Investigating the fitness of sea turtles nesting in South Africa
- Le Gouvello du Timat, Diane Z M
- Authors: Le Gouvello du Timat, Diane Z M
- Date: 2020
- Subjects: Sea turtles -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48445 , vital:40877
- Description: The South African rookeries of the South Western Indian Ocean (SWIO) loggerhead and leatherback regional management units have been continuously monitored for more than 5 decades, representing one of the longest-running sea turtle beach protection and monitoring programmes in the world. Although such conservation has been successful in protecting adults on land when they come to nest, it might not be enough to ensure population recovery if survival is not ensured across all life stages. Sea turtles are particularly vulnerable to direct threats and changing environmental conditions because they are long-lived, slow maturing, and have low survival rates at early life stages, making them conservation-dependent. These characteristics also render them difficult to conserve as a consequence of their wide geographic distributions, spanning multiple jurisdictions and legislative systems with different conservation targets, and a complex life cycle with changes in habitats and diets at different life stages. Sea turtle populations have been severely depleted as a result of historical over-exploitation and current threats including fisheries bycatch, direct harvest, habitat loss, pollution and pathogens, and climate change. In many cases however, population declines have been reversed by a variety of effective conservation measures such as beach protection programs, and marine protected areas, enabling successful population recovery around the world. Despite protection and apparent increase in abundance, indirect pressures can still affect turtle populations. Therefore, it is fundamental to evaluate the effectiveness of conservation measures (using fitness traits such as female and hatchling sizes) and examine underlying trends. The aim of this thesis was thus to evaluate the fitness of loggerhead and leatherback sea turtles nesting in South Africa. Long-term female size trends over time were evaluated and the populations were split between first-time nesters and experienced nesters. As sea turtle reproductive output (clutch size only) is correlated with female size and evidence is showing that in some populations individual female size is decreasing, the effects of maternal body size on reproductive output and hatchling fitness were investigated for both species. Crawling and swimming speeds were used as proxies of hatchling fitness, because these two traits positively influence their survival. An oceanic model was further used in combination with a particle tracking framework to estimate, for the first time, post-hatchling dispersal of loggerhead and leatherback turtles in the SWIO. I investigated whether the trend in female size for loggerhead turtles nesting in South Africa is a result of their foraging strategy to determine if there is a foraging dichotomy (neritic and oceanic). Despite an apparent increasing population, a significant 3.7 and 3.6 cm decrease in the size of both recruit and remingrant female loggerhead turtles, but a stable mean size of leatherbacks for both age groups was observed. I hypothesise that these contradictory effects are attributable to the very distinct foraging ecologies of the two turtle species and speculate that these variations in carapace length may be driven by environmental change. The reproductive strategy of both loggerhead and leatherback turtles nesting in South Africa supports the optimal egg size theory with larger turtles producing larger clutches but not larger eggs. Egg size was thus constant irrespective of maternal length. Hatchlings with longer carapaces and flippers had higher swimming speed, suggesting that larger hatchlings are fitter (potentially higher survival) than smaller ones by spending less time in high predation risk areas (i.e. beach and nearshore). The model revealed that dispersal trajectories of both loggerhead and leatherback sea turtle hatchlings were very similar and simulations indicated that initial active swimming (frenzy) as well as variability in oceanic conditions strongly influenced dispersal of virtual hatchlings. The trends observed in this study emphasize the importance of long-term monitoring, examining not only abundance but also individual size, to understand population dynamics, support recovery planning and prioritize future conservation practices. Furthermore, the findings of this study have important implications for overall population growth if smaller hatchlings of lower fitness are produced as a result of climate change and thus have decreased dispersal abilities and lower likelihood of survival.
- Full Text:
- Date Issued: 2020
- Authors: Le Gouvello du Timat, Diane Z M
- Date: 2020
- Subjects: Sea turtles -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48445 , vital:40877
- Description: The South African rookeries of the South Western Indian Ocean (SWIO) loggerhead and leatherback regional management units have been continuously monitored for more than 5 decades, representing one of the longest-running sea turtle beach protection and monitoring programmes in the world. Although such conservation has been successful in protecting adults on land when they come to nest, it might not be enough to ensure population recovery if survival is not ensured across all life stages. Sea turtles are particularly vulnerable to direct threats and changing environmental conditions because they are long-lived, slow maturing, and have low survival rates at early life stages, making them conservation-dependent. These characteristics also render them difficult to conserve as a consequence of their wide geographic distributions, spanning multiple jurisdictions and legislative systems with different conservation targets, and a complex life cycle with changes in habitats and diets at different life stages. Sea turtle populations have been severely depleted as a result of historical over-exploitation and current threats including fisheries bycatch, direct harvest, habitat loss, pollution and pathogens, and climate change. In many cases however, population declines have been reversed by a variety of effective conservation measures such as beach protection programs, and marine protected areas, enabling successful population recovery around the world. Despite protection and apparent increase in abundance, indirect pressures can still affect turtle populations. Therefore, it is fundamental to evaluate the effectiveness of conservation measures (using fitness traits such as female and hatchling sizes) and examine underlying trends. The aim of this thesis was thus to evaluate the fitness of loggerhead and leatherback sea turtles nesting in South Africa. Long-term female size trends over time were evaluated and the populations were split between first-time nesters and experienced nesters. As sea turtle reproductive output (clutch size only) is correlated with female size and evidence is showing that in some populations individual female size is decreasing, the effects of maternal body size on reproductive output and hatchling fitness were investigated for both species. Crawling and swimming speeds were used as proxies of hatchling fitness, because these two traits positively influence their survival. An oceanic model was further used in combination with a particle tracking framework to estimate, for the first time, post-hatchling dispersal of loggerhead and leatherback turtles in the SWIO. I investigated whether the trend in female size for loggerhead turtles nesting in South Africa is a result of their foraging strategy to determine if there is a foraging dichotomy (neritic and oceanic). Despite an apparent increasing population, a significant 3.7 and 3.6 cm decrease in the size of both recruit and remingrant female loggerhead turtles, but a stable mean size of leatherbacks for both age groups was observed. I hypothesise that these contradictory effects are attributable to the very distinct foraging ecologies of the two turtle species and speculate that these variations in carapace length may be driven by environmental change. The reproductive strategy of both loggerhead and leatherback turtles nesting in South Africa supports the optimal egg size theory with larger turtles producing larger clutches but not larger eggs. Egg size was thus constant irrespective of maternal length. Hatchlings with longer carapaces and flippers had higher swimming speed, suggesting that larger hatchlings are fitter (potentially higher survival) than smaller ones by spending less time in high predation risk areas (i.e. beach and nearshore). The model revealed that dispersal trajectories of both loggerhead and leatherback sea turtle hatchlings were very similar and simulations indicated that initial active swimming (frenzy) as well as variability in oceanic conditions strongly influenced dispersal of virtual hatchlings. The trends observed in this study emphasize the importance of long-term monitoring, examining not only abundance but also individual size, to understand population dynamics, support recovery planning and prioritize future conservation practices. Furthermore, the findings of this study have important implications for overall population growth if smaller hatchlings of lower fitness are produced as a result of climate change and thus have decreased dispersal abilities and lower likelihood of survival.
- Full Text:
- Date Issued: 2020
Evaluation of a plant-herbivore system in determining potential efficacy of a candidate biological control agent, cornops aquaticum for water hyacinth, eichhornia crassipes
- Authors: Bownes, Angela
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Grasshoppers , Biological pest control agents -- South Africa , Weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5687 , http://hdl.handle.net/10962/d1005373
- Description: Water hyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a freefloating aquatic macrophyte of Neotropical origin, was introduced into South Africa as an ornamental aquarium plant in the early 1900’s. By the 1970’s it had reached pest proportions in dams and rivers around the country. Due to the sustainability, cost efficiency and low environmental risk associated with biological control, this has been a widely used method in an attempt to reduce infestations to below the threshold where they cause economic and ecological damage. To date, five arthropod and one pathogen biocontrol agents have been introduced for the control of water hyacinth but their impact has been variable. It is believed that their efficacy is hampered by the presence of highly eutrophic systems in South Africa in which plant growth is prolific and the negative effects of herbivory are therefore mitigated. It is for these reasons that new, potentially more damaging biocontrol agents are being considered for release. The water hyacinth grasshopper, Cornops aquaticum Brüner (Orthoptera: Acrididae), which is native to South America and Mexico, was brought into quarantine in Pretoria, South Africa in 1995. Although the grasshopper was identified as one of the most damaging insects associated with water hyacinth in its native range, it has not been considered as a biocontrol agent for water hyacinth anywhere else in the world. After extensive host-range testing which revealed it to be safe for release, a release permit for this candidate agent was issued in 2007. However, host specificity testing is no longer considered to be the only important component of pre-release screening of candidate biocontrol agents. Investigating biological and ecological aspects of the plant-herbivore system that will assist in determination of potential establishment, efficacy and the ability to build up good populations in the recipient environment are some of the important factors. This thesis is a pre-release evaluation of C. aquaticum to determine whether it is sufficiently damaging to water hyacinth to warrant its release. It investigated interactions between the grasshopper and water hyacinth under a range of nutrient conditions found in South African water bodies as well as the impact of the grasshopper on the competitive performance of water hyacinth. Both plant growth rates and the response of water hyacinth to herbivory by the grasshopper were influenced by nutrient availability to the plants. The ability of water hyacinth to compensate for loss of tissue through herbivory was greater under eutrophic nutrient conditions. However, a negative linear relationship was found between grasshopper biomass and water hyacinth performance parameters such as biomass accumulation and leaf production, even under eutrophic conditions. Water hyacinth’s compensatory ability in terms of its potential to mitigate to detrimental effects of insect feeding was dependent on the amount of damage caused by herbivory by the grasshopper. Plant biomass and the competitive ability of water hyacinth in relation to another freefloating aquatic weed species were reduced by C. aquaticum under eutrophic nutrient conditions, in a short space of time. It was also found that grasshopper feeding and characteristics related to their population dynamics such as fecundity and survival were significantly influenced by water nutrient availability and that environmental nutrient availability will influence the control potential of this species should it be released in South Africa. Cornops aquaticum shows promise as a biocontrol agent for water hyacinth but additional factors that were not investigated in this study such as compatibility with the South African climate and the current water hyacinth biocontrol agents need to be combined with these data to make a decision on its release. Possible management options for this species if it is to be introduced into South Africa are discussed.
