Biological control potential of ectomycorrhizal fungi against Fusarium circinatum on Pinus patula seedlings
- Chartier FitzGerald, Veronique C, Dames, Joanna F, Hawley, Grant L
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
- Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
- Full Text:
- Date Issued: 2020
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
- Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
- Full Text:
- Date Issued: 2020
Biology, stock assessment and angler attitudes towards the introduction of slot size limits for a recreationally important species Sparodon durbanensis (Sparidae) in South Africa
- Authors: Hewett, Kyle
- Date: 2020
- Subjects: Sparidae -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48389 , vital:40855
- Description: Sparodon durbanensis (white musselcracker) is an endemic fish species in the Family Sparidae found in shallow (< 20 m) coastal waters from the Western Cape to KwaZulu-Natal. It is large-growing, late-maturing, long-lived and is a popular target species in the South African marine shore-based line and spear fisheries. Management regulations for the species have remained the same for over two decades despite anecdotal information of population declines. However, since the last life history-information for S. durbanensis was collected in the late 1980s, there is a paucity of contemporary information needed to inform wise management. The aim of this study was to collect contemporary socio-ecological information on the species and its fishery in order to better inform the management of the species. In order to do this, the growth-rate of historical and contemporary samples of Sparodon durbanensis was compared, a length-based stock assessment was performed and the knowledge and attitudes of anglers towards the introduction of improved regulations were investigated. The growth-rate was compared using otolith width as a proxy for fish growth. It was found that the growth-rate had remained relatively stable between 1963 and 2010, suggesting that S. durbanensis may be resilient to the increasing levels of environmental variability observed throughout its range and that the historical growth parameters determined for this species may remain applicable for contemporary stock assessment. The batch fecundity was determined for 50 mm size classes and used to estimate the percentage cumulative population batch fecundity using historical 803 mm FL (904 mm TL) and contemporary 776 mm FL (874 mm TL) length structure, respectively. Based on these observations a suitable harvest slot limit of 600-850 mm TL was suggested. A Length-Based Spawning Potential Ratio (SPR) model was used to provide the first formal stock assessment for S. durbanensis. The input parameters of M/k=1.44, L∞=1021 mm FL, L50=350 mm FL and L95=800 mm FL and length composition data comprising of 134 lengths obtained from a collection of competitive angling catches, estimated a SPR of 41%, which is above the 40% target reference point. A total of 126 online and face– to-face, replica questionnaires were completed by spearfishermen and recreational shore anglers. Responses indicated that anglers that target S. durbanensis are generally a specialized group who are knowledgeable about the biology and ecology of the species and are passionate about the conservation of the species. Participants indicated that Marine Protected Areas are likely the most effective regulation in the current suite of regulations used to manage the fishery and suggested that poor law enforcement was the major factor inhibiting the efficacy of fishery regulations. New proposed regulations, such as a harvest slot limit (and particularly the one between 600-850 mm TL) for S. durbanensis, was well supported, however participants suggested that non-compliance was a concern. Although, the SPR remained above the 40% target reference point, further declines in the stock status should be prevented through the implementation of a 600-850 mm TL harvest slot limit. Based on the findings of this study, this limit should provide protection against both growth and recruitment overfishing by providing protection to sexually immature, fast growing fish and to large adults that contribute the greatest proportion to population replenishment.
- Full Text:
- Date Issued: 2020
- Authors: Hewett, Kyle
- Date: 2020
- Subjects: Sparidae -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48389 , vital:40855
- Description: Sparodon durbanensis (white musselcracker) is an endemic fish species in the Family Sparidae found in shallow (< 20 m) coastal waters from the Western Cape to KwaZulu-Natal. It is large-growing, late-maturing, long-lived and is a popular target species in the South African marine shore-based line and spear fisheries. Management regulations for the species have remained the same for over two decades despite anecdotal information of population declines. However, since the last life history-information for S. durbanensis was collected in the late 1980s, there is a paucity of contemporary information needed to inform wise management. The aim of this study was to collect contemporary socio-ecological information on the species and its fishery in order to better inform the management of the species. In order to do this, the growth-rate of historical and contemporary samples of Sparodon durbanensis was compared, a length-based stock assessment was performed and the knowledge and attitudes of anglers towards the introduction of improved regulations were investigated. The growth-rate was compared using otolith width as a proxy for fish growth. It was found that the growth-rate had remained relatively stable between 1963 and 2010, suggesting that S. durbanensis may be resilient to the increasing levels of environmental variability observed throughout its range and that the historical growth parameters determined for this species may remain applicable for contemporary stock assessment. The batch fecundity was determined for 50 mm size classes and used to estimate the percentage cumulative population batch fecundity using historical 803 mm FL (904 mm TL) and contemporary 776 mm FL (874 mm TL) length structure, respectively. Based on these observations a suitable harvest slot limit of 600-850 mm TL was suggested. A Length-Based Spawning Potential Ratio (SPR) model was used to provide the first formal stock assessment for S. durbanensis. The input parameters of M/k=1.44, L∞=1021 mm FL, L50=350 mm FL and L95=800 mm FL and length composition data comprising of 134 lengths obtained from a collection of competitive angling catches, estimated a SPR of 41%, which is above the 40% target reference point. A total of 126 online and face– to-face, replica questionnaires were completed by spearfishermen and recreational shore anglers. Responses indicated that anglers that target S. durbanensis are generally a specialized group who are knowledgeable about the biology and ecology of the species and are passionate about the conservation of the species. Participants indicated that Marine Protected Areas are likely the most effective regulation in the current suite of regulations used to manage the fishery and suggested that poor law enforcement was the major factor inhibiting the efficacy of fishery regulations. New proposed regulations, such as a harvest slot limit (and particularly the one between 600-850 mm TL) for S. durbanensis, was well supported, however participants suggested that non-compliance was a concern. Although, the SPR remained above the 40% target reference point, further declines in the stock status should be prevented through the implementation of a 600-850 mm TL harvest slot limit. Based on the findings of this study, this limit should provide protection against both growth and recruitment overfishing by providing protection to sexually immature, fast growing fish and to large adults that contribute the greatest proportion to population replenishment.
- Full Text:
- Date Issued: 2020
Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)
- Taylor, Peter J, Kearney, Theresa, Dalton, Desire L, Chakona, Gamuchirai, Kelly, Christopher M R, Barker, Nigel P
- Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M R , Barker, Nigel P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453158 , vital:75227 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
- Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
- Full Text:
- Date Issued: 2020
- Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M R , Barker, Nigel P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453158 , vital:75227 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
- Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
- Full Text:
- Date Issued: 2020
Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)
- Taylor, Peter J, Kearney, Theresa, Dalton, Desire L, Chakona, Gamuchirai, Kelly, Christopher M R, Barker, Nigel P
- Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M R , Barker, Nigel P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425481 , vital:72249 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
- Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
- Full Text:
- Date Issued: 2020
- Authors: Taylor, Peter J , Kearney, Theresa , Dalton, Desire L , Chakona, Gamuchirai , Kelly, Christopher M R , Barker, Nigel P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425481 , vital:72249 , xlink:href="https://doi.org/10.1093/zoolinnean/zlz134"
- Description: Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).
