Phylogeography and epifauna of two intertidal seaweeds on the coast of South Africa
- Authors: Mmonwa, Lucas Kolobe
- Date: 2009
- Subjects: Phylogeography -- South Africa , Marine algae -- South Africa , Red algae -- South Africa , Gelidium -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5738 , http://hdl.handle.net/10962/d1005424 , Phylogeography -- South Africa , Marine algae -- South Africa , Red algae -- South Africa , Gelidium -- South Africa
- Description: Southern African biogeographic boundaries delimit the phylogeographic distribution of some coastal and estuarine invertebrates. This study investigated the impact of these boundaries on the phylogeographic distribution of two intertidal red seaweeds, Gelidium pristoides and Hypnea spicifera using the mitochondrial Cox2-3 spacer and the nuclear ITS1 regions. G. pristoides spores have short distance-dispersal, while long distance-dispersal is more likely in H. spicifera via spores and drifting fertile thallus fragments. Both markers revealed a south-western and south-eastern lineage within G. pristoides but the breaks between lineages do not coincide with any recognised biogeographic limits. The Cox2-3 spacer revealed a boundary between the two lineages at the Alexandria Coastal Dunefield (ACD) and ITS1 at the Gamtoos-Van Stadens Dunefields (GVD) which is approximately 80km west of the ACD. The minor difference between the two markers regarding location of the phylogeographic boundary is probably due to the dating differences between the two dunefields. The ACD as developed currently is superimposed on the ancient dunefields which formed during the Pleistocene, coinciding with the Cox2-3 spacer sequences divergence which dates back 500,000 - 580,000 years. The GVD formed during the Holocene (6,500 - 4,000 years ago), coinciding with the ITS1 sequences divergence which dates 4,224 - 4,928 years ago. Thus, these phylogeographic boundaries probably appeared without the influence of biogeographic boundaries, but rather due to the lack of suitable habitat in the dunefields, coupled with short dispersal-distances of the spores. Analysis of the ITS1 and Cox2-3 spacer regions in H. spicifera revealed that the species is characterized by uniform genetic structure along the coastline. This reflects the species`s potential for long range expansion as it inhabits both the intertidal and subtidal zones; and this presumably leads to high gene flow among populations. The ITS1 sequences showed minimal genetic variation of one substitution between the gametophyte and tetrasporophyte generations within H. spicifera. This suggests the predominance of asexual reproduction, which reduces gene flow and fixes alleles between generations. ANOSIM and Bray-Curtis cluster analyses showed scale-dependant variation in the abundances of epifauna (mainly amphipod, isopod, mollusc and polychaete species) on G. pristoides. At small local (within site) and large (among sites) scales, there were weak and no structure in epifaunal abundances respectively. However, at larger, biogeographic scales, samples from the same biogeographic region tended to be clustered together. Thus, there was a group containing predominantly south coast samples and a group containing east coast samples mixed with the remaining south coast samples. Such scale-dependant variation in epifaunal abundances is probably due to the effects of factors driving species richness at small local (within site) scales (e.g. wave exposure, seaweed biomass) and at larger, biogeographic scales (e.g. surface sea temperature). Moreover, at very small (individual samples) scales; there was no correlation between epifauna composition and genotype of the seaweed. Seaweed samples characterized by distinct ITS1 or Cox2-3 spacer sequences did not show any significant differences in epifaunal composition. Although the distributional pattern of the epifaunal community observed at large biogeographic scale is not clear, it seems to be associated with the biogeographic regions. However, phylogeographic distribution of Gelidium pristoides is not connected to biogeographic regions. Thus, at larger, biogeographic scales, there is no correlation between phylogeographic distribution of G. pristoides and distribution of the associated fauna
- Full Text:
- Date Issued: 2009
- Authors: Mmonwa, Lucas Kolobe
- Date: 2009
- Subjects: Phylogeography -- South Africa , Marine algae -- South Africa , Red algae -- South Africa , Gelidium -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5738 , http://hdl.handle.net/10962/d1005424 , Phylogeography -- South Africa , Marine algae -- South Africa , Red algae -- South Africa , Gelidium -- South Africa
- Description: Southern African biogeographic boundaries delimit the phylogeographic distribution of some coastal and estuarine invertebrates. This study investigated the impact of these boundaries on the phylogeographic distribution of two intertidal red seaweeds, Gelidium pristoides and Hypnea spicifera using the mitochondrial Cox2-3 spacer and the nuclear ITS1 regions. G. pristoides spores have short distance-dispersal, while long distance-dispersal is more likely in H. spicifera via spores and drifting fertile thallus fragments. Both markers revealed a south-western and south-eastern lineage within G. pristoides but the breaks between lineages do not coincide with any recognised biogeographic limits. The Cox2-3 spacer revealed a boundary between the two lineages at the Alexandria Coastal Dunefield (ACD) and ITS1 at the Gamtoos-Van Stadens Dunefields (GVD) which is approximately 80km west of the ACD. The minor difference between the two markers regarding location of the phylogeographic boundary is probably due to the dating differences between the two dunefields. The ACD as developed currently is superimposed on the ancient dunefields which formed during the Pleistocene, coinciding with the Cox2-3 spacer sequences divergence which dates back 500,000 - 580,000 years. The GVD formed during the Holocene (6,500 - 4,000 years ago), coinciding with the ITS1 sequences divergence which dates 4,224 - 4,928 years ago. Thus, these phylogeographic boundaries probably appeared without the influence of biogeographic boundaries, but rather due to the lack of suitable habitat in the dunefields, coupled with short dispersal-distances of the spores. Analysis of the ITS1 and Cox2-3 spacer regions in H. spicifera revealed that the species is characterized by uniform genetic structure along the coastline. This reflects the species`s potential for long range expansion as it inhabits both the intertidal and subtidal zones; and this presumably leads to high gene flow among populations. The ITS1 sequences showed minimal genetic variation of one substitution between the gametophyte and tetrasporophyte generations within H. spicifera. This suggests the predominance of asexual reproduction, which reduces gene flow and fixes alleles between generations. ANOSIM and Bray-Curtis cluster analyses showed scale-dependant variation in the abundances of epifauna (mainly amphipod, isopod, mollusc and polychaete species) on G. pristoides. At small local (within site) and large (among sites) scales, there were weak and no structure in epifaunal abundances respectively. However, at larger, biogeographic scales, samples from the same biogeographic region tended to be clustered together. Thus, there was a group containing predominantly south coast samples and a group containing east coast samples mixed with the remaining south coast samples. Such scale-dependant variation in epifaunal abundances is probably due to the effects of factors driving species richness at small local (within site) scales (e.g. wave exposure, seaweed biomass) and at larger, biogeographic scales (e.g. surface sea temperature). Moreover, at very small (individual samples) scales; there was no correlation between epifauna composition and genotype of the seaweed. Seaweed samples characterized by distinct ITS1 or Cox2-3 spacer sequences did not show any significant differences in epifaunal composition. Although the distributional pattern of the epifaunal community observed at large biogeographic scale is not clear, it seems to be associated with the biogeographic regions. However, phylogeographic distribution of Gelidium pristoides is not connected to biogeographic regions. Thus, at larger, biogeographic scales, there is no correlation between phylogeographic distribution of G. pristoides and distribution of the associated fauna
- Full Text:
- Date Issued: 2009
The design and synthesis of novel HIV-1 protease inhibitors
- Authors: Tukulula, Matshawandile
- Date: 2009
- Subjects: Protease Inhibitors HIV infections -- Treatment AIDS (Disease) -- Treatment HIV (Viruses) Indolizine -- Derivatives Heterocyclic compounds -- Derivatives Nuclear magnetic resonance Quinoline
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4305 , http://hdl.handle.net/10962/d1004963
- Description: This study has focused on the synthesis of truncated analogues of the hydroxyethylene dipeptide isosteres, such as Ritonavir®, currently in clinical use as HIV-1 protease inhibitors. The reactions of pyridine-2- and quinoline-2-carbaldehydes with methyl acrylate, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) or 3- hydroxyquinuclidine (3-HQ) as nucleophilic catalysts, have afforded a series of Baylis- Hillman adducts, acetylation and cyclisation of which have provided access to a series of indolizine-2-carboxylate esters. The carboxylic acids, obtained by base-catalyzed hydrolysis of these esters, have been coupled with various protected (and unprotected) amino compounds using the peptide coupling agent, 1,1’-carbonyldiimidazole (CDI), to afford a series of indolizine-2-carboxamides as indolizine-based truncated Ritonavir® analogues in quantitative yield. Aza-Michael reactions of pyridine-3-carbaldehydederived Baylis-Hillman adducts with various amino compounds have provided access to a range of pyridine-based products as mixtures of diastereomeric aza-Michael products. The assignment of the relative stereochemistry of the aza-Michael products has been established using 1-D and 2-NOESY experiments and computer modelling techniques. Computer modelling studies have also been conducted on selected aza-Michael products using ACCELRYS Cerius2 software, followed by interactive docking into the HIV-1 protease receptor site, using AUTODOCK 4.0. The docking studies have revealed hydrogen-bonding interactions between the enzyme and the synthetic ligands. Saturation Transfer Difference (STD) NMR experiments have also indicated binding of some of the aza-Michael products to the HIV-1 protease subtype C enzyme, thus indicating their binding and possible inhibitory potential.
