,4,5-trihydroxybenzoate (methyl gallate) (7)] were isolated from the stem MeOH extract. All these com-pounds displayed some antibacterial activity against the eight pathogens with highest activity againstS.saprophyticus(2mg/ml). Furthermore, this is thefirst report of compounds1,2,3,4,6and7isolated fromA. cordifoliaand where a complete set of 2D-NMR data for fridelane-3-one-28-al (4) is presented.Conclusion:The study demonstrated that the antibacterial activities ofA. cordifoliaextracts may be dueto the presence of the seven isolated compounds, where compounds3–6showed the best activity. Theobserved activity against gastrointestinal, skin, respiratory and urinary tract pathogens supports thetraditional use for the treatment of such ailments.
- Full Text:
- Date Issued: 2016
- Authors: Siwe-Noundou, Xavier , Krause, Rui W M , van Vuuren, Sandy , Tantoh Ndinteh, Derek , Olivier, D K
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195418 , vital:45563 , xlink:href="https://doi.org/10.1016/j.jep.2015.12.043"
- Description: Ethnopharmacological relevance:The leaves, stems and roots ofAlchornea cordifolia(Schumach. andThonn.) Müll. Arg. are used as traditional medicine in many African countries for the management ofgastrointestinal, respiratory and urinary tract infections as well as for the treatment of wounds.Aim of the study:To determine the in vitro antibacterial activity of the crude extracts of leaves and stemsofA. cordifoliaon gastrointestinal, skin, respiratory and urinary tract pathogens and to identify thecompounds in the extracts that may be responsible for this activity.Materials and methods:The antibacterial activities of crude extracts [hexane, chloroform (CHCl3), ethylacetate (EtOAc), ethanol (EtOH), methanol (MeOH) and water (H2O)] as well as pure compounds isolatedfrom these extracts were evaluated by means of the micro-dilution assay against four Gram-positivebacteria, i.e.Bacillus cereusATCC 11778,Enterococcus faecalisATCC 29212, Staphylococcus aureusATCC25923 andS. saprophyticusATCC 15305,as well as four Gram-negative bacterial strains, i.e.EscherichiacoliATCC 25922, Klebsiella pneumoniaeATCC 13883, Moraxella catarrhalisATCC 23246 andProteus mir-abilisATCC 43071. The isolation of the active constituents was undertaken by bio-autographic assays inconjunction with chromatographic techniques. The identification and characterisation of the isolatedcompounds were done using mass spectrometry (MS) and Fourier transformed infrared spectrometry(FTIR) as well as 1D- and 2D- nuclear magnetic resonance (NMR) analyses.Results:The leaves and stems ofA. cordifoliaexhibited varied antibacterial activity against all eight pa-thogens. Most of the MIC values ranged between 63 and 2000mg/ml. The highest activities for the crudeextracts (63mg/ml) were observed againstS. saprophyticus[stem (EtOAc, CHCl3and hexane), leaves(MeOH, EtOH, EtOAc and CHCl3)],E. coli[stem (MeOH and EtOH), leaves (MeOH, EtOH, EtOAc andCHCl3)],M. catarrhalis[leaves (EtOAc and CHCl3)],K. pneumoniae[stem (CHCl3), leaves (CHCl3)] andS.aureus[leaves (CHCl3)]. Seven constituents [stigmasterol (1), stigmasta-4,22-dien-3-one (2), friedelin (3),friedelane-3-one-28-al (4), 3-O-acetyl-aleuritolic acid (5), 3-O-acetyl-erythrodiol (6) and methyl-3,4,5-trihydroxybenzoate (methyl gallate) (7)] were isolated from the stem MeOH extract. All these com-pounds displayed some antibacterial activity against the eight pathogens with highest activity againstS.saprophyticus(2mg/ml). Furthermore, this is thefirst report of compounds1,2,3,4,6and7isolated fromA. cordifoliaand where a complete set of 2D-NMR data for fridelane-3-one-28-al (4) is presented.Conclusion:The study demonstrated that the antibacterial activities ofA. cordifoliaextracts may be dueto the presence of the seven isolated compounds, where compounds3–6showed the best activity. Theobserved activity against gastrointestinal, skin, respiratory and urinary tract pathogens supports thetraditional use for the treatment of such ailments.
- Full Text:
- Date Issued: 2016
Aquatic–terrestrial trophic linkages via riverine invertebrates in a South African catchment
- Authors: Moyo, Sydney
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54427 , vital:26564
- Description: Rivers play a vital role in human livelihoods and are likely to undergo substantial alteration due to climate and land use changes from an increasing human population. Mitigating the pressures facing rivers in the world requires scientists and environmental managers to understand the ecological mechanisms, and ultimately the strength, of connections between ecosystems. This understanding of connections between adjacent habitats will enable environmental managers to predict the consequences of perturbing these linkages in the future. In this thesis, aquatic-terrestrial linkages in rivers were investigated using ecologically meaningful variables including abundances, biomasses, stable isotopes and fatty acids. This study is part of a larger project entitled “Connectivity through allochthony: reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa”, in which a team of researchers assessed a variety of pathways connecting riverine and estuarine systems to land within a catchment in the Eastern Cape, South Africa. I conceptualised the flow of energy within a temperate southern hemisphere river (the Kowie River) within theoretical models of energy flow such as the River Continuum Concept (RCC; presents lotic systems as being longitudinally linked with food webs in shaded headwaters being principally driven by allochthonous energy, with the addition of autochthonous food as a minor carbon source in the lower reaches) and the Riverine Productivity Model (RPM; proposes consumers derive most of their energy from local production of phytoplankton, benthic algae and aquatic plants, as well as directly from riparian zones via terrestrial leaf litter). Using the RCC as a starting point, I collected macroinvertebrates (September 2012 to May 2013) along a longitudinal gradient and grouped them into functional feeding groups (FFGs). The results revealed that gatherers and filterers dominated in the Kowie River, and together represented 50 – 83% of the invertebrate assemblages. There was a general paucity of shredders (relative abundance was ≤ 10% across all sites and seasons). The changes in relative abundances of different FFGs did not follow predictions of the RCC along the longitudinal gradient, as there were no correlations of community structure with some physical attributes (stream width, canopy cover, distance of river) that changed along the river continuum. However, FFG abundances were related to water velocity, total dissolved solids and canopy cover. Broadly, the Kowie River data showed that changes in relative abundances of FFGs along the river continuum could not be explained by changes in physical attributes alone, and may be highly influenced by the availability of food and the chemistry of the stream. Analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes was used to estimate the contributions of algal and land-based production to consumers over space (six sites) and time (November 2012 to September 2013). Carbon contributions determined by the use of mixing models (Stable Isotope Analysis in R) revealed that consumers in the headwater assimilated mainly terrestrially-derived organic matter, with consumers in the middle and lower reaches assimilating autochthonous basal resources (macrophytes and algae). The findings from this river supported aspects of the RCC (at the headwaters; terrestrial organic matter made up 41% of consumer diets), but overall the data supported the predictions of the RPM (local production made the highest contributions of 50 – 86% to all FFGs across all seasons). The carbon isotopes of consumers and their food sources changed substantially every season, indicating that samples of food sources and consumers should be analysed many times throughout the year to capture that variability and to ensure that ephemeral components of the food web are not missed. To validate the findings from the isotope data, fatty acids were used as complementary tracers to determine the contributions of algal versus terrestrial organic matter to the consumers. Fatty acid tracers for terrestrial (Ʃω3/Ʃω6; 18:2ω6; 18:3ω3) vs aquatic (Ʃω3/Ʃω6; 20:5ω3) sources corroborated the findings from the isotope data set, as the mean ratio of Ʃω3/Ʃω6 in consumers was less than one at the headwaters (indicating allochthony), while middle and lower reaches were associated with Ʃω3/Ʃω6 > 1 (indicating autochthony). In addition to the tracer and FFG analyses for examining trophic connections between land and river, the bidirectional exchange of organisms between the riparian zone and the river was assessed using floating pyramidal traps (to measure emergence) and pan traps (for infalling invertebrates) placed at different sites in the river and the biomass in each trap was determined. The exchanges were variable over space and time, with emergence peaking in summer (169 to 1402 mg m-2 day-1) and declining in winter (3 to 28 mg m-2 day-1). Similarly, infalling invertebrates increased in summer (413 to 679 mg m-2 day-1) and declined in winter (11 to 220 mg m-2 day-1). Biomass measurements are indications of quantity that ignore nutritional quality, so I determined the bidirectional flow of invertebrates using absolute concentrations of physiologically important biochemical compounds (essential and polyunsaturated fatty acids). The fluxes of emergent and infalling arthropods peaked in summer (emergence = 0.3 to 18 mg m-2 day-1 and terrestrial infall = 0.3 to 3 mg m-2 day-1) and declined in winter (emergence = 0.01 to 0.51 mg m-2 day-1 and terrestrial infall = 0.01 to 0.03 mg m-2 day-1). However, during some seasons, no significant differences in polyunsaturated fatty acid flux in either direction were observed; this finding indicated the balance of reciprocal subsidisation via reciprocal flows of animals. Factors such as air temperature and algal productivity affected the reciprocal flows between adjacent habitats, with algal productivity being positively related to emergence while air temperature was positively correlated to infalling terrestrial invertebrates. This research enhances the growing body of literature on the function of riverine systems and offers some invaluable information on the flow of energy and the role played by invertebrates in translocating nutrients from terrestrial systems to aquatic systems and vice versa. This study unifies the concepts of the RCC and RPM and shows that these concepts are not limited only to large rivers, but are applicable to small southern temperate rivers too. However, some tenets of the theoretical models were challenged. For example, it challenges the proposition by the RCC that the fine particulate organic matter leaked from upstream breakdown of coarse particulate organic matter is predominantly allochthonous. Additionally, this study showed that in the headwaters, the RPM underestimated the role of autochthony. Overall, the results showed that the Kowie River and its riparian area are intrinsically connected. Once we understand the mechanisms controlling connections and subsidies across ecotones, we can then start to predict the consequences of disruptions to these connections by climate change and/or land use changes. To make predictions about future perturbations to rivers and riparian zones, studies like this, which considers the form and magnitude of subsidies, are needed to provide baseline information. Algal resources (e.g. epiphyton), macrophytes, riparian plants, terrestrial organisms and aquatic organisms all contributed to aquatic and terrestrial linkages in the Kowie River; therefore, it is important to conserve the different components of these ecosystems.