- Full Text:
- Date Issued: 2009
- Authors: Bownes, Angela
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Grasshoppers , Biological pest control agents -- South Africa , Weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5687 , http://hdl.handle.net/10962/d1005373
- Description: Water hyacinth, Eichhornia crassipes Mart. Solms-Laubach (Pontederiaceae), a freefloating aquatic macrophyte of Neotropical origin, was introduced into South Africa as an ornamental aquarium plant in the early 1900’s. By the 1970’s it had reached pest proportions in dams and rivers around the country. Due to the sustainability, cost efficiency and low environmental risk associated with biological control, this has been a widely used method in an attempt to reduce infestations to below the threshold where they cause economic and ecological damage. To date, five arthropod and one pathogen biocontrol agents have been introduced for the control of water hyacinth but their impact has been variable. It is believed that their efficacy is hampered by the presence of highly eutrophic systems in South Africa in which plant growth is prolific and the negative effects of herbivory are therefore mitigated. It is for these reasons that new, potentially more damaging biocontrol agents are being considered for release. The water hyacinth grasshopper, Cornops aquaticum Brüner (Orthoptera: Acrididae), which is native to South America and Mexico, was brought into quarantine in Pretoria, South Africa in 1995. Although the grasshopper was identified as one of the most damaging insects associated with water hyacinth in its native range, it has not been considered as a biocontrol agent for water hyacinth anywhere else in the world. After extensive host-range testing which revealed it to be safe for release, a release permit for this candidate agent was issued in 2007. However, host specificity testing is no longer considered to be the only important component of pre-release screening of candidate biocontrol agents. Investigating biological and ecological aspects of the plant-herbivore system that will assist in determination of potential establishment, efficacy and the ability to build up good populations in the recipient environment are some of the important factors. This thesis is a pre-release evaluation of C. aquaticum to determine whether it is sufficiently damaging to water hyacinth to warrant its release. It investigated interactions between the grasshopper and water hyacinth under a range of nutrient conditions found in South African water bodies as well as the impact of the grasshopper on the competitive performance of water hyacinth. Both plant growth rates and the response of water hyacinth to herbivory by the grasshopper were influenced by nutrient availability to the plants. The ability of water hyacinth to compensate for loss of tissue through herbivory was greater under eutrophic nutrient conditions. However, a negative linear relationship was found between grasshopper biomass and water hyacinth performance parameters such as biomass accumulation and leaf production, even under eutrophic conditions. Water hyacinth’s compensatory ability in terms of its potential to mitigate to detrimental effects of insect feeding was dependent on the amount of damage caused by herbivory by the grasshopper. Plant biomass and the competitive ability of water hyacinth in relation to another freefloating aquatic weed species were reduced by C. aquaticum under eutrophic nutrient conditions, in a short space of time. It was also found that grasshopper feeding and characteristics related to their population dynamics such as fecundity and survival were significantly influenced by water nutrient availability and that environmental nutrient availability will influence the control potential of this species should it be released in South Africa. Cornops aquaticum shows promise as a biocontrol agent for water hyacinth but additional factors that were not investigated in this study such as compatibility with the South African climate and the current water hyacinth biocontrol agents need to be combined with these data to make a decision on its release. Possible management options for this species if it is to be introduced into South Africa are discussed.
- Full Text:
- Date Issued: 2009
The effect of elevated CO₂ on Phaseolus vulgaris L. cv Contender
- Authors: Mjwara, Jabulani Michael
- Date: 1997
- Subjects: Plants -- Effect of carbon dioxide on Kidney bean
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4215 , http://hdl.handle.net/10962/d1003784
- Description: The response of Phaseolus vulgaris L. cv. Contender grown in controlled environmental conditions, at either ambient or elevated (360 and 700 μmol mol ̄¹, respectively) CO₂ concentrations ([CO₂]), was monitored from 10 days after germination (DAG) until the onset of senescence. Elevated CO₂ had a pronounced effect on total plant height (TPH), leaf area (LA), dry weight (DW) accumulation and specific leaf area (SLA). All of these were significantly increased by elevated [CO₂] with the exception of SLA, which was significantly reduced. Except for higher initial relative growth rates (RGR) in CO₂-enriched plants, RGR did not differ significantly between the two CO₂ treatments throughout the remainder of growth period. While growth parameters clearly differed between CO₂ treatments, the effects of CO₂ on many physiological processes including net assimilation rate (NAR), Rubisco activity, and some foliar nutrient concentrations were largely transient. For example, CO₂ enrichment significantly increased NAR, but from 20 DAG onward, NAR declined to levels measured on plants grown under ambient CO₂. Similarly, the decline in both foliar N concentration and Rubisco activity in CO₂-enriched plants after 20 DAG was significantly greater than the decline observed for ambient CO₂ plants. Soluble leaf protein and total chlorophylls (a+b) were also significantly reduced in plants grown under elevated CO₂. Chlorophyll (a/b) ratios increased with time underelevated CO₂, indicating that the rate of decline of chlorophyll b was higher than that of chorophyll α. No significant changes in total carotenoid (x+c) levels were observed in either CO₂ treatment. Under enhanced CO₂, the foliar concentrations of K and Mn were increased significantly, while P, Ca, Fe and Zn were reduced significantly. However, changes in Mg and Cu concentrations were not significant. High CO₂-grown plants also exhibited pronounced leaf discoloration or chlorosis, coupled with a significant reduction in leaf longevity. The levels of non-structural carbohydrates (sucrose, glucose, fructose and starch) and nitrogenous compounds (nitrogen, total soluble proteins and free amino acids) were determined for leaves and developing seeds of P. vulgaris. Leaf tissue of elevated CO₂-grown plants accumulated significantly higher levels of both soluble sugars and starch. Leaf ultrastructure revealed considerable erilargement of starch grain sizes with surface areas more than five times larger compared to those of control plants. No apparent differences in structure and membrane integrity of chloroplasts in both CO₂ treatments were noted. Although ambient CO₂-grown plants had comparatively low levels of non-structural carbohydrates (NSC), they accumulated significantly higher levels of nitrogenous compounds. The levels of NSC were consistently higher in seeds of plants grown under elevated CO₂. In comparison to plants grown at elevated [CO₂], pods and seeds of ambient CO₂-grown plants had significantly larger pools of free amino compounds and N. Stomatal conductance (gs) declined significantly, as expected for plants grown under elevated CO₂. This was accompanied by a decline in transpiration rates (E). Reduced gs and E led to high AlE ratio, which meant improved water use efficiency (WUE) values for CO₂-enriched bean plants. Leaf carbon isotope discrimination (∆) against the heavier isotope of carbon (¹³C), has been used to select for high WUE in C₃ plants. In plants grown at elevated CO₂ concentration, ,1 was significantly reduced. Although ∆ was negatively correlated with WUE in both CO₂ treatments, the correlation was steeper and highly negative for CO₂-enriched plants. These results indicate underlying differences in gas-exchange physiology, including stomatal responses between ambient and elevated CO₂-grown plants. Photosynthetic acclimation was investigated using the response of assimilation to internal carbon dioxide concentration (A/C₁ curves). At early stages of growth, the initial slope of the A/C₁ response curve did not differ with CO₂ treatment. In contrast, CO₂-saturated photosynthetic rate (Amax) was significantly higher in plants grown under elevated versus ambient CO₂ at 15 DAG. However, at subsequent stages of growth both the initial slope and Amax declined in bean plants grown in elevated CO₂. Apparent carboxylation efficiency (ACE, estimated from the initial slope of A/C₁ response) values followed a similar trend and were significantly reduced in CO₂-enriched plants. These results indicate that acclimation or negative adjustment of photosynthesis may have been caused by a combination of both stomatal and biochemical limitations. Bean plants grown under conditions of elevated atmospheric CO₂ flowered 3 to 4 days earlier, and produced significantly more flowers and pods than plants grown at ambient conditions. Plants grown at elevated CO₂ aborted 22 and 20% more flowers and pods, respectively, than plants grown at ambient CO₂. Elevated CO₂ also significantly increased the number of tillers or lateral branches produced by plants, which contributed to a significant increase in pod number and seed yield in these plants. Although plants grown at elevated CO₂ produced on average 8 seeds per pod, while plants grown under ambient CO2 conditions produced 5 seeds per pod, the greater number of seeds was offset by lower seed weights in plants grown under _ elevated CO₂. Thus, despite high seed yield in beans grown under elevated CO₂, the harvest index (HI) did not change significantly between CO₂ treatments.