- Full Text:
- Date Issued: 2009
- Authors: Tukulula, Matshawandile
- Date: 2009
- Subjects: Protease Inhibitors HIV infections -- Treatment AIDS (Disease) -- Treatment HIV (Viruses) Indolizine -- Derivatives Heterocyclic compounds -- Derivatives Nuclear magnetic resonance Quinoline
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4305 , http://hdl.handle.net/10962/d1004963
- Description: This study has focused on the synthesis of truncated analogues of the hydroxyethylene dipeptide isosteres, such as Ritonavir®, currently in clinical use as HIV-1 protease inhibitors. The reactions of pyridine-2- and quinoline-2-carbaldehydes with methyl acrylate, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) or 3- hydroxyquinuclidine (3-HQ) as nucleophilic catalysts, have afforded a series of Baylis- Hillman adducts, acetylation and cyclisation of which have provided access to a series of indolizine-2-carboxylate esters. The carboxylic acids, obtained by base-catalyzed hydrolysis of these esters, have been coupled with various protected (and unprotected) amino compounds using the peptide coupling agent, 1,1’-carbonyldiimidazole (CDI), to afford a series of indolizine-2-carboxamides as indolizine-based truncated Ritonavir® analogues in quantitative yield. Aza-Michael reactions of pyridine-3-carbaldehydederived Baylis-Hillman adducts with various amino compounds have provided access to a range of pyridine-based products as mixtures of diastereomeric aza-Michael products. The assignment of the relative stereochemistry of the aza-Michael products has been established using 1-D and 2-NOESY experiments and computer modelling techniques. Computer modelling studies have also been conducted on selected aza-Michael products using ACCELRYS Cerius2 software, followed by interactive docking into the HIV-1 protease receptor site, using AUTODOCK 4.0. The docking studies have revealed hydrogen-bonding interactions between the enzyme and the synthetic ligands. Saturation Transfer Difference (STD) NMR experiments have also indicated binding of some of the aza-Michael products to the HIV-1 protease subtype C enzyme, thus indicating their binding and possible inhibitory potential.
- Full Text:
- Date Issued: 2009
A fluvial geomorphological study of river rehabilitation in the Kouga region, Eastern Cape
- Authors: Pietersen, Adrian
- Date: 2009
- Subjects: Fluvial geomorphology -- South Africa -- Eastern Cape , Alien plants -- South Africa -- Eastern Cape , Kouga Riparian Rehabilitation Project , Stream conservation -- South Africa -- Eastern Cape , Wattles (Plants) -- South Africa -- Eastern Cape , Riparian restoration -- South Africa -- Eastern Cape , Acacia mearnsii -- South Africa -- Eastern Cape , Kouga Region (South Africa) , Kouga River (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4887 , http://hdl.handle.net/10962/d1015228
- Description: The Kouga Riparian Rehabilitation Project (KRRP) is seen as a pilot rehabilitation project in the Kouga region that is heavily invaded with Acacia mearnsii along the riparian zones of many mountain streams. Clearing of these black wattles and re-planting of indigenous vegetation are imperative to rehabilitation efforts. In this context, two invaded catchments were identified - the Baviaans and the Heuningnes. The aim of this research is to characterise the effects that the woody alien invasive Acacia mearnsii has had on the river channel morphology of the Baviaans and Heuningnes Rivers. A desktop and initial field analysis of the relevant study area catchments was completed. This was followed by a comparison of the channel morphology of the various study channel reaches using fixed channel transects. Ecological resource quality objectives (RQOs) for river rehabilitation from a fluvial geomorphological viewpoint were then established. A long-term monitoring protocol to assess whether or not these RQOs will be achieved was recommended. Follow-up channel transects were measured post wattle clearance in the Baviaans and short-term (<2yrs) changes in channel form were described. Differences in terms of the effect of Acacia mearnsii on channel form were then interpreted by direct comparison and through statistical analysis. Results indicate a number of significant differences between those channels impacted by black wattle infestation and those channels seen as unimpacted and natural. Short-term changes (<2yrs) that occurred within the study period post Baviaans wattle clearance were shown to be minimal for channel form as well as for bed material. The lack of any clear relationship or explanation between channel form and other channel controls suggests vegetation as the primary control. Vegetation, specifically the invasive alien vegetation, is the key controlling variable acting on channel form in the two study catchments.
- Full Text:
- Date Issued: 2009
- Authors: Pietersen, Adrian
- Date: 2009
- Subjects: Fluvial geomorphology -- South Africa -- Eastern Cape , Alien plants -- South Africa -- Eastern Cape , Kouga Riparian Rehabilitation Project , Stream conservation -- South Africa -- Eastern Cape , Wattles (Plants) -- South Africa -- Eastern Cape , Riparian restoration -- South Africa -- Eastern Cape , Acacia mearnsii -- South Africa -- Eastern Cape , Kouga Region (South Africa) , Kouga River (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4887 , http://hdl.handle.net/10962/d1015228
- Description: The Kouga Riparian Rehabilitation Project (KRRP) is seen as a pilot rehabilitation project in the Kouga region that is heavily invaded with Acacia mearnsii along the riparian zones of many mountain streams. Clearing of these black wattles and re-planting of indigenous vegetation are imperative to rehabilitation efforts. In this context, two invaded catchments were identified - the Baviaans and the Heuningnes. The aim of this research is to characterise the effects that the woody alien invasive Acacia mearnsii has had on the river channel morphology of the Baviaans and Heuningnes Rivers. A desktop and initial field analysis of the relevant study area catchments was completed. This was followed by a comparison of the channel morphology of the various study channel reaches using fixed channel transects. Ecological resource quality objectives (RQOs) for river rehabilitation from a fluvial geomorphological viewpoint were then established. A long-term monitoring protocol to assess whether or not these RQOs will be achieved was recommended. Follow-up channel transects were measured post wattle clearance in the Baviaans and short-term (<2yrs) changes in channel form were described. Differences in terms of the effect of Acacia mearnsii on channel form were then interpreted by direct comparison and through statistical analysis. Results indicate a number of significant differences between those channels impacted by black wattle infestation and those channels seen as unimpacted and natural. Short-term changes (<2yrs) that occurred within the study period post Baviaans wattle clearance were shown to be minimal for channel form as well as for bed material. The lack of any clear relationship or explanation between channel form and other channel controls suggests vegetation as the primary control. Vegetation, specifically the invasive alien vegetation, is the key controlling variable acting on channel form in the two study catchments.
- Full Text:
- Date Issued: 2009
An investigation into the design and implementation of an internet-scale network simulator
- Authors: Richter, John Peter Frank
- Date: 2009
- Subjects: Computer simulation , Computer network resources , Computer networks , Internet
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4597 , http://hdl.handle.net/10962/d1004840 , Computer simulation , Computer network resources , Computer networks , Internet
- Description: Simulation is a complex task with many research applications - chiey as a research tool, to test and evaluate hypothetical scenarios. Though many simulations execute similar operations and utilise similar data, there are few simulation frameworks or toolkits that allow researchers to rapidly develop their concepts. Those that are available to researchers are limited in scope, or use old technology that is no longer useful to modern researchers. As a result of this, many researchers build their own simulations without a framework, wasting time and resources on a system that could already cater for the majority of their simulation's requirements. In this work, a system is proposed for the creation of a scalable, dynamic-resolution network simulation framework that provides scalable scope for researchers, using modern technologies and languages. This framework should allow researchers to rapidly develop a broad range of semantically-rich simulations, without the necessity of superor grid-computers or clusters. Design and implementation are discussed and alternative network simulations are compared to the proposed framework. A series of simulations, focusing on malware, is run on an implementation of this framework, and the results are compared to expectations for the outcomes of those simulations. In conclusion, a critical review of the simulator is made, considering any extensions or shortcomings that need to be addressed.
- Full Text:
- Date Issued: 2009
- Authors: Richter, John Peter Frank
- Date: 2009
- Subjects: Computer simulation , Computer network resources , Computer networks , Internet
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4597 , http://hdl.handle.net/10962/d1004840 , Computer simulation , Computer network resources , Computer networks , Internet
- Description: Simulation is a complex task with many research applications - chiey as a research tool, to test and evaluate hypothetical scenarios. Though many simulations execute similar operations and utilise similar data, there are few simulation frameworks or toolkits that allow researchers to rapidly develop their concepts. Those that are available to researchers are limited in scope, or use old technology that is no longer useful to modern researchers. As a result of this, many researchers build their own simulations without a framework, wasting time and resources on a system that could already cater for the majority of their simulation's requirements. In this work, a system is proposed for the creation of a scalable, dynamic-resolution network simulation framework that provides scalable scope for researchers, using modern technologies and languages. This framework should allow researchers to rapidly develop a broad range of semantically-rich simulations, without the necessity of superor grid-computers or clusters. Design and implementation are discussed and alternative network simulations are compared to the proposed framework. A series of simulations, focusing on malware, is run on an implementation of this framework, and the results are compared to expectations for the outcomes of those simulations. In conclusion, a critical review of the simulator is made, considering any extensions or shortcomings that need to be addressed.