- Full Text:
- Date Issued: 2016
- Authors: Moyo, Sydney
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54427 , vital:26564
- Description: Rivers play a vital role in human livelihoods and are likely to undergo substantial alteration due to climate and land use changes from an increasing human population. Mitigating the pressures facing rivers in the world requires scientists and environmental managers to understand the ecological mechanisms, and ultimately the strength, of connections between ecosystems. This understanding of connections between adjacent habitats will enable environmental managers to predict the consequences of perturbing these linkages in the future. In this thesis, aquatic-terrestrial linkages in rivers were investigated using ecologically meaningful variables including abundances, biomasses, stable isotopes and fatty acids. This study is part of a larger project entitled “Connectivity through allochthony: reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa”, in which a team of researchers assessed a variety of pathways connecting riverine and estuarine systems to land within a catchment in the Eastern Cape, South Africa. I conceptualised the flow of energy within a temperate southern hemisphere river (the Kowie River) within theoretical models of energy flow such as the River Continuum Concept (RCC; presents lotic systems as being longitudinally linked with food webs in shaded headwaters being principally driven by allochthonous energy, with the addition of autochthonous food as a minor carbon source in the lower reaches) and the Riverine Productivity Model (RPM; proposes consumers derive most of their energy from local production of phytoplankton, benthic algae and aquatic plants, as well as directly from riparian zones via terrestrial leaf litter). Using the RCC as a starting point, I collected macroinvertebrates (September 2012 to May 2013) along a longitudinal gradient and grouped them into functional feeding groups (FFGs). The results revealed that gatherers and filterers dominated in the Kowie River, and together represented 50 – 83% of the invertebrate assemblages. There was a general paucity of shredders (relative abundance was ≤ 10% across all sites and seasons). The changes in relative abundances of different FFGs did not follow predictions of the RCC along the longitudinal gradient, as there were no correlations of community structure with some physical attributes (stream width, canopy cover, distance of river) that changed along the river continuum. However, FFG abundances were related to water velocity, total dissolved solids and canopy cover. Broadly, the Kowie River data showed that changes in relative abundances of FFGs along the river continuum could not be explained by changes in physical attributes alone, and may be highly influenced by the availability of food and the chemistry of the stream. Analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes was used to estimate the contributions of algal and land-based production to consumers over space (six sites) and time (November 2012 to September 2013). Carbon contributions determined by the use of mixing models (Stable Isotope Analysis in R) revealed that consumers in the headwater assimilated mainly terrestrially-derived organic matter, with consumers in the middle and lower reaches assimilating autochthonous basal resources (macrophytes and algae). The findings from this river supported aspects of the RCC (at the headwaters; terrestrial organic matter made up 41% of consumer diets), but overall the data supported the predictions of the RPM (local production made the highest contributions of 50 – 86% to all FFGs across all seasons). The carbon isotopes of consumers and their food sources changed substantially every season, indicating that samples of food sources and consumers should be analysed many times throughout the year to capture that variability and to ensure that ephemeral components of the food web are not missed. To validate the findings from the isotope data, fatty acids were used as complementary tracers to determine the contributions of algal versus terrestrial organic matter to the consumers. Fatty acid tracers for terrestrial (Ʃω3/Ʃω6; 18:2ω6; 18:3ω3) vs aquatic (Ʃω3/Ʃω6; 20:5ω3) sources corroborated the findings from the isotope data set, as the mean ratio of Ʃω3/Ʃω6 in consumers was less than one at the headwaters (indicating allochthony), while middle and lower reaches were associated with Ʃω3/Ʃω6 > 1 (indicating autochthony). In addition to the tracer and FFG analyses for examining trophic connections between land and river, the bidirectional exchange of organisms between the riparian zone and the river was assessed using floating pyramidal traps (to measure emergence) and pan traps (for infalling invertebrates) placed at different sites in the river and the biomass in each trap was determined. The exchanges were variable over space and time, with emergence peaking in summer (169 to 1402 mg m-2 day-1) and declining in winter (3 to 28 mg m-2 day-1). Similarly, infalling invertebrates increased in summer (413 to 679 mg m-2 day-1) and declined in winter (11 to 220 mg m-2 day-1). Biomass measurements are indications of quantity that ignore nutritional quality, so I determined the bidirectional flow of invertebrates using absolute concentrations of physiologically important biochemical compounds (essential and polyunsaturated fatty acids). The fluxes of emergent and infalling arthropods peaked in summer (emergence = 0.3 to 18 mg m-2 day-1 and terrestrial infall = 0.3 to 3 mg m-2 day-1) and declined in winter (emergence = 0.01 to 0.51 mg m-2 day-1 and terrestrial infall = 0.01 to 0.03 mg m-2 day-1). However, during some seasons, no significant differences in polyunsaturated fatty acid flux in either direction were observed; this finding indicated the balance of reciprocal subsidisation via reciprocal flows of animals. Factors such as air temperature and algal productivity affected the reciprocal flows between adjacent habitats, with algal productivity being positively related to emergence while air temperature was positively correlated to infalling terrestrial invertebrates. This research enhances the growing body of literature on the function of riverine systems and offers some invaluable information on the flow of energy and the role played by invertebrates in translocating nutrients from terrestrial systems to aquatic systems and vice versa. This study unifies the concepts of the RCC and RPM and shows that these concepts are not limited only to large rivers, but are applicable to small southern temperate rivers too. However, some tenets of the theoretical models were challenged. For example, it challenges the proposition by the RCC that the fine particulate organic matter leaked from upstream breakdown of coarse particulate organic matter is predominantly allochthonous. Additionally, this study showed that in the headwaters, the RPM underestimated the role of autochthony. Overall, the results showed that the Kowie River and its riparian area are intrinsically connected. Once we understand the mechanisms controlling connections and subsidies across ecotones, we can then start to predict the consequences of disruptions to these connections by climate change and/or land use changes. To make predictions about future perturbations to rivers and riparian zones, studies like this, which considers the form and magnitude of subsidies, are needed to provide baseline information. Algal resources (e.g. epiphyton), macrophytes, riparian plants, terrestrial organisms and aquatic organisms all contributed to aquatic and terrestrial linkages in the Kowie River; therefore, it is important to conserve the different components of these ecosystems.