- Full Text:
- Date Issued: 1997
- Authors: Mjwara, Jabulani Michael
- Date: 1997
- Subjects: Plants -- Effect of carbon dioxide on Kidney bean
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4215 , http://hdl.handle.net/10962/d1003784
- Description: The response of Phaseolus vulgaris L. cv. Contender grown in controlled environmental conditions, at either ambient or elevated (360 and 700 μmol mol ̄¹, respectively) CO₂ concentrations ([CO₂]), was monitored from 10 days after germination (DAG) until the onset of senescence. Elevated CO₂ had a pronounced effect on total plant height (TPH), leaf area (LA), dry weight (DW) accumulation and specific leaf area (SLA). All of these were significantly increased by elevated [CO₂] with the exception of SLA, which was significantly reduced. Except for higher initial relative growth rates (RGR) in CO₂-enriched plants, RGR did not differ significantly between the two CO₂ treatments throughout the remainder of growth period. While growth parameters clearly differed between CO₂ treatments, the effects of CO₂ on many physiological processes including net assimilation rate (NAR), Rubisco activity, and some foliar nutrient concentrations were largely transient. For example, CO₂ enrichment significantly increased NAR, but from 20 DAG onward, NAR declined to levels measured on plants grown under ambient CO₂. Similarly, the decline in both foliar N concentration and Rubisco activity in CO₂-enriched plants after 20 DAG was significantly greater than the decline observed for ambient CO₂ plants. Soluble leaf protein and total chlorophylls (a+b) were also significantly reduced in plants grown under elevated CO₂. Chlorophyll (a/b) ratios increased with time underelevated CO₂, indicating that the rate of decline of chlorophyll b was higher than that of chorophyll α. No significant changes in total carotenoid (x+c) levels were observed in either CO₂ treatment. Under enhanced CO₂, the foliar concentrations of K and Mn were increased significantly, while P, Ca, Fe and Zn were reduced significantly. However, changes in Mg and Cu concentrations were not significant. High CO₂-grown plants also exhibited pronounced leaf discoloration or chlorosis, coupled with a significant reduction in leaf longevity. The levels of non-structural carbohydrates (sucrose, glucose, fructose and starch) and nitrogenous compounds (nitrogen, total soluble proteins and free amino acids) were determined for leaves and developing seeds of P. vulgaris. Leaf tissue of elevated CO₂-grown plants accumulated significantly higher levels of both soluble sugars and starch. Leaf ultrastructure revealed considerable erilargement of starch grain sizes with surface areas more than five times larger compared to those of control plants. No apparent differences in structure and membrane integrity of chloroplasts in both CO₂ treatments were noted. Although ambient CO₂-grown plants had comparatively low levels of non-structural carbohydrates (NSC), they accumulated significantly higher levels of nitrogenous compounds. The levels of NSC were consistently higher in seeds of plants grown under elevated CO₂. In comparison to plants grown at elevated [CO₂], pods and seeds of ambient CO₂-grown plants had significantly larger pools of free amino compounds and N. Stomatal conductance (gs) declined significantly, as expected for plants grown under elevated CO₂. This was accompanied by a decline in transpiration rates (E). Reduced gs and E led to high AlE ratio, which meant improved water use efficiency (WUE) values for CO₂-enriched bean plants. Leaf carbon isotope discrimination (∆) against the heavier isotope of carbon (¹³C), has been used to select for high WUE in C₃ plants. In plants grown at elevated CO₂ concentration, ,1 was significantly reduced. Although ∆ was negatively correlated with WUE in both CO₂ treatments, the correlation was steeper and highly negative for CO₂-enriched plants. These results indicate underlying differences in gas-exchange physiology, including stomatal responses between ambient and elevated CO₂-grown plants. Photosynthetic acclimation was investigated using the response of assimilation to internal carbon dioxide concentration (A/C₁ curves). At early stages of growth, the initial slope of the A/C₁ response curve did not differ with CO₂ treatment. In contrast, CO₂-saturated photosynthetic rate (Amax) was significantly higher in plants grown under elevated versus ambient CO₂ at 15 DAG. However, at subsequent stages of growth both the initial slope and Amax declined in bean plants grown in elevated CO₂. Apparent carboxylation efficiency (ACE, estimated from the initial slope of A/C₁ response) values followed a similar trend and were significantly reduced in CO₂-enriched plants. These results indicate that acclimation or negative adjustment of photosynthesis may have been caused by a combination of both stomatal and biochemical limitations. Bean plants grown under conditions of elevated atmospheric CO₂ flowered 3 to 4 days earlier, and produced significantly more flowers and pods than plants grown at ambient conditions. Plants grown at elevated CO₂ aborted 22 and 20% more flowers and pods, respectively, than plants grown at ambient CO₂. Elevated CO₂ also significantly increased the number of tillers or lateral branches produced by plants, which contributed to a significant increase in pod number and seed yield in these plants. Although plants grown at elevated CO₂ produced on average 8 seeds per pod, while plants grown under ambient CO2 conditions produced 5 seeds per pod, the greater number of seeds was offset by lower seed weights in plants grown under _ elevated CO₂. Thus, despite high seed yield in beans grown under elevated CO₂, the harvest index (HI) did not change significantly between CO₂ treatments.
- Full Text:
- Date Issued: 1997
The quantification of fucoxanthin from selected South African marine brown algae (Phaeophyta) using HPLC-UV/Vis
- Authors: Mubaiwa, Byron Tawanda
- Date: 2015
- Subjects: Marine algae , Brown algae , High performance liquid chromatography , Functional foods , Xanthophylls , Carotenoids , Extraction (Chemistry)
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3868 , http://hdl.handle.net/10962/d1017879
- Description: Marine brown algae (seaweeds) are a rich source of fucoxanthin, a xanthophyll carotenoid that is naturally, an accessory pigment in the process of photosynthesis of sea vegetation such as Sargassum incisifolium. Fucoxanthin has been exploited by nutraceutical companies for its anti-obesity effects that has resulted in an increase of seaweed slimming preparations such as FucoThin™. The field is getting widespread consumer attention as interest in fucoxanthin has also transcended to its widespread biological potential which include cytotoxicity, anti-diabetic, anti-oxidant, anti-inflammatory and anti-plasmodium effects. We therefore wanted to identify a reliable source(s) of fucoxanthin from diverse samples of South African marine brown algae in order to explore our medicinal chemistry interests around the cytotoxicity and anti-malarial potential of fucoxanthin. A known source, Sargassum incisifolium, was used to isolate (maceration in CH₂Cl₂/MeOH at 35 °C followed by a hexane/EtOAc step gradient silica column of the crude extract and reversed phase semi-prep HPLC) and characterize (1D and 2D NMR) fucoxanthin (reference standard) in order to develop an analytical method for its determination in selected diverse brown algae commonly found in South Africa. The HPLC [Column: Phenomenex® Synergi™ (250 x 3.0 mm i.d); Mobile phase: ACN/H2O (95:5)] method developed for this analysis was validated according the guidelines set by the International Conference on Harmonization (ICH). Fifteen species were then assessed for fucoxanthin content (μg/g of dried weight) using the developed method. Stability studies on fucoxanthin were also carried out to assess photo- and pH degradation of fucoxanthin. Zonaria subarticulata (KOS130226-18) from Kenton-On-Sea beach and Sargassum incisifolium (PA130427-1) from Port Alfred beach were found to be the highest producers of fucoxanthin with 0.50 mg/g and 0.45 mg/g dried weight respectively. Fucoxanthin was found to be both photo-labile and sensitive to both acidic and basic pH environments. However, the pigment was more photostable in pure as opposed to extract form and also showed to be more stable at pH 10.0. Our findings show that Z. subarticulata and S. incisifolium could be reliable sources of fucoxanthin and can be considered as the algae to use in optimized extraction procedures in further studies. Also, when working with fucoxanthin, it is important to protect it from light. Any consideration of taking fucoxanthin preparation orally (as a nutraceutical) should consider protecting the active from the harsh conditions of the gastrointestinal tract. Any upscale production of fucoxanthin from seaweed should consider variations such as geographical, seasonal, lifecycle stage, etc. of identified algae as these may be important factors in obtaining effective concentrations of fucoxanthin.
