Aza boron-pyridyl-isoindoline analogues
- Zhang, Hui, Wu, Yanping, Fan, Minhui, Xiao, Xuqiong, Mack, John, Kubheka, Gugu, Nyokong, Tebello, Lu, Hua
- Authors: Zhang, Hui , Wu, Yanping , Fan, Minhui , Xiao, Xuqiong , Mack, John , Kubheka, Gugu , Nyokong, Tebello , Lu, Hua
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232912 , vital:50037 , xlink:href="https://doi.org/10.1039/C7NJ00707H"
- Description: Several aza boron-pyridyl-isoindoline analogues are synthesized through a facile and scale-up two step reaction using 1,2-naphthalenedicarbonitrile as a starting material. These analogues show broad envelopes of intense vibrational bands in the absorption spectra with moderate fluorescence quantum yields in solution and the solid-state. An analysis of the structure–property relationships is described based on X-ray crystallography, optical spectroscopy, and theoretical calculations.
- Full Text:
- Date Issued: 2017
- Authors: Zhang, Hui , Wu, Yanping , Fan, Minhui , Xiao, Xuqiong , Mack, John , Kubheka, Gugu , Nyokong, Tebello , Lu, Hua
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232912 , vital:50037 , xlink:href="https://doi.org/10.1039/C7NJ00707H"
- Description: Several aza boron-pyridyl-isoindoline analogues are synthesized through a facile and scale-up two step reaction using 1,2-naphthalenedicarbonitrile as a starting material. These analogues show broad envelopes of intense vibrational bands in the absorption spectra with moderate fluorescence quantum yields in solution and the solid-state. An analysis of the structure–property relationships is described based on X-ray crystallography, optical spectroscopy, and theoretical calculations.
- Full Text:
- Date Issued: 2017
Enantioselective electrochemical carbon-chloride bond cleavage of hexachlorocyclohexanes (HCHs) catalyzed by Mn (III) Cl-phthalocyanine
- Wen, Junxia, Yu, Baoqui, Huang, Tingting, Mack, John, Wildervanck, Martijn, Nyokong, Tebello, Li, Minzhi, Zhu, Weihua, Liang, Xu
- Authors: Wen, Junxia , Yu, Baoqui , Huang, Tingting , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189252 , vital:44831 , xlink:href="https://doi.org/10.1016/j.jelechem.2017.09.020"
- Description: A lipophilic and electron-rich metallophthalocyanine Mn(III)Cl(α,α′-n-OC5H11)8Pc has been synthesized and characterized. A series of electrochemical experiments demonstrate that the Mn(III)Cl(α,α′-n-OC5H11)8Pc complex can be used as a catalyst for highly efficient carbon-chloride bond cleavage of environmental toxic hexachlorocyclohexanes (HCHs) through electrochemical catalysis, and that the increased catalytic efficiency is related to the enantiomeric carbon-chloride σ-bond of HCHs.
- Full Text:
- Date Issued: 2017
- Authors: Wen, Junxia , Yu, Baoqui , Huang, Tingting , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189252 , vital:44831 , xlink:href="https://doi.org/10.1016/j.jelechem.2017.09.020"
- Description: A lipophilic and electron-rich metallophthalocyanine Mn(III)Cl(α,α′-n-OC5H11)8Pc has been synthesized and characterized. A series of electrochemical experiments demonstrate that the Mn(III)Cl(α,α′-n-OC5H11)8Pc complex can be used as a catalyst for highly efficient carbon-chloride bond cleavage of environmental toxic hexachlorocyclohexanes (HCHs) through electrochemical catalysis, and that the increased catalytic efficiency is related to the enantiomeric carbon-chloride σ-bond of HCHs.
- Full Text:
- Date Issued: 2017
Characterization of conjugates of NaYF4
- Watkins, Zane, Uddin, Imran, Britton, Jonathan, Nyokong, Tebello
- Authors: Watkins, Zane , Uddin, Imran , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/238132 , vital:50589 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.10.011"
- Description: NaYF4:Er/Yb/Gd upconversion nanoparticles (UCNP) capped with amino groups were covalently attached to chloro aluminium tetrasulphonated phthalocyanine (ClAlTSPc) and chloro aluminium tetracarboxy phthalocyanine (ClAlTCPc). The conjugates were characterized using different techniques such as infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). There was a decrease in the intensity of fluorescence emission spectra of the UCNPs at 658 nm in the presence of the phthalocyanines. This decrease indicates an energy transfer between the donor UCNP and conjugated accepting phthalocyanine (Pc), due to Förster resonance energy transfer (FRET). FRET efficiencies of 18% and 21% for ClAlTSPc and ClAlTCPc, respectively, were obtained. Oxygen generation by ClAlTSPc following FRET was proved.
- Full Text:
- Date Issued: 2017
- Authors: Watkins, Zane , Uddin, Imran , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/238132 , vital:50589 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.10.011"
- Description: NaYF4:Er/Yb/Gd upconversion nanoparticles (UCNP) capped with amino groups were covalently attached to chloro aluminium tetrasulphonated phthalocyanine (ClAlTSPc) and chloro aluminium tetracarboxy phthalocyanine (ClAlTCPc). The conjugates were characterized using different techniques such as infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). There was a decrease in the intensity of fluorescence emission spectra of the UCNPs at 658 nm in the presence of the phthalocyanines. This decrease indicates an energy transfer between the donor UCNP and conjugated accepting phthalocyanine (Pc), due to Förster resonance energy transfer (FRET). FRET efficiencies of 18% and 21% for ClAlTSPc and ClAlTCPc, respectively, were obtained. Oxygen generation by ClAlTSPc following FRET was proved.
- Full Text:
- Date Issued: 2017
Academy of Pharmaceutical Sciences
- Authors: Walker, Roderick B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184768 , vital:44270 , xlink:href="https://hdl.handle.net/10520/EJC-98c37d47c"
- Description: It is an honour and a pleasure to report on the activities of the Academy of Pharmaceutical Sciences since the PSSA AGM in 2016. The Academy of Pharmaceutical Sciences of the Pharmaceutical Society of South Africa (APSSA) held their 37th Annual Conference and 38th Annual General Meeting at the All African Congress on Pharmacology and Pharmacy. The conference was jointly organised by the Academy of Pharmaceutical Sciences of South Africa (APSSA), the South African Society for Basic and Clinical Pharmacology (SASBCP) on behalf of Pharmacology for Africa (Pharfa) and the Toxicology Society of South Africa (ToxSA). The annual APSSA conference was hosted by the Department of Pharmaceutical Sciences, Tshwane University of Technology under the leadership of Dr Ilze Vermaak and was held from 5-8 October 2016 at Misty Hills Conference Centre, situated close to the Cradle of Humankind.
- Full Text:
- Date Issued: 2017
- Authors: Walker, Roderick B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184768 , vital:44270 , xlink:href="https://hdl.handle.net/10520/EJC-98c37d47c"
- Description: It is an honour and a pleasure to report on the activities of the Academy of Pharmaceutical Sciences since the PSSA AGM in 2016. The Academy of Pharmaceutical Sciences of the Pharmaceutical Society of South Africa (APSSA) held their 37th Annual Conference and 38th Annual General Meeting at the All African Congress on Pharmacology and Pharmacy. The conference was jointly organised by the Academy of Pharmaceutical Sciences of South Africa (APSSA), the South African Society for Basic and Clinical Pharmacology (SASBCP) on behalf of Pharmacology for Africa (Pharfa) and the Toxicology Society of South Africa (ToxSA). The annual APSSA conference was hosted by the Department of Pharmaceutical Sciences, Tshwane University of Technology under the leadership of Dr Ilze Vermaak and was held from 5-8 October 2016 at Misty Hills Conference Centre, situated close to the Cradle of Humankind.