- Full Text:
- Date Issued: 2016
Are people responsive to a more sustainable, decentralized, and user-driven management of urban metabolism?:
- Chelleri, Lorenzo, Kua, Harn W, Rodriguez Sanchez, Juan P, Nahiduzzaman, Kh M, Thondhlana, Gladman
- Authors: Chelleri, Lorenzo , Kua, Harn W , Rodriguez Sanchez, Juan P , Nahiduzzaman, Kh M , Thondhlana, Gladman
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144299 , vital:38329 , https://orcid.org/0000-0001-8253-0264
- Description: Smart, green, and resilient city paradigms have been mainly promoted through top-down and technocratic approaches. However, based on the notion to return to “the right to the city”, emerging community-driven initiatives are providing self-managed infrastructures contributing to urban sustainability transitions. This paper explores the relevance of the behavioral aspects of people-centered approaches in dealing with two different facets of urban metabolism: physical infrastructure (involvement with the management of decentralized infrastructures) and consumption patterns (involvement in proactive reduction of resources used). In the first case we assessed community perceptions about the roles, benefits, and willingness to proactively engage in the management of decentralized green infrastructures in Bogotá City, Colombia. For the second facet, we measured the effectiveness of change agents in re-shaping energy consumption decisions within urban social networks in South Africa and Saudi Arabia. This paper’s results show that pre-determined and standardized strategies do not guarantee positive, nor homogeneous, results in terms of meeting sustainability targets, or promoting community involvement. Hence, a better integration of people-centered and top-down approaches is needed through context-dependent policies, for enhancing both users’ appreciation of and commitment to urban metabolism participative management.
- Full Text:
- Date Issued: 2016
- Authors: Chelleri, Lorenzo , Kua, Harn W , Rodriguez Sanchez, Juan P , Nahiduzzaman, Kh M , Thondhlana, Gladman
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144299 , vital:38329 , https://orcid.org/0000-0001-8253-0264
- Description: Smart, green, and resilient city paradigms have been mainly promoted through top-down and technocratic approaches. However, based on the notion to return to “the right to the city”, emerging community-driven initiatives are providing self-managed infrastructures contributing to urban sustainability transitions. This paper explores the relevance of the behavioral aspects of people-centered approaches in dealing with two different facets of urban metabolism: physical infrastructure (involvement with the management of decentralized infrastructures) and consumption patterns (involvement in proactive reduction of resources used). In the first case we assessed community perceptions about the roles, benefits, and willingness to proactively engage in the management of decentralized green infrastructures in Bogotá City, Colombia. For the second facet, we measured the effectiveness of change agents in re-shaping energy consumption decisions within urban social networks in South Africa and Saudi Arabia. This paper’s results show that pre-determined and standardized strategies do not guarantee positive, nor homogeneous, results in terms of meeting sustainability targets, or promoting community involvement. Hence, a better integration of people-centered and top-down approaches is needed through context-dependent policies, for enhancing both users’ appreciation of and commitment to urban metabolism participative management.
- Full Text:
- Date Issued: 2016
Art investment in South Africa: portfolio diversification and art market efficiency
- Botha, Ferdi, Snowball, Jeanette D, Scott, Brett
- Authors: Botha, Ferdi , Snowball, Jeanette D , Scott, Brett
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64794 , vital:28601 , http://www.dx.doi.org/10.17159/2222-3436/2016/v19n3a4
- Description: Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel art price index offered the opportunity to test this theory in the South African context. Moreover, this paper tests whether art prices are efficient. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A vector autoregression of the art price index, Johannesburg stock exchange all-share index, house price index, and South African government bond index were used. Results show that, when there are increased returns on the stock market in a preceding period and wealth increases, there is a change in the Citadel art price index in the same direction. No significant difference was found between the house price index and the art price index, or between the art and government bond price indices. The art market is also found to be inefficient, thereby exacerbating the risk of investing in art. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Date Issued: 2016
- Authors: Botha, Ferdi , Snowball, Jeanette D , Scott, Brett
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64794 , vital:28601 , http://www.dx.doi.org/10.17159/2222-3436/2016/v19n3a4
- Description: Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel art price index offered the opportunity to test this theory in the South African context. Moreover, this paper tests whether art prices are efficient. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A vector autoregression of the art price index, Johannesburg stock exchange all-share index, house price index, and South African government bond index were used. Results show that, when there are increased returns on the stock market in a preceding period and wealth increases, there is a change in the Citadel art price index in the same direction. No significant difference was found between the house price index and the art price index, or between the art and government bond price indices. The art market is also found to be inefficient, thereby exacerbating the risk of investing in art. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Date Issued: 2016
Assessing estuarine nursery habitats for Cape Stumpnose (Rhabdosargus holubi), (Pisces: Sparidae) in a warm-temperate estuary in the Eastern Cape, South Africa
- Authors: Leslie, Timothy David
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3178 , vital:20381
- Description: The nursery role hypothesis provides an approach for assessing the nursery function of habitat types within estuaries. This study attempted to assess the nursery value of the dominant estuarine habitats in the Bushmans Estuary for Rhabdosargus holubi (Steindachner 1881) by analysing habitat complexity, relative abundance and behaviour of R. holubi and using stomach contents analysis and dietary diatom composition as indicative of feeding habitat. Structural habitat complexity was assessed in Zostera capensis (Setchell) seagrass and Spartina maritima (Curtis Fernald) salt marsh by sampling above-ground stem density and length, and total cover per unit area (Ct/At). Dimensionless habitat complexity indices such as the interstitial spatial index (ISI) at three magnifications and fractal geometry at two magnifications were used to further analyse habitat complexity. Above-ground biomass (P<0.05) in each season and canopy height (P<0.001) were significantly higher in salt marsh than in seagrass whilst stem density was significantly higher in seagrass than in salt marsh in each season (P<0.001). Each dimensionless index indicated that complexity is notably higher in seagrass than in the salt marsh. Using dimensionless indices that analyse complexity at different spatial scales provided a better analysis of habitat complexity than canopy height and biomass as it allowed for direct comparisons between habitat types. Underwater video cameras were deployed in seagrass, salt marsh and sand flat habitats to assess the relative abundance and behaviour of R. holubi. The relative abundance of R. holubi was significantly higher in seagrass than salt marsh and sand flats, whilst the behaviour of R. holubi indicated a high degree of habitat use in structured habitats and a low degree of habitat use in unstructured sand flat habitats. This indicated that not only are juvenile R. holubi a vegetation-associated species, but also a species that prefers seagrass to salt marsh.
- Full Text:
- Date Issued: 2016
- Authors: Leslie, Timothy David
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3178 , vital:20381
- Description: The nursery role hypothesis provides an approach for assessing the nursery function of habitat types within estuaries. This study attempted to assess the nursery value of the dominant estuarine habitats in the Bushmans Estuary for Rhabdosargus holubi (Steindachner 1881) by analysing habitat complexity, relative abundance and behaviour of R. holubi and using stomach contents analysis and dietary diatom composition as indicative of feeding habitat. Structural habitat complexity was assessed in Zostera capensis (Setchell) seagrass and Spartina maritima (Curtis Fernald) salt marsh by sampling above-ground stem density and length, and total cover per unit area (Ct/At). Dimensionless habitat complexity indices such as the interstitial spatial index (ISI) at three magnifications and fractal geometry at two magnifications were used to further analyse habitat complexity. Above-ground biomass (P<0.05) in each season and canopy height (P<0.001) were significantly higher in salt marsh than in seagrass whilst stem density was significantly higher in seagrass than in salt marsh in each season (P<0.001). Each dimensionless index indicated that complexity is notably higher in seagrass than in the salt marsh. Using dimensionless indices that analyse complexity at different spatial scales provided a better analysis of habitat complexity than canopy height and biomass as it allowed for direct comparisons between habitat types. Underwater video cameras were deployed in seagrass, salt marsh and sand flat habitats to assess the relative abundance and behaviour of R. holubi. The relative abundance of R. holubi was significantly higher in seagrass than salt marsh and sand flats, whilst the behaviour of R. holubi indicated a high degree of habitat use in structured habitats and a low degree of habitat use in unstructured sand flat habitats. This indicated that not only are juvenile R. holubi a vegetation-associated species, but also a species that prefers seagrass to salt marsh.