- Full Text:
- Date Issued: 2020
Blockchain readiness for countries towards 2030- the barriers and benefits of adopting blockchain technology
- Authors: Moonsamy, Devakumaran
- Date: 2020
- Subjects: Blockchains (Databases) Financial institutions -- Technological innovations
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/49725 , vital:41783
- Description: This study investigates the factors of blockchain that will promote sustainable business towards the year 2030. The study provides an outlook to areas where business might be vulnerable in the event of blockchain implementation. The findings of this study were identified by means of an online questionnaire that targeted specialists in the arena of blockchain and business management. By a thematic analysis, the outcome of the study guides, precautions, and prepares organisations for what may come in the future of blockchain.
- Full Text:
- Date Issued: 2020
- Authors: Moonsamy, Devakumaran
- Date: 2020
- Subjects: Blockchains (Databases) Financial institutions -- Technological innovations
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/49725 , vital:41783
- Description: This study investigates the factors of blockchain that will promote sustainable business towards the year 2030. The study provides an outlook to areas where business might be vulnerable in the event of blockchain implementation. The findings of this study were identified by means of an online questionnaire that targeted specialists in the arena of blockchain and business management. By a thematic analysis, the outcome of the study guides, precautions, and prepares organisations for what may come in the future of blockchain.
- Full Text:
- Date Issued: 2020
BODIPY dyes for application in the photo-oxidation of pollutants, photodynamic antimicrobial chemotherapy, and nonlinear optics
- Authors: Kelechi, Lebechi Augustus
- Date: 2020
- Subjects: Dyes and dyeing -- Chemistry , Fluorescent probes , Fluorescence spectroscopy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/140298 , vital:37859
- Description: The synthesis and structural characterization of a series of BODIPY dyes to analyze both the effects of halogenations at the 2,6-positions and the introduction of styryl groups at the 3,5-positions. The photophysical properties of these dyes were investigated to determine their suitability as singlet oxygen-generating photosensitiser dyes for application in photocatalytic degradation of azo dyes and in photodynamic antimicrobial chemotherapy (PACT). Upon halogenation, the dyes showed high to moderate singlet oxygen quantum yields. The potential utility of electrospun polystyrene (PS) nanofibres embedded with halogenated BODIPY dyes for the photocatalytic degradation of Orange G and Methyl Orange from textile industry effluents were investigated. A comparison of the singlet oxygen quantum yield of the BODIPY dyes in solution and when embedded in the PS nanofibres support demonstrates that its photosensitiser properties are maintained in the nanofibre mats. The photocatalytic degradation properties of the PS nanofibres for Orange G and Methyl Orange were determined by using a 530 nm and 660 nm light-emitting diodes. The rate of photodegradation increases with both the Orange G and Methyl Orange concentrations and follows pseudo-first-order kinetics. The PACT activities of brominated BODIPYs on Escherichia coli and Staphylococcus aureus were investigated. Log reduction values of over 9 were obtained during the photoinactivation of Staphylococcus aureus. To be able to red-shift the main spectral band of the BODIPY dyes into the therapeutic window, styryl groups were introduced at the 3,5-positions through a modified Knoevenagel condensation reaction. Because the red-shifted spectral band lies above 532 nm, the second harmonic of the Nd:YAG laser, there is very minute absorption at this wavelength. One of the novel brominated BODIPY dyes was investigated for its potential utility as optical limiting materials in nonlinear optics (NLO), and the dyes demonstrated typical nonlinear absorption behaviour characterised by reverse saturable absorption (RSA) in Z-scan measurements. Excellent optical limiting parameters were obtained for third-order susceptibility and hyperpolarisability.
- Full Text:
- Date Issued: 2020
- Authors: Kelechi, Lebechi Augustus
- Date: 2020
- Subjects: Dyes and dyeing -- Chemistry , Fluorescent probes , Fluorescence spectroscopy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/140298 , vital:37859
- Description: The synthesis and structural characterization of a series of BODIPY dyes to analyze both the effects of halogenations at the 2,6-positions and the introduction of styryl groups at the 3,5-positions. The photophysical properties of these dyes were investigated to determine their suitability as singlet oxygen-generating photosensitiser dyes for application in photocatalytic degradation of azo dyes and in photodynamic antimicrobial chemotherapy (PACT). Upon halogenation, the dyes showed high to moderate singlet oxygen quantum yields. The potential utility of electrospun polystyrene (PS) nanofibres embedded with halogenated BODIPY dyes for the photocatalytic degradation of Orange G and Methyl Orange from textile industry effluents were investigated. A comparison of the singlet oxygen quantum yield of the BODIPY dyes in solution and when embedded in the PS nanofibres support demonstrates that its photosensitiser properties are maintained in the nanofibre mats. The photocatalytic degradation properties of the PS nanofibres for Orange G and Methyl Orange were determined by using a 530 nm and 660 nm light-emitting diodes. The rate of photodegradation increases with both the Orange G and Methyl Orange concentrations and follows pseudo-first-order kinetics. The PACT activities of brominated BODIPYs on Escherichia coli and Staphylococcus aureus were investigated. Log reduction values of over 9 were obtained during the photoinactivation of Staphylococcus aureus. To be able to red-shift the main spectral band of the BODIPY dyes into the therapeutic window, styryl groups were introduced at the 3,5-positions through a modified Knoevenagel condensation reaction. Because the red-shifted spectral band lies above 532 nm, the second harmonic of the Nd:YAG laser, there is very minute absorption at this wavelength. One of the novel brominated BODIPY dyes was investigated for its potential utility as optical limiting materials in nonlinear optics (NLO), and the dyes demonstrated typical nonlinear absorption behaviour characterised by reverse saturable absorption (RSA) in Z-scan measurements. Excellent optical limiting parameters were obtained for third-order susceptibility and hyperpolarisability.
- Full Text:
- Date Issued: 2020
BODIPY dyes for use in nonlinear optics and optical sensing
- Authors: Kubheka, Gugu Patience
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163352 , vital:41032 , doi:10.21504/10962/163352
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Department of Chemistry, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Kubheka, Gugu Patience
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163352 , vital:41032 , doi:10.21504/10962/163352
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Department of Chemistry, 2020.