- Full Text:
- Date Issued: 2017
Investigation on the nature of records management in the office of the Premier Supply Chain management
- Authors: Vakalisa, Ndileka
- Date: 2017
- Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27606 , vital:69319
- Description: The purpose of the study was to investigate on the nature of records management in the office of the Premier Supply Chain Management. This study focuses on the Supply Chain Unit in the office of the Premier in the Eastern Cape Province of South Africa. The study sought to investigate the classification systems in place that is records management policy, procedure manual and file plans. The legal framework that regulates archives. Data was collected using open-ended questionnaire. The target population of this study included all the officials within the Office of the Premier. The sample of 15 was derived from the supply chain management officials, records management managers and directors. The study adopted a qualitative research methodology, which is multimethod in its orientation, which involves an interpretative, naturalistic emphasis to its subject issue. Findings from the study revealed that the unit had its internal records management policy, an official framework document that outlined the processes involved in organising records within the department. Thus, there are policy frameworks within the department even though not clearly described to other employees, which might lead to risks in the management of records. The study also revealed that most records personnel were not trained to effectively manage records. It was also indicated that there is a lack of proper filing system and or electronic records management system. Hence, for effective and efficient records management, the study recommends the creation of a web-based integrated system for communication and where records can be accessed within one system. The study also recommends proper training of records personnel to mitigate risks. Hence, the study recommends that senior management create and implement a records management program that clearly outlines the procedures of records management, risks factors and how to minimize them. This will aide in good practice, uniformity, standardization, high levels of professionalism, accountability, and transparency. , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2017
- Full Text:
- Date Issued: 2017
- Authors: Vakalisa, Ndileka
- Date: 2017
- Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27606 , vital:69319
- Description: The purpose of the study was to investigate on the nature of records management in the office of the Premier Supply Chain Management. This study focuses on the Supply Chain Unit in the office of the Premier in the Eastern Cape Province of South Africa. The study sought to investigate the classification systems in place that is records management policy, procedure manual and file plans. The legal framework that regulates archives. Data was collected using open-ended questionnaire. The target population of this study included all the officials within the Office of the Premier. The sample of 15 was derived from the supply chain management officials, records management managers and directors. The study adopted a qualitative research methodology, which is multimethod in its orientation, which involves an interpretative, naturalistic emphasis to its subject issue. Findings from the study revealed that the unit had its internal records management policy, an official framework document that outlined the processes involved in organising records within the department. Thus, there are policy frameworks within the department even though not clearly described to other employees, which might lead to risks in the management of records. The study also revealed that most records personnel were not trained to effectively manage records. It was also indicated that there is a lack of proper filing system and or electronic records management system. Hence, for effective and efficient records management, the study recommends the creation of a web-based integrated system for communication and where records can be accessed within one system. The study also recommends proper training of records personnel to mitigate risks. Hence, the study recommends that senior management create and implement a records management program that clearly outlines the procedures of records management, risks factors and how to minimize them. This will aide in good practice, uniformity, standardization, high levels of professionalism, accountability, and transparency. , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2017
- Full Text:
- Date Issued: 2017
Comparative fish ecology in three periodically connected rivers in the upper Zambezi and Okavango ecoregions
- Authors: Taylor, Geraldine Claire
- Date: 2017
- Subjects: Fishes Ecology Zambia Zambezi District , Floodplain ecology Zambia Zambezi District , Stable isotopes , Fishes Food Zambia Zambezi District , Fishes Mortality Zambia Zambezi District , Fish populations Zambia Zambezi District , Fishes Growth
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/65055 , vital:28660 , DOI https://doi.org/10.21504/10962/65055
- Description: The Upper Zambezi, Kavango and Kwando rivers are three periodically interlinked floodplain rivers which share the same Upper Zambezian floodplain ichthyofauna. The aim of this thesis was to compare the biology and ecology of the fish communities in these three rivers. The objective was to test the hypothesis that fish community composition and assemblage structure, fish diets, food web structure and trophic dynamics, fish growth rates and total mortality are influenced by the differing flood magnitudes of the three rivers, in support of the flood pulse concept. To understand the abiotic characteristics of each river, water temperature, flood regime, total dissolved inorganic nitrogen concentrations and water quality parameters were measured and compared between rivers. Water temperatures varied seasonally, and seven day moving averages peaked above 30 °C in January, and fell to between 16 and 19 °C in June. The Zambezi River had the largest flood (6.14 m), followed by the Kavango River (3.80 m), while the Kwando River had the smallest flood (0.65 m). Total dissolved inorganic nitrogen concentrations were low in the Kavango and Zambezi Rivers (0.2 - 0.6 mg/l), and slightly higher in the Kwando River (<1 mg/l). Conductivity, total dissolved solids and total dissolved inorganic nitrogen concentrations decreased with the flood (dilution effect). Using biomass catch per unit effort data from experimental gillnets, fish community composition and assemblage structure was described, and differed between rivers in all hydrological seasons. In the Zambezi and Kavango rivers, fish assemblages varied with hydrological season as a result of the homogenising influence of the flood pulse, while in the Kwando River fish assemblages did not differ seasonally as flood pulses were small and often irregular. Differences in community composition were attributed to the abundance of Hydrocynus vittatus, a large bodied open water predator, in the Zambezi and Kavango rivers, and its relative absence in the Kwando River. Based on the results of the community composition, six focus species were chosen that were abundant and representative of the various feeding modes and life history strategies of the fish community. These were the striped robber Brycinus lateralis, sharptooth catfish Clarias gariepinus, blunttooth catfish Clarias ngamensis, African pike Hepsetus cuvieri, silver catfish Schilbe intermedius and purpleface largemouth Serranochromis macrocephalus. Stomach contents analysis was then used to compare the feeding ecology of the six example species between rivers. Clarias gariepinus, C. ngamensis and S. intermedius were piscivorous in the Zambezi and Kavango rivers, and preyed upon more invertebrates in the Kwando River, while Hepsetus cuvieri and S. macrocephalus were piscivorous in all three rivers. Differences in diets were attributed to seasonal prey abundance, with prey fishes abundant during falling and low water when the Zambezi and Kavango rivers were sampled, while invertebrates were abundant during rising and high water when the Kwando River was sampled. Prey mastication by B. lateralis made prey identification difficult. For other predators, the usefulness of stomach contents analysis for dietary descriptions was restricted by the high proportion of empty stomachs. As a result, whole ecosystem stable isotope analysis was used to gain a holistic understanding of the food web structure and fish feeding ecology of the three rivers. The Zambezi and Kavango river food webs were supported by C enriched resources such as C4 and C3 riparian vegetation from the floodplain, while the Kwando River food web was based on C depleted resources such as filamentous algae and aquatic macrophytes. The Zambezi River food web had a restricted nitrogen range, with reduced food chain length and the predators in this river did not occupy such elevated trophic positions compared to in the Kavango and Kwando river food webs. This was attributed to the overfishing of the primary and tertiary consumers in the Zambezi River, a phenomenon known to reduce food chain length. Focussing on predator communities, in the Zambezi and Kavango rivers, H. vittatus isotopic niche width was large and overlapped significantly with most other predators, while in the Kwando River predator niches were more distinct. This supported previously proposed hypotheses by describing H. vittatus as a dominant predator which excludes all other fishes by predation or competition. Despite the dominance of H. vittatus, C. gariepinus occupied the position of top predator in all three rivers, and information on the habitat use, feeding habits and trophic niches of the serranochromine cichlids added understanding of their ecology. Lastly, age was determined using sectioned sagittal otoliths for C. gariepinus, C. ngamensis, S. intermedius and S. macrocephalus and using whole asteriscus otoliths for B. lateralis and H. cuvieri, and growth was modelled using the von Bertalanffy growth equation. Growth performance was high in the Zambezi and Kavango rivers, and lower in the Kwando River, most likely in response to the varying flood magnitudes. Total mortality rates, estimated using Hoenig’s maximum-age based equation, were high in the Zambezi River as a result of the high fishing pressure on this river. Overall floodplain fish ecology in the Zambezi, Kavango and Kwando rivers was influenced by the flood pulse, as was predicted by the flood pulse concept. Periodic and equilibrium life history strategists were found to adapt either to the pulsing environments of the Zambezi and Kavango rivers, or to the more stable environment of the Kwando River, and large bodied, long lived periodic strategists such as C. gariepinus tended to be highly plastic and able to thrive in most conditions. Data also suggested that Zambezi River food web structure and fish mortality rates have been impacted by overfishing, for which more information is needed to conserve and manage this system. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2018