- Full Text:
- Date Issued: 2016
Assessment of water quality based on diatom indices in a small temperate river system, Kowie River, South Africa
- Dalu, Tatenda, Bere, Taurai, Froneman, P William
- Authors: Dalu, Tatenda , Bere, Taurai , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123896 , vital:35514 , http://dx.doi.org/10.4314/wsa.v42i2.02
- Description: This study aimed to assess the impact of land use patterns on water quality and benthic diatom community structure and to test the applicability of diatom indices developed in other regions of the world to a small temperate southern African river system. Sampling was conducted at eight study sites along the length of the river on four separate occasions. Multivariate data analyses were performed on the diatom community dataset to specify the main gradients of floristic variation and to detect and visualize similarities in diatom samples in relation to land-use patterns within the catchment. One hundred and twelve (112) diatom species belonging to 36 genera were recorded during the study. Canonical correspondence analysis (CCA) demonstrated that variations in the benthic diatom community structure were best explained by ammonium, nitrate, conductivity, pH, temperature, resistivity and water flow. OMNIDIA was used for calculation of selected diatom water quality indices. A number of the indices, e.g., the trophic diatom index (TDI), eutrophication/pollution index and biological index of water quality (BIWQ), either under- or over-estimated the water quality of the system. With few exceptions, there were no significant correlations (p> 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.
- Full Text:
- Date Issued: 2016
- Authors: Dalu, Tatenda , Bere, Taurai , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123896 , vital:35514 , http://dx.doi.org/10.4314/wsa.v42i2.02
- Description: This study aimed to assess the impact of land use patterns on water quality and benthic diatom community structure and to test the applicability of diatom indices developed in other regions of the world to a small temperate southern African river system. Sampling was conducted at eight study sites along the length of the river on four separate occasions. Multivariate data analyses were performed on the diatom community dataset to specify the main gradients of floristic variation and to detect and visualize similarities in diatom samples in relation to land-use patterns within the catchment. One hundred and twelve (112) diatom species belonging to 36 genera were recorded during the study. Canonical correspondence analysis (CCA) demonstrated that variations in the benthic diatom community structure were best explained by ammonium, nitrate, conductivity, pH, temperature, resistivity and water flow. OMNIDIA was used for calculation of selected diatom water quality indices. A number of the indices, e.g., the trophic diatom index (TDI), eutrophication/pollution index and biological index of water quality (BIWQ), either under- or over-estimated the water quality of the system. With few exceptions, there were no significant correlations (p> 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.
- Full Text:
- Date Issued: 2016
Audit, investigation, search, seizure and access to information
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131245 , vital:36541 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 5 of the Tax Administration Act, which supplements the various fiscal statutes, empowers SARS to call for information on taxpayers, conduct audits, investigations and in certain instances to search premises and seize goods and records. For this purpose, taxpayers are required to keep proper books and records (see § 8.2 and § 4). The purpose of a tax audit is to verify the accuracy and timing of an assessment, but more specifically to ensure accuracy and full disclosure in terms of the law. In the event that an audit reveals non-compliance, criminal and/or civil charges may be initiated by SARS (see § 8.5).
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131245 , vital:36541 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 5 of the Tax Administration Act, which supplements the various fiscal statutes, empowers SARS to call for information on taxpayers, conduct audits, investigations and in certain instances to search premises and seize goods and records. For this purpose, taxpayers are required to keep proper books and records (see § 8.2 and § 4). The purpose of a tax audit is to verify the accuracy and timing of an assessment, but more specifically to ensure accuracy and full disclosure in terms of the law. In the event that an audit reveals non-compliance, criminal and/or civil charges may be initiated by SARS (see § 8.5).
- Full Text: false
- Date Issued: 2016
Back to the future: revival, relevance and route of an anarchist/syndicalist approach for twenty-first-century left, labour and national liberation movements
- Authors: van der Walt, Lucien
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144812 , vital:38381 , DOI: 10.1080/02589001.2016.1235365
- Description: The failings of classical Marxism, social democracy and anti-imperialist nationalism point to the need for a radical left politics at a distance from the state. This paper examines the impact, revival and promise of the anarchist/syndicalist tradition, a rich, continuous praxis in labour, left, anti-imperialist, anti-racist and egalitarian movements, worldwide, since the 1860s. Outlining its core ideas – anti-hierarchy, anti-capitalism, anti-statism, opposition to social and economic inequality, internationalist class-based mobilisation – and critique of mainstream Marxism and nationalism, it highlights the arguments there is a basic incompatibility between state rule, and bottom-up, egalitarian, democratic, socialist relationships. The anarchist/syndicalist project cannot be reduced to an organising style, protest politics or spontaneism: for it, transition to a just, self-managed society requires organised popular capacity for a revolutionary rupture, developed through prefigurative, class-based, democratic organs of counter-power, including syndicalist unions aiming at collectivised property, and revolutionary counter-culture. Success needs formal organisation, unified strategy and anarchist / syndicalist political organisations.
- Full Text:
- Date Issued: 2016
- Authors: van der Walt, Lucien
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144812 , vital:38381 , DOI: 10.1080/02589001.2016.1235365
- Description: The failings of classical Marxism, social democracy and anti-imperialist nationalism point to the need for a radical left politics at a distance from the state. This paper examines the impact, revival and promise of the anarchist/syndicalist tradition, a rich, continuous praxis in labour, left, anti-imperialist, anti-racist and egalitarian movements, worldwide, since the 1860s. Outlining its core ideas – anti-hierarchy, anti-capitalism, anti-statism, opposition to social and economic inequality, internationalist class-based mobilisation – and critique of mainstream Marxism and nationalism, it highlights the arguments there is a basic incompatibility between state rule, and bottom-up, egalitarian, democratic, socialist relationships. The anarchist/syndicalist project cannot be reduced to an organising style, protest politics or spontaneism: for it, transition to a just, self-managed society requires organised popular capacity for a revolutionary rupture, developed through prefigurative, class-based, democratic organs of counter-power, including syndicalist unions aiming at collectivised property, and revolutionary counter-culture. Success needs formal organisation, unified strategy and anarchist / syndicalist political organisations.