- Full Text:
- Date Issued: 2020
Body mass and condition of a fynbos bird community investigating impacts of time, weather and raptor abundance from long-term citizen-science datasets
- Lee, Alan T K, Barnard, Phoebe, Fraser, Mike, Lennard, Chris, Smit, Ben, Oschadleus, Hans-Dieter
- Authors: Lee, Alan T K , Barnard, Phoebe , Fraser, Mike , Lennard, Chris , Smit, Ben , Oschadleus, Hans-Dieter
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441546 , vital:73897 , https://doi.org/10.2989/00306525.2019.1683093
- Description: Variation in body size, especially mass, is a function of local environmental conditions for any given species. Recent recorded decreases in body size of endotherms have been attributed to climate change in some cases. This prediction is based on the trend of smaller body size of endotherms in warmer climates (Bergmann’s rule) and it implies genetic responses rather than phenotypic flexibility. Alternatively, selection for smaller body size or lower mass could be explained by the starvation-predation hypothesis, where lighter individuals have a higher probability of escaping pursuing predators, such as raptors. Evidence that climate warming is driving patterns of size selection in birds in recent times has been mixed. We inspected data on 40 bird species contributed by bird ringers to the South African Ringing Scheme (SAFRING) for changes in body mass and condition as a function of time (year), minimum temperature of the day of capture, maximum temperature of the previous day, and rainfall data in the south-western Cape Floristic Region (fynbos) around Cape Town, South Africa, for the period 1988–2015. The region shows a warming trend over the study period (0.035 °C yr−1). Interannual body mass and condition change were poorly explained by year or temperature. High daily minimum temperature explained loss of body condition for four species, whereas evidence from recaptured birds indicated negative effects of increasing maximum daily temperature, as well as rain. For the alternative hypothesis, because raptor abundance is stable or only weakly declining, there is little evidence to suggest these as a driver influencing mass trends. Any decrease in body mass over the study period that we observed for birds appear more likely to be plastic responses to stress associated with temperature or rainfall at this time, rather than systematic selection for smaller body size, as predicted by Bergmann’s Rule.
- Full Text:
- Date Issued: 2020
- Authors: Lee, Alan T K , Barnard, Phoebe , Fraser, Mike , Lennard, Chris , Smit, Ben , Oschadleus, Hans-Dieter
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441546 , vital:73897 , https://doi.org/10.2989/00306525.2019.1683093
- Description: Variation in body size, especially mass, is a function of local environmental conditions for any given species. Recent recorded decreases in body size of endotherms have been attributed to climate change in some cases. This prediction is based on the trend of smaller body size of endotherms in warmer climates (Bergmann’s rule) and it implies genetic responses rather than phenotypic flexibility. Alternatively, selection for smaller body size or lower mass could be explained by the starvation-predation hypothesis, where lighter individuals have a higher probability of escaping pursuing predators, such as raptors. Evidence that climate warming is driving patterns of size selection in birds in recent times has been mixed. We inspected data on 40 bird species contributed by bird ringers to the South African Ringing Scheme (SAFRING) for changes in body mass and condition as a function of time (year), minimum temperature of the day of capture, maximum temperature of the previous day, and rainfall data in the south-western Cape Floristic Region (fynbos) around Cape Town, South Africa, for the period 1988–2015. The region shows a warming trend over the study period (0.035 °C yr−1). Interannual body mass and condition change were poorly explained by year or temperature. High daily minimum temperature explained loss of body condition for four species, whereas evidence from recaptured birds indicated negative effects of increasing maximum daily temperature, as well as rain. For the alternative hypothesis, because raptor abundance is stable or only weakly declining, there is little evidence to suggest these as a driver influencing mass trends. Any decrease in body mass over the study period that we observed for birds appear more likely to be plastic responses to stress associated with temperature or rainfall at this time, rather than systematic selection for smaller body size, as predicted by Bergmann’s Rule.
- Full Text:
- Date Issued: 2020
Body mass and condition of a fynbos bird community investigating impacts of time, weather and raptor abundance from long-term citizen-science datasets
- Lee, Alan T K, Barnard, Phoebe, Fraser, Mike, Lennard, Chris, Smit, Ben, Oschadleus, Hans-Dieter
- Authors: Lee, Alan T K , Barnard, Phoebe , Fraser, Mike , Lennard, Chris , Smit, Ben , Oschadleus, Hans-Dieter
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448383 , vital:74726 , https://doi.org/10.2989/00306525.2019.1683093
- Description: Variation in body size, especially mass, is a function of local environmental conditions for any given species. Recent recorded decreases in body size of endotherms have been attributed to climate change in some cases. This prediction is based on the trend of smaller body size of endotherms in warmer climates (Bergmann’s rule) and it implies genetic responses rather than phenotypic flexibility. Alternatively, selection for smaller body size or lower mass could be explained by the starvation-predation hypothesis, where lighter individuals have a higher probability of escaping pursuing predators, such as raptors. Evidence that climate warming is driving patterns of size selection in birds in recent times has been mixed. We inspected data on 40 bird species contributed by bird ringers to the South African Ringing Scheme (SAFRING) for changes in body mass and condition as a function of time (year), minimum temperature of the day of capture, maximum temperature of the previous day, and rainfall data in the south-western Cape Floristic Region (fynbos) around Cape Town, South Africa, for the period 1988–2015.
- Full Text:
- Date Issued: 2020
- Authors: Lee, Alan T K , Barnard, Phoebe , Fraser, Mike , Lennard, Chris , Smit, Ben , Oschadleus, Hans-Dieter
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448383 , vital:74726 , https://doi.org/10.2989/00306525.2019.1683093
- Description: Variation in body size, especially mass, is a function of local environmental conditions for any given species. Recent recorded decreases in body size of endotherms have been attributed to climate change in some cases. This prediction is based on the trend of smaller body size of endotherms in warmer climates (Bergmann’s rule) and it implies genetic responses rather than phenotypic flexibility. Alternatively, selection for smaller body size or lower mass could be explained by the starvation-predation hypothesis, where lighter individuals have a higher probability of escaping pursuing predators, such as raptors. Evidence that climate warming is driving patterns of size selection in birds in recent times has been mixed. We inspected data on 40 bird species contributed by bird ringers to the South African Ringing Scheme (SAFRING) for changes in body mass and condition as a function of time (year), minimum temperature of the day of capture, maximum temperature of the previous day, and rainfall data in the south-western Cape Floristic Region (fynbos) around Cape Town, South Africa, for the period 1988–2015.
- Full Text:
- Date Issued: 2020
BTC price volatility: fundamentals versus information
- Gbadebo, Adedeji Daniel, Adekunle, Ahmed Oluwatobi, Adebayo-Oke Abdulrauf Lukman, Adedokun, Wole, Akande, Joseph
- Authors: Gbadebo, Adedeji Daniel , Adekunle, Ahmed Oluwatobi , Adebayo-Oke Abdulrauf Lukman , Adedokun, Wole , Akande, Joseph
- Date: 2020
- Subjects: Bitcoin price volatility , Bitcoin market fundamentals , Autoregressive Distributed Lag (ARDL)
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/6978 , vital:52630 , https://doi.org/10.1080/23311975.2021.1984624
- Description: This paper offers a plausible response to “what explains the sporadic volatility in the price of Bitcoin?” We hypothesized that market “fundamentals” and “information demands” are key drivers of Bitcoin’s unpredictable price fluctuation. We adopt the transfer-function [Autoregressive Distributed Lag, ARDL] model and its Bounds testing approach to verify how the volatility of the price of Bitcoin responds to its transaction volume, cryptocurrency market capitalisation, world market equity index and Google search. We found the existence of long-run cointegration relation and observed that all the variables except the equity index positively explain the volatility of Bitcoin price. The result established evidence that market fundamentals drive erratic swing in Bitcoin price than information.