- Full Text:
- Date Issued: 2017
- Authors: Taylor, Geraldine Claire
- Date: 2017
- Subjects: Fishes Ecology Zambia Zambezi District , Floodplain ecology Zambia Zambezi District , Stable isotopes , Fishes Food Zambia Zambezi District , Fishes Mortality Zambia Zambezi District , Fish populations Zambia Zambezi District , Fishes Growth
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/65055 , vital:28660 , DOI https://doi.org/10.21504/10962/65055
- Description: The Upper Zambezi, Kavango and Kwando rivers are three periodically interlinked floodplain rivers which share the same Upper Zambezian floodplain ichthyofauna. The aim of this thesis was to compare the biology and ecology of the fish communities in these three rivers. The objective was to test the hypothesis that fish community composition and assemblage structure, fish diets, food web structure and trophic dynamics, fish growth rates and total mortality are influenced by the differing flood magnitudes of the three rivers, in support of the flood pulse concept. To understand the abiotic characteristics of each river, water temperature, flood regime, total dissolved inorganic nitrogen concentrations and water quality parameters were measured and compared between rivers. Water temperatures varied seasonally, and seven day moving averages peaked above 30 °C in January, and fell to between 16 and 19 °C in June. The Zambezi River had the largest flood (6.14 m), followed by the Kavango River (3.80 m), while the Kwando River had the smallest flood (0.65 m). Total dissolved inorganic nitrogen concentrations were low in the Kavango and Zambezi Rivers (0.2 - 0.6 mg/l), and slightly higher in the Kwando River (<1 mg/l). Conductivity, total dissolved solids and total dissolved inorganic nitrogen concentrations decreased with the flood (dilution effect). Using biomass catch per unit effort data from experimental gillnets, fish community composition and assemblage structure was described, and differed between rivers in all hydrological seasons. In the Zambezi and Kavango rivers, fish assemblages varied with hydrological season as a result of the homogenising influence of the flood pulse, while in the Kwando River fish assemblages did not differ seasonally as flood pulses were small and often irregular. Differences in community composition were attributed to the abundance of Hydrocynus vittatus, a large bodied open water predator, in the Zambezi and Kavango rivers, and its relative absence in the Kwando River. Based on the results of the community composition, six focus species were chosen that were abundant and representative of the various feeding modes and life history strategies of the fish community. These were the striped robber Brycinus lateralis, sharptooth catfish Clarias gariepinus, blunttooth catfish Clarias ngamensis, African pike Hepsetus cuvieri, silver catfish Schilbe intermedius and purpleface largemouth Serranochromis macrocephalus. Stomach contents analysis was then used to compare the feeding ecology of the six example species between rivers. Clarias gariepinus, C. ngamensis and S. intermedius were piscivorous in the Zambezi and Kavango rivers, and preyed upon more invertebrates in the Kwando River, while Hepsetus cuvieri and S. macrocephalus were piscivorous in all three rivers. Differences in diets were attributed to seasonal prey abundance, with prey fishes abundant during falling and low water when the Zambezi and Kavango rivers were sampled, while invertebrates were abundant during rising and high water when the Kwando River was sampled. Prey mastication by B. lateralis made prey identification difficult. For other predators, the usefulness of stomach contents analysis for dietary descriptions was restricted by the high proportion of empty stomachs. As a result, whole ecosystem stable isotope analysis was used to gain a holistic understanding of the food web structure and fish feeding ecology of the three rivers. The Zambezi and Kavango river food webs were supported by C enriched resources such as C4 and C3 riparian vegetation from the floodplain, while the Kwando River food web was based on C depleted resources such as filamentous algae and aquatic macrophytes. The Zambezi River food web had a restricted nitrogen range, with reduced food chain length and the predators in this river did not occupy such elevated trophic positions compared to in the Kavango and Kwando river food webs. This was attributed to the overfishing of the primary and tertiary consumers in the Zambezi River, a phenomenon known to reduce food chain length. Focussing on predator communities, in the Zambezi and Kavango rivers, H. vittatus isotopic niche width was large and overlapped significantly with most other predators, while in the Kwando River predator niches were more distinct. This supported previously proposed hypotheses by describing H. vittatus as a dominant predator which excludes all other fishes by predation or competition. Despite the dominance of H. vittatus, C. gariepinus occupied the position of top predator in all three rivers, and information on the habitat use, feeding habits and trophic niches of the serranochromine cichlids added understanding of their ecology. Lastly, age was determined using sectioned sagittal otoliths for C. gariepinus, C. ngamensis, S. intermedius and S. macrocephalus and using whole asteriscus otoliths for B. lateralis and H. cuvieri, and growth was modelled using the von Bertalanffy growth equation. Growth performance was high in the Zambezi and Kavango rivers, and lower in the Kwando River, most likely in response to the varying flood magnitudes. Total mortality rates, estimated using Hoenig’s maximum-age based equation, were high in the Zambezi River as a result of the high fishing pressure on this river. Overall floodplain fish ecology in the Zambezi, Kavango and Kwando rivers was influenced by the flood pulse, as was predicted by the flood pulse concept. Periodic and equilibrium life history strategists were found to adapt either to the pulsing environments of the Zambezi and Kavango rivers, or to the more stable environment of the Kwando River, and large bodied, long lived periodic strategists such as C. gariepinus tended to be highly plastic and able to thrive in most conditions. Data also suggested that Zambezi River food web structure and fish mortality rates have been impacted by overfishing, for which more information is needed to conserve and manage this system. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2018
- Full Text:
- Date Issued: 2017
Predicting the risk of non-target damage to a close relative of a target weed using sequential no-choice tests, paired-choice tests and olfactory discrimination experiments
- Sutton, Guy F, Paterson, Iain D, Compton, Stephen G, Paynter, Quentin
- Authors: Sutton, Guy F , Paterson, Iain D , Compton, Stephen G , Paynter, Quentin
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417511 , vital:71459 , xlink:href="https://doi.org/10.1080/09583157.2015.1118615"
- Description: We investigated host-plant utilisation by the candidate biocontrol agent Paradibolia coerulea (Coleoptera: Chrysomelidae) on the target plant Spathodea campanulata Beauv. (Bignoniaceae) and a closely related non-target plant, Kigelia africana (Lam.) Benth. (Bignoniaceae). Paired-choice and sequential no-choice experiments were performed and coupled with olfactory discrimination experiments to test the insects’ responses to volatiles from both plant species as well as to cues from conspecific beetles. Although K. africana was utilised by P. coerulea, S. campanulata was preferred for both adult feeding and oviposition. Interestingly, whereas females were attracted to olfactory cues emitted by S. campanulata, males demonstrated no such olfactory discrimination. Females were also attracted to cues deposited by males, and males were deterred by cues from other males, but neither sex responded to female olfactory cues. Very few eggs were recorded on K. africana and none of the larvae that hatched on K. africana survived the first instar. Both S. campanulata and K. africana are suitable for adult feeding, but persistent utilisation of K. africana in the field is unlikely because larval development is only possible on S. campanulata and because the adult females are strongly attracted to volatiles emitted by the target plant. Nevertheless, if P. coerulea is released as a biocontrol agent, spill-over adult feeding could potentially occur on K. africana growing sympatrically with S. campanulata. Because P. coerulea cannot complete its development on K. africana, non-target damage will only occur where the target plant is present, with an intensity dependent on densities of adult beetles locally.