- Full Text:
- Date Issued: 2016
Behaviour and trophic ecology of oceanic triggerfish (Canthidermis maculata) and rainbow runner (Elagatis bipinnulata) associated with floating objects in the open ocean
- Forget, Fabien Rocky Gilbert
- Authors: Forget, Fabien Rocky Gilbert
- Date: 2016
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/193531 , vital:45340
- Description: The oceanic triggerfish (Canthidermis maculata) and rainbow runner (Elagatis bipinnulata) are epipelagic species that commonly associate with floating objects throughout the world’s tropical oceans. Besides tunas, these two species often form the bulk of the aggregation and are major non-target species (bycatch) incidentally captured at fish aggregation devices (FADs) by tropical tuna purse seiners. Despite being abundant, little is known about their basic biology, ecology and associative behavior with floating objects. This thesis aims to address knowledge gaps in their associative behavior and ecology at floating objects and attempts to explore potential bycatch mitigation methods. Acoustic telemetry was used to characterise several aspects of the two species’ behavior at floating objects. Fish were captured and tagged at drifting FADs in the core of the western Indian Ocean tuna fishing grounds. Prolonged remote observations were obtained through satellite linked receivers which provided fine-scale data on the behavior of oceanic triggerfish (n= 46 919 cumulated observation days) and rainbow runner (n= 24 538 cumulated observation days). The two species remained associated with the same floating object for periods extending up to several months. The mean residence time estimated using a survival analysis was 65 days for oceanic triggerfish and 94 days for rainbow runner. A distinct diel pattern in association was observed; the two species were closely associated to the FAD during the night and increased their home range during the day while performing short excursions (oceanic triggerfish mean: 2.0 hours ±1.6 SD; rainbow runner mean: 2.4 hours ±2.2 SD) away from the FAD. Similarly, distinct patterns in the vertical movements and locomotory activity (measured using accelerometer tags) were observed as the two species increased their vertical movements and activity levels during the day. Generally, their vertical movements were largely restricted to the mixed layer (< 60 m). At night, the two species remained close to the surface (0-5 m) where they appear to be in a resting state. An interesting behavioural switch in activity levels and vertical distribution was observed for oceanic triggerfish which coincided with a change in the environment as the FAD drifted close to a cold-core cyclonic eddy. Ambient light appears to be the key stimulus triggering the observed diel behavioural patterns. species-specific vulnerability for target species, skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares), bigeye tuna (Thunnus obesus) and non-target species, including silky shark (Carcharhinus falciformis), oceanic triggerfish, and rainbow runner, to the purse seine fishing gear were investigated. Hourly presence rates at FADs over 24 hours were examined to assess whether the capture rate of non-target species could be reduced at specific times during the day. Silky sharks displayed a similar associative pattern to that of targeted tunas. Moreover, the vulnerability of both target and non-target species were close to the maximum during the period of behavioural transitions at sunrise when the majority of the fishing sets are made. As such, a change in set time in the western Indian Ocean does not appear to be a feasible method to reduce capture rates of non-target species. Stomach content and stable isotope analysis were conducted on oceanic triggerfish (stomach n = 152, isotope n = 65) and rainbow runner (stomach n = 156, isotope n = 71) incidentally captured individuals at FADs by purse seiners. Typical FAD-associated prey items represented a minor component of their diet as they predominantly foraged on zooplankton and micronekton in the water column, suggesting that oceanic triggerfish and rainbow runner do not associate to floating objects for direct trophic advantages. Overlap in their dietary and isotopic niches indicates an intermediate level of competition. Overall, the spatial and trophic ecology of both species are remarkably similar and prolonged associations with FADs indicates that floating objects play a significant ecological role in the pelagic environment for the two species. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2016
- Full Text:
- Date Issued: 2016
- Authors: Forget, Fabien Rocky Gilbert
- Date: 2016
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/193531 , vital:45340
- Description: The oceanic triggerfish (Canthidermis maculata) and rainbow runner (Elagatis bipinnulata) are epipelagic species that commonly associate with floating objects throughout the world’s tropical oceans. Besides tunas, these two species often form the bulk of the aggregation and are major non-target species (bycatch) incidentally captured at fish aggregation devices (FADs) by tropical tuna purse seiners. Despite being abundant, little is known about their basic biology, ecology and associative behavior with floating objects. This thesis aims to address knowledge gaps in their associative behavior and ecology at floating objects and attempts to explore potential bycatch mitigation methods. Acoustic telemetry was used to characterise several aspects of the two species’ behavior at floating objects. Fish were captured and tagged at drifting FADs in the core of the western Indian Ocean tuna fishing grounds. Prolonged remote observations were obtained through satellite linked receivers which provided fine-scale data on the behavior of oceanic triggerfish (n= 46 919 cumulated observation days) and rainbow runner (n= 24 538 cumulated observation days). The two species remained associated with the same floating object for periods extending up to several months. The mean residence time estimated using a survival analysis was 65 days for oceanic triggerfish and 94 days for rainbow runner. A distinct diel pattern in association was observed; the two species were closely associated to the FAD during the night and increased their home range during the day while performing short excursions (oceanic triggerfish mean: 2.0 hours ±1.6 SD; rainbow runner mean: 2.4 hours ±2.2 SD) away from the FAD. Similarly, distinct patterns in the vertical movements and locomotory activity (measured using accelerometer tags) were observed as the two species increased their vertical movements and activity levels during the day. Generally, their vertical movements were largely restricted to the mixed layer (< 60 m). At night, the two species remained close to the surface (0-5 m) where they appear to be in a resting state. An interesting behavioural switch in activity levels and vertical distribution was observed for oceanic triggerfish which coincided with a change in the environment as the FAD drifted close to a cold-core cyclonic eddy. Ambient light appears to be the key stimulus triggering the observed diel behavioural patterns. species-specific vulnerability for target species, skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares), bigeye tuna (Thunnus obesus) and non-target species, including silky shark (Carcharhinus falciformis), oceanic triggerfish, and rainbow runner, to the purse seine fishing gear were investigated. Hourly presence rates at FADs over 24 hours were examined to assess whether the capture rate of non-target species could be reduced at specific times during the day. Silky sharks displayed a similar associative pattern to that of targeted tunas. Moreover, the vulnerability of both target and non-target species were close to the maximum during the period of behavioural transitions at sunrise when the majority of the fishing sets are made. As such, a change in set time in the western Indian Ocean does not appear to be a feasible method to reduce capture rates of non-target species. Stomach content and stable isotope analysis were conducted on oceanic triggerfish (stomach n = 152, isotope n = 65) and rainbow runner (stomach n = 156, isotope n = 71) incidentally captured individuals at FADs by purse seiners. Typical FAD-associated prey items represented a minor component of their diet as they predominantly foraged on zooplankton and micronekton in the water column, suggesting that oceanic triggerfish and rainbow runner do not associate to floating objects for direct trophic advantages. Overlap in their dietary and isotopic niches indicates an intermediate level of competition. Overall, the spatial and trophic ecology of both species are remarkably similar and prolonged associations with FADs indicates that floating objects play a significant ecological role in the pelagic environment for the two species. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2016
- Full Text:
- Date Issued: 2016
Binding and entry of a non-enveloped T=4 insect RNA virus is triggered by alkaline pH
- Penkler, David L, Jiwaji, Meesbah, Domitrovic, Tatiana, Short, James R, Johnson, John E, Dorrington, Rosemary A
- Authors: Penkler, David L , Jiwaji, Meesbah , Domitrovic, Tatiana , Short, James R , Johnson, John E , Dorrington, Rosemary A
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65995 , vital:28875 , https://doi.org/10.1016/j.virol.2016.08.028
- Description: publisher version , Tetraviruses are small, non-enveloped, RNA viruses that exclusively infect lepidopteran insects. Their particles comprise 240 copies of a single capsid protein precursor (CP), which undergoes autoproteolytic cleavage during maturation. The molecular mechanisms of capsid assembly and maturation are well understood, but little is known about the viral infectious lifecycle due to a lack of tissue culture cell lines that are susceptible to tetravirus infection. We show here that binding and entry of the alphatetravirus, Helicoverpa armigera stunt virus (HaSV), is triggered by alkaline pH. At pH 9.0, wild-type HaSV virus particles undergo conformational changes that induce membrane-lytic activity and binding to Spodoptera frugiperda Sf9 cells. Binding is followed by entry and infection, with virus replication complexes detected by immunofluorescence microscopy within 2 h post-infection and the CP after 12 h. HaSV particles produced in S. frugiperda Sf9 cells are infectious. Helicoverpa armigera larval virus biofeed assays showed that pre-treatment with the V-ATPase inhibitor, Bafilomycin A1, resulted in a 50% decrease in larval mortality and stunting, while incubation of virus particles at pH 9.0 prior to infection restored infectivity. Together, these data show that HaSV, and likely other tetraviruses, requires the alkaline environment of the lepidopteran larval midgut for binding and entry into host cells.
- Full Text: false
- Date Issued: 2016
- Authors: Penkler, David L , Jiwaji, Meesbah , Domitrovic, Tatiana , Short, James R , Johnson, John E , Dorrington, Rosemary A
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65995 , vital:28875 , https://doi.org/10.1016/j.virol.2016.08.028
- Description: publisher version , Tetraviruses are small, non-enveloped, RNA viruses that exclusively infect lepidopteran insects. Their particles comprise 240 copies of a single capsid protein precursor (CP), which undergoes autoproteolytic cleavage during maturation. The molecular mechanisms of capsid assembly and maturation are well understood, but little is known about the viral infectious lifecycle due to a lack of tissue culture cell lines that are susceptible to tetravirus infection. We show here that binding and entry of the alphatetravirus, Helicoverpa armigera stunt virus (HaSV), is triggered by alkaline pH. At pH 9.0, wild-type HaSV virus particles undergo conformational changes that induce membrane-lytic activity and binding to Spodoptera frugiperda Sf9 cells. Binding is followed by entry and infection, with virus replication complexes detected by immunofluorescence microscopy within 2 h post-infection and the CP after 12 h. HaSV particles produced in S. frugiperda Sf9 cells are infectious. Helicoverpa armigera larval virus biofeed assays showed that pre-treatment with the V-ATPase inhibitor, Bafilomycin A1, resulted in a 50% decrease in larval mortality and stunting, while incubation of virus particles at pH 9.0 prior to infection restored infectivity. Together, these data show that HaSV, and likely other tetraviruses, requires the alkaline environment of the lepidopteran larval midgut for binding and entry into host cells.