- Full Text:
- Date Issued: 2009
Mariculture as a means to add value to the east coast rock lobster Panulirus homarus rubellus subsistence fishery : a physiological approach to define transport and growout protocols for wild caught juveniles
- Authors: Kemp, J O G
- Date: 2009
- Subjects: Lobster fisheries -- South Africa , Lobster culture -- South Africa , Lobsters -- Growth -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5299 , http://hdl.handle.net/10962/d1005144
- Description: In a context of declining capture fisheries and public pressure for greater access to marine resources, marine aquaculture is receiving increasing interest from the South African government as a means to increase the diversity of economic activities in coastal regions, thereby providing employment and reducing poverty. The east coast rock lobster Panulirus homarus rubellus is currently harvested by subsistence fisherman along the former Transkei coastline of south-east South Africa and presents a possible opportunity for ongrowing wild juvenile lobsters in culture facilities. Lack of compliance coupled with poor enforcement of the minimum size limit (65 mm carapace length) has resulted in the ongoing harvest of undersize size lobsters by subsistence fishers. Generally, fishers either consume these undersize lobsters or sell them to tourists for low prices. In line with international trends in rock lobster aquaculture, interest has subsequently arisen in the possibilities of ongrowing these undersize lobsters as a means of adding value to the P. h rubellus resource for subsistence fishers. The aim of this physiological study was to assess the biological feasibility of harvesting, transporting and culturing wild caught juvenile lobsters, thereby provide empirical data to inform the development of suitable transport and culture protocols. The experimental objectives were to asses the effect of temperature on growth and survival of P. h. rubellus, as well as the effects of a suite of extrinsic and intrinsic factors on ammonia excretion and oxygen consumption. Juvenile lobsters were collected by hand from near-shore reefs (2-15 m depth) off Mdumbi in the former Transkei, Eastern Cape Province and transported by road (7 hours) to the Port Alfred Marine Research Laboratory where they were held in a recirculating culture system. The effect of temperature over a range of 9.7 °C (18.9±0.7 to 28.6±1.5 °C) on the growth and survival of juvenile P. h. rubellus fed a diet of fresh mussel flesh was investigated. Specific growth rate (SGR) was significantly different between temperatures (p = 0.01), with the highest values recorded for the 24 °C and 28 °C treatments. There was no significant difference in moult increment (MI) between temperatures, however, intermoult period (IMP) differed significantly between temperatures (p = 0.0015) with mean IMP lowest at 24 °C, although not significantly different from the means of the 26 °C and 28 °C treatments. IMP was highest at 19 °C and 21 °C. Apparent feed intake was significantly different between treatments (p < 0.0001) and exhibited a strong positive correlation with increasing temperature. Food conversion ratio (FCR) differed significantly between temperatures (p = 0.02) with 24 °C exhibiting the most efficient FCR. The results for growth rate and food conversion efficiency suggested that 24 °C is optimal for the growout of juvenile P. h. rubellus. In the second study, the effect of body weight, emersion, daily rhythm, feeding and ambient ammonia on the total ammonia nitrogen (TAN) excretion rate was investigated. Body weight (n = 16, range of 16.8 – 322 g) was positively correlated to daytime TAN excretion rate (mg h⁻¹). Re-immersion after one hour emersion in a moist environment was characterized by a significant increase in TAN excretion rate for the first hour compared to pre-immersion levels. The amount of TAN excreted during this period was as expected if basal TAN excretion rates were maintained during emersion. TAN excretion rates returned to pre-emersion levels by the end of the second hour. There was no evidence of a daily rhythm in TAN excretion rate for P. h. rubellus. TAN excretion rates were elevated following feeding. An initial peak in TAN excretion rate after seven hours (7.58 times pre-feeding rate) was followed by a smaller peak after 13 hours (6.69 times pre-feeding rate). TAN excretion rate dropped to levels not significantly different from pre-feeding levels after 23 hours and consistently returned to pre-feeding levels after 42 hours. The TAN excretion rates of lobster exposed for two hours to an ambient TAN concentration of 1.02±0.10 mg l⁻¹ and 2.3± 0.2 mg l⁻¹ were not significantly different from TAN excretion rates recorded at low ambient water TAN prior to exposure. Exposure to an ambient TAN concentration of 4.45±0.78 mg l⁻¹ had a significant effect on the TAN excretion rate, with pronounced ammonia uptake occurring for all animals at this concentration. The third study investigated the effects of body weight, diurnal rhythm, feeding and emersion on lobster oxygen consumption. Body weight was positively correlated to both standard and active oxygen consumption (mg O2 h⁻¹) while body weight was negatively correlated to mass-specific standard oxygen uptake (mg O2 g⁻¹ h⁻¹). Diurnal rhythm exhibited a strong effect on the lobsters oxygen consumption, with average night time values 67% greater than those recorded during the day. This was related to activity driven by intrinsic nocturnal foraging behaviour. Feeding resulted in a classic specific dynamic action (SDA) response, with postprandial oxygen consumption increasing to a peak before decreasing gradually to preprandial levels. Emersion resulted in a significant increase in oxygen consumption, with lobsters rapidly recovering to pre-emersion levels after four hours. Results from these studies suggest that the capture, transport and culture of juvenile P. h. rubellus is biologically feasible. Empirical data generated were used to provide recommendations regarding species optimised transport and culture protocols. A purge time of 48 hours before transport is suggested to ensure that ammonia excretion and oxygen consumption are at basal levels. Furthermore, emersed transport for a period of one hour is characterised by rapid recovery upon re-immersion. In order to prevent the accumulation of stressors, it is suggested that consecutive periods of emersion are interjected with recovery periods (five hours) in water to allow the removal of accumulated ammonia and repayment of the oxygen debt incurred. The recorded ammonia rates indicate that a biological filter size of 4.8 m³ is recommended for 1000 kg of fed lobsters in a culture situation, although this can be reduced considerably if lobsters are being held without feeding (0.72 m³). A flow rate of 112 l kg⁻¹ h⁻¹ is required to meet the metabolic requirements of lobsters. Bottlenecks to the viable commercial culture of P. h. rubellus, and the ability of this practice to provide the socio-economic benefits that were envisioned, are discussed.