- Full Text:
- Date Issued: 2015
- Authors: Mubaiwa, Byron Tawanda
- Date: 2015
- Subjects: Marine algae , Brown algae , High performance liquid chromatography , Functional foods , Xanthophylls , Carotenoids , Extraction (Chemistry)
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3868 , http://hdl.handle.net/10962/d1017879
- Description: Marine brown algae (seaweeds) are a rich source of fucoxanthin, a xanthophyll carotenoid that is naturally, an accessory pigment in the process of photosynthesis of sea vegetation such as Sargassum incisifolium. Fucoxanthin has been exploited by nutraceutical companies for its anti-obesity effects that has resulted in an increase of seaweed slimming preparations such as FucoThin™. The field is getting widespread consumer attention as interest in fucoxanthin has also transcended to its widespread biological potential which include cytotoxicity, anti-diabetic, anti-oxidant, anti-inflammatory and anti-plasmodium effects. We therefore wanted to identify a reliable source(s) of fucoxanthin from diverse samples of South African marine brown algae in order to explore our medicinal chemistry interests around the cytotoxicity and anti-malarial potential of fucoxanthin. A known source, Sargassum incisifolium, was used to isolate (maceration in CH₂Cl₂/MeOH at 35 °C followed by a hexane/EtOAc step gradient silica column of the crude extract and reversed phase semi-prep HPLC) and characterize (1D and 2D NMR) fucoxanthin (reference standard) in order to develop an analytical method for its determination in selected diverse brown algae commonly found in South Africa. The HPLC [Column: Phenomenex® Synergi™ (250 x 3.0 mm i.d); Mobile phase: ACN/H2O (95:5)] method developed for this analysis was validated according the guidelines set by the International Conference on Harmonization (ICH). Fifteen species were then assessed for fucoxanthin content (μg/g of dried weight) using the developed method. Stability studies on fucoxanthin were also carried out to assess photo- and pH degradation of fucoxanthin. Zonaria subarticulata (KOS130226-18) from Kenton-On-Sea beach and Sargassum incisifolium (PA130427-1) from Port Alfred beach were found to be the highest producers of fucoxanthin with 0.50 mg/g and 0.45 mg/g dried weight respectively. Fucoxanthin was found to be both photo-labile and sensitive to both acidic and basic pH environments. However, the pigment was more photostable in pure as opposed to extract form and also showed to be more stable at pH 10.0. Our findings show that Z. subarticulata and S. incisifolium could be reliable sources of fucoxanthin and can be considered as the algae to use in optimized extraction procedures in further studies. Also, when working with fucoxanthin, it is important to protect it from light. Any consideration of taking fucoxanthin preparation orally (as a nutraceutical) should consider protecting the active from the harsh conditions of the gastrointestinal tract. Any upscale production of fucoxanthin from seaweed should consider variations such as geographical, seasonal, lifecycle stage, etc. of identified algae as these may be important factors in obtaining effective concentrations of fucoxanthin.
- Full Text:
- Date Issued: 2015
Social networks in recently established human settlements in Grahamstown East/Rhini, South Africa
- Authors: Mukorombindo, Yeukai Chido
- Date: 2012
- Subjects: Social networks -- South Africa -- Grahamstown Human settlements -- South Africa -- Grahamstown Social capital (Sociology) Grahamstown (South Africa) -- Social life and customs Poor -- Social networks -- South Africa -- Grahamstown Grahamstown (South Africa) -- Social conditions Social change -- South Africa -- Grahamstown Informal sector (Economics) -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3310 , http://hdl.handle.net/10962/d1003098
- Description: This thesis attempts to understand the concepts of social capital and social networks within the South African government’s current policy on “human settlements”. It considers the association between social networks, social capital and social cohesion, community development and improved general quality of life. The thesis also explores the possibility and challenges of using social capital and social networks amongst low income urban communities as a viable strategy against poverty and for the development of sustainable human settlements. The thesis will examine the nature and form in which informal social networks function in a low income urban community in South Africa and the benefits that arise from these. The thesis particularly looked at informal social security networks in the form of savings clubs/stokvels and burial societies as well as other informal social networks such as religious associations and neighbourhood social support groups. The study discovered that in light of the high unemployment rate, high poverty levels and increasing urban economic pressures, most low income households cannot access or rely on social networks as a means of survival but on grants and wages. Social security networks are only accessible to those who can afford monthly membership contributions thereby excluding the poorest of the poor. For those who can afford to be members of social security networks, the benefits are limited and they do not adequately address household needs. The study also showed how those who cannot afford to be members of social security networks still have access to some sort of communal social support. Neighbours stand out as valuable in this regard. However, the casual neighbourhood support networks are not ‘resource rich’ mainly due to, the inability of people to donate and reciprocate. Religious networks are mainly identified with emotional, psychological and spiritual well-being, providing friendship, comfort and advice but these benefits are only provided to members only in their time of need. The theoretical understanding of social networks producing social capital which is seen as being beneficial to the poorest of the poor is questioned, as the results show the inequalities and divisions that exist within informal social networks themselves. On the other hand, all the social networks considered in this thesis have managed to contribute towards strengthening neighbourly relations, trust, building community identity and promoting values of ubuntu- sharing and caring for one another which in the long-run benefits the community, both members and non-members alike.
- Full Text:
- Date Issued: 2012
- Authors: Mukorombindo, Yeukai Chido
- Date: 2012
- Subjects: Social networks -- South Africa -- Grahamstown Human settlements -- South Africa -- Grahamstown Social capital (Sociology) Grahamstown (South Africa) -- Social life and customs Poor -- Social networks -- South Africa -- Grahamstown Grahamstown (South Africa) -- Social conditions Social change -- South Africa -- Grahamstown Informal sector (Economics) -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3310 , http://hdl.handle.net/10962/d1003098
- Description: This thesis attempts to understand the concepts of social capital and social networks within the South African government’s current policy on “human settlements”. It considers the association between social networks, social capital and social cohesion, community development and improved general quality of life. The thesis also explores the possibility and challenges of using social capital and social networks amongst low income urban communities as a viable strategy against poverty and for the development of sustainable human settlements. The thesis will examine the nature and form in which informal social networks function in a low income urban community in South Africa and the benefits that arise from these. The thesis particularly looked at informal social security networks in the form of savings clubs/stokvels and burial societies as well as other informal social networks such as religious associations and neighbourhood social support groups. The study discovered that in light of the high unemployment rate, high poverty levels and increasing urban economic pressures, most low income households cannot access or rely on social networks as a means of survival but on grants and wages. Social security networks are only accessible to those who can afford monthly membership contributions thereby excluding the poorest of the poor. For those who can afford to be members of social security networks, the benefits are limited and they do not adequately address household needs. The study also showed how those who cannot afford to be members of social security networks still have access to some sort of communal social support. Neighbours stand out as valuable in this regard. However, the casual neighbourhood support networks are not ‘resource rich’ mainly due to, the inability of people to donate and reciprocate. Religious networks are mainly identified with emotional, psychological and spiritual well-being, providing friendship, comfort and advice but these benefits are only provided to members only in their time of need. The theoretical understanding of social networks producing social capital which is seen as being beneficial to the poorest of the poor is questioned, as the results show the inequalities and divisions that exist within informal social networks themselves. On the other hand, all the social networks considered in this thesis have managed to contribute towards strengthening neighbourly relations, trust, building community identity and promoting values of ubuntu- sharing and caring for one another which in the long-run benefits the community, both members and non-members alike.
- Full Text:
- Date Issued: 2012
Effects of coastal topography on physiology, behaviour and genetics of indigenous (Perna perna) and invasive (Mytilus galloprovincialis) mussels
- Authors: Nicastro, Katy R
- Date: 2008
- Subjects: Mussels -- Ecology -- South Africa , Perna -- Physiology -- South Africa , Perna -- Behavior -- South Africa , Mussels -- Behavior -- Environmental factors -- South Africa , Mussels -- Habitat -- South Africa , Mytilus galloprovincialis , Mytilus galloprovincialis -- Physiology -- South Africa , Mytilus galloprovincialis -- Behavior -- South Africa , Mytilus galloprovincialis -- Genetics -- South Africa , Coastal ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5833 , http://hdl.handle.net/10962/d1008262
- Description: Organisms inhabit environments that have many dimensions, each of which can vary temporally and spatially. The spatial-temporal variations of environmental stressors and disturbances may have major but different effects on indigenous and invasive species, favouring either of them at different times and places. The invasive mussel Mytilus galloprovincialis invaded the South African coast 30 years ago and, on the south coast of South Africa, it now competes and co-exists with the indigenous Perna perna in the lower eulittoral zone (referred to here as the mussel zone) The invasive and indigenous species dominate the upper and the lower mussel zones respectively, while the two co-exist in the mid-zone. My results show that intertidal mussels experience, and respond to, spatial and temporal fluctuations of several biotic and abiotic stressors. The invasive and the indigenous species adopt different strategies when reacting to environmental factors and their physiological and behavioural responses vary in time and in different habitats as different pressures become of overriding importance. Attachment strength of both species decreased in summer and increased in winter, and was higher on the open coast than in bays for both species, showing a strong positive correlation with wave force in time and space. P. perna had significantly higher attachment strength than M. galloprovincialis but, contrary to previous studies, the difference in gonad index between the two species varied according to the habitat. In bay habitats, M. galloprovincialis had a higher maximum reproductive effort than P. perna, however, on the open coast, there was no significant difference between the two species, suggesting that for the invasive species wave action is a limiting factor not only in terms of the attachment strength but also of energy availability for reproductive tissue development. Major spawning events occurred during periods of low wave action while minor spawning coincided with periods of intense hydrodynamic stress. On the open coast, gonad index was negatively correlated with attachment strength for both species while, in bays, there was no correlation between these two factors for either. The two species also showed different behaviour. In the field, M. galloprovincialis moved significantly more than P. perna over a period of six months. The higher mobility of the invasive species was also confirmed in the laboratory where, in general, M. galloprovincialis formed clumps more readily than P. perna. Taken collectively, these results suggest that channelling more energy into attachment strength limits reproductive tissue development and that, while the indigenous species invests more in byssal production, the invasive species adopts a more dynamic strategy looking for aggregation or a safer arrangement. Higher endolithic infestation and a greater expression of heat shock proteins (Hsps) in mussel populations on the open coast than in bays indicate that this habitat is a more stressful environment not only in terms of wave action. Endolith damaged mussels had significantly lower attachment strengths and condition indices than clean mussels, probably due to the need to channel energy into shell repair. The constant shell repair and expression of Hsps typical of open coast populations are energetically demanding processes. These observations suggest that on the open coast, mussels are subjected to more severe energetic constraints than in bay habitats. Wave and sand stress fluctuated seasonally with the former having a greater effect on mussel mortality on the open coast and the latter a higher impact on bay populations. Overall, mussel mortality rates were higher on the open coast than in bays. My results show that populations on the open coast had fewer private haplotypes and less genetic endemism than those inside bays. Gene flow analysis showed the relatively stable bay habitats act as source populations with greater genetic migration rates out of bays than into them. These differences in genetic structure on scales of las of kilometers show that coastal configuration strongly affects selection, larval dispersal and haplotype diversity. Environmental gradients that are key factors in species distribution over large geographical scales can also be responsible for micro-scale distributions. My results show that M. galloprovincialis colonizes the upper mussel zone where temperature is high, but is less tolerant to this stressor and has to maintain a high expression of Hsps. This suggests that temperature is probably a limiting factor in its invasion towards the sub-tropical east coast. There are inter- and intra-specific differences in responses to the environment which highlight the efforts of M. galloprovincialis and P. perna to optimize resource utilization for survival and reproduction. Determining these differences is crucial to understanding patterns of co-existence between competing indigenous and invasive species.