- Full Text: false
- Date Issued: 2016
Bioinformatic characterization of type-specific sequence and structural features in auxiliary activity family 9 proteins:
- Moses, Vuyani, Hatherley, Rowan, Tastan Bishop, Özlem
- Authors: Moses, Vuyani , Hatherley, Rowan , Tastan Bishop, Özlem
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148358 , vital:38732 , DOI: 10.1186/s13068-016-0655-2
- Description: Due to the impending depletion of fossil fuels, it has become important to identify alternative energy sources. The biofuel industry has proven to be a promising alternative. However, owing to the complex nature of plant biomass, hence the degradation, biofuel production remains a challenge. The copper-dependent Auxiliary Activity family 9 (AA9) proteins have been found to act synergistically with other cellulose-degrading enzymes resulting in an increased rate of cellulose breakdown. AA9 proteins are lytic polysaccharide monooxygenase (LPMO) enzymes, otherwise known as polysaccharide monooxygenases (PMOs). They are further classified as Type 1, 2 or 3 PMOs, depending on the different cleavage products formed. As AA9 proteins are known to exhibit low sequence conservation, the analysis of unique features of AA9 domains of these enzymes should provide insights for the better understanding of how different AA9 PMO types function.
- Full Text:
- Date Issued: 2016
- Authors: Moses, Vuyani , Hatherley, Rowan , Tastan Bishop, Özlem
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148358 , vital:38732 , DOI: 10.1186/s13068-016-0655-2
- Description: Due to the impending depletion of fossil fuels, it has become important to identify alternative energy sources. The biofuel industry has proven to be a promising alternative. However, owing to the complex nature of plant biomass, hence the degradation, biofuel production remains a challenge. The copper-dependent Auxiliary Activity family 9 (AA9) proteins have been found to act synergistically with other cellulose-degrading enzymes resulting in an increased rate of cellulose breakdown. AA9 proteins are lytic polysaccharide monooxygenase (LPMO) enzymes, otherwise known as polysaccharide monooxygenases (PMOs). They are further classified as Type 1, 2 or 3 PMOs, depending on the different cleavage products formed. As AA9 proteins are known to exhibit low sequence conservation, the analysis of unique features of AA9 domains of these enzymes should provide insights for the better understanding of how different AA9 PMO types function.
- Full Text:
- Date Issued: 2016
Biological activity of extracellular and intracellular polysaccharides from Pleurotus tuber-regium hybrid and mutant strains
- Bamigboye, Comfort Olukemi, Oloke, Julius Kola, Dames, Joanna Felicity
- Authors: Bamigboye, Comfort Olukemi , Oloke, Julius Kola , Dames, Joanna Felicity
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69056 , vital:29376 , http://pubs.sciepub.com/jfnr/4/7/2/
- Description: Publisher version , Pleurotus tuber-regium (Fr.) Singer (1951) is a unique sclerotium-forming edible and medicinal mushroom. Interestingly, both the sclerotium and mushroom are edible and are often used for curing various ailments. Previous studies have focused on the antimicrobial and antioxidant activity of the extracellular polysaccharide (EPS) from wild P. tuber-regium. There has been no report on the intracellular polysaccharide (IPS) of the wild mycelia, likewise there is very meager information on the improvement of the perceived potentials of P. tuber-regium. This research study analysed the EPS and IPS fractions of P. tuber-regium hybrid and mutant strains. The antimicrobial potential of the IPS and EPS fractions, their scavenging activity on 1, 1-diphenyl–2picryhydrazyl (DPPH) and Hydroxyl radicals were also determined. Both IPS and EPS fractions of P. tuber-regium hybrids and mutants showed increased DPPH and hydroxyl scavenging activity over the wild P. tuber-regium with an EC50 mostly 1 mg/ml. The antimicrobial activity of the IPS from a mutant strain had an IC50 of 15.6 mg/ml compared to the wild type (18.75 mg /ml). This study showed that selected mutant and hybrids of P. tuber-regium had increased radical scavenging activity indicating potentially increased biological activity that could offer increased benefit as a neutraceutical.
- Full Text: false
- Date Issued: 2016
- Authors: Bamigboye, Comfort Olukemi , Oloke, Julius Kola , Dames, Joanna Felicity
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69056 , vital:29376 , http://pubs.sciepub.com/jfnr/4/7/2/
- Description: Publisher version , Pleurotus tuber-regium (Fr.) Singer (1951) is a unique sclerotium-forming edible and medicinal mushroom. Interestingly, both the sclerotium and mushroom are edible and are often used for curing various ailments. Previous studies have focused on the antimicrobial and antioxidant activity of the extracellular polysaccharide (EPS) from wild P. tuber-regium. There has been no report on the intracellular polysaccharide (IPS) of the wild mycelia, likewise there is very meager information on the improvement of the perceived potentials of P. tuber-regium. This research study analysed the EPS and IPS fractions of P. tuber-regium hybrid and mutant strains. The antimicrobial potential of the IPS and EPS fractions, their scavenging activity on 1, 1-diphenyl–2picryhydrazyl (DPPH) and Hydroxyl radicals were also determined. Both IPS and EPS fractions of P. tuber-regium hybrids and mutants showed increased DPPH and hydroxyl scavenging activity over the wild P. tuber-regium with an EC50 mostly 1 mg/ml. The antimicrobial activity of the IPS from a mutant strain had an IC50 of 15.6 mg/ml compared to the wild type (18.75 mg /ml). This study showed that selected mutant and hybrids of P. tuber-regium had increased radical scavenging activity indicating potentially increased biological activity that could offer increased benefit as a neutraceutical.
- Full Text: false
- Date Issued: 2016
Building capacity for green, just and sustainable futures – a new knowledge field requiring transformative research methodology
- Rosenberg, Eureta, Ramsarup, Presha, Gumede, Sibusisiwe, Lotz-Sisitka, Heila
- Authors: Rosenberg, Eureta , Ramsarup, Presha , Gumede, Sibusisiwe , Lotz-Sisitka, Heila
- Date: 2016
- Subjects: Sustainable development -- South Africa , Renewable energy sources , Climatic changes , Clean energy
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59613 , vital:27631 , http://joe.ukzn.ac.za/Libraries/No_65_2016/JoE_complete.sflb.ashx
- Description: Education has contributed to a society-wide awareness of environmental issues, and we are increasingly confronted with the need for new ways to generate energy, save water and reduce pollution. Thus new forms of work are emerging and government, employers and educators need to know what ‘green’ skills South Africa needs and has. This creates a new demand for ‘green skills’ research. We propose that this new knowledge field – like some other educational fields – requires a transformative approach to research methodology. In conducting reviews of existing research, we found that a transformative approach requires a reframing of key concepts commonly used in researching work and learning; multi-layered, mixed method studies; researching within and across diverse knowledge fields including non-traditional fields; and both newly configured national platforms and new conceptual frameworks to help us integrate coherently across these. Critical realism is presented as a helpful underpinning for such conceptual frameworks, and implications for how universities prepare educational researchers are flagged.
- Full Text:
- Date Issued: 2016
- Authors: Rosenberg, Eureta , Ramsarup, Presha , Gumede, Sibusisiwe , Lotz-Sisitka, Heila
- Date: 2016
- Subjects: Sustainable development -- South Africa , Renewable energy sources , Climatic changes , Clean energy
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59613 , vital:27631 , http://joe.ukzn.ac.za/Libraries/No_65_2016/JoE_complete.sflb.ashx
- Description: Education has contributed to a society-wide awareness of environmental issues, and we are increasingly confronted with the need for new ways to generate energy, save water and reduce pollution. Thus new forms of work are emerging and government, employers and educators need to know what ‘green’ skills South Africa needs and has. This creates a new demand for ‘green skills’ research. We propose that this new knowledge field – like some other educational fields – requires a transformative approach to research methodology. In conducting reviews of existing research, we found that a transformative approach requires a reframing of key concepts commonly used in researching work and learning; multi-layered, mixed method studies; researching within and across diverse knowledge fields including non-traditional fields; and both newly configured national platforms and new conceptual frameworks to help us integrate coherently across these. Critical realism is presented as a helpful underpinning for such conceptual frameworks, and implications for how universities prepare educational researchers are flagged.