- Full Text:
- Date Issued: 2020
- Authors: Gbadebo, Adedeji Daniel , Adekunle, Ahmed Oluwatobi , Adebayo-Oke Abdulrauf Lukman , Adedokun, Wole , Akande, Joseph
- Date: 2020
- Subjects: Bitcoin price volatility , Bitcoin market fundamentals , Autoregressive Distributed Lag (ARDL)
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/6978 , vital:52630 , https://doi.org/10.1080/23311975.2021.1984624
- Description: This paper offers a plausible response to “what explains the sporadic volatility in the price of Bitcoin?” We hypothesized that market “fundamentals” and “information demands” are key drivers of Bitcoin’s unpredictable price fluctuation. We adopt the transfer-function [Autoregressive Distributed Lag, ARDL] model and its Bounds testing approach to verify how the volatility of the price of Bitcoin responds to its transaction volume, cryptocurrency market capitalisation, world market equity index and Google search. We found the existence of long-run cointegration relation and observed that all the variables except the equity index positively explain the volatility of Bitcoin price. The result established evidence that market fundamentals drive erratic swing in Bitcoin price than information.
- Full Text:
- Date Issued: 2020
Budget Deficits, the Savings Gap and Current Account Deficits in the Southern African Development Community
- Authors: Kopeledi, Alyssa
- Date: 2020
- Subjects: Budget deficits -- South Africa Accounts current
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/12392 , vital:39259
- Description: This study examines the validity of the triple deficit hypothesis for a selected number of SADC countries, utilising secondary annual data for the period 1996-2018. Based on previous studies and theory, current account deficit was chosen as the dependent variable and budget deficit and the savings gap as the independent variables. The study makes use of both first generation and second-generation unit root tests to examine the time series properties of the data. The empirical results show that the data is integrated of different orders. Kao, Pedroni and Westerlund cointegration tests were carried out to examine the long-term relationship between the variables of interest. The empirical results revealed that there is a long-term relationship between current account deficit, budget deficit s and the savings gap. The long-run model under the Autoregressive Distributed Lag test revealed that, a positive and significant relationship exists between budget deficit and current account deficit at a significance level of 10% and a negative and insignificant relationship exists between savings gap and current account deficit in the long run. This suggests that an improvement in the current account balance in SADC countries requires fiscal stringency
- Full Text:
- Date Issued: 2020
- Authors: Kopeledi, Alyssa
- Date: 2020
- Subjects: Budget deficits -- South Africa Accounts current
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/12392 , vital:39259
- Description: This study examines the validity of the triple deficit hypothesis for a selected number of SADC countries, utilising secondary annual data for the period 1996-2018. Based on previous studies and theory, current account deficit was chosen as the dependent variable and budget deficit and the savings gap as the independent variables. The study makes use of both first generation and second-generation unit root tests to examine the time series properties of the data. The empirical results show that the data is integrated of different orders. Kao, Pedroni and Westerlund cointegration tests were carried out to examine the long-term relationship between the variables of interest. The empirical results revealed that there is a long-term relationship between current account deficit, budget deficit s and the savings gap. The long-run model under the Autoregressive Distributed Lag test revealed that, a positive and significant relationship exists between budget deficit and current account deficit at a significance level of 10% and a negative and insignificant relationship exists between savings gap and current account deficit in the long run. This suggests that an improvement in the current account balance in SADC countries requires fiscal stringency
- Full Text:
- Date Issued: 2020
Building a flexible and inexpensive multi-layer switch for software-defined networks
- Authors: Magwenzi, Tinashe
- Date: 2020
- Subjects: Software-defined networking (Computer network technology) , Telecommunication -- Switching systems , OpenFlow (Computer network protocol) , Local area networks (Computer networks)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/142841 , vital:38122
- Description: Software-Defined Networking (SDN) is a paradigm which enables the realisation of programmable network through the separation of the control logic from the forwarding functions. This separation is a departure from the traditional architecture. Much of the work done in SDN enabled devices has concentrated on higher end, high speed networks (10s GBit/s 100s GBit/s), rather than the relatively low bandwidth links (10s MBit/s to a few GBit/s) which are seen, for example, in South Africa. As SDN is increasingly becoming more accepted, due to its advantages over the traditional networks, it has been adopted for industrial purposes such as networking in data centres and network providers. The demand for programmable networks is increasing but is limited by the ability of providers to upgrade their infrastructure. In addition, as access to the Internet has become less expensive, the use of Internet is increasing in academic institutions, NGOs, and small to medium enterprises. This thesis details a means of building and managing a small scale Software-Defined Network using commodity hardware and open source tools. Core to the SDN Network illustrated in this thesis is the prototype of a multi-layer SDN switch. The proposed device is targeted to serve lower bandwidth communication (in relation to commercially produced high speed SDN-enabled devices). The performance of the prototype multilayer switch had shown to achieve: data-rates of up to 99.998%, average latencies that are under 40µs during forwarding/switching and under 100µs during routing while using packet sizes between 64 bytes and 1518 bytes, and a jitter of less than 15µs during all tests. This research explores in detail the design, development, and management of a multi-layer switch and its placement and integration in small scale SDN network. This includes testing of Layer 2 forwarding and Layer 3 routing, OpenFlow compliance testing, the management of the switch using created SDN applications, and real life network functionality such as forwarding, routing and VLAN networking to demonstrate its real world applicability.
- Full Text:
- Date Issued: 2020
- Authors: Magwenzi, Tinashe
- Date: 2020
- Subjects: Software-defined networking (Computer network technology) , Telecommunication -- Switching systems , OpenFlow (Computer network protocol) , Local area networks (Computer networks)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/142841 , vital:38122
- Description: Software-Defined Networking (SDN) is a paradigm which enables the realisation of programmable network through the separation of the control logic from the forwarding functions. This separation is a departure from the traditional architecture. Much of the work done in SDN enabled devices has concentrated on higher end, high speed networks (10s GBit/s 100s GBit/s), rather than the relatively low bandwidth links (10s MBit/s to a few GBit/s) which are seen, for example, in South Africa. As SDN is increasingly becoming more accepted, due to its advantages over the traditional networks, it has been adopted for industrial purposes such as networking in data centres and network providers. The demand for programmable networks is increasing but is limited by the ability of providers to upgrade their infrastructure. In addition, as access to the Internet has become less expensive, the use of Internet is increasing in academic institutions, NGOs, and small to medium enterprises. This thesis details a means of building and managing a small scale Software-Defined Network using commodity hardware and open source tools. Core to the SDN Network illustrated in this thesis is the prototype of a multi-layer SDN switch. The proposed device is targeted to serve lower bandwidth communication (in relation to commercially produced high speed SDN-enabled devices). The performance of the prototype multilayer switch had shown to achieve: data-rates of up to 99.998%, average latencies that are under 40µs during forwarding/switching and under 100µs during routing while using packet sizes between 64 bytes and 1518 bytes, and a jitter of less than 15µs during all tests. This research explores in detail the design, development, and management of a multi-layer switch and its placement and integration in small scale SDN network. This includes testing of Layer 2 forwarding and Layer 3 routing, OpenFlow compliance testing, the management of the switch using created SDN applications, and real life network functionality such as forwarding, routing and VLAN networking to demonstrate its real world applicability.
