Asymmetric price transmission: an empirical analysis of the relationship between UG-2 chrome ore, charge chrome, nickel and Chinese domestic 304 stainless steel cold rolled coil
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
Asymmetrical zinc (II) phthalocyanines cobalt tungstate nanomaterial conjugates for photodegradation of methylene blue
- Mgidlana, Sithi, Nyokong, Tebello
- Authors: Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184991 , vital:44314 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113421"
- Description: Herein, we present syntheses of three asymmetrical zinc(II) phthalocyanine (ZnPc) complexes and hydrothermal synthesis of cobalt tungstate nanoparticles. The ZnPc derivatives were covalently linked to cobalt tungstate nanoparticles. Photophysical and photochemical behaviour of Pcs and nanoconjugates were investigated. The nanoconjugates generated higher triplet quantum yield and singlet oxygen quantum yield than the ZnPcs alone. Furthermore, in this paper photocatalytic efficiencies of ZnPc complexes and nanoconjugates were investigated for the degradation of methylene blue and higher photocatalytic behaviour was observed for the conjugates. The kinetic model was used to study photocatalytic behaviour of all the prepared photocatalysts.
- Full Text:
- Date Issued: 2021
- Authors: Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184991 , vital:44314 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113421"
- Description: Herein, we present syntheses of three asymmetrical zinc(II) phthalocyanine (ZnPc) complexes and hydrothermal synthesis of cobalt tungstate nanoparticles. The ZnPc derivatives were covalently linked to cobalt tungstate nanoparticles. Photophysical and photochemical behaviour of Pcs and nanoconjugates were investigated. The nanoconjugates generated higher triplet quantum yield and singlet oxygen quantum yield than the ZnPcs alone. Furthermore, in this paper photocatalytic efficiencies of ZnPc complexes and nanoconjugates were investigated for the degradation of methylene blue and higher photocatalytic behaviour was observed for the conjugates. The kinetic model was used to study photocatalytic behaviour of all the prepared photocatalysts.
- Full Text:
- Date Issued: 2021
Attitudes and preferences towards elements of formal and informal public green spaces in two South African towns
- Manyani, Amanda, Shackleton, Charlie M, Cocks, Michelle L
- Authors: Manyani, Amanda , Shackleton, Charlie M , Cocks, Michelle L
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402203 , vital:69830 , xlink:href="https://doi.org/10.1016/j.landurbplan.2021.104147"
- Description: Different types of public urban green spaces (PUGS) contain various natural (such as trees, pools, flowerbeds) and artificial elements (such as benches, play equipment, fountains) which contribute to the enjoyment and experience of users. However, which elements users most require, appreciate or notice has rarely been examined as the basis of their choice for specific PUGS, especially in poorer neighbourhoods and countries, where formal PUGS may be limited. The study was carried out in two towns in the Eastern Cape province of South Africa, both characterized by high poverty and unemployment levels, low literacy rates and many people living without basic infrastructure and services. To understand the meanings people, have for specific PUGS elements, formal and informal PUGS and peri-urban municipal commonages were assessed with respect to the natural and artificial elements present. A survey of 360 households was conducted across two towns by targeting PUGS users and households within 100 m from the designated PUGS. Approximately 63% of the respondents visited PUGS, with informal PUGS being the most frequented. However, they were strong negative feelings towards some natural elements because of their unkempt nature. Issues of safety, cultural restrictions and lack of recreational facilities were mentioned as some of the specific deterrents against visiting the closest PUGS among different user and age groups. Most respondents emphasized the need for PUGS that are well laid out with maintained lawns, recreational facilities and open vegetation. Thus, the current design and available features within the studied PUGS do not meet local preferences and needs and thus do not contribute to enjoyment as much as they could. Attention needs to be given to understand and incorporate the elements that invoke positive attitudes among urban residents.
- Full Text:
- Date Issued: 2021
- Authors: Manyani, Amanda , Shackleton, Charlie M , Cocks, Michelle L
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402203 , vital:69830 , xlink:href="https://doi.org/10.1016/j.landurbplan.2021.104147"
- Description: Different types of public urban green spaces (PUGS) contain various natural (such as trees, pools, flowerbeds) and artificial elements (such as benches, play equipment, fountains) which contribute to the enjoyment and experience of users. However, which elements users most require, appreciate or notice has rarely been examined as the basis of their choice for specific PUGS, especially in poorer neighbourhoods and countries, where formal PUGS may be limited. The study was carried out in two towns in the Eastern Cape province of South Africa, both characterized by high poverty and unemployment levels, low literacy rates and many people living without basic infrastructure and services. To understand the meanings people, have for specific PUGS elements, formal and informal PUGS and peri-urban municipal commonages were assessed with respect to the natural and artificial elements present. A survey of 360 households was conducted across two towns by targeting PUGS users and households within 100 m from the designated PUGS. Approximately 63% of the respondents visited PUGS, with informal PUGS being the most frequented. However, they were strong negative feelings towards some natural elements because of their unkempt nature. Issues of safety, cultural restrictions and lack of recreational facilities were mentioned as some of the specific deterrents against visiting the closest PUGS among different user and age groups. Most respondents emphasized the need for PUGS that are well laid out with maintained lawns, recreational facilities and open vegetation. Thus, the current design and available features within the studied PUGS do not meet local preferences and needs and thus do not contribute to enjoyment as much as they could. Attention needs to be given to understand and incorporate the elements that invoke positive attitudes among urban residents.
- Full Text:
- Date Issued: 2021
Ball-type phthalocyanines and reduced graphene oxide nanoparticles as separate and combined corrosion inhibitors of aluminium in HCl
- Nnaji, Nnaemeka, Nawji, Njemuwa, Mack, John, Nyokong, Tebello
- Authors: Nnaji, Nnaemeka , Nawji, Njemuwa , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185421 , vital:44385 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130279"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for reduced graphene oxide nanosheets (rGONS), tetrakis-[4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)] (diphthalocyaninato gallium (III) chloride) (2) and tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato gallium(III) chloride) (1). Corrosion inhibition effects of rGONS, 1 and 2 were evaluated alone and in combination in 1.0 M hydrochloric acid solution using electrochemical techniques. The mechanism of aluminum corrosion inhibition revealed predominantly anodic character for rGONS and predominantly cathodic character for 1, 2, and conjugates with rGONS . The polarization technique gave inhibition efficiency values of 96.5% and 96.9% respectively for 1 and 2, which increased in the presence of rGONS to 97.4% and 98.1%, respectively, for the highest concentrations of 1 and 2. Scanning electron microscopy revealed effective metal surface protection by the inhibitors by formation of protective films.
- Full Text:
- Date Issued: 2021
- Authors: Nnaji, Nnaemeka , Nawji, Njemuwa , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185421 , vital:44385 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130279"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for reduced graphene oxide nanosheets (rGONS), tetrakis-[4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)] (diphthalocyaninato gallium (III) chloride) (2) and tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyaninato gallium(III) chloride) (1). Corrosion inhibition effects of rGONS, 1 and 2 were evaluated alone and in combination in 1.0 M hydrochloric acid solution using electrochemical techniques. The mechanism of aluminum corrosion inhibition revealed predominantly anodic character for rGONS and predominantly cathodic character for 1, 2, and conjugates with rGONS . The polarization technique gave inhibition efficiency values of 96.5% and 96.9% respectively for 1 and 2, which increased in the presence of rGONS to 97.4% and 98.1%, respectively, for the highest concentrations of 1 and 2. Scanning electron microscopy revealed effective metal surface protection by the inhibitors by formation of protective films.
- Full Text:
- Date Issued: 2021
Barriers to access second-trimester abortion: A case report
- Authors: Ramprakash, Kaswa
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3330 , vital:43314 , https://doi.org/10.4102/safp.v63i1.5028
- Description: Despite the implementation of the Choice on Termination of Pregnancy (CTOP) Act, many women continue to procure illegal abortions in South Africa. A lack of knowledge of the CTOP Act and poor access to legal abortion in public health facilities is a big challenge. In the scope of the CTOP Act, the termination of pregnancy is a time-restricted health service, and women presented to a health care facility in the second trimester have encounter more obstacles to access the services. Keywords: Abortion; termination of pregnancy; CTOP Act; Illegal; Second Trimester.