- Full Text:
- Date Issued: 2016
Can local use assist in controlling invasive alien species in tropical forests?: The case of Lantana camara in southern India
- Kannan, Ramesh, Shackleton, Charlie M, Krishnan, Smitha, Shaanker, Ramanan U
- Authors: Kannan, Ramesh , Shackleton, Charlie M , Krishnan, Smitha , Shaanker, Ramanan U
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180423 , vital:43387 , xlink:href="https://doi.org/10.1016/j.foreco.2016.06.016"
- Description: Many invasive alien species (IAS) are used by local communities for a variety of subsistence and income generating purposes. This frequently poses a conflict of interest for their removal due to forest conservation and biodiversity concerns. However, if local use can simultaneously check or control specific IAS, the conflict can be avoided and both development and forest conservation perspectives accommodated in the short to medium term. We examine this for Lantana camara invasion in southern India through assessment of the demand for and impacts of harvesting on this globally problematic IAS. We interviewed local artisans regarding their knowledge and quantities of Lantana used, along with forest surveys to estimate Lantana densities and size classes in harvested and unharvested sites, and lastly we undertook controlled cutting in moist and dry deciduous forests in both the wet and dry seasons to examine rate of regrowth and mortality. Over the entire study area the abundance of Lantana far outweighed local demand, but at small scales around villages, density and size classes were significantly reduced through harvesting. The controlled cutting experiment showed marked seasonal differences, with the most severe cutting intensity resulting in significant mortality when Lantana plants were cut in the wet season, but with limited effect when cut in the dry season. We conclude that promoting local use of IAS may be a feasible approach in controlling them and thereby limiting their impacts in forests.
- Full Text:
- Date Issued: 2016
- Authors: Kannan, Ramesh , Shackleton, Charlie M , Krishnan, Smitha , Shaanker, Ramanan U
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180423 , vital:43387 , xlink:href="https://doi.org/10.1016/j.foreco.2016.06.016"
- Description: Many invasive alien species (IAS) are used by local communities for a variety of subsistence and income generating purposes. This frequently poses a conflict of interest for their removal due to forest conservation and biodiversity concerns. However, if local use can simultaneously check or control specific IAS, the conflict can be avoided and both development and forest conservation perspectives accommodated in the short to medium term. We examine this for Lantana camara invasion in southern India through assessment of the demand for and impacts of harvesting on this globally problematic IAS. We interviewed local artisans regarding their knowledge and quantities of Lantana used, along with forest surveys to estimate Lantana densities and size classes in harvested and unharvested sites, and lastly we undertook controlled cutting in moist and dry deciduous forests in both the wet and dry seasons to examine rate of regrowth and mortality. Over the entire study area the abundance of Lantana far outweighed local demand, but at small scales around villages, density and size classes were significantly reduced through harvesting. The controlled cutting experiment showed marked seasonal differences, with the most severe cutting intensity resulting in significant mortality when Lantana plants were cut in the wet season, but with limited effect when cut in the dry season. We conclude that promoting local use of IAS may be a feasible approach in controlling them and thereby limiting their impacts in forests.
- Full Text:
- Date Issued: 2016
Case Studies for UNECCC, UNESCO and CEE The COPART Climate Train
- Authors: McGarry, Dylan K
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391120 , vital:68622 , xlink:href="https://eeasa.org.za/wp-content/uploads/2017/05/EEASA-Bullitin-2016_18-July-issue-42.pdf"
- Description: To create a listening and educational platform that used various disciplines to understand the impact of Climate Change across South Africa. The objective was to create a multigenre educational space for citizens of South Africa as a means to participate in Climate discussions as an alternative to the COP17 negotiations held in South Africa at the time.
- Full Text:
- Date Issued: 2016
- Authors: McGarry, Dylan K
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391120 , vital:68622 , xlink:href="https://eeasa.org.za/wp-content/uploads/2017/05/EEASA-Bullitin-2016_18-July-issue-42.pdf"
- Description: To create a listening and educational platform that used various disciplines to understand the impact of Climate Change across South Africa. The objective was to create a multigenre educational space for citizens of South Africa as a means to participate in Climate discussions as an alternative to the COP17 negotiations held in South Africa at the time.
- Full Text:
- Date Issued: 2016
Changing practices, changing values?: a Bernsteinian analysis of knowledge production and knowledge exchange in two UK universities
- Little, Brenda, Abbas, Andrea, Singh, Mala
- Authors: Little, Brenda , Abbas, Andrea , Singh, Mala
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66934 , vital:29002 , https://doi.org/10.1007/978-94-017-7369-0_8
- Description: publisher version , Bernstein’s concept of classification and framing links notions of knowledge, democracy and social justice, providing a perspective from which to address critical questions of what knowledge is produced, who has access to it, and how knowledge is distributed. Bernstein’s conceptual framework is used to inform an analysis of national policies steering knowledge production and knowledge transfer in the UK, and the changing practices and values associated with knowledge production and knowledge transfer in two UK institutional case study universities. The analysis reveals how reputational and financial consequences of the formal assessment of research quality interacts with the institutional and disciplinary contexts of research units to differently shape what knowledge is valued and produced, and with whom it is shared. Five discursive areas, each involving a complex set of classifications (power) and framings (control) are identified, namely: the national research assessment framework; the economic value of research; discourses of social and academic values; academic freedoms; and mixed-discipline research and the interdisciplinary nature of real world problems. Though competing and sometimes contradictory values seem to underlie academics’ knowledge work, it seems that the strong framing for knowledge production and knowledge exchange provided by national policies steers staff efforts towards economised codes of knowledge. The conclusion suggests that such a strong steer does not value social transformation in all its diverse non-economistic dimensions and limits universities’ potential to transform societies to further social justice.
- Full Text: false
- Date Issued: 2016
- Authors: Little, Brenda , Abbas, Andrea , Singh, Mala
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/66934 , vital:29002 , https://doi.org/10.1007/978-94-017-7369-0_8
- Description: publisher version , Bernstein’s concept of classification and framing links notions of knowledge, democracy and social justice, providing a perspective from which to address critical questions of what knowledge is produced, who has access to it, and how knowledge is distributed. Bernstein’s conceptual framework is used to inform an analysis of national policies steering knowledge production and knowledge transfer in the UK, and the changing practices and values associated with knowledge production and knowledge transfer in two UK institutional case study universities. The analysis reveals how reputational and financial consequences of the formal assessment of research quality interacts with the institutional and disciplinary contexts of research units to differently shape what knowledge is valued and produced, and with whom it is shared. Five discursive areas, each involving a complex set of classifications (power) and framings (control) are identified, namely: the national research assessment framework; the economic value of research; discourses of social and academic values; academic freedoms; and mixed-discipline research and the interdisciplinary nature of real world problems. Though competing and sometimes contradictory values seem to underlie academics’ knowledge work, it seems that the strong framing for knowledge production and knowledge exchange provided by national policies steers staff efforts towards economised codes of knowledge. The conclusion suggests that such a strong steer does not value social transformation in all its diverse non-economistic dimensions and limits universities’ potential to transform societies to further social justice.
- Full Text: false
- Date Issued: 2016
Characterization and Electrocatalytic Activity of Nanocomposites Consisting of Nanosized Cobalt Tetraaminophenoxy Phthalocyanine, Multi‐walled Carbon Nanotubes and Gold Nanoparticles
- Shumba, Munyaradzi, Nyokong, Tebello
- Authors: Shumba, Munyaradzi , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188659 , vital:44773 , xlink:href="https://doi.org/10.1002/elan.201501058"
- Description: Glassy carbon electrodes were modified with composites containing cobalt tetraaminophenoxy phthalocyanine nanoparticles (CoTAPhPcNP), multi-walled carbon nanotubes (MWCNT) and gold nanorods (AuNRs). The modified electrodes were studied for their electrocatalytic behavior towards the reduction of hydrogen peroxide. Phthalocyanine nanoparticles significantly improved electron transfer kinetics as compared to phthalocyanines which are not in the nanoparticle form when alone or in the presence of multiwalled carbon nanotubes (MWCNTs). CoTAPhPcNP-MWCNT-GCE proved to be suitable for hydrogen peroxide detection with a catalytic rate constant of 3.45×103 M−1 s−1 and a detection limit of 1.61×10−7 M. Adsorption Gibbs free energy ΔGo was found to be −19.22 kJ mol−1 for CoTAPhPcNP-MWCNT-GCE.