- Full Text:
- Date Issued: 2008
- Authors: Nicastro, Katy R
- Date: 2008
- Subjects: Mussels -- Ecology -- South Africa , Perna -- Physiology -- South Africa , Perna -- Behavior -- South Africa , Mussels -- Behavior -- Environmental factors -- South Africa , Mussels -- Habitat -- South Africa , Mytilus galloprovincialis , Mytilus galloprovincialis -- Physiology -- South Africa , Mytilus galloprovincialis -- Behavior -- South Africa , Mytilus galloprovincialis -- Genetics -- South Africa , Coastal ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5833 , http://hdl.handle.net/10962/d1008262
- Description: Organisms inhabit environments that have many dimensions, each of which can vary temporally and spatially. The spatial-temporal variations of environmental stressors and disturbances may have major but different effects on indigenous and invasive species, favouring either of them at different times and places. The invasive mussel Mytilus galloprovincialis invaded the South African coast 30 years ago and, on the south coast of South Africa, it now competes and co-exists with the indigenous Perna perna in the lower eulittoral zone (referred to here as the mussel zone) The invasive and indigenous species dominate the upper and the lower mussel zones respectively, while the two co-exist in the mid-zone. My results show that intertidal mussels experience, and respond to, spatial and temporal fluctuations of several biotic and abiotic stressors. The invasive and the indigenous species adopt different strategies when reacting to environmental factors and their physiological and behavioural responses vary in time and in different habitats as different pressures become of overriding importance. Attachment strength of both species decreased in summer and increased in winter, and was higher on the open coast than in bays for both species, showing a strong positive correlation with wave force in time and space. P. perna had significantly higher attachment strength than M. galloprovincialis but, contrary to previous studies, the difference in gonad index between the two species varied according to the habitat. In bay habitats, M. galloprovincialis had a higher maximum reproductive effort than P. perna, however, on the open coast, there was no significant difference between the two species, suggesting that for the invasive species wave action is a limiting factor not only in terms of the attachment strength but also of energy availability for reproductive tissue development. Major spawning events occurred during periods of low wave action while minor spawning coincided with periods of intense hydrodynamic stress. On the open coast, gonad index was negatively correlated with attachment strength for both species while, in bays, there was no correlation between these two factors for either. The two species also showed different behaviour. In the field, M. galloprovincialis moved significantly more than P. perna over a period of six months. The higher mobility of the invasive species was also confirmed in the laboratory where, in general, M. galloprovincialis formed clumps more readily than P. perna. Taken collectively, these results suggest that channelling more energy into attachment strength limits reproductive tissue development and that, while the indigenous species invests more in byssal production, the invasive species adopts a more dynamic strategy looking for aggregation or a safer arrangement. Higher endolithic infestation and a greater expression of heat shock proteins (Hsps) in mussel populations on the open coast than in bays indicate that this habitat is a more stressful environment not only in terms of wave action. Endolith damaged mussels had significantly lower attachment strengths and condition indices than clean mussels, probably due to the need to channel energy into shell repair. The constant shell repair and expression of Hsps typical of open coast populations are energetically demanding processes. These observations suggest that on the open coast, mussels are subjected to more severe energetic constraints than in bay habitats. Wave and sand stress fluctuated seasonally with the former having a greater effect on mussel mortality on the open coast and the latter a higher impact on bay populations. Overall, mussel mortality rates were higher on the open coast than in bays. My results show that populations on the open coast had fewer private haplotypes and less genetic endemism than those inside bays. Gene flow analysis showed the relatively stable bay habitats act as source populations with greater genetic migration rates out of bays than into them. These differences in genetic structure on scales of las of kilometers show that coastal configuration strongly affects selection, larval dispersal and haplotype diversity. Environmental gradients that are key factors in species distribution over large geographical scales can also be responsible for micro-scale distributions. My results show that M. galloprovincialis colonizes the upper mussel zone where temperature is high, but is less tolerant to this stressor and has to maintain a high expression of Hsps. This suggests that temperature is probably a limiting factor in its invasion towards the sub-tropical east coast. There are inter- and intra-specific differences in responses to the environment which highlight the efforts of M. galloprovincialis and P. perna to optimize resource utilization for survival and reproduction. Determining these differences is crucial to understanding patterns of co-existence between competing indigenous and invasive species.
- Full Text:
- Date Issued: 2008
Die psigopaat as kliënt in die Maatskaplike Werk
- Authors: Venter, Pieter Viviers
- Date: 1977
- Language: Afrikaans
- Type: Thesis , Masters , MSocSc
- Identifier: vital:21106 , http://hdl.handle.net/10962/6410
- Full Text:
- Date Issued: 1977
- Authors: Venter, Pieter Viviers
- Date: 1977
- Language: Afrikaans
- Type: Thesis , Masters , MSocSc
- Identifier: vital:21106 , http://hdl.handle.net/10962/6410
- Full Text:
- Date Issued: 1977
Investigation into the provision of service excellence in a selected bank in the Port Elizabeth metropole
- Authors: Keet, Marius
- Date: 2000
- Subjects: Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10838 , http://hdl.handle.net/10948/31 , Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Description: In this research customer service excellence in First National Bank in the Port Elizabeth metropole was investigated. From the industry and competitor analysis it can be concluded that banking is a highly competitive industry that is undergoing constant change because of fierce competition. The literature survey was aimed at placing the concept of service quality, excellence and customer loyalty which lead to customer retention into perspective. The concept of total quality management outlining the specific requirements of how the concept can be utilised and how a service quality programme can be implemented was discussed. The purpose of the empirical study was to test customers’ perceptions of service provided by First National Bank and to contribute with useful information to the bank studied. From these findings improvements and recommendations were suggested as a guideline for any bank to follow to improve customer service levels. The empirical study results were satisfactory and informative. The meaningful positive responses that were identified can be utilised as competitive marketing strategies by FNB. The meaningful negative concerns the bank should consider improving upon and attention should be given to the language and SBU differences outlined.
- Full Text:
- Date Issued: 2000
- Authors: Keet, Marius
- Date: 2000
- Subjects: Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10838 , http://hdl.handle.net/10948/31 , Banks and banking -- South Africa , Bank management , Consumer satisfaction , Quality assurance -- Management
- Description: In this research customer service excellence in First National Bank in the Port Elizabeth metropole was investigated. From the industry and competitor analysis it can be concluded that banking is a highly competitive industry that is undergoing constant change because of fierce competition. The literature survey was aimed at placing the concept of service quality, excellence and customer loyalty which lead to customer retention into perspective. The concept of total quality management outlining the specific requirements of how the concept can be utilised and how a service quality programme can be implemented was discussed. The purpose of the empirical study was to test customers’ perceptions of service provided by First National Bank and to contribute with useful information to the bank studied. From these findings improvements and recommendations were suggested as a guideline for any bank to follow to improve customer service levels. The empirical study results were satisfactory and informative. The meaningful positive responses that were identified can be utilised as competitive marketing strategies by FNB. The meaningful negative concerns the bank should consider improving upon and attention should be given to the language and SBU differences outlined.