- Full Text:
- Date Issued: 2021
- Authors: Ramprakash, Kaswa
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3330 , vital:43314 , https://doi.org/10.4102/safp.v63i1.5028
- Description: Despite the implementation of the Choice on Termination of Pregnancy (CTOP) Act, many women continue to procure illegal abortions in South Africa. A lack of knowledge of the CTOP Act and poor access to legal abortion in public health facilities is a big challenge. In the scope of the CTOP Act, the termination of pregnancy is a time-restricted health service, and women presented to a health care facility in the second trimester have encounter more obstacles to access the services. Keywords: Abortion; termination of pregnancy; CTOP Act; Illegal; Second Trimester.
- Full Text:
- Date Issued: 2021
Barriers to Implementing Information Communication Technology (ICT) in Managing Small to Medium Tourism Enterprises (SMTEs): the Case of Hogsback, Eastern Cape,SouthAfrica
- Authors: Mxunyelwa, Siyabonga
- Date: 2021
- Subjects: Hogsback, South Africa Small and medium-sized enterprises Small Business Information Communication Technology (ICT) Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6031 , vital:45083 , https://www.ijicc.net/images/Vol_15/Iss_10/151057_Mxunyelwa_2021_E_R.pdf
- Description: Information Communication Technology is recognised worldwide for its contribution towardsSMTEs development and the economy. However, the level of ICT implementation as a management tool, its contribution and the extent of benefits on SMTEs is a debateable phenomenon. The purpose of this study was to investigate the barriers to the implementation of ICT within the context of small and medium tourism enterprises in Hogsback. Both quantitative and qualitative research methods were applied in this study. Questionnaire interviews were conducted with owner/managers in Hogsback. The stratified sampling methodwas utilised to collect data. The study indicates that (46.2%) of the business respondents wereoperating the accommodation establishments. The findings of the study underscores that (25.6%) of the business owners identified the barriers of ICT appears to be high costs. Further(23.1%) stated that accessing technology was also an impediment. Moreover, the study elucidates that (94.9%) of the SMTE concur that implementation ICT as a management tool helps to meet objectives of the business for the daily operations of the business. It is therefore recommended that ICT be implemented as a management tool for small and medium tourism enterprises. Furthermore, the study recommends that the managers/owners should invest in technology to ensure the success of the SMTEs in all aspects. Furthermore, the study serves asthe basis for future studies in the area of ICT within the SMTE sector
- Full Text:
- Date Issued: 2021
- Authors: Mxunyelwa, Siyabonga
- Date: 2021
- Subjects: Hogsback, South Africa Small and medium-sized enterprises Small Business Information Communication Technology (ICT) Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6031 , vital:45083 , https://www.ijicc.net/images/Vol_15/Iss_10/151057_Mxunyelwa_2021_E_R.pdf
- Description: Information Communication Technology is recognised worldwide for its contribution towardsSMTEs development and the economy. However, the level of ICT implementation as a management tool, its contribution and the extent of benefits on SMTEs is a debateable phenomenon. The purpose of this study was to investigate the barriers to the implementation of ICT within the context of small and medium tourism enterprises in Hogsback. Both quantitative and qualitative research methods were applied in this study. Questionnaire interviews were conducted with owner/managers in Hogsback. The stratified sampling methodwas utilised to collect data. The study indicates that (46.2%) of the business respondents wereoperating the accommodation establishments. The findings of the study underscores that (25.6%) of the business owners identified the barriers of ICT appears to be high costs. Further(23.1%) stated that accessing technology was also an impediment. Moreover, the study elucidates that (94.9%) of the SMTE concur that implementation ICT as a management tool helps to meet objectives of the business for the daily operations of the business. It is therefore recommended that ICT be implemented as a management tool for small and medium tourism enterprises. Furthermore, the study recommends that the managers/owners should invest in technology to ensure the success of the SMTEs in all aspects. Furthermore, the study serves asthe basis for future studies in the area of ICT within the SMTE sector
- Full Text:
- Date Issued: 2021
Biological control of cactaceae in South Africa
- Paterson, Iain D, Klein, Hildegard, Muskett, Phillippa C, Griffith, Tamzin C, Mayonde, Samalesu, Mofokeng, Kedibone, Mnqeta, Zezethu, Venter, Nic
- Authors: Paterson, Iain D , Klein, Hildegard , Muskett, Phillippa C , Griffith, Tamzin C , Mayonde, Samalesu , Mofokeng, Kedibone , Mnqeta, Zezethu , Venter, Nic
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:71034 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a4"
- Description: Cactaceae are among the most problematic invasive alien plants in South Africa, posing serious negative consequences to agriculture and natural ecosystems. Fortunately, South Africa has a long and successful history of controlling cactus weeds using biological control (biocontrol). This paper reviews all the biocontrol programmes against invasive alien Cactaceae in South Africa, focusing on the decade since the last review published in 2011, up to, and including 2020. Biocontrol programmes against 16 target weeds are summarised, all of which rely on either the galling mealybug, Hypogeococcus sp. (Pseudococcidae), or various species or intraspecific lineages of cochineal insects (Dactylopius spp., Dactylopiidae) as agents. New agents are being considered for the three target weed species, Opuntia elata Salm-Dyck, Opuntia megapotamica Arechav. and Trichocereus spachianus (Lem.) Riccob., while permission to release a new agent against Cylindropuntia pallida (Rose) F.M. Knuth has recently been granted. The biocontrol agent, Dactylopius opuntiae (Cockrell) ‘stricta’, which has been utilised for the successful control of Opuntia stricta Haw., has shown some promise as an agent against one of the worst cactus weeds in the country, the North Cape/Free State variety of Opuntia engelmannii Salm-Dyck. Post-release monitoring and recent observations of the status of control for the 11 other cactus weeds, all of which have well-established agents, are provided. Taxonomic uncertainties and misidentifications of both target weeds and agents has been a constraint to biocontrol efforts, but this has been partially overcome through the use of genetic techniques. Biocontrol is particularly successful in controlling cactus weeds compared to most other taxonomic groups, and it is likely that past successes can be repeated with new target weeds. Mass-rearing and redistribution of agents are essential to gain the maximum possible benefit from cactus biocontrol agents, and recent increases in mass-rearing outputs have been beneficial.
- Full Text:
- Date Issued: 2021
- Authors: Paterson, Iain D , Klein, Hildegard , Muskett, Phillippa C , Griffith, Tamzin C , Mayonde, Samalesu , Mofokeng, Kedibone , Mnqeta, Zezethu , Venter, Nic
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:71034 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a4"
- Description: Cactaceae are among the most problematic invasive alien plants in South Africa, posing serious negative consequences to agriculture and natural ecosystems. Fortunately, South Africa has a long and successful history of controlling cactus weeds using biological control (biocontrol). This paper reviews all the biocontrol programmes against invasive alien Cactaceae in South Africa, focusing on the decade since the last review published in 2011, up to, and including 2020. Biocontrol programmes against 16 target weeds are summarised, all of which rely on either the galling mealybug, Hypogeococcus sp. (Pseudococcidae), or various species or intraspecific lineages of cochineal insects (Dactylopius spp., Dactylopiidae) as agents. New agents are being considered for the three target weed species, Opuntia elata Salm-Dyck, Opuntia megapotamica Arechav. and Trichocereus spachianus (Lem.) Riccob., while permission to release a new agent against Cylindropuntia pallida (Rose) F.M. Knuth has recently been granted. The biocontrol agent, Dactylopius opuntiae (Cockrell) ‘stricta’, which has been utilised for the successful control of Opuntia stricta Haw., has shown some promise as an agent against one of the worst cactus weeds in the country, the North Cape/Free State variety of Opuntia engelmannii Salm-Dyck. Post-release monitoring and recent observations of the status of control for the 11 other cactus weeds, all of which have well-established agents, are provided. Taxonomic uncertainties and misidentifications of both target weeds and agents has been a constraint to biocontrol efforts, but this has been partially overcome through the use of genetic techniques. Biocontrol is particularly successful in controlling cactus weeds compared to most other taxonomic groups, and it is likely that past successes can be repeated with new target weeds. Mass-rearing and redistribution of agents are essential to gain the maximum possible benefit from cactus biocontrol agents, and recent increases in mass-rearing outputs have been beneficial.