- Full Text:
- Date Issued: 2009
- Authors: Kemp, J O G
- Date: 2009
- Subjects: Lobster fisheries -- South Africa , Lobster culture -- South Africa , Lobsters -- Growth -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5299 , http://hdl.handle.net/10962/d1005144
- Description: In a context of declining capture fisheries and public pressure for greater access to marine resources, marine aquaculture is receiving increasing interest from the South African government as a means to increase the diversity of economic activities in coastal regions, thereby providing employment and reducing poverty. The east coast rock lobster Panulirus homarus rubellus is currently harvested by subsistence fisherman along the former Transkei coastline of south-east South Africa and presents a possible opportunity for ongrowing wild juvenile lobsters in culture facilities. Lack of compliance coupled with poor enforcement of the minimum size limit (65 mm carapace length) has resulted in the ongoing harvest of undersize size lobsters by subsistence fishers. Generally, fishers either consume these undersize lobsters or sell them to tourists for low prices. In line with international trends in rock lobster aquaculture, interest has subsequently arisen in the possibilities of ongrowing these undersize lobsters as a means of adding value to the P. h rubellus resource for subsistence fishers. The aim of this physiological study was to assess the biological feasibility of harvesting, transporting and culturing wild caught juvenile lobsters, thereby provide empirical data to inform the development of suitable transport and culture protocols. The experimental objectives were to asses the effect of temperature on growth and survival of P. h. rubellus, as well as the effects of a suite of extrinsic and intrinsic factors on ammonia excretion and oxygen consumption. Juvenile lobsters were collected by hand from near-shore reefs (2-15 m depth) off Mdumbi in the former Transkei, Eastern Cape Province and transported by road (7 hours) to the Port Alfred Marine Research Laboratory where they were held in a recirculating culture system. The effect of temperature over a range of 9.7 °C (18.9±0.7 to 28.6±1.5 °C) on the growth and survival of juvenile P. h. rubellus fed a diet of fresh mussel flesh was investigated. Specific growth rate (SGR) was significantly different between temperatures (p = 0.01), with the highest values recorded for the 24 °C and 28 °C treatments. There was no significant difference in moult increment (MI) between temperatures, however, intermoult period (IMP) differed significantly between temperatures (p = 0.0015) with mean IMP lowest at 24 °C, although not significantly different from the means of the 26 °C and 28 °C treatments. IMP was highest at 19 °C and 21 °C. Apparent feed intake was significantly different between treatments (p < 0.0001) and exhibited a strong positive correlation with increasing temperature. Food conversion ratio (FCR) differed significantly between temperatures (p = 0.02) with 24 °C exhibiting the most efficient FCR. The results for growth rate and food conversion efficiency suggested that 24 °C is optimal for the growout of juvenile P. h. rubellus. In the second study, the effect of body weight, emersion, daily rhythm, feeding and ambient ammonia on the total ammonia nitrogen (TAN) excretion rate was investigated. Body weight (n = 16, range of 16.8 – 322 g) was positively correlated to daytime TAN excretion rate (mg h⁻¹). Re-immersion after one hour emersion in a moist environment was characterized by a significant increase in TAN excretion rate for the first hour compared to pre-immersion levels. The amount of TAN excreted during this period was as expected if basal TAN excretion rates were maintained during emersion. TAN excretion rates returned to pre-emersion levels by the end of the second hour. There was no evidence of a daily rhythm in TAN excretion rate for P. h. rubellus. TAN excretion rates were elevated following feeding. An initial peak in TAN excretion rate after seven hours (7.58 times pre-feeding rate) was followed by a smaller peak after 13 hours (6.69 times pre-feeding rate). TAN excretion rate dropped to levels not significantly different from pre-feeding levels after 23 hours and consistently returned to pre-feeding levels after 42 hours. The TAN excretion rates of lobster exposed for two hours to an ambient TAN concentration of 1.02±0.10 mg l⁻¹ and 2.3± 0.2 mg l⁻¹ were not significantly different from TAN excretion rates recorded at low ambient water TAN prior to exposure. Exposure to an ambient TAN concentration of 4.45±0.78 mg l⁻¹ had a significant effect on the TAN excretion rate, with pronounced ammonia uptake occurring for all animals at this concentration. The third study investigated the effects of body weight, diurnal rhythm, feeding and emersion on lobster oxygen consumption. Body weight was positively correlated to both standard and active oxygen consumption (mg O2 h⁻¹) while body weight was negatively correlated to mass-specific standard oxygen uptake (mg O2 g⁻¹ h⁻¹). Diurnal rhythm exhibited a strong effect on the lobsters oxygen consumption, with average night time values 67% greater than those recorded during the day. This was related to activity driven by intrinsic nocturnal foraging behaviour. Feeding resulted in a classic specific dynamic action (SDA) response, with postprandial oxygen consumption increasing to a peak before decreasing gradually to preprandial levels. Emersion resulted in a significant increase in oxygen consumption, with lobsters rapidly recovering to pre-emersion levels after four hours. Results from these studies suggest that the capture, transport and culture of juvenile P. h. rubellus is biologically feasible. Empirical data generated were used to provide recommendations regarding species optimised transport and culture protocols. A purge time of 48 hours before transport is suggested to ensure that ammonia excretion and oxygen consumption are at basal levels. Furthermore, emersed transport for a period of one hour is characterised by rapid recovery upon re-immersion. In order to prevent the accumulation of stressors, it is suggested that consecutive periods of emersion are interjected with recovery periods (five hours) in water to allow the removal of accumulated ammonia and repayment of the oxygen debt incurred. The recorded ammonia rates indicate that a biological filter size of 4.8 m³ is recommended for 1000 kg of fed lobsters in a culture situation, although this can be reduced considerably if lobsters are being held without feeding (0.72 m³). A flow rate of 112 l kg⁻¹ h⁻¹ is required to meet the metabolic requirements of lobsters. Bottlenecks to the viable commercial culture of P. h. rubellus, and the ability of this practice to provide the socio-economic benefits that were envisioned, are discussed.
- Full Text:
- Date Issued: 2009
An investigation into the development of environmental education as a field of practice in South African National Parks
- Authors: Taljaard, Sandra
- Date: 2009
- Subjects: Environmental education -- South Africa National parks and reserves -- South Africa Environmental education -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1603 , http://hdl.handle.net/10962/d1003485
- Description: This study looks at aspects of the development of environmental education in South African National Parks (SANParks), in relation to the emergence of national and organisational policy frameworks. In order to put current environmental education practices into context, the study firstly looks at the historical development line of environmental education in SANParks, as well as in the broader national context. This provides a framework within which the processes of change and development can be traced in terms of social, political and economic influences on an international and national front. The study finds that the promulgation of legislation, including the Constitution, National Acts and various other policies, reflected the trends of thinking and set the pace in a democratic South Africa, which led to the emergence of more explicit processes and refined policies. Popkewitz’s finding, that education emerged in modernity, is used in the study to illustrate this tendency. It finds that these changes in South Africa resulted in the establishment of more structured environmental education processes within SANParks, and led to the expansion, diversification and strengthening of environmental education as a field of practice over time. The study traces significant processes of recontextualisation of international and national environmental education related policies according to the framework established by Bernstein (1980). These processes of recontextualisation were followed in the formulation processes of SANParks policy and strategy documents in the period from 1999 to 2005, and resulted in an official pedagogic discourse for environmental education in SANParks. The study establishes a second level of recontextualisation, that is, the official pedagogic discourse of environmental education in SANParks is recontextualised to a pedagogic discourse of reproduction. The pedagogic discourse of reproduction relates to park practices, where contextualisation within park-based programmes appears to be strong. The park-based programmes resemble a ‘curriculum in practice’, which brings us to Cornbleth’s critical curriculum approach. The study utilises this approach to explore and explain the meaning of the critical perspective taken on curriculum construction and change efforts at park implementation level (Cornbleth, 1990). The study finds that the contextualisation of park programmes and practices lead to variety in park programmes, which adds richness to environmental education programmes and activities, and further highlights the fact that environmental education practices are prolific in national parks. The study also finds that historical and contextual processes associated with specific parks strongly characterise environmental education programmes and practices in those parks, and that partnership programmes, such as the Kids in Parks programme, contribute towards, and enhance the growth of environmental education as a specialised field of practice in SANParks. The study comments on the need for environmental education practices in SANParks to be reviewed and expanded in line with the contemporary approach towards the environment as a social construct of interacting components. These components include the biophysical, social, economic and political dimensions. The study also highlights the need for the recognition and acknowledgement of the long, historical development line of environmental education in SANParks in order to build on established structures in a holistic way. The study further determines a need for strong leadership to successfully expand this specialised field of practice and encourages a participatory approach in the review and further development of this field of practice in SANParks. The study ultimately finds that environmental education in SANParks has a long and rich development profile, which has placed it in a strong position for further development. However, it concludes that there is a great need for a rejuvenated approach, which requires expert knowledge, professionalism and broad based networking approach to enable meaningful expansion within this specialised field of practice.
- Full Text:
- Date Issued: 2009
- Authors: Taljaard, Sandra
- Date: 2009
- Subjects: Environmental education -- South Africa National parks and reserves -- South Africa Environmental education -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1603 , http://hdl.handle.net/10962/d1003485
- Description: This study looks at aspects of the development of environmental education in South African National Parks (SANParks), in relation to the emergence of national and organisational policy frameworks. In order to put current environmental education practices into context, the study firstly looks at the historical development line of environmental education in SANParks, as well as in the broader national context. This provides a framework within which the processes of change and development can be traced in terms of social, political and economic influences on an international and national front. The study finds that the promulgation of legislation, including the Constitution, National Acts and various other policies, reflected the trends of thinking and set the pace in a democratic South Africa, which led to the emergence of more explicit processes and refined policies. Popkewitz’s finding, that education emerged in modernity, is used in the study to illustrate this tendency. It finds that these changes in South Africa resulted in the establishment of more structured environmental education processes within SANParks, and led to the expansion, diversification and strengthening of environmental education as a field of practice over time. The study traces significant processes of recontextualisation of international and national environmental education related policies according to the framework established by Bernstein (1980). These processes of recontextualisation were followed in the formulation processes of SANParks policy and strategy documents in the period from 1999 to 2005, and resulted in an official pedagogic discourse for environmental education in SANParks. The study establishes a second level of recontextualisation, that is, the official pedagogic discourse of environmental education in SANParks is recontextualised to a pedagogic discourse of reproduction. The pedagogic discourse of reproduction relates to park practices, where contextualisation within park-based programmes appears to be strong. The park-based programmes resemble a ‘curriculum in practice’, which brings us to Cornbleth’s critical curriculum approach. The study utilises this approach to explore and explain the meaning of the critical perspective taken on curriculum construction and change efforts at park implementation level (Cornbleth, 1990). The study finds that the contextualisation of park programmes and practices lead to variety in park programmes, which adds richness to environmental education programmes and activities, and further highlights the fact that environmental education practices are prolific in national parks. The study also finds that historical and contextual processes associated with specific parks strongly characterise environmental education programmes and practices in those parks, and that partnership programmes, such as the Kids in Parks programme, contribute towards, and enhance the growth of environmental education as a specialised field of practice in SANParks. The study comments on the need for environmental education practices in SANParks to be reviewed and expanded in line with the contemporary approach towards the environment as a social construct of interacting components. These components include the biophysical, social, economic and political dimensions. The study also highlights the need for the recognition and acknowledgement of the long, historical development line of environmental education in SANParks in order to build on established structures in a holistic way. The study further determines a need for strong leadership to successfully expand this specialised field of practice and encourages a participatory approach in the review and further development of this field of practice in SANParks. The study ultimately finds that environmental education in SANParks has a long and rich development profile, which has placed it in a strong position for further development. However, it concludes that there is a great need for a rejuvenated approach, which requires expert knowledge, professionalism and broad based networking approach to enable meaningful expansion within this specialised field of practice.