- Full Text:
- Date Issued: 2017
- Authors: Sutton, Guy F , Paterson, Iain D , Compton, Stephen G , Paynter, Quentin
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417511 , vital:71459 , xlink:href="https://doi.org/10.1080/09583157.2015.1118615"
- Description: We investigated host-plant utilisation by the candidate biocontrol agent Paradibolia coerulea (Coleoptera: Chrysomelidae) on the target plant Spathodea campanulata Beauv. (Bignoniaceae) and a closely related non-target plant, Kigelia africana (Lam.) Benth. (Bignoniaceae). Paired-choice and sequential no-choice experiments were performed and coupled with olfactory discrimination experiments to test the insects’ responses to volatiles from both plant species as well as to cues from conspecific beetles. Although K. africana was utilised by P. coerulea, S. campanulata was preferred for both adult feeding and oviposition. Interestingly, whereas females were attracted to olfactory cues emitted by S. campanulata, males demonstrated no such olfactory discrimination. Females were also attracted to cues deposited by males, and males were deterred by cues from other males, but neither sex responded to female olfactory cues. Very few eggs were recorded on K. africana and none of the larvae that hatched on K. africana survived the first instar. Both S. campanulata and K. africana are suitable for adult feeding, but persistent utilisation of K. africana in the field is unlikely because larval development is only possible on S. campanulata and because the adult females are strongly attracted to volatiles emitted by the target plant. Nevertheless, if P. coerulea is released as a biocontrol agent, spill-over adult feeding could potentially occur on K. africana growing sympatrically with S. campanulata. Because P. coerulea cannot complete its development on K. africana, non-target damage will only occur where the target plant is present, with an intensity dependent on densities of adult beetles locally.
- Full Text:
- Date Issued: 2017
Genetic matching of invasive populations of the African tulip tree, Spathodea campanulata Beauv.(Bignoniaceae), to their native distribution: Maximising the likelihood of selecting host-compatible biological control agents
- Sutton, Guy F, Paterson, Iain D, Paynter, Quentin
- Authors: Sutton, Guy F , Paterson, Iain D , Paynter, Quentin
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405797 , vital:70207 , xlink:href="https://doi.org/10.1016/j.biocontrol.2017.08.015"
- Description: Spathodea campanulata Beauv (Bignoniaceae) has become a highly damaging environmental and agricultural weed in the Pacific Islands. It has been targeted for biological control due to the costly and inefficient nature of physical and chemical control methods. Determining the origin of weed populations has been increasingly recognised as an important component of successful biological control programmes, and may be important for the biological control of S. campanulata due to the high degree of morphological variability within the species, as well as the broad native distribution. Genetic matching, using inter-simple sequence repeats (ISSR’s), and morphological data found support for invasive Pacific Island S. campanulata plants originating from West Africa. Pacific and West African plants were genetically most similar, and were differentiated from native plants from East/Central Africa by PCA and Bayesian-clustering (STRUCTURE) analyses. Genetic data was corroborated by morphological data which showed that West African and Pacific Islands plants had more sparsely pubescent leaves compared to plants from East/Central Africa. Populations in South Africa, where the plant is introduced but not problematic, originated from a different source population than those in the Pacific Islands, probably in East/Central Africa. A greater sampling effort is required before the origin of the South African populations can be determined with certainty. Herbivores and pathogens for the Pacific Islands should be collected from West Africa as they are more likely to be compatible with S. campanulata plants in this region.
- Full Text:
- Date Issued: 2017
- Authors: Sutton, Guy F , Paterson, Iain D , Paynter, Quentin
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405797 , vital:70207 , xlink:href="https://doi.org/10.1016/j.biocontrol.2017.08.015"
- Description: Spathodea campanulata Beauv (Bignoniaceae) has become a highly damaging environmental and agricultural weed in the Pacific Islands. It has been targeted for biological control due to the costly and inefficient nature of physical and chemical control methods. Determining the origin of weed populations has been increasingly recognised as an important component of successful biological control programmes, and may be important for the biological control of S. campanulata due to the high degree of morphological variability within the species, as well as the broad native distribution. Genetic matching, using inter-simple sequence repeats (ISSR’s), and morphological data found support for invasive Pacific Island S. campanulata plants originating from West Africa. Pacific and West African plants were genetically most similar, and were differentiated from native plants from East/Central Africa by PCA and Bayesian-clustering (STRUCTURE) analyses. Genetic data was corroborated by morphological data which showed that West African and Pacific Islands plants had more sparsely pubescent leaves compared to plants from East/Central Africa. Populations in South Africa, where the plant is introduced but not problematic, originated from a different source population than those in the Pacific Islands, probably in East/Central Africa. A greater sampling effort is required before the origin of the South African populations can be determined with certainty. Herbivores and pathogens for the Pacific Islands should be collected from West Africa as they are more likely to be compatible with S. campanulata plants in this region.
- Full Text:
- Date Issued: 2017
Forest degradation and invasive species synergistically impact Mimusops andongensis (Sapotaceae) in Lama Forest Reserve, Benin
- Sinasson, Gisèle K, Shackleton, Charlie M, Glèlè Kakaï, Romain L, Sinsin, Brice
- Authors: Sinasson, Gisèle K , Shackleton, Charlie M , Glèlè Kakaï, Romain L , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182038 , vital:43792 , xlink:href="https://doi.org/10.1111/btp.12370"
- Description: Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non-degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long-term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata.
- Full Text:
- Date Issued: 2017
- Authors: Sinasson, Gisèle K , Shackleton, Charlie M , Glèlè Kakaï, Romain L , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182038 , vital:43792 , xlink:href="https://doi.org/10.1111/btp.12370"
- Description: Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non-degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long-term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata.
- Full Text:
- Date Issued: 2017
Local knowledge on the uses, habitat, and change in abundance of multipurpose mimusops species in Benin
- Sinasson Gisèle K, Shackleton, Charlie M, Assogbadjo, Achille E, Sinsin, Brice
- Authors: Sinasson Gisèle K , Shackleton, Charlie M , Assogbadjo, Achille E , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181105 , vital:43699 , xlink:href="https://doi.org/10.1007/s12231-017-9370-6"
- Description: Multipurpose NTFP species typically experience higher harvest demand because of their multiple uses, which, when combined with unsustainable land use practices, may threaten population viability. We assessed local knowledge on the uses, habitat, and population status of Mimusops andongensis and Mimusops kummel, both multipurpose NTFP species in Benin, to promote their valorization and conservation and thus sustain local knowledge on their uses for domestication issues. One hundred households were randomly selected for structured interviews for M. andongensis and 500 for M. kummel. The relationship between age, sex, and ethnic groups and the species uses was assessed using comparison and correspondence analyses. Nearly all organs of the species were used. Both species were mainly exploited for medicinal purposes but also in construction and as firewood. We found similarities in some uses of the species organs, although the species occur in different ecological zones and are used by different ethnic groups. This result should be considered for the valorization of the species. Most informants reported that populations of M. andongensis were decreasing, although some felt that they were increasing, whereas less than one-third said that M. kummel was decreasing. There were strong relationships between gender, age, and ethnic affiliation of the users and the exploited organs of both species. Potential uses exist based on both the past and current uses of the species and in comparison to other countries where they are exploited. Local ethnoecological knowledge and practices will help to valorize and conserve the species. However, further research on the species’ seed germination and propagation ability are also necessary.
- Full Text:
- Date Issued: 2017
- Authors: Sinasson Gisèle K , Shackleton, Charlie M , Assogbadjo, Achille E , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181105 , vital:43699 , xlink:href="https://doi.org/10.1007/s12231-017-9370-6"
- Description: Multipurpose NTFP species typically experience higher harvest demand because of their multiple uses, which, when combined with unsustainable land use practices, may threaten population viability. We assessed local knowledge on the uses, habitat, and population status of Mimusops andongensis and Mimusops kummel, both multipurpose NTFP species in Benin, to promote their valorization and conservation and thus sustain local knowledge on their uses for domestication issues. One hundred households were randomly selected for structured interviews for M. andongensis and 500 for M. kummel. The relationship between age, sex, and ethnic groups and the species uses was assessed using comparison and correspondence analyses. Nearly all organs of the species were used. Both species were mainly exploited for medicinal purposes but also in construction and as firewood. We found similarities in some uses of the species organs, although the species occur in different ecological zones and are used by different ethnic groups. This result should be considered for the valorization of the species. Most informants reported that populations of M. andongensis were decreasing, although some felt that they were increasing, whereas less than one-third said that M. kummel was decreasing. There were strong relationships between gender, age, and ethnic affiliation of the users and the exploited organs of both species. Potential uses exist based on both the past and current uses of the species and in comparison to other countries where they are exploited. Local ethnoecological knowledge and practices will help to valorize and conserve the species. However, further research on the species’ seed germination and propagation ability are also necessary.