- Full Text:
- Date Issued: 2021
Biological control of invasive climbing plants in South Africa
- King, Anthony M, Paterson, Iain D, Simelane, David O, Mawela, Khethani V, Mngeta, Zezethu, Van der Westhuizen, Liamé
- Authors: King, Anthony M , Paterson, Iain D , Simelane, David O , Mawela, Khethani V , Mngeta, Zezethu , Van der Westhuizen, Liamé
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/413471 , vital:71041 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a17"
- Description: Vines and other climbing plants typically invest their resources into growth at the expense of accumulating self-supporting biomass. Adaptive traits that have arisen because of the life history needs of climbing species, such as rapid and extensive growth, as well as resilience to physical damage, make these plants highly competitive. Introduced climbing species therefore have the potential to be particularly damaging in novel ranges where they escape pressure from natural enemies. In South Africa, invasive climbing species negatively influence biodiversity and plant-community structure, and as conventional management is often difficult, biological control (biocontrol) is viewed as the only viable long-term control method. This paper consolidates the work done on biocontrol programmes against climbing species in South Africa, including Anredera cordifolia (Ten.) Steenis (Basellaceae), Cardiospermum grandiflorum Sw. (Sapindaceae), Dolichandra unguis-cati (L.) L.G.Lohmann (Bignoniaceae) and Pereskia aculeata Miller (Cactaceae). To date, these programmes have investigated some 27 potential biocontrol agents, of which nine have been approved for release in the country. Since 2010, three new agents have been introduced, and considerable progress made with post-release evaluations of all the introduced agents. Some positive results have been achieved, most notably the successful reduction in seed set of C. grandiflorum due to Cissanthonomus tuberculipennis Hustache (Curculionidae), but considerable variation in efficacy over time and between infestations has been recorded for many of the other agents. Further work may help explain the factors limiting success, leading to improved control, but in some cases, such as for A. cordifolia, new biocontrol agents should be considered.
- Full Text:
- Date Issued: 2021
- Authors: King, Anthony M , Paterson, Iain D , Simelane, David O , Mawela, Khethani V , Mngeta, Zezethu , Van der Westhuizen, Liamé
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/413471 , vital:71041 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a17"
- Description: Vines and other climbing plants typically invest their resources into growth at the expense of accumulating self-supporting biomass. Adaptive traits that have arisen because of the life history needs of climbing species, such as rapid and extensive growth, as well as resilience to physical damage, make these plants highly competitive. Introduced climbing species therefore have the potential to be particularly damaging in novel ranges where they escape pressure from natural enemies. In South Africa, invasive climbing species negatively influence biodiversity and plant-community structure, and as conventional management is often difficult, biological control (biocontrol) is viewed as the only viable long-term control method. This paper consolidates the work done on biocontrol programmes against climbing species in South Africa, including Anredera cordifolia (Ten.) Steenis (Basellaceae), Cardiospermum grandiflorum Sw. (Sapindaceae), Dolichandra unguis-cati (L.) L.G.Lohmann (Bignoniaceae) and Pereskia aculeata Miller (Cactaceae). To date, these programmes have investigated some 27 potential biocontrol agents, of which nine have been approved for release in the country. Since 2010, three new agents have been introduced, and considerable progress made with post-release evaluations of all the introduced agents. Some positive results have been achieved, most notably the successful reduction in seed set of C. grandiflorum due to Cissanthonomus tuberculipennis Hustache (Curculionidae), but considerable variation in efficacy over time and between infestations has been recorded for many of the other agents. Further work may help explain the factors limiting success, leading to improved control, but in some cases, such as for A. cordifolia, new biocontrol agents should be considered.
- Full Text:
- Date Issued: 2021
Biological control of South African plants that are invasive elsewhere in the world: A review of earlier and current programmes
- Olckers, Terence, Coetzee, Julie A, Egli, Daniella, Martin, Grant D, Paterson, Iain D, Sutton, Guy F, Wood, Alan R
- Authors: Olckers, Terence , Coetzee, Julie A , Egli, Daniella , Martin, Grant D , Paterson, Iain D , Sutton, Guy F , Wood, Alan R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414336 , vital:71137 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a21"
- Description: South Africa supports a rich floral diversity, with 21 643 native plant taxa that include a high proportion (76.3%) of endemic species, and many of these favoured as ornamentals, both locally and globally. Consequently, South Africa has contributed substantially to global plant invasions, with 1093 native taxa (5% of all species) naturalized in other countries. At least 80 taxa are invasive in natural or semi-natural ecosystems elsewhere, while an additional 132 taxa are potentially invasive. Of the global naturalized flora, 8.2% originate from South Africa and largely comprise species of Poaceae, Asteraceae, Iridaceae and Fabaceae. Australia, in particular, but also Europe and North America are major recipients of South African weeds. However, few countries have targeted South African plants for biological control (biocontrol), with most efforts undertaken by Australia. Previous and current targets have involved only 26 species with 17 agents (15 insects, one mite and one rust fungus) of South African origin released on five target species in Australia and the United States of America. South Africa’s history of weed biocontrol, together with a large cohort of active scientists, is currently facilitating several internationally funded programmes targeting invasive plants of South African origin. In particular, the recently inaugurated Centre for Biological Control at Rhodes University and the University of KwaZulu-Natal have provided the impetus for novel efforts on five new target species and renewed efforts on four previously targeted species. In this contribution, we review the history of earlier biocontrol programmes against weeds of South African origin and the status of projects currently in progress in South Africa.
- Full Text:
- Date Issued: 2021
- Authors: Olckers, Terence , Coetzee, Julie A , Egli, Daniella , Martin, Grant D , Paterson, Iain D , Sutton, Guy F , Wood, Alan R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414336 , vital:71137 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a21"
- Description: South Africa supports a rich floral diversity, with 21 643 native plant taxa that include a high proportion (76.3%) of endemic species, and many of these favoured as ornamentals, both locally and globally. Consequently, South Africa has contributed substantially to global plant invasions, with 1093 native taxa (5% of all species) naturalized in other countries. At least 80 taxa are invasive in natural or semi-natural ecosystems elsewhere, while an additional 132 taxa are potentially invasive. Of the global naturalized flora, 8.2% originate from South Africa and largely comprise species of Poaceae, Asteraceae, Iridaceae and Fabaceae. Australia, in particular, but also Europe and North America are major recipients of South African weeds. However, few countries have targeted South African plants for biological control (biocontrol), with most efforts undertaken by Australia. Previous and current targets have involved only 26 species with 17 agents (15 insects, one mite and one rust fungus) of South African origin released on five target species in Australia and the United States of America. South Africa’s history of weed biocontrol, together with a large cohort of active scientists, is currently facilitating several internationally funded programmes targeting invasive plants of South African origin. In particular, the recently inaugurated Centre for Biological Control at Rhodes University and the University of KwaZulu-Natal have provided the impetus for novel efforts on five new target species and renewed efforts on four previously targeted species. In this contribution, we review the history of earlier biocontrol programmes against weeds of South African origin and the status of projects currently in progress in South Africa.
- Full Text:
- Date Issued: 2021
Book Review Quinn, L.(ed.) 2019. Re-imagining Curriculum: Spaces for Disruption
- Authors: McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185865 , vital:44441 , xlink:href="https://journals.co.za/doi/abs/10.14426/cristal.v9i1.434"
- Description: This book is in some ways a continuation of the conversation begun with Reimaging Academic Staff Development: Spaces for Disruption (2012), also edited by Lynn Quinn. But the 2019 volume takes a much wider viewpoint including, as it does, twenty chapters by forty-two authors who are academics and academic developers across institutional types from Australia, Canada, South Africa, the United States of America, the United Kingdom, and the West Indies. Quinn and Vorster (2019: 2) state in Chapter One that the purpose of the book is 'to share theoretical perspectives and practical ideas for ways in which academic developers (and academic leaders) can work in partnership with lecturers and students to respond to the urgent calls for curriculum transformation and decolonisation'. This captures the four threads that run throughout the collection.
- Full Text:
- Date Issued: 2021
- Authors: McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185865 , vital:44441 , xlink:href="https://journals.co.za/doi/abs/10.14426/cristal.v9i1.434"
- Description: This book is in some ways a continuation of the conversation begun with Reimaging Academic Staff Development: Spaces for Disruption (2012), also edited by Lynn Quinn. But the 2019 volume takes a much wider viewpoint including, as it does, twenty chapters by forty-two authors who are academics and academic developers across institutional types from Australia, Canada, South Africa, the United States of America, the United Kingdom, and the West Indies. Quinn and Vorster (2019: 2) state in Chapter One that the purpose of the book is 'to share theoretical perspectives and practical ideas for ways in which academic developers (and academic leaders) can work in partnership with lecturers and students to respond to the urgent calls for curriculum transformation and decolonisation'. This captures the four threads that run throughout the collection.