- Full Text:
- Date Issued: 2009
The principle of inclusion-exclusion and möbius function as counting techniques in finite fuzzy subsets
- Authors: Talwanga, Matiki
- Date: 2009
- Subjects: Fuzzy logic , Fuzzy sets , Fuzzy systems , Möbius function
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5413 , http://hdl.handle.net/10962/d1005227 , Fuzzy logic , Fuzzy sets , Fuzzy systems , Möbius function
- Description: The broad goal in this thesis is to enumerate elements and fuzzy subsets of a finite set enjoying some useful properties through the well-known counting technique of the principle of inclusion-exclusion. We consider the set of membership values to be finite and uniformly spaced in the real unit interval. Further we define an equivalence relation with regards to the cardinalities of fuzzy subsets providing the Möbius function and Möbius inversion in that context.
- Full Text:
- Date Issued: 2009
- Authors: Talwanga, Matiki
- Date: 2009
- Subjects: Fuzzy logic , Fuzzy sets , Fuzzy systems , Möbius function
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5413 , http://hdl.handle.net/10962/d1005227 , Fuzzy logic , Fuzzy sets , Fuzzy systems , Möbius function
- Description: The broad goal in this thesis is to enumerate elements and fuzzy subsets of a finite set enjoying some useful properties through the well-known counting technique of the principle of inclusion-exclusion. We consider the set of membership values to be finite and uniformly spaced in the real unit interval. Further we define an equivalence relation with regards to the cardinalities of fuzzy subsets providing the Möbius function and Möbius inversion in that context.
- Full Text:
- Date Issued: 2009
The popularity of tabloids: a reception analysis of the Daily Sun amongst Grahamstown readers
- Authors: Mapudzi, Hatikanganwi
- Date: 2009
- Subjects: Daily Sun Tabloid newspapers -- South Africa Tabloid newspapers -- South Africa -- Circulation Local mass media -- Research -- South Africa Readership surveys -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3457 , http://hdl.handle.net/10962/d1002911
- Description: Tabloid journalism has and continues to spark controversy. Scholarly considerations of tabloid journalism often question its contribution to democratic causes. However, little academic attention has been given to the question of how tabloids are understood and evaluated by their audiences. This study considered a range of audience responses to the Daily Sun by analysing the way some of its readers understand and evaluate it. The study examined the appeal of this popular tabloid to some Grahamstown readers. Reception analysis was employed to determine why these people read the Daily Sun. In particular, the active audience theory was used as a framework to conduct the research. To achieve the objectives of the study, qualitative research methods such as focus group interviews and individual in-depth interviews were employed. Looking at the findings, many of the respondents acknowledged they read the tabloid for interpersonal communication, diversion and entertainment. The results also revealed that their lived context plays a major role in their reading of stories. In a wider context, the research contributes to an understanding of the popularity of tabloid newspapers.
- Full Text:
- Date Issued: 2009
- Authors: Mapudzi, Hatikanganwi
- Date: 2009
- Subjects: Daily Sun Tabloid newspapers -- South Africa Tabloid newspapers -- South Africa -- Circulation Local mass media -- Research -- South Africa Readership surveys -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3457 , http://hdl.handle.net/10962/d1002911
- Description: Tabloid journalism has and continues to spark controversy. Scholarly considerations of tabloid journalism often question its contribution to democratic causes. However, little academic attention has been given to the question of how tabloids are understood and evaluated by their audiences. This study considered a range of audience responses to the Daily Sun by analysing the way some of its readers understand and evaluate it. The study examined the appeal of this popular tabloid to some Grahamstown readers. Reception analysis was employed to determine why these people read the Daily Sun. In particular, the active audience theory was used as a framework to conduct the research. To achieve the objectives of the study, qualitative research methods such as focus group interviews and individual in-depth interviews were employed. Looking at the findings, many of the respondents acknowledged they read the tabloid for interpersonal communication, diversion and entertainment. The results also revealed that their lived context plays a major role in their reading of stories. In a wider context, the research contributes to an understanding of the popularity of tabloid newspapers.
- Full Text:
- Date Issued: 2009
Coping with xenophobia : Senegalese migrants in Port Elizabeth
- Authors: Barbali, Silvana Claudia
- Date: 2009
- Subjects: Xenophobia -- South Africa -- Port Elizabeth Migrant labor -- South Africa -- Port Elizabeth Immigrants -- South Africa -- Port Elizabeth Foreign workers -- South Africa -- Port Elizabeth Aliens -- South Africa -- Social conditions Immigrants -- Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2102 , http://hdl.handle.net/10962/d1002665
- Description: This thesis seeks to investigate Senegalese migrants' experiences of xenophobia in South Africa. It explores prevailing theories used to explain the phenomenon of xenophobia and uses data collected via anthropological fieldwork to support arguments made. It is argued that a culture of migration in Senegal and the significance of migration as a rite of passage in Senegalese masculinity assists migrants to orientate themselves in host countries, and influences the way Senegalese are „received‟ by South Africans. In addition, Senegalese Islam (Sufi Orientation), which organises its members into brotherhoods, assists in the social integration of Senegalese men in Port Elizabeth. The men belong to the Mouride Brotherhood and the thesis shows how membership to the brotherhood provides a strong network of support for migrant men without resulting in the enclaving of the men in the broader social and economic context of Port Elizabeth. This has important implications for the individual and collective migration experience of Senegalese and influences the men's creation of meaning in their experiences as migrants. The thesis makes use of the concept of transnationalism to analyse the complex and multifaceted nature of transnational migration, arguing that migration experiences are influenced by a range of transnational factors and is deeply culturally influenced. The research suggests that migration experts and government departments in South Africa should take these complexities into account when formulating new programmes and policies for migrants.
- Full Text:
- Date Issued: 2009
- Authors: Barbali, Silvana Claudia
- Date: 2009
- Subjects: Xenophobia -- South Africa -- Port Elizabeth Migrant labor -- South Africa -- Port Elizabeth Immigrants -- South Africa -- Port Elizabeth Foreign workers -- South Africa -- Port Elizabeth Aliens -- South Africa -- Social conditions Immigrants -- Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2102 , http://hdl.handle.net/10962/d1002665
- Description: This thesis seeks to investigate Senegalese migrants' experiences of xenophobia in South Africa. It explores prevailing theories used to explain the phenomenon of xenophobia and uses data collected via anthropological fieldwork to support arguments made. It is argued that a culture of migration in Senegal and the significance of migration as a rite of passage in Senegalese masculinity assists migrants to orientate themselves in host countries, and influences the way Senegalese are „received‟ by South Africans. In addition, Senegalese Islam (Sufi Orientation), which organises its members into brotherhoods, assists in the social integration of Senegalese men in Port Elizabeth. The men belong to the Mouride Brotherhood and the thesis shows how membership to the brotherhood provides a strong network of support for migrant men without resulting in the enclaving of the men in the broader social and economic context of Port Elizabeth. This has important implications for the individual and collective migration experience of Senegalese and influences the men's creation of meaning in their experiences as migrants. The thesis makes use of the concept of transnationalism to analyse the complex and multifaceted nature of transnational migration, arguing that migration experiences are influenced by a range of transnational factors and is deeply culturally influenced. The research suggests that migration experts and government departments in South Africa should take these complexities into account when formulating new programmes and policies for migrants.
- Full Text:
- Date Issued: 2009
National identity and nation-building in post-apartheid South Africa
- Authors: Stinson, Andrew Todd
- Date: 2009
- Subjects: Post-apartheid era -- South Africa , South Africa -- Politics and government -- 1994- , Nationalism -- South Africa , Civil society -- South Africa , Democracy -- South Africa , South Africa -- Social policy , Ethnicity -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2832 , http://hdl.handle.net/10962/d1003042
- Description: Throughout South Africa’s post-Apartheid history, the ANC-led government has undertaken a distinct nation-building program in pursuit of “a truly united, democratic and prosperous South Africa” (ANC, 2007). This is reflected in a two-pronged approach, coupling political and socioeconomic transformation with the social-psychological aspect of forging a broad and inclusive national consciousness. The ANC’s “rainbow nation” approach embraces cultural diversity through what I shall call the practice of “interculturalism”. Interculturalism is a way of recognizing commonalities, reducing tensions and promoting the formation of social partnerships among different cultural groups. The ANC has also promoted a civic culture based on the principles of liberal democracy, non-racism, equality and the protection of individual rights. Interculturalism and civic nationalism are critically important factors to South African nation-building since together they foster a shared public culture and support meaningful participation in the creation of a truly just and democratic South Africa. Unfortunately, in many ways South African society remains deeply divided by race, ethnicity and economic inequality. This thesis analyses various theoretical approaches to national identity and nationbuilding with the aim of identifying several concepts which arguably throw light on the problems of South African nation-building and national identity formation. It is argued that interculturalism and civic nationalism are context appropriate approaches which have been adopted by the ANC to further an inclusive sense of shared public culture and promote participation in the creation of a shared public future. These approaches have led to the limited emergence of a broad South African national identity. However, South Africa’s commitment to socio-economic transformation has been less successful in generating widespread support for a broad national identity. While some of those previously disadvantaged under Apartheid have benefited from poverty alleviation schemes, service delivery initiatives and black economic empowerment programs, many continue to suffer from homelessness, unemployment and worsening economic conditions. Increasing economic marginalization has caused growing discontent among South Africa’s poor and constitutes the biggest threat to the formation of a cohesive national identity in South African society. Ultimately, it is argued that while interculturalism and civic nationalism have played an important role in fostering the growth of a broad national identity, true South African social cohesion will fail to emerge without a massive and sustained commitment to wide-ranging socio-economic transformation.