- Full Text:
- Date Issued: 2000
Civil engineering components for a conceptual elevated light rail transit model with reference to Nelson Mandela Bay
- Authors: Zang, Jin
- Date: 2009
- Subjects: Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9593 , http://hdl.handle.net/10948/769 , Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Description: The increase of motor vehicles, especially in cities, cause transport problems of traffic congestion, vehicle accidents, air pollution and a lack of public spaces. The increasing number of motor vehicles consumes huge amounts of finite petrol energy and emits large amounts of gases that are harmful to the atmosphere and the natural environment. Therefore, the current road transport network is not a sustainable form of public transport for the future. In order to seek a suitable transportation mode, the Infrastructure and Engineering Business Unit of the Nelson Mandela Bay Municipality (NMBM) did some feasibility studies about light rail transit (LRT) from 1984 to 1988. The NMBM-report (1988: 8) concluded that a LRT system would provide the most suitable and primary mode to serve Nelson Mandela Bay (NMB). Although LRT was regarded as the most suitable primary mode of transport at that time (1988), further studies that were reported in 2006 recommended an alternative public transportation system. This research refers to these studies done for the NMB area and other studies and reports for other areas, but focus on the identification of the most suitable civil engineering components for a conceptual elevated light rail transit (ELRT) model. Electrical driven LRT systems have advantages over internal-combustion driven vehicles in terms of environmental protection. Traditional LRT systems are at ground level and are integrated with the existing road network. Some successful LRT systems indicate that the success of LRT systems is mainly dependent on integration with the existing road network. However, the integration of road transport systems with LRT systems cause increased congestion and accidents. An ELRT system can solve these problems. Bangkok has already built an ELRT system to solve its severe traffic congestion. 4 In order to develop a conceptual ELRT model, this research aimed to determine the most suitable civil engineering components for a conceptual ELRT model, including: (i) the most suitable type of bridge foundation; (ii) the most suitable type bridge girder; (iii) the most suitable type of sleeper; and (iv) whether the track should be a ballasted or non-ballasted type. The grounded theory approach was adopted to build up sets of data from which the most suitable components could be selected. In addition, design analyses were done of the various types of components to determine their suitability for a conceptual ELRT model. Experienced engineers and experts were also consulted to identify the most suitable components. After analyses and selection of the most suitable components, outstanding experts were approached to evaluate the components that showed up as the most suitable through the research. The research results indicated that bored and cast-in-place piles, a double-cell trapezoidal segmental box girder, and twin-block sleepers on a non-ballasted sleeper bed are the most suitable civil engineering components.
- Full Text:
- Date Issued: 2009
- Authors: Zang, Jin
- Date: 2009
- Subjects: Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9593 , http://hdl.handle.net/10948/769 , Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Description: The increase of motor vehicles, especially in cities, cause transport problems of traffic congestion, vehicle accidents, air pollution and a lack of public spaces. The increasing number of motor vehicles consumes huge amounts of finite petrol energy and emits large amounts of gases that are harmful to the atmosphere and the natural environment. Therefore, the current road transport network is not a sustainable form of public transport for the future. In order to seek a suitable transportation mode, the Infrastructure and Engineering Business Unit of the Nelson Mandela Bay Municipality (NMBM) did some feasibility studies about light rail transit (LRT) from 1984 to 1988. The NMBM-report (1988: 8) concluded that a LRT system would provide the most suitable and primary mode to serve Nelson Mandela Bay (NMB). Although LRT was regarded as the most suitable primary mode of transport at that time (1988), further studies that were reported in 2006 recommended an alternative public transportation system. This research refers to these studies done for the NMB area and other studies and reports for other areas, but focus on the identification of the most suitable civil engineering components for a conceptual elevated light rail transit (ELRT) model. Electrical driven LRT systems have advantages over internal-combustion driven vehicles in terms of environmental protection. Traditional LRT systems are at ground level and are integrated with the existing road network. Some successful LRT systems indicate that the success of LRT systems is mainly dependent on integration with the existing road network. However, the integration of road transport systems with LRT systems cause increased congestion and accidents. An ELRT system can solve these problems. Bangkok has already built an ELRT system to solve its severe traffic congestion. 4 In order to develop a conceptual ELRT model, this research aimed to determine the most suitable civil engineering components for a conceptual ELRT model, including: (i) the most suitable type of bridge foundation; (ii) the most suitable type bridge girder; (iii) the most suitable type of sleeper; and (iv) whether the track should be a ballasted or non-ballasted type. The grounded theory approach was adopted to build up sets of data from which the most suitable components could be selected. In addition, design analyses were done of the various types of components to determine their suitability for a conceptual ELRT model. Experienced engineers and experts were also consulted to identify the most suitable components. After analyses and selection of the most suitable components, outstanding experts were approached to evaluate the components that showed up as the most suitable through the research. The research results indicated that bored and cast-in-place piles, a double-cell trapezoidal segmental box girder, and twin-block sleepers on a non-ballasted sleeper bed are the most suitable civil engineering components.
- Full Text:
- Date Issued: 2009
Essential fatty acids and ascorbic acid- interactions and effects on melanoma growth
- Authors: Gardiner, Neil Stockenstrom
- Date: 1990
- Subjects: Fatty acids , Melanoma , Mice -- Diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4549 , http://hdl.handle.net/10962/d1018230
- Description: The present study was carried out to determine the effects and possible mechanisms of action of the essential fatty acids (EFAs) (linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (AA)) and ascorbic acid (Asc) on BL6 murine melanoma growth in cell culture and in mice. Interactions between the nutrients in influencing melanoma growth as well as possible mechanisms of the interactions were also examined in the above systems. Cell culture studies revealed that all three EFAs (0-SOμg/ml) and Asc (0-200μg/ml) significantly inhibited melanoma growth at the concentrations used. The EF As were also found to significantly inhibit growth, although to a lesser extent than BL6 cells, of monkey kidney (LLCMK) cells which were used as a non-malignant control cell line. Asc in contrast was found not to inhibit growth of these cells. Supplementation of Asc (lOO)μg/ml) to EFA containing (0-50μg/ml) medium was found to significantly increase inhibition of cell growth in both cell lines, and in the BL6 cells in particular, after taking into account the growth inhibitory effects of Asc in the absence of EFAs. The mechanism of cell growth inhibition by the EF As appeared to involve lipid peroxidation but not enhanced prostaglandin (PG) or leukotriene (LT) synthesis. While Asc was found to increase both lipid peroxidation and PG synthesis in the cells, these mechanisms and enhanced LT synthesis did not appear to have played a role in the inhibition of cell growth by Asc or in the growth inhibitory interaction between Asc and the EF As. In vivo studies revealed that diets containing essential or polyunsaturated fatty acids (EFAs/PUFAs) in the form of vegetable oils, and in particular GLA in the form of evening primrose oil, significantly promoted melanoma growth in mice when compared with an EFA/PUFA free diet containing predominantly saturated fats (SF). Supplementary dietary Asc in contrast was found to significantly inhibit melanoma growth in mice fed EFA/PUFA, and in particular GLA, containing diets but not in mice fed SF cont~g diets. This result appears to indicate the occurrence of an interaction between the two nutrients. Ul The mechanism of tumour promotion by the EP As/PUP As did not appear to have involved enhanced PG or LT synthesis or lipid peroxidation. Since dietary EPA/PUPA manipulation was found to significantly alter the EPA content of tissues, including the melanomas, the mechanism of tumour promotion may have involved changes in the EPA composition of the tumour cells. While supplementary Asc was found to significantly increase the Asc content of certain tissues, including the melanomas, which may have played a role in tumour growth inhibition by Asc, it was found not to affect the EPA content of tissues. Enhanced PG or LT synthesis and lipid perox:idation did not appear to have been involved in the tumour growth inhibitory interaction between Asc and the EP As/PUP As. THe activity of the enzyme delta-6-desaturase, a key enzyme in EF A metabolism which catalyses the desaturation of LA to GLA, and the influence of Asc on activity of the enzyme were also examined. The cultured cells, and BL6 cells in particular, were found to contain significant activity of the enzyme. Whereas murine liver microsomal fractions were found to contain delta-6-desaturase activity, microsomes from melanomas grown in mice were found to lack activity of the enzyme. The significant tumour promoting effects of the GLA containing EPO diet may have been the result of the lack of delta-6-desaturase activity in tumour cells grown in mice. Asc was found to stimulate activity of the enzyme in cultured BL6 cells but not in LLCM.K cells, while dietary Asc and EF A/PUP A manipulation did not influence activity of the enzyme in microsomal fractions. This study has confirmed previous reports of the in vivo tumour promoting effects of dietary EP As/PUP As and the tumour growth inhibitory effects of Asc. The in vitro cell growth inhibitory effects of Asc and the EP As also confirm the results of previous reports. Previous studies investigating possible interactions between Asc and EP As/PUP As in influencing tumour cell growth could not be located in the relevant literature. This study may therefore be one of the first investigations of any such interaction between these nutrients in tumour cells. While this study was not able to identify the mechanisms involved in the different tumour promoting or tumour growth inhibitory effects of the two nutrients in the two systems, it did eliminate a number of potential mechanisms. The results of this study also emphasise the difficulty of attempting to compare the results of in vitro and in vivo studies.