- Full Text:
- Date Issued: 2017
We’re talking about semantics here: Axiological condensation in the South African parliament
- Siebörger, Ian, Adendorff, Ralph D
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385389 , vital:68015 , xlink:href="https://doi.org/10.1075/fol.24.2.03sie"
- Description: This article describes how procedural knowledge is produced in a meeting of the South African parliament’s Portfolio Committee on Transport, using concepts from Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). Members of this committee argue over whether or not to amend a draft committee report and in the process co-construct procedural norms for future committee meetings. Participants on both sides of the argument use axiological condensation, in which actions and ideas are associated with each other and charged with a particular moral or affective value ( Maton 2014 : 130) to portray their version of the procedure to be followed as morally superior to that of their opponents. They also use axiological rarefaction ( Maton 2014 : 130) to reinforce their positions by making apparent concessions to those on the other side of the argument. This is revealed through an analysis of the coupling of ideation and Appraisal ( Martin 2000 : 161) in the logogenetic unfolding of members’ talk, combined with elements of Interactional Sociolinguistics ( Gumperz 1982 ). The analysis suggests that axiological condensation and rarefaction in this meeting reflect competing visions of what it means to be ‘pro-democracy’ in post-apartheid South Africa.
- Full Text:
- Date Issued: 2017
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385389 , vital:68015 , xlink:href="https://doi.org/10.1075/fol.24.2.03sie"
- Description: This article describes how procedural knowledge is produced in a meeting of the South African parliament’s Portfolio Committee on Transport, using concepts from Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). Members of this committee argue over whether or not to amend a draft committee report and in the process co-construct procedural norms for future committee meetings. Participants on both sides of the argument use axiological condensation, in which actions and ideas are associated with each other and charged with a particular moral or affective value ( Maton 2014 : 130) to portray their version of the procedure to be followed as morally superior to that of their opponents. They also use axiological rarefaction ( Maton 2014 : 130) to reinforce their positions by making apparent concessions to those on the other side of the argument. This is revealed through an analysis of the coupling of ideation and Appraisal ( Martin 2000 : 161) in the logogenetic unfolding of members’ talk, combined with elements of Interactional Sociolinguistics ( Gumperz 1982 ). The analysis suggests that axiological condensation and rarefaction in this meeting reflect competing visions of what it means to be ‘pro-democracy’ in post-apartheid South Africa.
- Full Text:
- Date Issued: 2017
Electrocatalytic application for gold nanoparticles decorated sulfur-nitrogen co-doped graphene oxide nanosheets and nanosized cobalt tetra aminophenoxy phthalocyanine conjugates
- Shumba, Munyaradzi S, Nyokong, Tebello
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188260 , vital:44739 , xlink:href="https://doi.org/10.1016/j.electacta.2017.03.154"
- Description: Sulfur and nitrogen affinity for gold is utilized to self-assemble gold nanorods (AuNRs) on S, N doped or S/N co-doped graphene oxide nanosheets (SGONS/AuNRs, NGONS/AuNRs or SNGONS/AuNRs) for enhancement of the electrocatalytic activity of nanosized cobalt tetra aminophenoxy phthalocyanine (complex 1) towards hydrogen peroxide detection. Of the electrodes containing AuNRs, 1-SNGONS/AuNRs-GCE gave the lowest limits of detection (LOD) of 0.012 μM followed by 1-SGONS/AuNRs-GCE and 1-AuNRs-SNGONS(seq)-GCE both with LOD of 0.016 μM. This work shows that in the absence of GONS (when AuNRs are alone and in the presence of 1 in 1/AuNRs-GCE), unfavorable detection limits are obtained and that doping of GONS is important in improving LOD. 1-SNGONS/AuNRs-GCE showed concentration dependent mechanisms resulting in two adsorption Gibbs energies (ΔGo) of −18.55 kJ mol−1 and −17.35 kJ mol−1 at high and low concentrations, respectively.
- Full Text:
- Date Issued: 2017
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188260 , vital:44739 , xlink:href="https://doi.org/10.1016/j.electacta.2017.03.154"
- Description: Sulfur and nitrogen affinity for gold is utilized to self-assemble gold nanorods (AuNRs) on S, N doped or S/N co-doped graphene oxide nanosheets (SGONS/AuNRs, NGONS/AuNRs or SNGONS/AuNRs) for enhancement of the electrocatalytic activity of nanosized cobalt tetra aminophenoxy phthalocyanine (complex 1) towards hydrogen peroxide detection. Of the electrodes containing AuNRs, 1-SNGONS/AuNRs-GCE gave the lowest limits of detection (LOD) of 0.012 μM followed by 1-SGONS/AuNRs-GCE and 1-AuNRs-SNGONS(seq)-GCE both with LOD of 0.016 μM. This work shows that in the absence of GONS (when AuNRs are alone and in the presence of 1 in 1/AuNRs-GCE), unfavorable detection limits are obtained and that doping of GONS is important in improving LOD. 1-SNGONS/AuNRs-GCE showed concentration dependent mechanisms resulting in two adsorption Gibbs energies (ΔGo) of −18.55 kJ mol−1 and −17.35 kJ mol−1 at high and low concentrations, respectively.
- Full Text:
- Date Issued: 2017
Effects of covalent versus non-covalent interactions on the electrocatalytic behavior of tetracarboxyphenoxyphthalocyanine in the presence of multi-walled carbon nanotubes
- Shumba, Munyaradzi S, Nyokong, Tebello
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188271 , vital:44740 , xlink:href="https://doi.org/10.1080/00958972.2017.1303679"
- Description: Tetracarboxyphenoxy phthalocyanine was covalently linked to multi-walled carbon nanotubes and the conjugate was used for modification of glassy carbon electrodes for the detection of hydrogen peroxide. The electrocatalytic behavior was examined by cyclic voltammetry, square wave voltammetry, and rotating disk electrode. The results show that covalent linking is attractive in terms of high detecting currents, low overpotential, and high catalytic rate constants. Very low detection limits were observed with CoTCPhPc-DAMN-MWCNT(linked)-GCE at 0.33 nM. The resulting catalytic rate constant was 1.1 × 103 M−1s−1.
- Full Text:
- Date Issued: 2017
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188271 , vital:44740 , xlink:href="https://doi.org/10.1080/00958972.2017.1303679"
- Description: Tetracarboxyphenoxy phthalocyanine was covalently linked to multi-walled carbon nanotubes and the conjugate was used for modification of glassy carbon electrodes for the detection of hydrogen peroxide. The electrocatalytic behavior was examined by cyclic voltammetry, square wave voltammetry, and rotating disk electrode. The results show that covalent linking is attractive in terms of high detecting currents, low overpotential, and high catalytic rate constants. Very low detection limits were observed with CoTCPhPc-DAMN-MWCNT(linked)-GCE at 0.33 nM. The resulting catalytic rate constant was 1.1 × 103 M−1s−1.
- Full Text:
- Date Issued: 2017
Nanocomposites of sulphur-nitrogen co-doped graphene oxide nanosheets and cobalt mono carboxyphenoxy phthalocyanines for facile electrocatalysis
- Shumba, Munyaradzi, Centane, Sixolile, Chindeka, Francis, Nyokong, Tebello
- Authors: Shumba, Munyaradzi , Centane, Sixolile , Chindeka, Francis , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239665 , vital:50753 , xlink:href="https://doi.org/10.1016/j.jelechem.2017.03.006"
- Description: Nanocomposites consisting of cobalt mono carboxyphenoxy phthalocyanine (CoMCPhPc) either covalently linked to graphene oxide nanosheets (GONS), sulphur doped graphene oxide nanosheets (SDGONS), nitrogen doped graphene oxide nanosheets (NDGONS) or sulphur/nitrogen co-doped graphene oxide nanosheets (SNDGONS) or sequentially added were used to modify glassy carbon electrode. The modified electrodes were characterised using several techniques: voltammetry, X-ray photon spectroscopy and scanning electron spectroscopy before testing their activity on the detection of hydrogen peroxide at pH 7. The presence of SNDGONS had a significant improvement on the currents as compared to CoMCPhPc modification alone in both sequentially added or covalently linked to MPcs. CoMCPhPc-SNDGONS(seq)-GCE and CoMCPhPc-SDGONS(linked)-GCE resulted in impressive limits of detection and catalytic rate constant values of 1.58 nM and 5.44 nM, 3.07 × 105 M−1 s−1 and 3.01 × 103 M−1 s−1 respectively. Gibbs energy value was determined to be −21.22 kJ mol−1 for CoMCPhPc-SNDGONS(linked)-GCE indicative of a facile spontaneous electroreduction reaction on the surface of this electrode.