- Full Text:
- Date Issued: 2009
- Authors: Stinson, Andrew Todd
- Date: 2009
- Subjects: Post-apartheid era -- South Africa , South Africa -- Politics and government -- 1994- , Nationalism -- South Africa , Civil society -- South Africa , Democracy -- South Africa , South Africa -- Social policy , Ethnicity -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2832 , http://hdl.handle.net/10962/d1003042
- Description: Throughout South Africa’s post-Apartheid history, the ANC-led government has undertaken a distinct nation-building program in pursuit of “a truly united, democratic and prosperous South Africa” (ANC, 2007). This is reflected in a two-pronged approach, coupling political and socioeconomic transformation with the social-psychological aspect of forging a broad and inclusive national consciousness. The ANC’s “rainbow nation” approach embraces cultural diversity through what I shall call the practice of “interculturalism”. Interculturalism is a way of recognizing commonalities, reducing tensions and promoting the formation of social partnerships among different cultural groups. The ANC has also promoted a civic culture based on the principles of liberal democracy, non-racism, equality and the protection of individual rights. Interculturalism and civic nationalism are critically important factors to South African nation-building since together they foster a shared public culture and support meaningful participation in the creation of a truly just and democratic South Africa. Unfortunately, in many ways South African society remains deeply divided by race, ethnicity and economic inequality. This thesis analyses various theoretical approaches to national identity and nationbuilding with the aim of identifying several concepts which arguably throw light on the problems of South African nation-building and national identity formation. It is argued that interculturalism and civic nationalism are context appropriate approaches which have been adopted by the ANC to further an inclusive sense of shared public culture and promote participation in the creation of a shared public future. These approaches have led to the limited emergence of a broad South African national identity. However, South Africa’s commitment to socio-economic transformation has been less successful in generating widespread support for a broad national identity. While some of those previously disadvantaged under Apartheid have benefited from poverty alleviation schemes, service delivery initiatives and black economic empowerment programs, many continue to suffer from homelessness, unemployment and worsening economic conditions. Increasing economic marginalization has caused growing discontent among South Africa’s poor and constitutes the biggest threat to the formation of a cohesive national identity in South African society. Ultimately, it is argued that while interculturalism and civic nationalism have played an important role in fostering the growth of a broad national identity, true South African social cohesion will fail to emerge without a massive and sustained commitment to wide-ranging socio-economic transformation.
- Full Text:
- Date Issued: 2009
A picture's worth a thousand words: a case study of grade 10 English language educators teaching visual literacy
- Authors: Leask-Smith, Lyn Ann
- Date: 2009
- Subjects: Visual literacy -- Study and teaching (Secondary) -- Case studies English language -- Study and teaching (Secondary) -- Case studies Teacher educators -- Training of -- Case studies English teachers -- Training of -- Case studies Teachers -- In-service training
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1702 , http://hdl.handle.net/10962/d1003585
- Description: The aim of this research was to better understand teacher's beliefs about visual literacy and to explore how their beliefs influence their teaching practice. In order to investigate this, a case study was conducted that comprised of lesson observations and semi-structured interviews with two secondary school English home language educators. The backdrop to the research was the implementation of the new national curriculum for grade 10. The participants, though well educated and experienced teachers, felt their training had been inadequate in the area of teaching visual literacy and although they acknowledged the importance of visual literacy, it seemed to have a fairly low priority in their actual teaching practice. In particular, very little attention was given to the production of multimodal texts by learners. The reason for this low priority may be related to the requirements of the formal assessment programme as well as limited lesson time in which to cover an extensive curriculum. The research findings would seem to suggest a need for in-service training in this area as well as access to suitable learning support materials and teacher resources.
- Full Text:
- Date Issued: 2009
- Authors: Leask-Smith, Lyn Ann
- Date: 2009
- Subjects: Visual literacy -- Study and teaching (Secondary) -- Case studies English language -- Study and teaching (Secondary) -- Case studies Teacher educators -- Training of -- Case studies English teachers -- Training of -- Case studies Teachers -- In-service training
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1702 , http://hdl.handle.net/10962/d1003585
- Description: The aim of this research was to better understand teacher's beliefs about visual literacy and to explore how their beliefs influence their teaching practice. In order to investigate this, a case study was conducted that comprised of lesson observations and semi-structured interviews with two secondary school English home language educators. The backdrop to the research was the implementation of the new national curriculum for grade 10. The participants, though well educated and experienced teachers, felt their training had been inadequate in the area of teaching visual literacy and although they acknowledged the importance of visual literacy, it seemed to have a fairly low priority in their actual teaching practice. In particular, very little attention was given to the production of multimodal texts by learners. The reason for this low priority may be related to the requirements of the formal assessment programme as well as limited lesson time in which to cover an extensive curriculum. The research findings would seem to suggest a need for in-service training in this area as well as access to suitable learning support materials and teacher resources.
- Full Text:
- Date Issued: 2009
An investigation of lower primary teachers' content knowledge of mathematics in Ohangwena region in Namibia
- Authors: Haufiku, Amon
- Date: 2009
- Subjects: SACMEQ Namibia. Presidential Commission on Education, Culture and Training Mathematics -- Study and teaching (Elementary) -- Namibia Education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1637 , http://hdl.handle.net/10962/d1003519
- Description: The poor performance in mathematics of learners in schools in Namibia, especially in the grades where learners sit for the national examinations, has been a concern of everybody. Since independence, the Ministry of Education in collaboration with several donor agencies has been aware of the poor performance in mathematics in the country. Several international and local studies have been made in an effort to identify the problems that are hindering learners’ performance in mathematics in Namibia. The findings of some studies that were conducted in the country such as the Southern Africa Consortium Monitoring Education Quality (2004), the Presidential Commission on Education, Culture and Training (1999), and the Mathematics and Science Teachers Extension Program (2002) revealed that the inadequate proficiency of primary teachers in mathematics content could be responsible for learners’ poor performance in mathematics. This study, therefore, is aimed at investigating the mathematical proficiency of lower primary (LP) teachers in Namibia. The study used three instruments to collect data namely, a profile questionnaire – to collect teachers’ demographic data, a proficiency test – to test their proficiency level of mathematics using the content of Grade 4 and 5 learners’ mathematics syllabi and a semi-structured interview schedule – to get views about their own mathematics content knowledge, attitudes towards mathematics as well as problems that hinder effective teaching and learning of mathematics at LP phase. The study was conducted with 30 lower primary teachers from five primary and combined schools in the Ohangwena circuit of the Ohangwena region. The study found out that: (1) the mathematical proficiency of LP teachers is below the Grade 7 Mathematics content. Most teachers are not able to solve the content of mathematics at upper primary (UP) phase. (2) LP education is receiving very little support from the Ministry compared to other phases. (3) There are no workshops or training courses organised for LP teachers. They do not receive enough textbooks and materials, their classrooms are overcrowded and teachers cannot pay attention to individual learners. (4) There is a dire need for LP Head of Departments (HODs) who are specialised at LP; most HODs for LP at schools are not specialised in this area. When it comes to views about future content of mathematics that should be given to LP teachers in Namibia, respondents recommended that future LP teachers should have knowledge of mathematics up to at least Grade 10 but preferably up to Grade 12. They do not want to be restricted to LP mathematics, but would like to have a broader knowledge of mathematics content. This would make them more confident in solving their children’s problems in mathematics. Overall, participants recognised the value of mathematics and the role that it plays in society.