- Full Text:
- Date Issued: 2021
Borneol-triarylcorrole hybrids with chiral-optical response and anticancer behaviours
- Fu, Bo, Wang, Lin, Yu, Xiaoxiao, Fang, Xianying, Mack, John, Dingiswayo, Somila, Nyokong, Tebello, Liang, Xu, Xu, Haijun
- Authors: Fu, Bo , Wang, Lin , Yu, Xiaoxiao , Fang, Xianying , Mack, John , Dingiswayo, Somila , Nyokong, Tebello , Liang, Xu , Xu, Haijun
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185294 , vital:44362 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109699"
- Description: A series of four multifunctional A2B type H3corroles with meso-borneol substituents at the B position have been synthesized and characterized. A detailed analysis of the optical properties was carried out, and a comparison was made with theoretical calculations to identify the key trends in the structure-property relationships. The meso-borneol substituent couples with the corrole core leading to clear CD signals in the B band region. Enhanced anti-cancer properties are observed in vitro relative to (−)-borneol with cell inhibition rates of up to 94%.
- Full Text:
- Date Issued: 2021
- Authors: Fu, Bo , Wang, Lin , Yu, Xiaoxiao , Fang, Xianying , Mack, John , Dingiswayo, Somila , Nyokong, Tebello , Liang, Xu , Xu, Haijun
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185294 , vital:44362 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109699"
- Description: A series of four multifunctional A2B type H3corroles with meso-borneol substituents at the B position have been synthesized and characterized. A detailed analysis of the optical properties was carried out, and a comparison was made with theoretical calculations to identify the key trends in the structure-property relationships. The meso-borneol substituent couples with the corrole core leading to clear CD signals in the B band region. Enhanced anti-cancer properties are observed in vitro relative to (−)-borneol with cell inhibition rates of up to 94%.
- Full Text:
- Date Issued: 2021
Breaking the Rules: Zodwa Wabantu and postfeminism in South Africa
- Authors: Boshoff, Priscilla A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177408 , vital:42819 , http://dx.doi.org/10.17645/mac.v9i2.3830
- Description: Zodwa Wabantu, a South African celebrity recently made popular by the Daily Sun, a local tabloid newspaper, is notorious as an older working-class woman who fearlessly challenges social norms of feminine respectability and beauty. Her assertion of sexual autonomy and her forays into self-surveillance and body-modification, mediated by the Daily Sun and other tabloid and social media platforms, could be read as a local iteration of a global postfeminist subjectivity. However, the widespread social opprobrium she faces must be accounted for: Using Connell’s model of the gender order together with a coloniality frame, I argue that northern critiques of postfeminism omit to consider the forms of patriarchy established by colonialism in southern locales such as South Africa. The local patriarchal gender order, made visible within the tabloid reportage, provides the context within which the meaning of Zodwa Wabanu’s contemporary postfeminist identity is constructed. I examine a range of Zodwa Wabantu’s (self)representations in Daily Sun and other digital media in the light of this context, and conclude that a close examination of the local gender order assists in understanding the limits of postfeminism’s hegemony.
- Full Text:
- Date Issued: 2021
- Authors: Boshoff, Priscilla A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177408 , vital:42819 , http://dx.doi.org/10.17645/mac.v9i2.3830
- Description: Zodwa Wabantu, a South African celebrity recently made popular by the Daily Sun, a local tabloid newspaper, is notorious as an older working-class woman who fearlessly challenges social norms of feminine respectability and beauty. Her assertion of sexual autonomy and her forays into self-surveillance and body-modification, mediated by the Daily Sun and other tabloid and social media platforms, could be read as a local iteration of a global postfeminist subjectivity. However, the widespread social opprobrium she faces must be accounted for: Using Connell’s model of the gender order together with a coloniality frame, I argue that northern critiques of postfeminism omit to consider the forms of patriarchy established by colonialism in southern locales such as South Africa. The local patriarchal gender order, made visible within the tabloid reportage, provides the context within which the meaning of Zodwa Wabanu’s contemporary postfeminist identity is constructed. I examine a range of Zodwa Wabantu’s (self)representations in Daily Sun and other digital media in the light of this context, and conclude that a close examination of the local gender order assists in understanding the limits of postfeminism’s hegemony.
- Full Text:
- Date Issued: 2021
Bridging through “women’s work"
- Authors: Magadla, Siphokazi
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298650 , vital:57724 , xlink:href="https://doi.org/10.1080/14616742.2020.1863158"
- Description: Bodomo’s bridge theory describes and predicts the long-term implications of African migrants’ activities and settlement in China. Drawing on research with African retail traders, university students, and corporate executives in China, I show that the bridge theory illuminates how African women and men rationalize their decisions to migrate to China within the context of the rise of Asia. Drawing on the literature regarding African women and work, I explain that structural economic conditions now force more Africans into economic sectors such as trade work that historically were dominated by African women. I demonstrate that African women’s roles as economic providers for their families and children in other sectors, such as university students and company executives, provide evidence of the continued “matricentric” nature of African households that rely on women’s economic productivity. I also examine the possibilities and limitations of building long-standing networks that shape African migrant settlement in China. I show that the historical theorization that characterizes global mobility as male – particularly regarding Africans – has contributed to the misrecognition of African women’s multiple activities in China.
- Full Text:
- Date Issued: 2021
- Authors: Magadla, Siphokazi
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298650 , vital:57724 , xlink:href="https://doi.org/10.1080/14616742.2020.1863158"
- Description: Bodomo’s bridge theory describes and predicts the long-term implications of African migrants’ activities and settlement in China. Drawing on research with African retail traders, university students, and corporate executives in China, I show that the bridge theory illuminates how African women and men rationalize their decisions to migrate to China within the context of the rise of Asia. Drawing on the literature regarding African women and work, I explain that structural economic conditions now force more Africans into economic sectors such as trade work that historically were dominated by African women. I demonstrate that African women’s roles as economic providers for their families and children in other sectors, such as university students and company executives, provide evidence of the continued “matricentric” nature of African households that rely on women’s economic productivity. I also examine the possibilities and limitations of building long-standing networks that shape African migrant settlement in China. I show that the historical theorization that characterizes global mobility as male – particularly regarding Africans – has contributed to the misrecognition of African women’s multiple activities in China.
- Full Text:
- Date Issued: 2021
Case Study For Linking Water Quality License Conditions With Resource Quality Objectives For The Leeutaaiboschspruit Industrial Complex Situated Within The Vaal Barrage Catchment Volume 1
- Odume, Oghenekaro N, Slaughter, Andrew R, Griffin, Neil J, Chili, Asanda
- Authors: Odume, Oghenekaro N , Slaughter, Andrew R , Griffin, Neil J , Chili, Asanda
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438074 , vital:73433 , ISBN 978-0-6392-0224-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 838-1 final web.pdf
- Description: In South Africa, the resource-directed measures (RDM) and the source-directed con-trols (SDC) are the two complementary strategies designed to ensure that water resources are used and protected. The RDM are directed at water resources to en-sure their protection, and include the Water Resource Classification System (WRCS), the classification of every significant water resource, the determination of the re-serve and the setting of resource quality objectives (RQOs). On the other hand, the SDC are measures imposed to restrict and control the use of water resources, not only in terms of ensuring water resource protection, but also in terms of ensuring that water resources are equitably allocated and are used efficiently. Water use li-cencing (WUL) is an example of an SDC instrument.
- Full Text:
- Date Issued: 2021
- Authors: Odume, Oghenekaro N , Slaughter, Andrew R , Griffin, Neil J , Chili, Asanda
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438074 , vital:73433 , ISBN 978-0-6392-0224-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 838-1 final web.pdf
- Description: In South Africa, the resource-directed measures (RDM) and the source-directed con-trols (SDC) are the two complementary strategies designed to ensure that water resources are used and protected. The RDM are directed at water resources to en-sure their protection, and include the Water Resource Classification System (WRCS), the classification of every significant water resource, the determination of the re-serve and the setting of resource quality objectives (RQOs). On the other hand, the SDC are measures imposed to restrict and control the use of water resources, not only in terms of ensuring water resource protection, but also in terms of ensuring that water resources are equitably allocated and are used efficiently. Water use li-cencing (WUL) is an example of an SDC instrument.