- Full Text:
- Date Issued: 2017
- Authors: Shumba, Munyaradzi , Centane, Sixolile , Chindeka, Francis , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239665 , vital:50753 , xlink:href="https://doi.org/10.1016/j.jelechem.2017.03.006"
- Description: Nanocomposites consisting of cobalt mono carboxyphenoxy phthalocyanine (CoMCPhPc) either covalently linked to graphene oxide nanosheets (GONS), sulphur doped graphene oxide nanosheets (SDGONS), nitrogen doped graphene oxide nanosheets (NDGONS) or sulphur/nitrogen co-doped graphene oxide nanosheets (SNDGONS) or sequentially added were used to modify glassy carbon electrode. The modified electrodes were characterised using several techniques: voltammetry, X-ray photon spectroscopy and scanning electron spectroscopy before testing their activity on the detection of hydrogen peroxide at pH 7. The presence of SNDGONS had a significant improvement on the currents as compared to CoMCPhPc modification alone in both sequentially added or covalently linked to MPcs. CoMCPhPc-SNDGONS(seq)-GCE and CoMCPhPc-SDGONS(linked)-GCE resulted in impressive limits of detection and catalytic rate constant values of 1.58 nM and 5.44 nM, 3.07 × 105 M−1 s−1 and 3.01 × 103 M−1 s−1 respectively. Gibbs energy value was determined to be −21.22 kJ mol−1 for CoMCPhPc-SNDGONS(linked)-GCE indicative of a facile spontaneous electroreduction reaction on the surface of this electrode.
- Full Text:
- Date Issued: 2017
The effects of expansive shrubs on plant species richness and soils in semi-arid communal lands, South Africa
- Sholto-Douglas, Craig, Shackleton, Charlie M, Ruwanza, Sheunesu, Dold, Tony
- Authors: Sholto-Douglas, Craig , Shackleton, Charlie M , Ruwanza, Sheunesu , Dold, Tony
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398394 , vital:69408 , xlink:href="https://doi.org/10.1002/ldr.2745"
- Description: Expansion by expansive species can have severe ecological, social and economic impacts through the reduction of ecosystem goods and services and species richness. However, expansion by expansive species may also offer benefits to ecosystems and humans, through the supply of ecosystem goods and services (such as firewood, fodder and fruits), as well as potentially offering refugia in heavily used landscapes. Here, we examine the effects of four expansive dwarf shrub species (Aspalathus subtingens, Dicerothamnus rhinocerotis, Pteronia incana and Oedera genistifolia) on plant species richness (at the point scale), vegetation cover, soil properties and whether the expansive species offer refugia to other species. Plant species richness, cover and soil properties were recorded in 1-m2 quadrats located within a mosaic of expanded and non-expanded patches for the four expansive shrub species. Plant species richness was significantly higher in the non-expanded areas compared to the expanded ones for all four expansive species. Some of the expansive shrubs provided refugia to certain plant species and limited the frequency of other species. With regard to species composition, there was little separation of expanded and non-expanded samples within sites, indicating that the site factors were stronger determinants of plant species richness and composition than expansion. Therefore, it is more likely that the reduction in species richness in expanded sites is caused by multiple drivers, including vegetation attributes cover, litter cover and soil nutrients (organic C, Zn and P) and soil compaction.
- Full Text:
- Date Issued: 2017
- Authors: Sholto-Douglas, Craig , Shackleton, Charlie M , Ruwanza, Sheunesu , Dold, Tony
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398394 , vital:69408 , xlink:href="https://doi.org/10.1002/ldr.2745"
- Description: Expansion by expansive species can have severe ecological, social and economic impacts through the reduction of ecosystem goods and services and species richness. However, expansion by expansive species may also offer benefits to ecosystems and humans, through the supply of ecosystem goods and services (such as firewood, fodder and fruits), as well as potentially offering refugia in heavily used landscapes. Here, we examine the effects of four expansive dwarf shrub species (Aspalathus subtingens, Dicerothamnus rhinocerotis, Pteronia incana and Oedera genistifolia) on plant species richness (at the point scale), vegetation cover, soil properties and whether the expansive species offer refugia to other species. Plant species richness, cover and soil properties were recorded in 1-m2 quadrats located within a mosaic of expanded and non-expanded patches for the four expansive shrub species. Plant species richness was significantly higher in the non-expanded areas compared to the expanded ones for all four expansive species. Some of the expansive shrubs provided refugia to certain plant species and limited the frequency of other species. With regard to species composition, there was little separation of expanded and non-expanded samples within sites, indicating that the site factors were stronger determinants of plant species richness and composition than expansion. Therefore, it is more likely that the reduction in species richness in expanded sites is caused by multiple drivers, including vegetation attributes cover, litter cover and soil nutrients (organic C, Zn and P) and soil compaction.
- Full Text:
- Date Issued: 2017
How compatible are urban livestock and urban green spaces and trees?: An assessment in a medium-sized South African town
- Shackleton, Charlie M, Guild, Jenny, Bromham, B, Impey, S, Jarrett, Mitchell, Ngubane, S, Steijl, K
- Authors: Shackleton, Charlie M , Guild, Jenny , Bromham, B , Impey, S , Jarrett, Mitchell , Ngubane, S , Steijl, K
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181048 , vital:43694 , xlink:href="https://doi.org/10.1080/19463138.2017.1314968"
- Description: Urban green spaces and trees provide multiple benefits to urban residents and the sustainability of cities. A poorly examined benefit is the provision of fodder to urban livestock. However, the presence and activities of livestock may be incompatible with other uses, although this has been little studied. We examined the impacts of livestock on trees and parks along a gradient of declining livestock density, complemented with a tree planting experiment to monitor damage. Neighbouring residents and park managers were interviewed regarding their perceptions of damage caused by livestock. The negative impacts on soil compaction, tree damage and death increased with increasing livestock densities. Thorny tree species were damaged significantly less (13 %) than non-thorny species (77 %), as were protected trees (25 %) relative to unprotected ones (65 %). There was more tree damage in public green spaces (PUGS) (54 %) than control sites (38 %). The majority of local residents felt that livestock should not be allowed in formal PUGS, and most urban park managers regarded livestock damage as a strong disincentive to plant trees. These results show the need for management of the trade-offs caused by livestock and greater appreciation of livestock as agents shaping aspects of PUGS.
- Full Text:
- Date Issued: 2017
- Authors: Shackleton, Charlie M , Guild, Jenny , Bromham, B , Impey, S , Jarrett, Mitchell , Ngubane, S , Steijl, K
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181048 , vital:43694 , xlink:href="https://doi.org/10.1080/19463138.2017.1314968"
- Description: Urban green spaces and trees provide multiple benefits to urban residents and the sustainability of cities. A poorly examined benefit is the provision of fodder to urban livestock. However, the presence and activities of livestock may be incompatible with other uses, although this has been little studied. We examined the impacts of livestock on trees and parks along a gradient of declining livestock density, complemented with a tree planting experiment to monitor damage. Neighbouring residents and park managers were interviewed regarding their perceptions of damage caused by livestock. The negative impacts on soil compaction, tree damage and death increased with increasing livestock densities. Thorny tree species were damaged significantly less (13 %) than non-thorny species (77 %), as were protected trees (25 %) relative to unprotected ones (65 %). There was more tree damage in public green spaces (PUGS) (54 %) than control sites (38 %). The majority of local residents felt that livestock should not be allowed in formal PUGS, and most urban park managers regarded livestock damage as a strong disincentive to plant trees. These results show the need for management of the trade-offs caused by livestock and greater appreciation of livestock as agents shaping aspects of PUGS.