- Full Text:
- Date Issued: 2009
- Authors: Haufiku, Amon
- Date: 2009
- Subjects: SACMEQ Namibia. Presidential Commission on Education, Culture and Training Mathematics -- Study and teaching (Elementary) -- Namibia Education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1637 , http://hdl.handle.net/10962/d1003519
- Description: The poor performance in mathematics of learners in schools in Namibia, especially in the grades where learners sit for the national examinations, has been a concern of everybody. Since independence, the Ministry of Education in collaboration with several donor agencies has been aware of the poor performance in mathematics in the country. Several international and local studies have been made in an effort to identify the problems that are hindering learners’ performance in mathematics in Namibia. The findings of some studies that were conducted in the country such as the Southern Africa Consortium Monitoring Education Quality (2004), the Presidential Commission on Education, Culture and Training (1999), and the Mathematics and Science Teachers Extension Program (2002) revealed that the inadequate proficiency of primary teachers in mathematics content could be responsible for learners’ poor performance in mathematics. This study, therefore, is aimed at investigating the mathematical proficiency of lower primary (LP) teachers in Namibia. The study used three instruments to collect data namely, a profile questionnaire – to collect teachers’ demographic data, a proficiency test – to test their proficiency level of mathematics using the content of Grade 4 and 5 learners’ mathematics syllabi and a semi-structured interview schedule – to get views about their own mathematics content knowledge, attitudes towards mathematics as well as problems that hinder effective teaching and learning of mathematics at LP phase. The study was conducted with 30 lower primary teachers from five primary and combined schools in the Ohangwena circuit of the Ohangwena region. The study found out that: (1) the mathematical proficiency of LP teachers is below the Grade 7 Mathematics content. Most teachers are not able to solve the content of mathematics at upper primary (UP) phase. (2) LP education is receiving very little support from the Ministry compared to other phases. (3) There are no workshops or training courses organised for LP teachers. They do not receive enough textbooks and materials, their classrooms are overcrowded and teachers cannot pay attention to individual learners. (4) There is a dire need for LP Head of Departments (HODs) who are specialised at LP; most HODs for LP at schools are not specialised in this area. When it comes to views about future content of mathematics that should be given to LP teachers in Namibia, respondents recommended that future LP teachers should have knowledge of mathematics up to at least Grade 10 but preferably up to Grade 12. They do not want to be restricted to LP mathematics, but would like to have a broader knowledge of mathematics content. This would make them more confident in solving their children’s problems in mathematics. Overall, participants recognised the value of mathematics and the role that it plays in society.
- Full Text:
- Date Issued: 2009
The impact on biodiversity, and integrated control, of water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae) on the Lake Nsezi - Nseleni River system
- Authors: Jones, Roy William
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Aquatic plants -- South Africa -- Nsezi, Lake , Aquatic weeds -- South Africa -- Nsezi, Lake , Invasive plants -- South Africa -- Nsezi, Lake
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5711 , http://hdl.handle.net/10962/d1005397 , Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Aquatic plants -- South Africa -- Nsezi, Lake , Aquatic weeds -- South Africa -- Nsezi, Lake , Invasive plants -- South Africa -- Nsezi, Lake
- Description: Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), a free floating aquatic plant was discovered by C. von Martius in 1823 in Brazil. It is believed to have been introduced into South Africa, as an ornamental plant, in 1908 to the Cape Province and Natal. Since its introduction, water hyacinth has spread throughout South Africa to the detriment of all aquatic systems that it has been introduced to directly or indirectly. The weed was first positively identified on the Nseleni and Mposa rivers on the Nseleni Nature Reserve which is a protected area near Richards Bay in KwaZulu- Natal in 1982 and formed a 100% cover of the river by 1983. An integrated management plan was implemented in 1995 and resulted in a reduction of the weed from a 100% cover to less than 20% cover in 5 years. The keys to success of the water hyacinth integrated management plan, presented here, were finding the source of the weed, mapping the extent of the water hyacinth infestation, identifying sources of nutrient pollution, appointing a champion to drive the programme, dividing the river into management units, consultation with interested and affected parties, judicious use of herbicides and biological control and a commitment to follow-up. This study further showed that water hyacinth on the Nseleni and Mposa river systems had a negative impact on the biodiversity of the protected area and the control of water hyacinth resulted in the recovery of the benthic invertebrate, amphibian, reptile, fish and avian fauna. The implementation of this integrated management plan was very cost-effective and serves as a model approach to the control of water hyacinth in both South Africa and the rest of the world.
- Full Text:
- Date Issued: 2009
- Authors: Jones, Roy William
- Date: 2009
- Subjects: Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Aquatic plants -- South Africa -- Nsezi, Lake , Aquatic weeds -- South Africa -- Nsezi, Lake , Invasive plants -- South Africa -- Nsezi, Lake
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5711 , http://hdl.handle.net/10962/d1005397 , Water hyacinth -- Control -- South Africa , Eichhornia crassipedes , Pontederiaceae , Aquatic plants -- South Africa -- Nsezi, Lake , Aquatic weeds -- South Africa -- Nsezi, Lake , Invasive plants -- South Africa -- Nsezi, Lake
- Description: Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), a free floating aquatic plant was discovered by C. von Martius in 1823 in Brazil. It is believed to have been introduced into South Africa, as an ornamental plant, in 1908 to the Cape Province and Natal. Since its introduction, water hyacinth has spread throughout South Africa to the detriment of all aquatic systems that it has been introduced to directly or indirectly. The weed was first positively identified on the Nseleni and Mposa rivers on the Nseleni Nature Reserve which is a protected area near Richards Bay in KwaZulu- Natal in 1982 and formed a 100% cover of the river by 1983. An integrated management plan was implemented in 1995 and resulted in a reduction of the weed from a 100% cover to less than 20% cover in 5 years. The keys to success of the water hyacinth integrated management plan, presented here, were finding the source of the weed, mapping the extent of the water hyacinth infestation, identifying sources of nutrient pollution, appointing a champion to drive the programme, dividing the river into management units, consultation with interested and affected parties, judicious use of herbicides and biological control and a commitment to follow-up. This study further showed that water hyacinth on the Nseleni and Mposa river systems had a negative impact on the biodiversity of the protected area and the control of water hyacinth resulted in the recovery of the benthic invertebrate, amphibian, reptile, fish and avian fauna. The implementation of this integrated management plan was very cost-effective and serves as a model approach to the control of water hyacinth in both South Africa and the rest of the world.
- Full Text:
- Date Issued: 2009
Bond market development in emerging economies: a case study of the Bond Exchange of South Africa (BESA)
- Authors: Hove, Tagara
- Date: 2009
- Subjects: Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:961 , http://hdl.handle.net/10962/d1002695 , Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Description: This study looks at the development of bond markets in emerging economies and focuses on the development of the Bond Exchange of South Africa (BESA). It explores the history, structure, performance and key issues related to the development of this market within the broader context of domestic, regional and global bond market development. BESA's experience provides valuable lessons for other emerging market economies also seeking to build bond markets. The sophistication of the local bond market is not enough to make it appealing to foreign borrowers. Market development demands an enabling market infrastructure and a background of macroeconomic stability, diversified market participants, deregulation of capital flows and an appropriate regulatory and supervisory environment.
- Full Text:
- Date Issued: 2009
- Authors: Hove, Tagara
- Date: 2009
- Subjects: Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:961 , http://hdl.handle.net/10962/d1002695 , Bond Exchange of South Africa , Bond market -- South Africa , Foreign exchange rates -- South Africa
- Description: This study looks at the development of bond markets in emerging economies and focuses on the development of the Bond Exchange of South Africa (BESA). It explores the history, structure, performance and key issues related to the development of this market within the broader context of domestic, regional and global bond market development. BESA's experience provides valuable lessons for other emerging market economies also seeking to build bond markets. The sophistication of the local bond market is not enough to make it appealing to foreign borrowers. Market development demands an enabling market infrastructure and a background of macroeconomic stability, diversified market participants, deregulation of capital flows and an appropriate regulatory and supervisory environment.
- Full Text:
- Date Issued: 2009
A needs analysis for the implementation of a complementary course in mathematics education for teachers of mathematics in Namibia: a case study
- Authors: Ilukena, Alex Mbonabi
- Date: 2009
- Subjects: Education -- Namibia -- Case studies Mathematics -- Study and teaching -- Namibia -- Case studies Mathematics teachers -- Training of -- Namibia -- Case studies Teacher educators -- Training of -- Case studies Teachers -- Training of -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1677 , http://hdl.handle.net/10962/d1003560
- Description: After the introduction of the Basic Education Teacher Diploma (BETD) in Namibia, a number of studies were conducted on how teachers, lecturers, stakeholders and the Namibian public perceived the BETD program and its implementation. However, very few studies focussed specifically on mathematics subject content knowledge and pedagogical content knowledge in the BETD. The purpose of this study was to investigate the need for a complementary course in mathematics education to address the lack of mathematical content and pedagogical knowledge in the Namibian BETD. The study involved five mathematics school teachers, two mathematics college lecturers in the Kavango educational region and a professor of mathematics education at the University of Namibia. These participants were purposefully selected because of their knowledge and experiences with various aspects of the BETD program. The motivation for conducting this study was to gain a better understanding of some of the issues that have been raised about the BETD program, particularly the perceived inadequacy of mathematical subject content and methodology since the inception of the program. The study adopts a qualitative approach in reporting participants’ reflections. The views of the focal educators and documents such as syllabi and course outlines were the main source of data. The findings indicate that despite the training that the three BETD mathematics graduates in this study received, the level of mathematics taught in a complementary course, such as an ACE, would clearly better equip mathematics teachers to teach proficiently and facilitate access to institutions of higher learning such as universities. The results of the study revealed that there was a need for the implementation of a complementary course to the BETD in mathematics education for teachers of mathematics in Namibia. This study also provided valuable insights into what such a course could look like.