- Full Text:
- Date Issued: 1990
- Authors: Gardiner, Neil Stockenstrom
- Date: 1990
- Subjects: Fatty acids , Melanoma , Mice -- Diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4549 , http://hdl.handle.net/10962/d1018230
- Description: The present study was carried out to determine the effects and possible mechanisms of action of the essential fatty acids (EFAs) (linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (AA)) and ascorbic acid (Asc) on BL6 murine melanoma growth in cell culture and in mice. Interactions between the nutrients in influencing melanoma growth as well as possible mechanisms of the interactions were also examined in the above systems. Cell culture studies revealed that all three EFAs (0-SOμg/ml) and Asc (0-200μg/ml) significantly inhibited melanoma growth at the concentrations used. The EF As were also found to significantly inhibit growth, although to a lesser extent than BL6 cells, of monkey kidney (LLCMK) cells which were used as a non-malignant control cell line. Asc in contrast was found not to inhibit growth of these cells. Supplementation of Asc (lOO)μg/ml) to EFA containing (0-50μg/ml) medium was found to significantly increase inhibition of cell growth in both cell lines, and in the BL6 cells in particular, after taking into account the growth inhibitory effects of Asc in the absence of EFAs. The mechanism of cell growth inhibition by the EF As appeared to involve lipid peroxidation but not enhanced prostaglandin (PG) or leukotriene (LT) synthesis. While Asc was found to increase both lipid peroxidation and PG synthesis in the cells, these mechanisms and enhanced LT synthesis did not appear to have played a role in the inhibition of cell growth by Asc or in the growth inhibitory interaction between Asc and the EF As. In vivo studies revealed that diets containing essential or polyunsaturated fatty acids (EFAs/PUFAs) in the form of vegetable oils, and in particular GLA in the form of evening primrose oil, significantly promoted melanoma growth in mice when compared with an EFA/PUFA free diet containing predominantly saturated fats (SF). Supplementary dietary Asc in contrast was found to significantly inhibit melanoma growth in mice fed EFA/PUFA, and in particular GLA, containing diets but not in mice fed SF cont~g diets. This result appears to indicate the occurrence of an interaction between the two nutrients. Ul The mechanism of tumour promotion by the EP As/PUP As did not appear to have involved enhanced PG or LT synthesis or lipid peroxidation. Since dietary EPA/PUPA manipulation was found to significantly alter the EPA content of tissues, including the melanomas, the mechanism of tumour promotion may have involved changes in the EPA composition of the tumour cells. While supplementary Asc was found to significantly increase the Asc content of certain tissues, including the melanomas, which may have played a role in tumour growth inhibition by Asc, it was found not to affect the EPA content of tissues. Enhanced PG or LT synthesis and lipid perox:idation did not appear to have been involved in the tumour growth inhibitory interaction between Asc and the EP As/PUP As. THe activity of the enzyme delta-6-desaturase, a key enzyme in EF A metabolism which catalyses the desaturation of LA to GLA, and the influence of Asc on activity of the enzyme were also examined. The cultured cells, and BL6 cells in particular, were found to contain significant activity of the enzyme. Whereas murine liver microsomal fractions were found to contain delta-6-desaturase activity, microsomes from melanomas grown in mice were found to lack activity of the enzyme. The significant tumour promoting effects of the GLA containing EPO diet may have been the result of the lack of delta-6-desaturase activity in tumour cells grown in mice. Asc was found to stimulate activity of the enzyme in cultured BL6 cells but not in LLCM.K cells, while dietary Asc and EF A/PUP A manipulation did not influence activity of the enzyme in microsomal fractions. This study has confirmed previous reports of the in vivo tumour promoting effects of dietary EP As/PUP As and the tumour growth inhibitory effects of Asc. The in vitro cell growth inhibitory effects of Asc and the EP As also confirm the results of previous reports. Previous studies investigating possible interactions between Asc and EP As/PUP As in influencing tumour cell growth could not be located in the relevant literature. This study may therefore be one of the first investigations of any such interaction between these nutrients in tumour cells. While this study was not able to identify the mechanisms involved in the different tumour promoting or tumour growth inhibitory effects of the two nutrients in the two systems, it did eliminate a number of potential mechanisms. The results of this study also emphasise the difficulty of attempting to compare the results of in vitro and in vivo studies.
- Full Text:
- Date Issued: 1990
Die utopie und der deutsche utopische roman seit 1939
- Krueger, Gustav Adolf Ludwig Werner
- Authors: Krueger, Gustav Adolf Ludwig Werner
- Date: 1971
- Subjects: German fiction -- 20th century , German literature -- History and criticism
- Language: German
- Type: Thesis , Masters , MA
- Identifier: vital:3631 , http://hdl.handle.net/10962/d1012711 , German fiction -- 20th century , German literature -- History and criticism
- Description: Wie bei jeder wissenschaftlichen Untersuchung stellt sich auch hier, bei einer Arbeit über den utopischen Roman, die Frage nach einer Begriffsbestimmung. In diesem Fall geht es um eine genaue Umreissung der Begriffe "Utopie", "Staatsroman", "Utopischer Roman" oder auch "Utopia-Roman", vorausgesetzt, dass man diese Begriffe überhaupt als Gattungsbezeichnungen zu benutzen gewillt ist. Intro., p. 1.
- Full Text:
- Date Issued: 1971
- Authors: Krueger, Gustav Adolf Ludwig Werner
- Date: 1971
- Subjects: German fiction -- 20th century , German literature -- History and criticism
- Language: German
- Type: Thesis , Masters , MA
- Identifier: vital:3631 , http://hdl.handle.net/10962/d1012711 , German fiction -- 20th century , German literature -- History and criticism
- Description: Wie bei jeder wissenschaftlichen Untersuchung stellt sich auch hier, bei einer Arbeit über den utopischen Roman, die Frage nach einer Begriffsbestimmung. In diesem Fall geht es um eine genaue Umreissung der Begriffe "Utopie", "Staatsroman", "Utopischer Roman" oder auch "Utopia-Roman", vorausgesetzt, dass man diese Begriffe überhaupt als Gattungsbezeichnungen zu benutzen gewillt ist. Intro., p. 1.
- Full Text:
- Date Issued: 1971
Drama in South African secondary schools meeting the challenges of educational change
- Authors: Carklin, Michael Larry
- Date: 1996
- Subjects: Drama in education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2133 , http://hdl.handle.net/10962/d1002365 , Drama in education -- South Africa
- Description: South Africa is undergoing fundamental transformation at all levels of government and civil society, requiring a firm commitment to redressing the legacy of apartheid and to the development of South Africa's people. Part of this commitment is to undertake research which complements transformation processes, investigating the most appropriate ways to meet the challenges posed by such change. This study examines the potential of drama in the secondary school to meet key educational challenges, motivating strongly for the inclusion of drama as part of the formal curriculum in all schools. Social transformation has been greatly influenced by policy such as the Reconstruction & Development Programme (RDP) and subsequent Government White Papers which identify the need to develop South Africa's human resources as crucial. It is in this light, arid in the context of great disparity that exists across the education spectrum, that learning experiences of high quality must be provided in schools. It is argued that drama, as an lift form and an educational medium, is able to provide such qualitatively sound learning experiences because it is essentially learner-centered, experiential and holistic, offering unique ways of knowing, understanding and gaining insights. However, the classroom drama experience needs careful conceptualisation itself, particularly in view of the fact that life experiences of pupils are characteriseg by multiplicity and diversity within a new era of social and cultural mixing, as well as increased global interaction through, for example, the mass media and the internet. This study thus argues from a post-structuralist perspective, which embraces notions of multiplicity, proposing a reconceptualisation of the classroom drama experience that challenges the oppositional or binary perspectives that have previously characterised the way we think about drama and education. Example~ include art versus utilitarianism; process versus product; drama versus theatre. Investigating the classroom drama experierice in the light of developments in postmodern theatre, this study proposes that classroom drama should be seen as a form of theatre itself and suggests the term theatricalisaction to describe this classroom-theatre process which is based on action, reflection, experience and creative expression. It becomes a theatre of activity or an activating theatre. In this light classroom drama is considered in a specifically South Mrican context. In particular, this study examines the ways in which the following contexts impact upon the drama experience: the education system, the place of the arts within that system, and cultural and linguistic diversity in the classroom. Drawing on policy documentation, conference proceedings and studies that have been carried out in multiculturalism and multilingualism, the specific educational challenges facing South Africans are identified. In further exploring the potential of drama to meeting these challenges, this study documents the results of surveys conducted with drama teachers and with ~students who have studied drama as one of their formal subjects, highlighting in particular their perceptions, perspectives and experiences regarding the aims and value of drama education. Finally, in light of the information gained from teachers and learners, and of the concepts and contexts investigated, this thesis considers the ways in which the drama experience can contribute to meeting three primary educational challenges: the building of a culture of learning; the development and empowerment of pupils; and the embracing of cultural and linguistic diversity. This study concludes that drama is able to contribute significantly to educational change because of the teaching and learning processes it offers as an art form, and in particular, a theatre form. It is such a participatory, democratic classroom-theatre which provides a teaching and learning approach that should be at the core of transformation.