- Full Text:
- Date Issued: 2017
Household wealth status and natural resource use in the Kat River valley, South Africa
- Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181301 , vital:43717 , xlink:href="https://doi.org/10.1016/j.ecolecon.2005.04.011"
- Description: Much work has demonstrated the significant role and value of non-timber forest products (NTFPs) in the livelihoods of rural people in southern Africa and elsewhere. The findings provide a mean or composite picture, averaged across the sample households within each community. Yet, within any given community, there is significant socio-economic differentiation. It is important to acknowledge such differentiation when considering policy and management interventions to support rural livelihoods and promote sustainable resource use. This paper reports on a study in South Africa, the objective of which was to explore wealth-related differences and similarities in the use and value of NTFPs. Data on NTFP consumption, purchase, and sale were collected from households in three rural villages. Households were divided into three wealth classes and patterns of NTFPs use between the classes examined. There was no difference in the proportions of households in each wealth class using NTFPs, nor the total number of NTFPs used per household. Yet, there was some supporting evidence that poorer households derive greater benefits from NTFPs than do wealthy or intermediate households. One clear difference was that, with increasing wealth, households purchased significantly more NTFPs, and a greater proportion of wealthy households did so. Conversely, a greater proportion of poor households were involved in the sale of one or more NTFPs, and they sold a greater number per household, compared to wealthy and intermediate households. Detailed examination of use and value of four NTFPs (fuelwood, wild fruits, edible herbs, and grass hand brushes) revealed that in all instances, the poorest households used more of the resource per capita than the other wealth classes. This was not the case for comparisons based on the total household as the unit of analysis. Gross annual direct-use value did not differ between the wealth classes for any of the four NTFPs examined, at the household level. But on a per capita basis, a significantly higher gross annual direct-use value was evident within poorer households for fuelwood and edible herbs. The significance of these differences is discussed.
- Full Text:
- Date Issued: 2006
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181301 , vital:43717 , xlink:href="https://doi.org/10.1016/j.ecolecon.2005.04.011"
- Description: Much work has demonstrated the significant role and value of non-timber forest products (NTFPs) in the livelihoods of rural people in southern Africa and elsewhere. The findings provide a mean or composite picture, averaged across the sample households within each community. Yet, within any given community, there is significant socio-economic differentiation. It is important to acknowledge such differentiation when considering policy and management interventions to support rural livelihoods and promote sustainable resource use. This paper reports on a study in South Africa, the objective of which was to explore wealth-related differences and similarities in the use and value of NTFPs. Data on NTFP consumption, purchase, and sale were collected from households in three rural villages. Households were divided into three wealth classes and patterns of NTFPs use between the classes examined. There was no difference in the proportions of households in each wealth class using NTFPs, nor the total number of NTFPs used per household. Yet, there was some supporting evidence that poorer households derive greater benefits from NTFPs than do wealthy or intermediate households. One clear difference was that, with increasing wealth, households purchased significantly more NTFPs, and a greater proportion of wealthy households did so. Conversely, a greater proportion of poor households were involved in the sale of one or more NTFPs, and they sold a greater number per household, compared to wealthy and intermediate households. Detailed examination of use and value of four NTFPs (fuelwood, wild fruits, edible herbs, and grass hand brushes) revealed that in all instances, the poorest households used more of the resource per capita than the other wealth classes. This was not the case for comparisons based on the total household as the unit of analysis. Gross annual direct-use value did not differ between the wealth classes for any of the four NTFPs examined, at the household level. But on a per capita basis, a significantly higher gross annual direct-use value was evident within poorer households for fuelwood and edible herbs. The significance of these differences is discussed.
- Full Text:
- Date Issued: 2006
Impact of fire frequency on woody community structure and soil nutrients in the Kruger National Park
- Shackleton, Charlie M, Scholes, Robert J
- Authors: Shackleton, Charlie M , Scholes, Robert J
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181874 , vital:43776 , xlink:href="https://doi.org/10.4102/koedoe.v43i1.210"
- Description: Although fire is recognised as an important determinant of the structure and function of South African savannas, there are few studies of long-term impacts. Controlled burning blocks of contrasting fire season and frequency have been maintained throughout the Kruger National Park for almost 50 years. This paper reports on a quantitative study of the Satara plots to determine the long-term impacts of fire frequency on woody community structure and soil nutrients. Increasing fire frequency significantly decreased woody plant basal area, biomass, density, height, and mean stem circumference. The number of stems per plant and the proportion of regenerative stems increased with increasing fire frequency. Effects on species richness of woody plants were inconsistent. There were no significant differences attributable to fire frequency for any of the soil variables except organic matter and magnesium. Organic carbon was highest in the fire exclusion treatment and lowest in soils from plots burnt triennially. Magnesium levels were greatest in the annually burnt soils and least in the triennial plots.
- Full Text:
- Date Issued: 2000
Impact of fire frequency on woody community structure and soil nutrients in the Kruger National Park
- Authors: Shackleton, Charlie M , Scholes, Robert J
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181874 , vital:43776 , xlink:href="https://doi.org/10.4102/koedoe.v43i1.210"
- Description: Although fire is recognised as an important determinant of the structure and function of South African savannas, there are few studies of long-term impacts. Controlled burning blocks of contrasting fire season and frequency have been maintained throughout the Kruger National Park for almost 50 years. This paper reports on a quantitative study of the Satara plots to determine the long-term impacts of fire frequency on woody community structure and soil nutrients. Increasing fire frequency significantly decreased woody plant basal area, biomass, density, height, and mean stem circumference. The number of stems per plant and the proportion of regenerative stems increased with increasing fire frequency. Effects on species richness of woody plants were inconsistent. There were no significant differences attributable to fire frequency for any of the soil variables except organic matter and magnesium. Organic carbon was highest in the fire exclusion treatment and lowest in soils from plots burnt triennially. Magnesium levels were greatest in the annually burnt soils and least in the triennial plots.