- Full Text:
- Date Issued: 2021
Cereal stem borer (Lepidoptera) assemblage structure in a sub-tropical agro-ecosystem, Eastern Cape Province, South Africa
- Authors: Niba, AS. , Mdazu, S.
- Date: 2021
- Subjects: Cereal products Stem borers Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6958 , vital:52619 , xlink:href="https://doi.org/10.1080/0035919X.2021.1893861"
- Description: Insect pests, especially lepidopterous stem borers, cause significant losses to cereal production at local and global scales. The borer species associated with cultivated grain cereals and alternative wild host plants were identified at three elevation gradients in the former Transkei area of the Eastern Cape Province, South Africa. Stem borer sampling was undertaken during maize crop and non-crop seasons in Port St Johns (PSJ), Mthatha and Elliot, sites that differ in elevation above sea level, annual precipitation and temperature. Morphologically identical borers retrieved from each sampling unit were recorded, processed and reared to adult stage for identification at an ambient temperature range of 25–28°C and a relative humidity range of 65–80%. Specimens were sorted first into morphospecies (MS1–MS6) based on external morphological characteristics. Six stem borer species (Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo orichalcocili, Chilo sacchariphagus and Chilo partellus) were collected during the survey. E. saccharina and C. orichalcocili were absent in PSJ; in Elliot, E. saccahrina occurred in very low numbers whereas C. partellus was absent. Busseola fusca was more abundant at high altitude (i.e. Elliot). Borer community structure in the study showed similarity between Mthatha and Elliot. Species richness and abundance across study sites were not statistically significant (P > 0.05). The study provides information on borer species occurrence in the study area, and techniques to identify larval stages for effective control by local farmers and extension workers. When designing strategies for borer control, elevation may not be a major concern at this spatial scale.
- Full Text:
- Date Issued: 2021
- Authors: Niba, AS. , Mdazu, S.
- Date: 2021
- Subjects: Cereal products Stem borers Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6958 , vital:52619 , xlink:href="https://doi.org/10.1080/0035919X.2021.1893861"
- Description: Insect pests, especially lepidopterous stem borers, cause significant losses to cereal production at local and global scales. The borer species associated with cultivated grain cereals and alternative wild host plants were identified at three elevation gradients in the former Transkei area of the Eastern Cape Province, South Africa. Stem borer sampling was undertaken during maize crop and non-crop seasons in Port St Johns (PSJ), Mthatha and Elliot, sites that differ in elevation above sea level, annual precipitation and temperature. Morphologically identical borers retrieved from each sampling unit were recorded, processed and reared to adult stage for identification at an ambient temperature range of 25–28°C and a relative humidity range of 65–80%. Specimens were sorted first into morphospecies (MS1–MS6) based on external morphological characteristics. Six stem borer species (Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo orichalcocili, Chilo sacchariphagus and Chilo partellus) were collected during the survey. E. saccharina and C. orichalcocili were absent in PSJ; in Elliot, E. saccahrina occurred in very low numbers whereas C. partellus was absent. Busseola fusca was more abundant at high altitude (i.e. Elliot). Borer community structure in the study showed similarity between Mthatha and Elliot. Species richness and abundance across study sites were not statistically significant (P > 0.05). The study provides information on borer species occurrence in the study area, and techniques to identify larval stages for effective control by local farmers and extension workers. When designing strategies for borer control, elevation may not be a major concern at this spatial scale.
- Full Text:
- Date Issued: 2021
Cereal stem borer (Lepidoptera) assemblage structure in a sub-tropical agro-ecosystem, Eastern Cape Province, South Africa
- Authors: Niba, AS. , Mdazu, S.
- Date: 2021
- Subjects: Cereal products Stem borers Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6948 , vital:52620 , xlink:href="https://doi.org/10.1080/0035919X.2021.1893861"
- Description: Insect pests, especially lepidopterous stem borers, cause significant losses to cereal production at local and global scales. The borer species associated with cultivated grain cereals and alternative wild host plants were identified at three elevation gradients in the former Transkei area of the Eastern Cape Province, South Africa. Stem borer sampling was undertaken during maize crop and non-crop seasons in Port St Johns (PSJ), Mthatha and Elliot, sites that differ in elevation above sea level, annual precipitation and temperature. Morphologically identical borers retrieved from each sampling unit were recorded, processed and reared to adult stage for identification at an ambient temperature range of 25–28°C and a relative humidity range of 65–80%. Specimens were sorted first into morphospecies (MS1–MS6) based on external morphological characteristics. Six stem borer species (Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo orichalcocili, Chilo sacchariphagus and Chilo partellus) were collected during the survey. E. saccharina and C. orichalcocili were absent in PSJ; in Elliot, E. saccahrina occurred in very low numbers whereas C. partellus was absent. Busseola fusca was more abundant at high altitude (i.e. Elliot). Borer community structure in the study showed similarity between Mthatha and Elliot. Species richness and abundance across study sites were not statistically significant (P > 0.05). The study provides information on borer species occurrence in the study area, and techniques to identify larval stages for effective control by local farmers and extension workers. When designing strategies for borer control, elevation may not be a major concern at this spatial scale.
- Full Text:
- Date Issued: 2021
- Authors: Niba, AS. , Mdazu, S.
- Date: 2021
- Subjects: Cereal products Stem borers Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6948 , vital:52620 , xlink:href="https://doi.org/10.1080/0035919X.2021.1893861"
- Description: Insect pests, especially lepidopterous stem borers, cause significant losses to cereal production at local and global scales. The borer species associated with cultivated grain cereals and alternative wild host plants were identified at three elevation gradients in the former Transkei area of the Eastern Cape Province, South Africa. Stem borer sampling was undertaken during maize crop and non-crop seasons in Port St Johns (PSJ), Mthatha and Elliot, sites that differ in elevation above sea level, annual precipitation and temperature. Morphologically identical borers retrieved from each sampling unit were recorded, processed and reared to adult stage for identification at an ambient temperature range of 25–28°C and a relative humidity range of 65–80%. Specimens were sorted first into morphospecies (MS1–MS6) based on external morphological characteristics. Six stem borer species (Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo orichalcocili, Chilo sacchariphagus and Chilo partellus) were collected during the survey. E. saccharina and C. orichalcocili were absent in PSJ; in Elliot, E. saccahrina occurred in very low numbers whereas C. partellus was absent. Busseola fusca was more abundant at high altitude (i.e. Elliot). Borer community structure in the study showed similarity between Mthatha and Elliot. Species richness and abundance across study sites were not statistically significant (P > 0.05). The study provides information on borer species occurrence in the study area, and techniques to identify larval stages for effective control by local farmers and extension workers. When designing strategies for borer control, elevation may not be a major concern at this spatial scale.