- Full Text:
- Date Issued: 2020
Building knowledge with theory: Unpacking complexity in doctoral writing
- Authors: Wilmot, Kirsten
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439480 , vital:73600 , https://www.ajol.info/index.php/cristal/article/view/203971
- Description: The use of theory to analyse and interpret empirical data is a valued practice in much social science doctoral research. A crucial aspect of this practice involves generating sophisticated theoretical understandings and critiques of phenomena in our social world. Despite the importance of theory, however, few concrete explanations of how to ‘theorise’exist in literature. This paper addresses this gap by demonstrating how a set of conceptual tools can be used to unpack what the craft of theorising looks like in explicit terms, and to reveal how this ability develops over time during the drafting process of dissertation writing. It does this by drawing on select texts from a successful doctoral dissertation, as well as an earlier draft version. In doing so, the paper provides an in-depth explanation of an essential process of doctoral research that is inherently known by many supervisors, yet seldom unpacked in explicit terms.
- Full Text:
- Date Issued: 2020
- Authors: Wilmot, Kirsten
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439480 , vital:73600 , https://www.ajol.info/index.php/cristal/article/view/203971
- Description: The use of theory to analyse and interpret empirical data is a valued practice in much social science doctoral research. A crucial aspect of this practice involves generating sophisticated theoretical understandings and critiques of phenomena in our social world. Despite the importance of theory, however, few concrete explanations of how to ‘theorise’exist in literature. This paper addresses this gap by demonstrating how a set of conceptual tools can be used to unpack what the craft of theorising looks like in explicit terms, and to reveal how this ability develops over time during the drafting process of dissertation writing. It does this by drawing on select texts from a successful doctoral dissertation, as well as an earlier draft version. In doing so, the paper provides an in-depth explanation of an essential process of doctoral research that is inherently known by many supervisors, yet seldom unpacked in explicit terms.
- Full Text:
- Date Issued: 2020
Calling rhythm as a predictor of the outcome of vocal interactions: flight departure in pale-winged starling pairs
- Hausberger, Martine, Giacalone, Aline, Harmand, Mariane, Craig, Adrian J F K, Henry, Laurence
- Authors: Hausberger, Martine , Giacalone, Aline , Harmand, Mariane , Craig, Adrian J F K , Henry, Laurence
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449283 , vital:74808 , https://doi.org/10.1007/s00114-019-1658-1
- Description: Vocal communication plays an important role in the regulation of social interactions and the coordination of activities in many animal species. Synchrony is an essential part of the establishment and maintenance of pair bonds, but few reports have investigated decision-making at the pair level. We investigated temporal characteristics of call exchanges in pale-winged starlings (Onychognathus nabouroup) that could predict whether one, two, or neither members of a pair would take off. Our analysis of these interactions revealed that the overall rhythm of a call exchange, as well as the acceleration towards the end of an interaction, were significantly associated with the type of behavioural outcome. Faster rhythms were associated with higher probabilities that both birds would fly away. Our results confirm the findings of previous studies showing that higher rates of alarm calls indicate imminent departure and highlight the relationship between temporal features of vocal interactions and their outcome.
- Full Text:
- Date Issued: 2020
- Authors: Hausberger, Martine , Giacalone, Aline , Harmand, Mariane , Craig, Adrian J F K , Henry, Laurence
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449283 , vital:74808 , https://doi.org/10.1007/s00114-019-1658-1
- Description: Vocal communication plays an important role in the regulation of social interactions and the coordination of activities in many animal species. Synchrony is an essential part of the establishment and maintenance of pair bonds, but few reports have investigated decision-making at the pair level. We investigated temporal characteristics of call exchanges in pale-winged starlings (Onychognathus nabouroup) that could predict whether one, two, or neither members of a pair would take off. Our analysis of these interactions revealed that the overall rhythm of a call exchange, as well as the acceleration towards the end of an interaction, were significantly associated with the type of behavioural outcome. Faster rhythms were associated with higher probabilities that both birds would fly away. Our results confirm the findings of previous studies showing that higher rates of alarm calls indicate imminent departure and highlight the relationship between temporal features of vocal interactions and their outcome.
- Full Text:
- Date Issued: 2020
Can fishing tourism contribute to conservation and sustainability via ecotourism?: a case study of the Fishery for Giant African Threadfin Polydactylus quadrifilis on the Kwanza Estuary, Angola
- Butler, Edward C, Childs, Amber-Robyn, Saayman, Andrea, Potts, Warren M
- Authors: Butler, Edward C , Childs, Amber-Robyn , Saayman, Andrea , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149253 , vital:38819 , https://doi.org/10.3390/su12104221
- Description: It has been suggested that tourism fisheries can raise the value of landed catch, provide alternative livelihoods for local artisanal fishers and, because recreationally caught fishes are often released, simultaneously conserve stocks. However, for fishing tourism to meet ecotourism standards, sustainable, local economic benefit is imperative. This study aimed to assess the direct economic contribution of the recreational fishery for Polydactylus quadrifilis on the Kwanza Estuary, Angola. The recreational fishery contributed significantly to economic productivity in an otherwise rural area, generating a total revenue (TR) of $236,826 per four-month fishing season.
- Full Text:
- Date Issued: 2020
- Authors: Butler, Edward C , Childs, Amber-Robyn , Saayman, Andrea , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149253 , vital:38819 , https://doi.org/10.3390/su12104221
- Description: It has been suggested that tourism fisheries can raise the value of landed catch, provide alternative livelihoods for local artisanal fishers and, because recreationally caught fishes are often released, simultaneously conserve stocks. However, for fishing tourism to meet ecotourism standards, sustainable, local economic benefit is imperative. This study aimed to assess the direct economic contribution of the recreational fishery for Polydactylus quadrifilis on the Kwanza Estuary, Angola. The recreational fishery contributed significantly to economic productivity in an otherwise rural area, generating a total revenue (TR) of $236,826 per four-month fishing season.
- Full Text:
- Date Issued: 2020
Carnivore intra-guild competition in Selati Game Reserve, Limpopo Province, South Africa
- Authors: Comley, Jessica
- Date: 2020
- Subjects: Hyenas -- Behavior -- South Africa , Hyenas -- South Africa , Hyenas -- Ecology -- South Africa , Top predators -- South Africa , Top predators -- Ecology -- South Africa , Animal communities -- South Africa , Animal behavior -- South Africa , Mutualism (Biology) -- South Africa , Coexistence of species -- South Africa , Game farms -- South Africa , Selati Game Reserve (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115558 , vital:34163
- Description: Carnivore intra-guild interactions can be important drivers of carnivore community composition and ecosystem functioning. Large carnivores are particularly important since they occupy the highest trophic levels and can exert extensive influences on subordinate carnivores and prey species. Given Africa’s rapidly expanding human population, enclosed reserves such as those found in South Africa, may become increasingly important for carnivore conservation. A major concern, however, is that the interactions and co-existence of multiple carnivores in these systems is poorly understood. Additionally, the majority of reserves in South Africa are small ( 400km²), potentially increasing the likelihood of competition. My research aimed to provide insight into the interactions and co-existence of a multi-carnivore community within a small, enclosed reserve in South Africa (Selati Game Reserve). I tackled this task by using a combination of field techniques including camera trap surveys, ungulate transect surveys, aerial count surveys, location data collected from collared large carnivores and scat and kill site analyses. I found that carnivore-carnivore interactions, and their associated impacts, varied within the carnivore guild and that co-existence may be due to trade-offs between various risks (i.e. interference and exploitative competition) and benefits (i.e. resources such as food and space). My findings also revealed that large carnivores, such as lions (Panthera leo), spotted hyaenas (Crocuta crocuta) and leopards (Panthera pardus) do not have homogenous effects and that site-specific research on multiple-carnivores is integral for conserving biodiversity and ecosystem dynamics. Lions were the dominant large carnivore (in terms of intra-guild predation, space use and resource use) despite being outnumbered seven to one by spotted hyaenas. Leopard occupancy was negatively influenced by lions and leopard diet overlapped almost completely (91%) with spotted hyaenas, suggesting increased kleptoparasitism of leopard kills by spotted hyaenas. While my study provides valuable insight into the complexity of carnivore intra-guild competition in a small, enclosed reserve it also highlights major research gaps and emphasises the need for ecosystem-based research throughout southern Africa to fully understand how multiple sympatric carnivores co-exist in these systems.