- Full Text:
- Date Issued: 2000
The effects of rhizobium inoculation on growth performance, forage production, nutrient and anti-nutrient content of lablab purpureus cultivars
- Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Authors: Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Date: 2017
- Subjects: Livestock productivity , Rhizobium japonicum
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22864 , vital:53011
- Description: Declining soil fertility and inadequate low quality feed resources limit smallholder livestock production in the semi-arid regions of Eastern Cape in South Africa. Smallholder farmers are facing problems of high cost of artificial fertilisers limiting them in production of cereal crops and also fodder for their livestock. This leads to poor nutrition, particularly in the dry season, it affects livestock production. Planting Lablab purpureus and inoculating with Rhizobium would limit the necessity for buying expensive protein supplements and nitrogen fertilisers. Lablab purpureus can provide feed in the dry season for the improvement of livestock production. The objective of this study was to investigate the effect of Bradyrhizobium japonicum inoculation on growth performance, biomass production, nutrient and anti-nutrient content of the two Lablab purpureus cultivars (Rongai and Highworth). The experiment was conducted at Fort Hare Research Farm in Alice, South Africa. Data was collected on plant seedling emergence, plant height, stem diameter, plant vigour, chlorophyll content, nodule numbers as well as dry matter content, biomass yield, nutrient and anti-nutrient contents at 30, 60 and 90 DAP. Samples of Lablab purpureus were harvested at flowering stage and analysed for dry matter content, biomass yield, chemical, mineral and anti-ntrient composition. The results showed that Rhizobium inoculation significantly increased (p<0.05) seedling emergence, plant height and stem diameter of both Lablab purpureus cultivars. Rhizobium inoculation had no significant effect (p>0.05) on chlorophyll content for both cultivars. Highworth had significantly higher (p<0.05) plant vigour than Rongai on both inoculated and uninoculated. Varieties and inoculation effects were significant (p<0.05) for number of nodules, nodulation rate, active nodules and nodule dry yield. Rhizobium inoculation significantly (p<0.05) increased fresh matter yield, dry matter yied and dry matter content on both cultivars. There were no significant differences (p>0.05) in NDF, ADIN, ADL, ADF, and Na between inoculated and uninoculated plants for both cultivars. The inoculation of Rhizobium improved CP (15.65%) in Highworth cultivar. The inoculation of Rhizobium significantly increased Ca (1.76-1.84%), Zn (191.91-2 8.33ppm) and Cu (3.50-6.16ppm) compared to un-inoculated plants. Varieties and Rhizobium had no interaction (p>0.05) with condensed tannin, hydrolysable tannin, total polyphenols and saponins . Therefore, the Rhizobium inoculation assisted in improving quality in terms of nutrient composition and decreasing anti-nutrients. It is recommended to use both cultivars of Lablab purpureus. Based on the results of this study it is concluded that Rhizobium inoculation increases yield and forage quality of Lablab purpureus. It is recommended that Highworth cultivar can be used by communal farmers in the Eastern Cape. This cultivar showed that it needs Rhizobium inoculation inorder to produce high quality that can increase livestock production. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017
- Authors: Senti, Sibongile Portia https://orcid.org/0000-0003-4906-9570
- Date: 2017
- Subjects: Livestock productivity , Rhizobium japonicum
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22864 , vital:53011
- Description: Declining soil fertility and inadequate low quality feed resources limit smallholder livestock production in the semi-arid regions of Eastern Cape in South Africa. Smallholder farmers are facing problems of high cost of artificial fertilisers limiting them in production of cereal crops and also fodder for their livestock. This leads to poor nutrition, particularly in the dry season, it affects livestock production. Planting Lablab purpureus and inoculating with Rhizobium would limit the necessity for buying expensive protein supplements and nitrogen fertilisers. Lablab purpureus can provide feed in the dry season for the improvement of livestock production. The objective of this study was to investigate the effect of Bradyrhizobium japonicum inoculation on growth performance, biomass production, nutrient and anti-nutrient content of the two Lablab purpureus cultivars (Rongai and Highworth). The experiment was conducted at Fort Hare Research Farm in Alice, South Africa. Data was collected on plant seedling emergence, plant height, stem diameter, plant vigour, chlorophyll content, nodule numbers as well as dry matter content, biomass yield, nutrient and anti-nutrient contents at 30, 60 and 90 DAP. Samples of Lablab purpureus were harvested at flowering stage and analysed for dry matter content, biomass yield, chemical, mineral and anti-ntrient composition. The results showed that Rhizobium inoculation significantly increased (p<0.05) seedling emergence, plant height and stem diameter of both Lablab purpureus cultivars. Rhizobium inoculation had no significant effect (p>0.05) on chlorophyll content for both cultivars. Highworth had significantly higher (p<0.05) plant vigour than Rongai on both inoculated and uninoculated. Varieties and inoculation effects were significant (p<0.05) for number of nodules, nodulation rate, active nodules and nodule dry yield. Rhizobium inoculation significantly (p<0.05) increased fresh matter yield, dry matter yied and dry matter content on both cultivars. There were no significant differences (p>0.05) in NDF, ADIN, ADL, ADF, and Na between inoculated and uninoculated plants for both cultivars. The inoculation of Rhizobium improved CP (15.65%) in Highworth cultivar. The inoculation of Rhizobium significantly increased Ca (1.76-1.84%), Zn (191.91-2 8.33ppm) and Cu (3.50-6.16ppm) compared to un-inoculated plants. Varieties and Rhizobium had no interaction (p>0.05) with condensed tannin, hydrolysable tannin, total polyphenols and saponins . Therefore, the Rhizobium inoculation assisted in improving quality in terms of nutrient composition and decreasing anti-nutrients. It is recommended to use both cultivars of Lablab purpureus. Based on the results of this study it is concluded that Rhizobium inoculation increases yield and forage quality of Lablab purpureus. It is recommended that Highworth cultivar can be used by communal farmers in the Eastern Cape. This cultivar showed that it needs Rhizobium inoculation inorder to produce high quality that can increase livestock production. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017
Prevalence of metabolic syndrome in adolescents living in Mthatha, south africa
- Sekokotla, Annah, Goswami, Nandu, Sewani-Rusike, Constance Rufaro, Iputo, Jehu Erapu, Nkeh-Chungag, Benedicta Ngwenchi
- Authors: Sekokotla, Annah , Goswami, Nandu , Sewani-Rusike, Constance Rufaro , Iputo, Jehu Erapu , Nkeh-Chungag, Benedicta Ngwenchi
- Date: 2017
- Subjects: South Africa Metabolic syndrome Journal article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5983 , vital:45061 , xlink:href="https://doi:10.2147/TCRM.S124291"
- Description: Objective Metabolic syndrome (MetS), defined as the clustering of three of five risk factors (hypertension, obesity, triglyceridemia, dyslipidemia and hyperglycemia), is being increasingly mentioned among children and adolescents despite there being no consensus on how it should be defined in this set of population. Furthermore, very few studies have focused on MetS in children and adolescents in sub-Saharan populations. This study, therefore, aimed at determining the prevalence of the MetS and contributing risk in adolescents living in Mthatha, South Africa. Research design and methods Four hundred and ten adolescents (age range: 13–18 years, both sexes) were recruited into this cross-sectional study. In addition to a lifestyle questionnaire being administered, anthropometric measurements (weight, height and waist circumferences) were carried out for each participant. Fasting venous blood was collected for lipid profile and blood glucose assessments. Blood pressure was also measured. MetS was assessed using appropriate diagnostic criteria for children and adolescents. Results Complete data sets were collected from 371 participants. Females showed an elevation in the risk factors for MetS. Of the 371 participants, 40.2% were overweight/obese (47.5% females; 22.5% males). MetS was diagnosed in 3.1% female participants compared with 6.0% in male participants. Conclusions More risk factors for the MetS are seen among the overweight/obese as compared to lean adolescents. Given the fact that childhood overweight/obesity often continues into adulthood, it is important to address the causes of increased risk for MetS earlier in life to prevent the development of disease in adult life.
- Full Text:
- Date Issued: 2017
- Authors: Sekokotla, Annah , Goswami, Nandu , Sewani-Rusike, Constance Rufaro , Iputo, Jehu Erapu , Nkeh-Chungag, Benedicta Ngwenchi
- Date: 2017
- Subjects: South Africa Metabolic syndrome Journal article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5983 , vital:45061 , xlink:href="https://doi:10.2147/TCRM.S124291"
- Description: Objective Metabolic syndrome (MetS), defined as the clustering of three of five risk factors (hypertension, obesity, triglyceridemia, dyslipidemia and hyperglycemia), is being increasingly mentioned among children and adolescents despite there being no consensus on how it should be defined in this set of population. Furthermore, very few studies have focused on MetS in children and adolescents in sub-Saharan populations. This study, therefore, aimed at determining the prevalence of the MetS and contributing risk in adolescents living in Mthatha, South Africa. Research design and methods Four hundred and ten adolescents (age range: 13–18 years, both sexes) were recruited into this cross-sectional study. In addition to a lifestyle questionnaire being administered, anthropometric measurements (weight, height and waist circumferences) were carried out for each participant. Fasting venous blood was collected for lipid profile and blood glucose assessments. Blood pressure was also measured. MetS was assessed using appropriate diagnostic criteria for children and adolescents. Results Complete data sets were collected from 371 participants. Females showed an elevation in the risk factors for MetS. Of the 371 participants, 40.2% were overweight/obese (47.5% females; 22.5% males). MetS was diagnosed in 3.1% female participants compared with 6.0% in male participants. Conclusions More risk factors for the MetS are seen among the overweight/obese as compared to lean adolescents. Given the fact that childhood overweight/obesity often continues into adulthood, it is important to address the causes of increased risk for MetS earlier in life to prevent the development of disease in adult life.
- Full Text:
- Date Issued: 2017