- Full Text:
- Date Issued: 2021
Chave Chemutengure Vhiri Rengoro : Husarungano Nerwendo Rwengano Dzevashona
- Authors: Mabasa, Ignatius T
- Date: 2021
- Subjects: Ethnology -- Zimbabwe , Zimbabwe -- Folklore , Shona (African people) -- Folklore , Ethnoscience , Decolonization in literature , Decolonization -- Africa , Autoethnography , Chemutengure , Subaltern
- Language: Shona
- Type: text , Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10962/174198 , vital:42454 , http://doi.org/10.21504/10962/174198
- Description: Tsvakurudzo ino inyaya yangu sasarungano nemunyori weChiShona, asiwo iri nyaya yevanhu veChiShona. Inyaya yekurerwa kwandakaitwa nengano, ndikaona ngano dzakandirera dzichipinzwa muzvikoro, dzichisangana nechirungu, dzichifambidzana nechirungu, nekuzopedzisira dzazvara mimwe misambo yengano. Basa rino maonero angu ndichishandisa nzira yetsvakurudzo inonzi husarungano, kureva muono wasarungano. Izvi zvinoreva kududzira nekutsanangura, kufungisisa nekupenengura humhizha hunowanikwa mutsika nemagariro angu, sasarungano ari kupfuurira mberi nekuita ngano munyika yazara chirungu. Naizvozvo, ini ndini musoro wenyaya yandiri kutaura, asiwo ndirini zvakare muiti wetsvakurudzo. Ndichishandisa zvandakasangana nazvo, nezvandinofunga nekuona sasarungano – ndinodzokera kuchimbo chinotaura nyaya yevaShona pakapinda vachena munyika yeZimbabwe. Ndinotsanangura zvinoreva Chemutengure, uye nekukosha kwacho mukufambisa ruzivo, mashoko nekutsanangura hupenyu hwedu sevanhu vatema vakanga vakadzvanyiriwa. Chemutengure mafungiro, imhenenguro, iyambiro nehungwaru. Ndinotsanangura ruzivo rwevanhu vangu nekushanduka kwarwo kwakakonzerwa nechirungu. Ndinoita izvi ndichipenengura ngano, mabhuku, nziyo, mafungiro nezvimwe zvimutengure zvakatakura ngano. Otoetinogirafu iyo yandichapa zita rekuti husarungano imhando yekuvhiya uchiita tsvakurudzo, uye inowanikwa pakati pehumhizha hwekunyora nyaya nekupenengura zvine chekuita nehumhizha hwetsika nemagariro evanhu. Husarungano hunovhurira musiwo vanhu vanowanzovharirwa kunze netsvakurudzo dzinoitwa mumayunivhesiti dzine mitauro isiri yavo uyewo dzimwe nguva isinganzwisisike zviri nyn’ore. Husarungano hunoshandisa rondedzero nengano kuti zvinhu zvinosanganisira hukama nezvakasanganikwa nazvo nevanhu zvinzwisisike, panguva imwechete pachiumbwa hukama pakati penguva dzakare nazvino, hukama pakati pevanoita tsvakurudzo nevavari kuita tsvakurudzo pamusoro pavo, hukama pakati pevanyori nevaverengi, vanasarungano nevateereri vengano (Adams nevamwe, 2015). Tsvakurudzo ino haisi kuzopedza zvese zvinofanira kutaurwa pamusoro pengano, tsika nemagariro evanhu vatema, kunyorwa kwemabhuku nezvimwe zvakawanda zvainobata nekutarisa, asi riripo kuratidza simba nehupfumi huri muruzivo rwevaShona rwuri kurariswa muberere memba, chirungu chichirariswa mumba. Shanduko yandiri kutarisa mubasa rino inoda kuti isu vanhu vatema tisarambe tichiverengera kuti tirongeke nekuronga mafambiro nemararamiro achaita ruzivo rwedu munyika iri kukoshesa ruzivo, maitiro nezvinhu zvinogadzirwa nevarungu. Kana tikasaronga kuti tipembedze nekuwanisa ruzivo rwedu mukana, tichaita mufakose – kurasikirwa nezvedu, nekusakwana kana kunyatsonzwisisa zvevamwe zvatiri kukoshesa. Ruzivo rwandakashandisa mubasa rino rwunosanganisira zvakaitika kwandiri kubva pandakatanga kuziva ngano dzandakaudzwa nambuya vangu, kubatsirwa kwangu nengano kuchikoro, kuve munyori wemabhuku, nekuenda kwangu mhiri kwemakungwa sasarungano. Zvakarewo ndiri kutarisa ngano dzakaunganidzwa nekunyorwa nemamishenari, ngano dzakanyorwa kare muNative Afffairs Department Annual (NADA), ngano dzakaitwa senziyo, ngano dzakaitwa neLiterature Bureau, nengano dzandave kuita dzemanon-governmental organisations (NGO), panhepfenyuro, paTwitter nezvimwe zvimutengure zvakasiyana-siyana. Hupfumi huri mungano, mazano ekuri kuenda ngano dzedu, nezvinoreva chemutengure senzira yemafungiro zvinobuda mutsvakurudzo ino. Chitsauko 1 ndicho chinozama kutevedza nzira yekuita tsvakurudzo inozivikanwa, asi Chitsauko 2 inyunyuto inoburitsa mukundo une chirungu sekuunzwa kwachakaitwa naCecil John Rhodes. Chitsauko 3 chinotambanudza nekujekesa kukosha kwechimbo Chemutengure, uyewo nekuti sezano, chemutengure chinotibata sei nhasi uno. Chitsauko 4 chinoronda nzira dzakafamba nadzo ngano dzekunze dzichipinda matiri, uyewo nezvakaitwa nengano dzedu pamusoro peshanduko yakanga yauya. Chitsauko 5 chinopa mienzaniso yezviteshi zvakamira ngano dzevatema padzakabva mumisha dzichienda kuzvikoro kusvika dzazove muzvimwe zvimutengure zvakadziendesa kure nasarungano. Chitsauko 6 chinotarisa dambudziko rine chirungu muhupenyu hwevanhu vatema, nekukosha kwekudada nerudzi rwedu. Chitsauko 7 chinopeta basa chichipa mazano, chichiratidza kuti ngano hadzifanire kufa nekuti dzakagara dzine simba rekufambirana nenguva. , This research is my story as a Shona folklorist and creative writer, but it is also the story of the Shona people. It is a story of how I am “a child” of storytelling, and how the stories that raised me got appropriated and incorporated into the colonial school system where they converged and mixed with western forms of storytelling to create hybrids. As a storyteller I use autoethnography – which offers an insider’s perspective - to interpret and explain, to reflect and analyse the art of storytelling in my culture. The alienation of indigenous knowledge and cultural practices – specifically storytelling, is what necessitates the use of autoethnography for this study. Autoethnography is a qualitative research method of writing and storytelling where the researcher is the subject and the researcher's experiences are the data. I, being a Shona storyteller and creative writer, will systematically journey back and analyse personal experiences in order to make sense of the Shona people’s cultural experiences. The research process will see me running away from depending on other people’s records about my people’s cultural history. Instead, I traverse back in time to consult and extract a theory from the Shona song called Chemutengure from around 1890 that tells the story of British colonisation from the perspective of the colonised. I theorise and explain Chemutengure’s pedagogical and epistemological significance in critiquing the plight of Africans suffering contact-induced change. I apply the Chemutengure theory to folktales, books, songs, paradigms and other agents that played an active role in producing new forms of storytelling and worldviews. Autoethnography is a type of research method that blends engaging creative writing and analysis of cultural experiences. It opens doors of research to the subalterns who are usually shut out by research that is done in universities. “Rather than producing esoteric, jargon-laden texts, many auto-ethnographers recognize a need to speak also to nonacademic audiences,” (Adams et al, 2015: 42) employing narrative and story-telling to give meaning to identities, relationships, and experiences, and to create relationships between past and present, researchers and participants, writers and readers, tellers and audiences, (Adams et al, 2015:23). This research will not exhaust all that needs to be explored and said about Shona folktales, creativity and culture, or its literature and the many cultural aspects it looks at. Rather, it seeks to highlight, decolonize and deconstruct colonial mentalities, while emancipating the Shona worldview that has been put on leash by colonialism and western capitalistic tendencies. The study also looks at positive change that occurs when cultures inform one another, but without turning a blind eye to the lack of mutuality and how the logic of capitalism has left Africa hemorrhaging ideologically. Drawing from personal experiences when I listened to my grandmother’s stories, the study looks at the influence of folktales on my creative writing career. I reflect on my experiences as a Fulbright Scholar, as well as my Canadian experiences as storyteller and writer-in-residence at the University of Manitoba. Besides analysing stories written by missionaries in early Shona school readers, I also discuss folktales published in the Native Affairs Department Annual (NADA); the folktales performed as songs; the comic tales published by the Literature Bureau; tales developed for private institutions, government and non-governmental organisations; stories on radio, Twitter and many other forms. Besides giving the subaltern a voice, this research attempts to artistically demonstrate the power and versatility of the Shona folktale, as well as the genre’s potential for growth and development. Chapter 1 introduces the autoethngraphy method as well as what I hope to achieve through the methodology and style of writing. Chapter 2 is a conversation between a representative of the colonised and Cecil John Rhodes the imperialist. Besides pointing out imperialism’s damage to indigenous identities, the chapter discusses how Africa and Europe’s paradigms are diametrically conflicting. Chapter 3 introduces, explains and analyses the song/theory Chemutengure, and how it applies to the condition of the native in postcolonial Africa today. Chapter 4 tracks the trajectory of foreign tales in Zimbabwe, and how they influenced native folktales. The response of local tales is also critiqued. Chapter 5 looks at the milestones in the structural transformation of indigenous folktales, and how they were appropriated and hitched a ride in the wagon of change. Chapter 6 is a reflection on the impact of westernisation and globalisation in the lives of Africans, and how confused the native has become without his cultural anchor. Chapter 7 concludes by acknowledging the inevitability of change, and suggests how cultural practices and perspectives must respond to social change so as to remain relevant.