- Full Text:
- Date Issued: 2020
- Authors: Comley, Jessica
- Date: 2020
- Subjects: Hyenas -- Behavior -- South Africa , Hyenas -- South Africa , Hyenas -- Ecology -- South Africa , Top predators -- South Africa , Top predators -- Ecology -- South Africa , Animal communities -- South Africa , Animal behavior -- South Africa , Mutualism (Biology) -- South Africa , Coexistence of species -- South Africa , Game farms -- South Africa , Selati Game Reserve (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115558 , vital:34163
- Description: Carnivore intra-guild interactions can be important drivers of carnivore community composition and ecosystem functioning. Large carnivores are particularly important since they occupy the highest trophic levels and can exert extensive influences on subordinate carnivores and prey species. Given Africa’s rapidly expanding human population, enclosed reserves such as those found in South Africa, may become increasingly important for carnivore conservation. A major concern, however, is that the interactions and co-existence of multiple carnivores in these systems is poorly understood. Additionally, the majority of reserves in South Africa are small ( 400km²), potentially increasing the likelihood of competition. My research aimed to provide insight into the interactions and co-existence of a multi-carnivore community within a small, enclosed reserve in South Africa (Selati Game Reserve). I tackled this task by using a combination of field techniques including camera trap surveys, ungulate transect surveys, aerial count surveys, location data collected from collared large carnivores and scat and kill site analyses. I found that carnivore-carnivore interactions, and their associated impacts, varied within the carnivore guild and that co-existence may be due to trade-offs between various risks (i.e. interference and exploitative competition) and benefits (i.e. resources such as food and space). My findings also revealed that large carnivores, such as lions (Panthera leo), spotted hyaenas (Crocuta crocuta) and leopards (Panthera pardus) do not have homogenous effects and that site-specific research on multiple-carnivores is integral for conserving biodiversity and ecosystem dynamics. Lions were the dominant large carnivore (in terms of intra-guild predation, space use and resource use) despite being outnumbered seven to one by spotted hyaenas. Leopard occupancy was negatively influenced by lions and leopard diet overlapped almost completely (91%) with spotted hyaenas, suggesting increased kleptoparasitism of leopard kills by spotted hyaenas. While my study provides valuable insight into the complexity of carnivore intra-guild competition in a small, enclosed reserve it also highlights major research gaps and emphasises the need for ecosystem-based research throughout southern Africa to fully understand how multiple sympatric carnivores co-exist in these systems.
- Full Text:
- Date Issued: 2020
Centrality of religiosity as a moderator of the relationship between workplace spirituality and organisational citizenship behaviour among police officers in the Raymond Mhlaba Local Municipality
- Authors: Noko, Sibongile
- Date: 2020
- Subjects: Religion in the workplace Employees -- Religious life Organizational change
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12491 , vital:39268
- Description: The significant positive relationships between workplace spirituality and organisational citizenship behaviour, as well as between centrality of religiosity and oganisational citizenship behaviour among police officers, confirm the relevance of social exchange theory and affective events theory to police officers’ behaviour. This study confirms the applicability of Social Exchange Theory (SET) and Affective Events Theory (AET). The current study utilized the SET and AET to examine the correlation between workplace spirituality and centrality of religiosity as well as organisational citizenship behaviour among Police officers in the Raymond Mlaba Local Municipality of the Eastern Cape. There is limited previous research concerning the influence of workplace spirituality and centrality of religiosity on organisational citizenship behaviour among police officers in the South African Police Services (SAPS) Department. A quantitative cross-sectional survey was conducted. The sample (N= 100) consist of Police officers from Raymond Mhlaba Local Municipality Police stations. Data were collected through the questionnaire method and SPSS was used for data analysis. A correlational analysis coupled with a simple linear regression analysis was utilised to determine whether there existed any significant relationship with the study’s theoretical attributes. The results of the simple linear regression indicated that workplace spirituality is positively correlated with organisational citizenship behaviour; which is similar to the centrality of religiosity. The results from multiple linear regression showed that the centrality of religiosity does moderate the correlation between workplace spirituality and organisational citizenship behaviour. The results of Multiple linear regression also showed that Workplace spirituality and centrality of religiosity both account for an extensively higher proportion vi of variance in organisational citizenship behaviour than in any of the two variables. This study augments existing knowledge on workplace spirituality, the centrality of religiosity and organisational citizenship behaviour among Police officers in the Raymond Mhlaba Local Municipality, which has largely been ignored by previous researchers, validates certain aspects of the SET and AET. The Station Commanders or Captains should give consideration on how to make the workplace more conducive to the centrality of religiosity and workplace spirituality; so that the Police officers can increase their organisational citizenship behaviour. Strategies need to be implemented to improve managerial and coworker support for Police officers through socialization and team building activities. However, to overcome feelings of occupational stress and their effects on well-being, employers should provide adequate information on any changes in the police service that may entail excessive work demand and dangerous working conditions.