- Full Text:
- Date Issued: 2016
- Authors: Shumba, Munyaradzi , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188659 , vital:44773 , xlink:href="https://doi.org/10.1002/elan.201501058"
- Description: Glassy carbon electrodes were modified with composites containing cobalt tetraaminophenoxy phthalocyanine nanoparticles (CoTAPhPcNP), multi-walled carbon nanotubes (MWCNT) and gold nanorods (AuNRs). The modified electrodes were studied for their electrocatalytic behavior towards the reduction of hydrogen peroxide. Phthalocyanine nanoparticles significantly improved electron transfer kinetics as compared to phthalocyanines which are not in the nanoparticle form when alone or in the presence of multiwalled carbon nanotubes (MWCNTs). CoTAPhPcNP-MWCNT-GCE proved to be suitable for hydrogen peroxide detection with a catalytic rate constant of 3.45×103 M−1 s−1 and a detection limit of 1.61×10−7 M. Adsorption Gibbs free energy ΔGo was found to be −19.22 kJ mol−1 for CoTAPhPcNP-MWCNT-GCE.
- Full Text:
- Date Issued: 2016
Co-designing research on transgressive learning in times of climate change
- Lotz-Sisitka, Heila, Ali, Million B, Mphepho, Gibson, Chaves, Martha, Macintyre, Thomas, Pesanayi, Tichaona V, Wals, Arjen E, Mukute, Mutizwa, Kronlid, David O, Tran, Duc, Joon, Deepika, McGarry, Dylan K
- Authors: Lotz-Sisitka, Heila , Ali, Million B , Mphepho, Gibson , Chaves, Martha , Macintyre, Thomas , Pesanayi, Tichaona V , Wals, Arjen E , Mukute, Mutizwa , Kronlid, David O , Tran, Duc , Joon, Deepika , McGarry, Dylan K
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182472 , vital:43833 , xlink:href="https://doi.org/10.1016/j.cosust.2016.04.004"
- Description: This paper reflects on the epistemological context for the co-design of a research programme on transformative, transgressive learning emerging at the nexus of climate change, water and food security, energy and social justice. It outlines a sequence of learning actions that we, as a group of collaborating partners in a Transformative Knowledge Network (TKN) undertook to co-design a research programme, firstly in situ in various case study contexts, and secondly together across case study contexts. Finally, it provides some reflections and learning points.
- Full Text:
- Date Issued: 2016
- Authors: Lotz-Sisitka, Heila , Ali, Million B , Mphepho, Gibson , Chaves, Martha , Macintyre, Thomas , Pesanayi, Tichaona V , Wals, Arjen E , Mukute, Mutizwa , Kronlid, David O , Tran, Duc , Joon, Deepika , McGarry, Dylan K
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182472 , vital:43833 , xlink:href="https://doi.org/10.1016/j.cosust.2016.04.004"
- Description: This paper reflects on the epistemological context for the co-design of a research programme on transformative, transgressive learning emerging at the nexus of climate change, water and food security, energy and social justice. It outlines a sequence of learning actions that we, as a group of collaborating partners in a Transformative Knowledge Network (TKN) undertook to co-design a research programme, firstly in situ in various case study contexts, and secondly together across case study contexts. Finally, it provides some reflections and learning points.
- Full Text:
- Date Issued: 2016
Co-management, land rights, and conflicts around South Africa’s Silaka Nature Reserve
- Thondhlana, Gladman, Cundill, Georgina, Kepe, Thembele
- Authors: Thondhlana, Gladman , Cundill, Georgina , Kepe, Thembele
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67781 , vital:29144 , https://doi.org/10.1080/08941920.2015.1089609
- Description: Publisher version , Globally, co-management of protected areas (PAs) offers promise in efforts to achieve ecological integrity and livelihood needs. Most co-management agreements are premised on joint decision making in defining equitable sharing of benefits from and the management responsibilities for natural resource management. However, co-managed PAs are often conflict ridden. The forceful closure of Silaka Nature Reserve in South Africa in 2013 by a local community epitomizes the conflicts that can emerge in co-management arrangements. Using Silaka Reserve as a case study, we ask questions related to the meaning of land to local people, with an interrogative focus beyond “material benefits” in co-management discourse. The results of this study show that apart from nonaccrual of material benefits, conflicts arise from nonrecognition of nonmaterial aspects such as cultural values of and historical attachment to land and limited involvement of land claimants in decision making. The implications for co-management as a desired outcome on settled land claims are discussed.
- Full Text: false
- Date Issued: 2016
- Authors: Thondhlana, Gladman , Cundill, Georgina , Kepe, Thembele
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67781 , vital:29144 , https://doi.org/10.1080/08941920.2015.1089609
- Description: Publisher version , Globally, co-management of protected areas (PAs) offers promise in efforts to achieve ecological integrity and livelihood needs. Most co-management agreements are premised on joint decision making in defining equitable sharing of benefits from and the management responsibilities for natural resource management. However, co-managed PAs are often conflict ridden. The forceful closure of Silaka Nature Reserve in South Africa in 2013 by a local community epitomizes the conflicts that can emerge in co-management arrangements. Using Silaka Reserve as a case study, we ask questions related to the meaning of land to local people, with an interrogative focus beyond “material benefits” in co-management discourse. The results of this study show that apart from nonaccrual of material benefits, conflicts arise from nonrecognition of nonmaterial aspects such as cultural values of and historical attachment to land and limited involvement of land claimants in decision making. The implications for co-management as a desired outcome on settled land claims are discussed.
- Full Text: false
- Date Issued: 2016
Collaborative learning of water conservation practices: cultivation and expansion of a learning network around rainwater harvesting demonstration sites in the Eastern Cape, South Africa
- Pesanayi, Tichaona V, Weaver, Kim N
- Authors: Pesanayi, Tichaona V , Weaver, Kim N
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392086 , vital:68720 , xlink:href="https://www.ajol.info/index.php/sajae/article/view/138570"
- Description: Learning together in mediated voluntary networks can mobilise skills and innovations that help to facilitate learning and uptake of rainwater harvesting and conservation practices. It boosts extension capacity while at the same time growing farmer capabilities, tapping on the distributed cognition. These practices help to heal wicked problems of drought and global change challenges affecting marginalised farmers in South Africa. South Africa has water, nutrition and food security challenges, especially the Eastern Cape Province where there is a relatively high level of poverty. These challenges place heavy pressure on the agricultural sector as it is the main user of the allocated water in the country. In this paper, the learning of and agency for rainwater harvesting and conservation practices are explored as responses to these challenges. Despite existing cultural histories of such practices among the amaXhosa people, information on these practices is not readily available to small-scale rural farmers who thus struggle for the want of knowing. This research forms part of a Water Research Commission project, Amanzi for Food, whose intention is to mediate collaborative and co-engaged learning among networked farmers, extension workers, researchers and agricultural educators through course-mediated use of Water Research Commission rainwater harvesting and conservation materials.
- Full Text:
- Date Issued: 2016
- Authors: Pesanayi, Tichaona V , Weaver, Kim N
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392086 , vital:68720 , xlink:href="https://www.ajol.info/index.php/sajae/article/view/138570"
- Description: Learning together in mediated voluntary networks can mobilise skills and innovations that help to facilitate learning and uptake of rainwater harvesting and conservation practices. It boosts extension capacity while at the same time growing farmer capabilities, tapping on the distributed cognition. These practices help to heal wicked problems of drought and global change challenges affecting marginalised farmers in South Africa. South Africa has water, nutrition and food security challenges, especially the Eastern Cape Province where there is a relatively high level of poverty. These challenges place heavy pressure on the agricultural sector as it is the main user of the allocated water in the country. In this paper, the learning of and agency for rainwater harvesting and conservation practices are explored as responses to these challenges. Despite existing cultural histories of such practices among the amaXhosa people, information on these practices is not readily available to small-scale rural farmers who thus struggle for the want of knowing. This research forms part of a Water Research Commission project, Amanzi for Food, whose intention is to mediate collaborative and co-engaged learning among networked farmers, extension workers, researchers and agricultural educators through course-mediated use of Water Research Commission rainwater harvesting and conservation materials.
- Full Text:
- Date Issued: 2016