- Full Text:
- Date Issued: 2021
- Authors: Mabasa, Ignatius T
- Date: 2021
- Subjects: Ethnology -- Zimbabwe , Zimbabwe -- Folklore , Shona (African people) -- Folklore , Ethnoscience , Decolonization in literature , Decolonization -- Africa , Autoethnography , Chemutengure , Subaltern
- Language: Shona
- Type: text , Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10962/174198 , vital:42454 , http://doi.org/10.21504/10962/174198
- Description: Tsvakurudzo ino inyaya yangu sasarungano nemunyori weChiShona, asiwo iri nyaya yevanhu veChiShona. Inyaya yekurerwa kwandakaitwa nengano, ndikaona ngano dzakandirera dzichipinzwa muzvikoro, dzichisangana nechirungu, dzichifambidzana nechirungu, nekuzopedzisira dzazvara mimwe misambo yengano. Basa rino maonero angu ndichishandisa nzira yetsvakurudzo inonzi husarungano, kureva muono wasarungano. Izvi zvinoreva kududzira nekutsanangura, kufungisisa nekupenengura humhizha hunowanikwa mutsika nemagariro angu, sasarungano ari kupfuurira mberi nekuita ngano munyika yazara chirungu. Naizvozvo, ini ndini musoro wenyaya yandiri kutaura, asiwo ndirini zvakare muiti wetsvakurudzo. Ndichishandisa zvandakasangana nazvo, nezvandinofunga nekuona sasarungano – ndinodzokera kuchimbo chinotaura nyaya yevaShona pakapinda vachena munyika yeZimbabwe. Ndinotsanangura zvinoreva Chemutengure, uye nekukosha kwacho mukufambisa ruzivo, mashoko nekutsanangura hupenyu hwedu sevanhu vatema vakanga vakadzvanyiriwa. Chemutengure mafungiro, imhenenguro, iyambiro nehungwaru. Ndinotsanangura ruzivo rwevanhu vangu nekushanduka kwarwo kwakakonzerwa nechirungu. Ndinoita izvi ndichipenengura ngano, mabhuku, nziyo, mafungiro nezvimwe zvimutengure zvakatakura ngano. Otoetinogirafu iyo yandichapa zita rekuti husarungano imhando yekuvhiya uchiita tsvakurudzo, uye inowanikwa pakati pehumhizha hwekunyora nyaya nekupenengura zvine chekuita nehumhizha hwetsika nemagariro evanhu. Husarungano hunovhurira musiwo vanhu vanowanzovharirwa kunze netsvakurudzo dzinoitwa mumayunivhesiti dzine mitauro isiri yavo uyewo dzimwe nguva isinganzwisisike zviri nyn’ore. Husarungano hunoshandisa rondedzero nengano kuti zvinhu zvinosanganisira hukama nezvakasanganikwa nazvo nevanhu zvinzwisisike, panguva imwechete pachiumbwa hukama pakati penguva dzakare nazvino, hukama pakati pevanoita tsvakurudzo nevavari kuita tsvakurudzo pamusoro pavo, hukama pakati pevanyori nevaverengi, vanasarungano nevateereri vengano (Adams nevamwe, 2015). Tsvakurudzo ino haisi kuzopedza zvese zvinofanira kutaurwa pamusoro pengano, tsika nemagariro evanhu vatema, kunyorwa kwemabhuku nezvimwe zvakawanda zvainobata nekutarisa, asi riripo kuratidza simba nehupfumi huri muruzivo rwevaShona rwuri kurariswa muberere memba, chirungu chichirariswa mumba. Shanduko yandiri kutarisa mubasa rino inoda kuti isu vanhu vatema tisarambe tichiverengera kuti tirongeke nekuronga mafambiro nemararamiro achaita ruzivo rwedu munyika iri kukoshesa ruzivo, maitiro nezvinhu zvinogadzirwa nevarungu. Kana tikasaronga kuti tipembedze nekuwanisa ruzivo rwedu mukana, tichaita mufakose – kurasikirwa nezvedu, nekusakwana kana kunyatsonzwisisa zvevamwe zvatiri kukoshesa. Ruzivo rwandakashandisa mubasa rino rwunosanganisira zvakaitika kwandiri kubva pandakatanga kuziva ngano dzandakaudzwa nambuya vangu, kubatsirwa kwangu nengano kuchikoro, kuve munyori wemabhuku, nekuenda kwangu mhiri kwemakungwa sasarungano. Zvakarewo ndiri kutarisa ngano dzakaunganidzwa nekunyorwa nemamishenari, ngano dzakanyorwa kare muNative Afffairs Department Annual (NADA), ngano dzakaitwa senziyo, ngano dzakaitwa neLiterature Bureau, nengano dzandave kuita dzemanon-governmental organisations (NGO), panhepfenyuro, paTwitter nezvimwe zvimutengure zvakasiyana-siyana. Hupfumi huri mungano, mazano ekuri kuenda ngano dzedu, nezvinoreva chemutengure senzira yemafungiro zvinobuda mutsvakurudzo ino. Chitsauko 1 ndicho chinozama kutevedza nzira yekuita tsvakurudzo inozivikanwa, asi Chitsauko 2 inyunyuto inoburitsa mukundo une chirungu sekuunzwa kwachakaitwa naCecil John Rhodes. Chitsauko 3 chinotambanudza nekujekesa kukosha kwechimbo Chemutengure, uyewo nekuti sezano, chemutengure chinotibata sei nhasi uno. Chitsauko 4 chinoronda nzira dzakafamba nadzo ngano dzekunze dzichipinda matiri, uyewo nezvakaitwa nengano dzedu pamusoro peshanduko yakanga yauya. Chitsauko 5 chinopa mienzaniso yezviteshi zvakamira ngano dzevatema padzakabva mumisha dzichienda kuzvikoro kusvika dzazove muzvimwe zvimutengure zvakadziendesa kure nasarungano. Chitsauko 6 chinotarisa dambudziko rine chirungu muhupenyu hwevanhu vatema, nekukosha kwekudada nerudzi rwedu. Chitsauko 7 chinopeta basa chichipa mazano, chichiratidza kuti ngano hadzifanire kufa nekuti dzakagara dzine simba rekufambirana nenguva. , This research is my story as a Shona folklorist and creative writer, but it is also the story of the Shona people. It is a story of how I am “a child” of storytelling, and how the stories that raised me got appropriated and incorporated into the colonial school system where they converged and mixed with western forms of storytelling to create hybrids. As a storyteller I use autoethnography – which offers an insider’s perspective - to interpret and explain, to reflect and analyse the art of storytelling in my culture. The alienation of indigenous knowledge and cultural practices – specifically storytelling, is what necessitates the use of autoethnography for this study. Autoethnography is a qualitative research method of writing and storytelling where the researcher is the subject and the researcher's experiences are the data. I, being a Shona storyteller and creative writer, will systematically journey back and analyse personal experiences in order to make sense of the Shona people’s cultural experiences. The research process will see me running away from depending on other people’s records about my people’s cultural history. Instead, I traverse back in time to consult and extract a theory from the Shona song called Chemutengure from around 1890 that tells the story of British colonisation from the perspective of the colonised. I theorise and explain Chemutengure’s pedagogical and epistemological significance in critiquing the plight of Africans suffering contact-induced change. I apply the Chemutengure theory to folktales, books, songs, paradigms and other agents that played an active role in producing new forms of storytelling and worldviews. Autoethnography is a type of research method that blends engaging creative writing and analysis of cultural experiences. It opens doors of research to the subalterns who are usually shut out by research that is done in universities. “Rather than producing esoteric, jargon-laden texts, many auto-ethnographers recognize a need to speak also to nonacademic audiences,” (Adams et al, 2015: 42) employing narrative and story-telling to give meaning to identities, relationships, and experiences, and to create relationships between past and present, researchers and participants, writers and readers, tellers and audiences, (Adams et al, 2015:23). This research will not exhaust all that needs to be explored and said about Shona folktales, creativity and culture, or its literature and the many cultural aspects it looks at. Rather, it seeks to highlight, decolonize and deconstruct colonial mentalities, while emancipating the Shona worldview that has been put on leash by colonialism and western capitalistic tendencies. The study also looks at positive change that occurs when cultures inform one another, but without turning a blind eye to the lack of mutuality and how the logic of capitalism has left Africa hemorrhaging ideologically. Drawing from personal experiences when I listened to my grandmother’s stories, the study looks at the influence of folktales on my creative writing career. I reflect on my experiences as a Fulbright Scholar, as well as my Canadian experiences as storyteller and writer-in-residence at the University of Manitoba. Besides analysing stories written by missionaries in early Shona school readers, I also discuss folktales published in the Native Affairs Department Annual (NADA); the folktales performed as songs; the comic tales published by the Literature Bureau; tales developed for private institutions, government and non-governmental organisations; stories on radio, Twitter and many other forms. Besides giving the subaltern a voice, this research attempts to artistically demonstrate the power and versatility of the Shona folktale, as well as the genre’s potential for growth and development. Chapter 1 introduces the autoethngraphy method as well as what I hope to achieve through the methodology and style of writing. Chapter 2 is a conversation between a representative of the colonised and Cecil John Rhodes the imperialist. Besides pointing out imperialism’s damage to indigenous identities, the chapter discusses how Africa and Europe’s paradigms are diametrically conflicting. Chapter 3 introduces, explains and analyses the song/theory Chemutengure, and how it applies to the condition of the native in postcolonial Africa today. Chapter 4 tracks the trajectory of foreign tales in Zimbabwe, and how they influenced native folktales. The response of local tales is also critiqued. Chapter 5 looks at the milestones in the structural transformation of indigenous folktales, and how they were appropriated and hitched a ride in the wagon of change. Chapter 6 is a reflection on the impact of westernisation and globalisation in the lives of Africans, and how confused the native has become without his cultural anchor. Chapter 7 concludes by acknowledging the inevitability of change, and suggests how cultural practices and perspectives must respond to social change so as to remain relevant.