- Full Text:
- Date Issued: 2020
- Authors: Noko, Sibongile
- Date: 2020
- Subjects: Religion in the workplace Employees -- Religious life Organizational change
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12491 , vital:39268
- Description: The significant positive relationships between workplace spirituality and organisational citizenship behaviour, as well as between centrality of religiosity and oganisational citizenship behaviour among police officers, confirm the relevance of social exchange theory and affective events theory to police officers’ behaviour. This study confirms the applicability of Social Exchange Theory (SET) and Affective Events Theory (AET). The current study utilized the SET and AET to examine the correlation between workplace spirituality and centrality of religiosity as well as organisational citizenship behaviour among Police officers in the Raymond Mlaba Local Municipality of the Eastern Cape. There is limited previous research concerning the influence of workplace spirituality and centrality of religiosity on organisational citizenship behaviour among police officers in the South African Police Services (SAPS) Department. A quantitative cross-sectional survey was conducted. The sample (N= 100) consist of Police officers from Raymond Mhlaba Local Municipality Police stations. Data were collected through the questionnaire method and SPSS was used for data analysis. A correlational analysis coupled with a simple linear regression analysis was utilised to determine whether there existed any significant relationship with the study’s theoretical attributes. The results of the simple linear regression indicated that workplace spirituality is positively correlated with organisational citizenship behaviour; which is similar to the centrality of religiosity. The results from multiple linear regression showed that the centrality of religiosity does moderate the correlation between workplace spirituality and organisational citizenship behaviour. The results of Multiple linear regression also showed that Workplace spirituality and centrality of religiosity both account for an extensively higher proportion vi of variance in organisational citizenship behaviour than in any of the two variables. This study augments existing knowledge on workplace spirituality, the centrality of religiosity and organisational citizenship behaviour among Police officers in the Raymond Mhlaba Local Municipality, which has largely been ignored by previous researchers, validates certain aspects of the SET and AET. The Station Commanders or Captains should give consideration on how to make the workplace more conducive to the centrality of religiosity and workplace spirituality; so that the Police officers can increase their organisational citizenship behaviour. Strategies need to be implemented to improve managerial and coworker support for Police officers through socialization and team building activities. However, to overcome feelings of occupational stress and their effects on well-being, employers should provide adequate information on any changes in the police service that may entail excessive work demand and dangerous working conditions.
- Full Text:
- Date Issued: 2020
Challenges experienced by educators of tourism and coping strategies
- Authors: Muller, Merilyn Elizabeth
- Date: 2020
- Subjects: Tourism -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/49964 , vital:41965
- Description: Education is imperative for the economy and for the employment of the youth, particularly given the high levels of youth unemployment in South Africa. The introduction of Tourism as a school subject is perceived as a gateway to employment opportunities for unemployed people and as a means to stimulate the economy of the country. Educators, especially in South African township schools, often teach in less favourable conditions and experience many challenges which require innovative solutions. This study contributes to an understanding of the challenges faced by educators teaching Tourism, especially educators teaching in township areas in the Nelson Mandela Bay district. Of particular importance is the coping strategies used by these educators to innovatively deal with these challenges. This purpose of the study was therefore to investigate the challenges experienced by educators that teach Tourism at township high schools in two Circuit Management Centres (CMC) in the Nelson Mandela Bay district in Port Elizabeth. A qualitative research design was followed with interviews as the empirical data collecting tool. The sample consisted of 16 educators teaching Tourism to Grade 11 and 12 learners at selected schools. The data collected was analysed qualitatively, using thematic analysis. The findings of this study revealed many challenges experienced by educators of Tourism at township schools in the Nelson Mandela Bay district. The key challenges for educators related to resources, learners, the system, teachers and infrastructure. The results revealed that the educators used a variety of coping techniques to deal with these challenges. The researcher makes recommendations to the different stakeholders in education to address these challenges, as well as make suggestions for future research.
- Full Text:
- Date Issued: 2020
- Authors: Muller, Merilyn Elizabeth
- Date: 2020
- Subjects: Tourism -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/49964 , vital:41965
- Description: Education is imperative for the economy and for the employment of the youth, particularly given the high levels of youth unemployment in South Africa. The introduction of Tourism as a school subject is perceived as a gateway to employment opportunities for unemployed people and as a means to stimulate the economy of the country. Educators, especially in South African township schools, often teach in less favourable conditions and experience many challenges which require innovative solutions. This study contributes to an understanding of the challenges faced by educators teaching Tourism, especially educators teaching in township areas in the Nelson Mandela Bay district. Of particular importance is the coping strategies used by these educators to innovatively deal with these challenges. This purpose of the study was therefore to investigate the challenges experienced by educators that teach Tourism at township high schools in two Circuit Management Centres (CMC) in the Nelson Mandela Bay district in Port Elizabeth. A qualitative research design was followed with interviews as the empirical data collecting tool. The sample consisted of 16 educators teaching Tourism to Grade 11 and 12 learners at selected schools. The data collected was analysed qualitatively, using thematic analysis. The findings of this study revealed many challenges experienced by educators of Tourism at township schools in the Nelson Mandela Bay district. The key challenges for educators related to resources, learners, the system, teachers and infrastructure. The results revealed that the educators used a variety of coping techniques to deal with these challenges. The researcher makes recommendations to the different stakeholders in education to address these challenges, as well as make suggestions for future research.
- Full Text:
- Date Issued: 2020
Challenges of electronic surveillance in combating crime and addressing developmental issues in Port Elizabeth
- Authors: Dyasi, Alutha Vusisizwe
- Date: 2020
- Subjects: Electronics in criminal investigation --South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/49823 , vital:41805
- Description: Crime has been prevalent in South Africa, particularly in Port Elizabeth where violent crimes such as attempted murder, murder, sexual offences, robbery and hijacking have been reported to the South African Police Service. These violent crimes are mostly prevalent in police precincts such as Gelvandale, Bethelsdorp, Kwazakhele, New Brighton and Walmer. As a result, development in these police precincts has been affected negatively. This is highlighted by how developmental issues such as poverty and unemployment have been ubiquitous due to the manner with which crime has an effect on development. ICT companies are continuously providing solutions to crime-related challenges. The emergence of new technologies, such as CCTV surveillance cameras, drones and facial recognition software have been proven to be a solution to combating crime in some developing countries in Africa. Thus, the purpose of this study was to examine the challenges of electronic surveillance in combating crime and addressing developmental issues in Port Elizabeth. The study found out that the developmental issues faced by communities in Port Elizabeth include unemployment, poverty, a high crime rate, substance abuse, and a lack of resources. In addition, the study concluded that, the lack of education and skills development, gangsterism, unemployment and poverty were amongst the main causes of crime in Port Elizabeth. The study also revealed that, the SAPS does not have enough electronic surveillance devices such as CCTV cameras installed in high crime areas, thus, recommendations were made on how electronic surveillance can be used to combat crime and address developmental issues
- Full Text:
- Date Issued: 2020
- Authors: Dyasi, Alutha Vusisizwe
- Date: 2020
- Subjects: Electronics in criminal investigation --South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/49823 , vital:41805