- Full Text:
- Date Issued: 1996
- Authors: Carklin, Michael Larry
- Date: 1996
- Subjects: Drama in education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2133 , http://hdl.handle.net/10962/d1002365 , Drama in education -- South Africa
- Description: South Africa is undergoing fundamental transformation at all levels of government and civil society, requiring a firm commitment to redressing the legacy of apartheid and to the development of South Africa's people. Part of this commitment is to undertake research which complements transformation processes, investigating the most appropriate ways to meet the challenges posed by such change. This study examines the potential of drama in the secondary school to meet key educational challenges, motivating strongly for the inclusion of drama as part of the formal curriculum in all schools. Social transformation has been greatly influenced by policy such as the Reconstruction & Development Programme (RDP) and subsequent Government White Papers which identify the need to develop South Africa's human resources as crucial. It is in this light, arid in the context of great disparity that exists across the education spectrum, that learning experiences of high quality must be provided in schools. It is argued that drama, as an lift form and an educational medium, is able to provide such qualitatively sound learning experiences because it is essentially learner-centered, experiential and holistic, offering unique ways of knowing, understanding and gaining insights. However, the classroom drama experience needs careful conceptualisation itself, particularly in view of the fact that life experiences of pupils are characteriseg by multiplicity and diversity within a new era of social and cultural mixing, as well as increased global interaction through, for example, the mass media and the internet. This study thus argues from a post-structuralist perspective, which embraces notions of multiplicity, proposing a reconceptualisation of the classroom drama experience that challenges the oppositional or binary perspectives that have previously characterised the way we think about drama and education. Example~ include art versus utilitarianism; process versus product; drama versus theatre. Investigating the classroom drama experierice in the light of developments in postmodern theatre, this study proposes that classroom drama should be seen as a form of theatre itself and suggests the term theatricalisaction to describe this classroom-theatre process which is based on action, reflection, experience and creative expression. It becomes a theatre of activity or an activating theatre. In this light classroom drama is considered in a specifically South Mrican context. In particular, this study examines the ways in which the following contexts impact upon the drama experience: the education system, the place of the arts within that system, and cultural and linguistic diversity in the classroom. Drawing on policy documentation, conference proceedings and studies that have been carried out in multiculturalism and multilingualism, the specific educational challenges facing South Africans are identified. In further exploring the potential of drama to meeting these challenges, this study documents the results of surveys conducted with drama teachers and with ~students who have studied drama as one of their formal subjects, highlighting in particular their perceptions, perspectives and experiences regarding the aims and value of drama education. Finally, in light of the information gained from teachers and learners, and of the concepts and contexts investigated, this thesis considers the ways in which the drama experience can contribute to meeting three primary educational challenges: the building of a culture of learning; the development and empowerment of pupils; and the embracing of cultural and linguistic diversity. This study concludes that drama is able to contribute significantly to educational change because of the teaching and learning processes it offers as an art form, and in particular, a theatre form. It is such a participatory, democratic classroom-theatre which provides a teaching and learning approach that should be at the core of transformation.
- Full Text:
- Date Issued: 1996
Implementation of safety measures in selected public high schools in the Alfred Nzo East education district
- Authors: Mditshwa, Simbongile
- Date: 2020
- Subjects: Schools -- Security measures School safety and security
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17895 , vital:41975
- Description: The main aim of the study was to find out how safety measures are implemented in selected public high schools in the Alfred Nzo East Education District. The study was motivated by multiple media reports about incidents that have to do with the safety of learners especially in rural public schools. This case study was grounded in the interpretive paradigm and the qualitative approach was adopted. The study was theoretically guided by the principles from both the Street-Level Bureaucracy (SLB) and the Rational Decision Making Model (RDMM). The data was collected from three schools in the Alfred Nzo East Education District, Eastern Cape, RSA. A purposive sampling technique was utilized to choose the research participants. A total of 21 human participants were involved in interviews where two teachers per school, two learners per school, two SGB parents and a principal were interviewed. Interviews were supplemented with short observations and document analysis. The findings of the research include the following: educators get a minimal empowerment to manage school safety in terms of access to school, scholar transport and on. The researched schools had no school-based safety policies. Some of the challenges included the level of roadworthiness of the vehicles that are used to transport school children which exposes learners to a high risk and that puts more pressure on school safety. Drugs and dangerous weapons are other factors which contribute to the instability of school safety. The researcher recommended that educators should be empowered through support from the principals and from the district coordinator through frequent policy implementation conference using online platform to minimize the costs of physical conferences. I recommended that the community must be active whistle-blowers for drug smuggling because drugs in schools emanate from the communities. Indemnity forms, release forms and school-based policies must be made available for implementation and referencing purposes. Schools should establish healthy relationship with external stakeholders like traditional leaders, SAPS and the Department of Social Development to curb lack of safety in schools.
- Full Text:
- Date Issued: 2020
- Authors: Mditshwa, Simbongile
- Date: 2020
- Subjects: Schools -- Security measures School safety and security
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17895 , vital:41975
- Description: The main aim of the study was to find out how safety measures are implemented in selected public high schools in the Alfred Nzo East Education District. The study was motivated by multiple media reports about incidents that have to do with the safety of learners especially in rural public schools. This case study was grounded in the interpretive paradigm and the qualitative approach was adopted. The study was theoretically guided by the principles from both the Street-Level Bureaucracy (SLB) and the Rational Decision Making Model (RDMM). The data was collected from three schools in the Alfred Nzo East Education District, Eastern Cape, RSA. A purposive sampling technique was utilized to choose the research participants. A total of 21 human participants were involved in interviews where two teachers per school, two learners per school, two SGB parents and a principal were interviewed. Interviews were supplemented with short observations and document analysis. The findings of the research include the following: educators get a minimal empowerment to manage school safety in terms of access to school, scholar transport and on. The researched schools had no school-based safety policies. Some of the challenges included the level of roadworthiness of the vehicles that are used to transport school children which exposes learners to a high risk and that puts more pressure on school safety. Drugs and dangerous weapons are other factors which contribute to the instability of school safety. The researcher recommended that educators should be empowered through support from the principals and from the district coordinator through frequent policy implementation conference using online platform to minimize the costs of physical conferences. I recommended that the community must be active whistle-blowers for drug smuggling because drugs in schools emanate from the communities. Indemnity forms, release forms and school-based policies must be made available for implementation and referencing purposes. Schools should establish healthy relationship with external stakeholders like traditional leaders, SAPS and the Department of Social Development to curb lack of safety in schools.
- Full Text:
- Date Issued: 2020
The contributions of phonological awareness and naming speed to the reading fluency, accuracy, comprehension and spelling of Grade 3 IsiXhosa readers
- Authors: Diemer, Maxine Nichole
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3245 , vital:20404
- Description: This thesis contributes to reading research in isiXhosa, where the role of various cognitive skills in reading has not yet been examined. One of the current debates in reading research centers on the contribution of cognitive skills, namely phonological awareness and naming speed, to reading. The exact relation between phonological awareness and naming speed, and their relation to literacy in different languages are also disputed. In this study, the contribution of phonological awareness and naming speed to literacy is examined in 52 Grade 3 isiXhosa speaking children. Measures for literacy included oral reading fluency, silent reading, comprehension and spelling. Phonological awareness was the biggest contributor to reading fluency, accuracy, comprehension and spelling, confirming that phonological processing is important for reading in all languages studied to date. The role of naming speed was narrower, contributing to the fluency and accuracy of reading only in the group with poor phonological awareness. The results can inform the teaching of reading isiXhosa where an approach that explicitly emphasises orthography-phonology relations at the phoneme level may be well suited especially since there are many letter groups to learn. This would enable higher accuracy in orthography-phonology correspondences and should also improve automaticity, which was lacking in the group with low levels of phonological awareness. The Psycholinguistic Grain Size Theory of reading can adequately inform the understanding of reading in isiXhosa, and findings from other languages with similar requirements can inform the teaching of reading in isiXhosa.
- Full Text:
- Date Issued: 2016
- Authors: Diemer, Maxine Nichole
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3245 , vital:20404
- Description: This thesis contributes to reading research in isiXhosa, where the role of various cognitive skills in reading has not yet been examined. One of the current debates in reading research centers on the contribution of cognitive skills, namely phonological awareness and naming speed, to reading. The exact relation between phonological awareness and naming speed, and their relation to literacy in different languages are also disputed. In this study, the contribution of phonological awareness and naming speed to literacy is examined in 52 Grade 3 isiXhosa speaking children. Measures for literacy included oral reading fluency, silent reading, comprehension and spelling. Phonological awareness was the biggest contributor to reading fluency, accuracy, comprehension and spelling, confirming that phonological processing is important for reading in all languages studied to date. The role of naming speed was narrower, contributing to the fluency and accuracy of reading only in the group with poor phonological awareness. The results can inform the teaching of reading isiXhosa where an approach that explicitly emphasises orthography-phonology relations at the phoneme level may be well suited especially since there are many letter groups to learn. This would enable higher accuracy in orthography-phonology correspondences and should also improve automaticity, which was lacking in the group with low levels of phonological awareness. The Psycholinguistic Grain Size Theory of reading can adequately inform the understanding of reading in isiXhosa, and findings from other languages with similar requirements can inform the teaching of reading in isiXhosa.
- Full Text:
- Date Issued: 2016
An environmental education portfolio: three small scale studies informing school greening activities and professional development of teachers in two rural Eastern Cape schools in SANBI's Greening the Nation Project
- Authors: Finca, Moffat Nkosiphendule
- Date: 2010
- Subjects: South African National Biodiversity Institute Environmental education -- South Africa -- Eastern Cape Teachers -- In-service training -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1737 , http://hdl.handle.net/10962/d1003621
- Full Text:
- Date Issued: 2010
- Authors: Finca, Moffat Nkosiphendule
- Date: 2010
- Subjects: South African National Biodiversity Institute Environmental education -- South Africa -- Eastern Cape Teachers -- In-service training -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1737 , http://hdl.handle.net/10962/d1003621
- Full Text:
- Date Issued: 2010
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