- Full Text:
- Date Issued: 2021
Clinical outcomes of hospitalised COVID-19 patients at Mthatha Regional Hospital, Eastern Cape, South Africa: A retrospective study
- Kaswa, Ramprakash, Yogeswaran, Parimalaranie, Cawe, Busisiwe
- Authors: Kaswa, Ramprakash , Yogeswaran, Parimalaranie , Cawe, Busisiwe
- Date: 2021
- Subjects: COVID-19 Diabetes Hypertension Diseases Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7330 , vital:53402 , xlink:href="https://doi.org/10.4102/safp.v63i1.5253"
- Description: Background: Coronavirus disease 2019 (COVID-19) is a public health crisis that threatens the current health system. The sudden expansion in the need for inpatient and intensive care facilities raised concerns about optimal clinical management and resource allocation. Despite the pressing need for evidence to make context-specific decisions on COVID-19 management, evidence from South Africa remained limited. This study aimed to describe the clinical characteristics and outcomes of COVID-19 hospitalised patients. Methods: A retrospective cross-sectional study design was used to evaluate the clinical outcomes of hospitalised adult patients (≥ 18 years old) with laboratory-confirmed COVID-19 illness at Mthatha Regional Hospital (MRH), Eastern Cape. Results: Of the 1814 patients tested for COVID-19 between 20 March 2020 and 31 July 2020 at MRH, two-thirds (65.4%) were female. About two-thirds (242) of the 392 patients (21.6%) who tested positive for this disease were hospitalised and one-third (150) were quarantined at home. The mean age of the patients tested for COVID-19 was 42.6 years and there was no difference between males and females. The mean age of hospitalised patients was 55.5 years and the mean age of hospitalised patients who died (61.3 years) was much higher than recovered (49.5 years). Overall, 188 (77.6%) hospitalised patients had clinical comorbidity on admission. Diabetes (36.8%) and hypertension (33.1%) were the most common comorbidities amongst COVID-19 hospitalised patients. Conclusion: The majority of the patients who were hospitalised for COVID-19 were elderly and had high baseline comorbidities. Advance age and underlying comorbidities (diabetes, hypertension and HIV) were associated with high mortality in hospitalised COVID-19 patients. Keywords: COVID-19, diabetes; hypertension; hospitalised; co-morbidity.
- Full Text:
- Date Issued: 2021
- Authors: Kaswa, Ramprakash , Yogeswaran, Parimalaranie , Cawe, Busisiwe
- Date: 2021
- Subjects: COVID-19 Diabetes Hypertension Diseases Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7330 , vital:53402 , xlink:href="https://doi.org/10.4102/safp.v63i1.5253"
- Description: Background: Coronavirus disease 2019 (COVID-19) is a public health crisis that threatens the current health system. The sudden expansion in the need for inpatient and intensive care facilities raised concerns about optimal clinical management and resource allocation. Despite the pressing need for evidence to make context-specific decisions on COVID-19 management, evidence from South Africa remained limited. This study aimed to describe the clinical characteristics and outcomes of COVID-19 hospitalised patients. Methods: A retrospective cross-sectional study design was used to evaluate the clinical outcomes of hospitalised adult patients (≥ 18 years old) with laboratory-confirmed COVID-19 illness at Mthatha Regional Hospital (MRH), Eastern Cape. Results: Of the 1814 patients tested for COVID-19 between 20 March 2020 and 31 July 2020 at MRH, two-thirds (65.4%) were female. About two-thirds (242) of the 392 patients (21.6%) who tested positive for this disease were hospitalised and one-third (150) were quarantined at home. The mean age of the patients tested for COVID-19 was 42.6 years and there was no difference between males and females. The mean age of hospitalised patients was 55.5 years and the mean age of hospitalised patients who died (61.3 years) was much higher than recovered (49.5 years). Overall, 188 (77.6%) hospitalised patients had clinical comorbidity on admission. Diabetes (36.8%) and hypertension (33.1%) were the most common comorbidities amongst COVID-19 hospitalised patients. Conclusion: The majority of the patients who were hospitalised for COVID-19 were elderly and had high baseline comorbidities. Advance age and underlying comorbidities (diabetes, hypertension and HIV) were associated with high mortality in hospitalised COVID-19 patients. Keywords: COVID-19, diabetes; hypertension; hospitalised; co-morbidity.
- Full Text:
- Date Issued: 2021
Coastal dunefields maintain pre‐Holocene genetic structure in a rocky shore red alga
- Mmonwa, Kolobe L, Barker, Nigel P, McQuaid, Christopher D, Teske, Peter R
- Authors: Mmonwa, Kolobe L , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444784 , vital:74298 , https://doi.org/10.1111/jpy.13182
- Description: Most intertidal algae have limited dispersal potential, and areas that lack hard substratum suitable for attachment are thus expected to isolate regional populations from each other. Here, we used nuclear and mitochondrial genetic data to compare genetic structure in two co‐distributed intertidal red algae with different dispersal potential along the South African coastline. Gelidium pristoides is divided into a south‐eastern and a south‐western evolutionary lineage separated by extensive, continuous sandy shoreline habitat adjacent to coastal dunefields. In contrast, Hypnea spicifera is genetically homogeneous throughout its range. In G. pristoides, the genetic breaks are associated with contemporary coastal dunefields. The age of the divergence event suggests that this may reflect the effect of older dispersal barriers, and that genetic structure was subsequently maintained by the formation of contemporary coastal dunefields.
- Full Text:
- Date Issued: 2021
- Authors: Mmonwa, Kolobe L , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444784 , vital:74298 , https://doi.org/10.1111/jpy.13182
- Description: Most intertidal algae have limited dispersal potential, and areas that lack hard substratum suitable for attachment are thus expected to isolate regional populations from each other. Here, we used nuclear and mitochondrial genetic data to compare genetic structure in two co‐distributed intertidal red algae with different dispersal potential along the South African coastline. Gelidium pristoides is divided into a south‐eastern and a south‐western evolutionary lineage separated by extensive, continuous sandy shoreline habitat adjacent to coastal dunefields. In contrast, Hypnea spicifera is genetically homogeneous throughout its range. In G. pristoides, the genetic breaks are associated with contemporary coastal dunefields. The age of the divergence event suggests that this may reflect the effect of older dispersal barriers, and that genetic structure was subsequently maintained by the formation of contemporary coastal dunefields.
- Full Text:
- Date Issued: 2021
Coastal pH variability and the eco-physiological and behavioural response of a coastal fish species in light of future ocean acidification
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
- Full Text:
- Date Issued: 2021
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
- Full Text:
- Date Issued: 2021