- Description: Crime has been prevalent in South Africa, particularly in Port Elizabeth where violent crimes such as attempted murder, murder, sexual offences, robbery and hijacking have been reported to the South African Police Service. These violent crimes are mostly prevalent in police precincts such as Gelvandale, Bethelsdorp, Kwazakhele, New Brighton and Walmer. As a result, development in these police precincts has been affected negatively. This is highlighted by how developmental issues such as poverty and unemployment have been ubiquitous due to the manner with which crime has an effect on development. ICT companies are continuously providing solutions to crime-related challenges. The emergence of new technologies, such as CCTV surveillance cameras, drones and facial recognition software have been proven to be a solution to combating crime in some developing countries in Africa. Thus, the purpose of this study was to examine the challenges of electronic surveillance in combating crime and addressing developmental issues in Port Elizabeth. The study found out that the developmental issues faced by communities in Port Elizabeth include unemployment, poverty, a high crime rate, substance abuse, and a lack of resources. In addition, the study concluded that, the lack of education and skills development, gangsterism, unemployment and poverty were amongst the main causes of crime in Port Elizabeth. The study also revealed that, the SAPS does not have enough electronic surveillance devices such as CCTV cameras installed in high crime areas, thus, recommendations were made on how electronic surveillance can be used to combat crime and address developmental issues
- Full Text:
- Date Issued: 2020
Change of perspectives and behaviour regarding lifestyle, with emphasis on dietary habits, in a rural community
- Authors: Barnard, Mariska
- Date: 2020
- Subjects: Food habits
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46384 , vital:39565
- Description: Background: The steady increase in deaths due to non-communicable diseases (NCDs) in South Africa is raising concern, as 63% of all deaths worldwide are attributed to NCDs and these diseases cause 36 million deaths each year, with 80 % of incidences occurring in low-and middle-income countries. In rural communities where income is increasing, the prevalence of NCDs are increasing as well. Due to the lack of NCD prevention and treatment in rural communities, it is expected that, if health promotion strategies are not implemented and socio-economic development in South Africa continues, there will soon be an uncontrollable NCD epidemic. It has been found that dietary risks affected people’s healthirrespective of their age, gender or residential sociodemographic development and that dietary improvement might prevent one in every five deaths worldwide.Aim:The aim of this study was to determine the factors that influence the perceptions and behaviour in a rural community with a low socio-economic status regarding dietary habits and to use the knowledge to formulate an effective dietary modification strategy.Designand methodology:For this study,action research with a quantitative and qualitative component was followed.The quantitative component focuses on measureable aspects, and the qualitative component focuses on meaning. Data was collected following the standard operating procedure for anthropometry, blood pressure and blood glucose. Further methods used were questionnaires, 24-hour dietary recalls and focus group discussions. Data were analysed using Microsoft Excel, FoodFinder3 and other calculations.Sample and setting:A convenience sample (n = 16) wasused and this study was undertaken on request of the non-governmental organization, Karoo Angels and included all participants who earn an income and who do not work for themselves, that were willing to participate and living in Rietbron and Vondeling, in the Sarah BaartmanDistrict in the Eastern Cape. Results:Weight changes took place, both the crafters in the mild thinness category gained weight, one gained 3.9 kg and the other 0.5 kg. The three crafters in the normal category did not have to gain or lose weight, but all three ofthem gained an average of 3.6 kg. For the group who had to lose weight, no statistically significant weight change took place from before the intervention (76.08 ±17.67 kg) to after the intervention (75.81 ± 17.81 kg, t(10) = 0.692, p = 0.505). The maximum weight lost ivwas 3.1 kg and the maximum weight gained was 3.2 kg. Changes took place regarding BMI, waist circumference, waist-to-hip ratio and neck circumference. Some positively changed their BMI status.After the implementation of the intervention, there was a slight decrease in frequency of alcohol consumption, but smoking and physical activity remained mostly the same. Hypertension was the most prevalent NCD and is linked to smoking and alcohol consumption which is prevalent in this study. Fruit and vegetable consumption is low, and a slight increase in consumption was evident. A maximum dietary diversityscore of seven and minimum of two, where the mean was 3.81was found. The crafters’ diet did not meet the DASH diet recommendation,the mean energy distribution is of all macronutrients differ with ±4% and none of the participants’ mean micronutrients intake met the recommendations of the DASH diet or RDA. Factors that prevent them from reaching their goals included low income, low availability of fruit, vegetables and transport and no storage for food.Conclusion:It is important to consider the individuals’ living conditions, resources, knowledge, motivation and social group. The environment and resources available have a significant impact on the lifestyle of the individuals. Directing efforts of behaviour change to increase dietary diversity as the main objective, might be a more efficient way to change behaviour.Recommendations:Future studies should consider doing this study over a longer time period. The involvement of a psychologist would also be beneficial to assist the process of behaviour change.
- Full Text:
- Date Issued: 2020
- Authors: Barnard, Mariska
- Date: 2020
- Subjects: Food habits
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46384 , vital:39565
- Description: Background: The steady increase in deaths due to non-communicable diseases (NCDs) in South Africa is raising concern, as 63% of all deaths worldwide are attributed to NCDs and these diseases cause 36 million deaths each year, with 80 % of incidences occurring in low-and middle-income countries. In rural communities where income is increasing, the prevalence of NCDs are increasing as well. Due to the lack of NCD prevention and treatment in rural communities, it is expected that, if health promotion strategies are not implemented and socio-economic development in South Africa continues, there will soon be an uncontrollable NCD epidemic. It has been found that dietary risks affected people’s healthirrespective of their age, gender or residential sociodemographic development and that dietary improvement might prevent one in every five deaths worldwide.Aim:The aim of this study was to determine the factors that influence the perceptions and behaviour in a rural community with a low socio-economic status regarding dietary habits and to use the knowledge to formulate an effective dietary modification strategy.Designand methodology:For this study,action research with a quantitative and qualitative component was followed.The quantitative component focuses on measureable aspects, and the qualitative component focuses on meaning. Data was collected following the standard operating procedure for anthropometry, blood pressure and blood glucose. Further methods used were questionnaires, 24-hour dietary recalls and focus group discussions. Data were analysed using Microsoft Excel, FoodFinder3 and other calculations.Sample and setting:A convenience sample (n = 16) wasused and this study was undertaken on request of the non-governmental organization, Karoo Angels and included all participants who earn an income and who do not work for themselves, that were willing to participate and living in Rietbron and Vondeling, in the Sarah BaartmanDistrict in the Eastern Cape. Results:Weight changes took place, both the crafters in the mild thinness category gained weight, one gained 3.9 kg and the other 0.5 kg. The three crafters in the normal category did not have to gain or lose weight, but all three ofthem gained an average of 3.6 kg. For the group who had to lose weight, no statistically significant weight change took place from before the intervention (76.08 ±17.67 kg) to after the intervention (75.81 ± 17.81 kg, t(10) = 0.692, p = 0.505). The maximum weight lost ivwas 3.1 kg and the maximum weight gained was 3.2 kg. Changes took place regarding BMI, waist circumference, waist-to-hip ratio and neck circumference. Some positively changed their BMI status.After the implementation of the intervention, there was a slight decrease in frequency of alcohol consumption, but smoking and physical activity remained mostly the same. Hypertension was the most prevalent NCD and is linked to smoking and alcohol consumption which is prevalent in this study. Fruit and vegetable consumption is low, and a slight increase in consumption was evident. A maximum dietary diversityscore of seven and minimum of two, where the mean was 3.81was found. The crafters’ diet did not meet the DASH diet recommendation,the mean energy distribution is of all macronutrients differ with ±4% and none of the participants’ mean micronutrients intake met the recommendations of the DASH diet or RDA. Factors that prevent them from reaching their goals included low income, low availability of fruit, vegetables and transport and no storage for food.Conclusion:It is important to consider the individuals’ living conditions, resources, knowledge, motivation and social group. The environment and resources available have a significant impact on the lifestyle of the individuals. Directing efforts of behaviour change to increase dietary diversity as the main objective, might be a more efficient way to change behaviour.Recommendations:Future studies should consider doing this study over a longer time period. The involvement of a psychologist would also be beneficial to assist the process of behaviour change.
- Full Text:
- Date Issued: 2020