- Full Text:
- Date Issued: 2009
- Authors: Ilukena, Alex Mbonabi
- Date: 2009
- Subjects: Education -- Namibia -- Case studies Mathematics -- Study and teaching -- Namibia -- Case studies Mathematics teachers -- Training of -- Namibia -- Case studies Teacher educators -- Training of -- Case studies Teachers -- Training of -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1677 , http://hdl.handle.net/10962/d1003560
- Description: After the introduction of the Basic Education Teacher Diploma (BETD) in Namibia, a number of studies were conducted on how teachers, lecturers, stakeholders and the Namibian public perceived the BETD program and its implementation. However, very few studies focussed specifically on mathematics subject content knowledge and pedagogical content knowledge in the BETD. The purpose of this study was to investigate the need for a complementary course in mathematics education to address the lack of mathematical content and pedagogical knowledge in the Namibian BETD. The study involved five mathematics school teachers, two mathematics college lecturers in the Kavango educational region and a professor of mathematics education at the University of Namibia. These participants were purposefully selected because of their knowledge and experiences with various aspects of the BETD program. The motivation for conducting this study was to gain a better understanding of some of the issues that have been raised about the BETD program, particularly the perceived inadequacy of mathematical subject content and methodology since the inception of the program. The study adopts a qualitative approach in reporting participants’ reflections. The views of the focal educators and documents such as syllabi and course outlines were the main source of data. The findings indicate that despite the training that the three BETD mathematics graduates in this study received, the level of mathematics taught in a complementary course, such as an ACE, would clearly better equip mathematics teachers to teach proficiently and facilitate access to institutions of higher learning such as universities. The results of the study revealed that there was a need for the implementation of a complementary course to the BETD in mathematics education for teachers of mathematics in Namibia. This study also provided valuable insights into what such a course could look like.
- Full Text:
- Date Issued: 2009
The conservation and management of freshwater fishes in the Greater Addo Elephant National Park
- Authors: Traas, Graham Ronald Louis
- Date: 2009
- Subjects: Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5247 , http://hdl.handle.net/10962/d1005090 , Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Description: Freshwater fish are the most imperilled vertebrate group with a high projected extinction rate. In general, the world's freshwater ichthyofauna is in a poor state and is threatened by habitat destruction, pollution, the effects of alien species, damming, water extraction and overfishing. Within South Africa, legislation supporting the conservation of aquatic habitats and its associated fauna is strong, but there is a lack of capacity and poor co-ordination between agencies responsible for the conservation and management. The Greater Addo Elephant National Park (GAENP) includes the upper catchments of five of the Sundays River tributaries. Since the optimal method of conserving freshwater aquatic biota is to conserve the headwaters of either the river or its tributaries, there is an opportunity to conserve the native ichthyofauna of the Sundays River system. The principal objective of this thesis was, therefore, to provide information pertinent to the conservation and management of the fishes in the Sundays River system. Sixteen species of freshwater and estuarine fish were sampled, of which eight were alien. Species composition in each of the rivers, with the exception of the Kabouga River, had changed significantly from previous studies. The distribution ranges of several indigenous species had reduced, while those of some alien species was increased. Two species not previously recorded, Labeo capensis and Gambusia affinis, were sampled. Alien species were sampled from all the tributaries. Diversity indices and community assemblage models were identified as approaches for monitoring the ichthyofauna in this species depauperate system. Diversity indices were not recommended for use as a monitoring tool, as they provided insufficient detail on community composition and structure. A modified depletion estimator was applied to multiple pass electrofishing data to determine the effects of various physico-chemical variables on the absolute abundance of Pseudobarbus afer, an endangered species. Pseudobarbus afer density was found to be positively correlated to the presence of boulders. Where P. afer were present, they were abundant. Of the total sampled catch, 21.8% was comprised of alien fishes. Clarias gariepinus was the most successful invader having penetrated all but one of the tributaries. Micropterus salmoides changed the species composition of the Wit River significantly through predation, and is potentially the most dangerous of the alien species in the Sundays River system, capable of extirpating a population of P. afer in as little as three days. Only one man-made barrier to the upstream migration of alien fishes was present on the tributaries, and several addition barriers are required to safeguard the populations of indigenous fish in the headwaters of these tributaries. Several management and conservation tools are presented and discussed, including river rehabilitation, translocation, eradication of alien species, erection of barrier weirs and captive breeding programmes. Public awareness and education is stressed because without support from the communities surrounding the GAENP, management plans for conservation of the indigenous ichthyofauna will, in all likelihood, fail.
- Full Text:
- Date Issued: 2009
- Authors: Traas, Graham Ronald Louis
- Date: 2009
- Subjects: Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5247 , http://hdl.handle.net/10962/d1005090 , Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Description: Freshwater fish are the most imperilled vertebrate group with a high projected extinction rate. In general, the world's freshwater ichthyofauna is in a poor state and is threatened by habitat destruction, pollution, the effects of alien species, damming, water extraction and overfishing. Within South Africa, legislation supporting the conservation of aquatic habitats and its associated fauna is strong, but there is a lack of capacity and poor co-ordination between agencies responsible for the conservation and management. The Greater Addo Elephant National Park (GAENP) includes the upper catchments of five of the Sundays River tributaries. Since the optimal method of conserving freshwater aquatic biota is to conserve the headwaters of either the river or its tributaries, there is an opportunity to conserve the native ichthyofauna of the Sundays River system. The principal objective of this thesis was, therefore, to provide information pertinent to the conservation and management of the fishes in the Sundays River system. Sixteen species of freshwater and estuarine fish were sampled, of which eight were alien. Species composition in each of the rivers, with the exception of the Kabouga River, had changed significantly from previous studies. The distribution ranges of several indigenous species had reduced, while those of some alien species was increased. Two species not previously recorded, Labeo capensis and Gambusia affinis, were sampled. Alien species were sampled from all the tributaries. Diversity indices and community assemblage models were identified as approaches for monitoring the ichthyofauna in this species depauperate system. Diversity indices were not recommended for use as a monitoring tool, as they provided insufficient detail on community composition and structure. A modified depletion estimator was applied to multiple pass electrofishing data to determine the effects of various physico-chemical variables on the absolute abundance of Pseudobarbus afer, an endangered species. Pseudobarbus afer density was found to be positively correlated to the presence of boulders. Where P. afer were present, they were abundant. Of the total sampled catch, 21.8% was comprised of alien fishes. Clarias gariepinus was the most successful invader having penetrated all but one of the tributaries. Micropterus salmoides changed the species composition of the Wit River significantly through predation, and is potentially the most dangerous of the alien species in the Sundays River system, capable of extirpating a population of P. afer in as little as three days. Only one man-made barrier to the upstream migration of alien fishes was present on the tributaries, and several addition barriers are required to safeguard the populations of indigenous fish in the headwaters of these tributaries. Several management and conservation tools are presented and discussed, including river rehabilitation, translocation, eradication of alien species, erection of barrier weirs and captive breeding programmes. Public awareness and education is stressed because without support from the communities surrounding the GAENP, management plans for conservation of the indigenous ichthyofauna will, in all likelihood, fail.
- Full Text:
- Date Issued: 2009
Interrogating gender constructions in the Daily Sun: an analysis of the coverage of the 'Charter for a Man' campaign against gender violence between November and December 2007
- Authors: Dewa, Nonhlanhla
- Date: 2009
- Subjects: Foucault, Michel, 1926-1984 -- Criticism and interpretation Daily Sun Women -- Violence against Mass media and women Abused women Tabloid newspapers Discourse analysis
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3426 , http://hdl.handle.net/10962/d1002879
- Description: The study seeks to interrogate the gender constructions in the Daily Sun’s “Charter for a Man” campaign which ran from 7 November to 7 December 2007. It coincided with the 16 Days of Activism against gender violence and was designed to lobby support for this campaign and discourage men from physically abusing women. The “Charter for a Man” listed nine principles that signatories were to abide by. It included a section to be signed by men to be submitted to and collected by the Daily Sun. The campaign was constructed as an intervention into the issue of gender violence. Consequently, the 30 news stories, four editorial pieces and 11 letters to the editor that were published during the campaign period make up the textual data analysed in the study. The news stories consisted of testimonies from abused women and some women abusers. In addition, celebrity signatories were selected to endorse the campaign and encourage other men to follow suit. In the editorials, the campaign was consistently flagged as a nation building initiative which all men were supposed to support. The letters to the editor consisted of readers who either supported or rejected the campaign. The study takes place against the context of a patriarchal society characterised by high levels of violence. Given this scenario, the study is informed by a concern with gender justice and therefore considers whether such a campaign, ostensibly aimed at eradicating gender violence, has the potential of being transformative of gender inequalities. The study set out to establish the kinds of masculinities and femininities that were variously constituted in the campaign as well as the gender discourses that were privileged. It is informed by the theories of feminist poststructuralism and Foucault’s conceptualisation of discourse. As the campaign is the initiative of a tabloid newspaper, it is also considered within the framework of newspaper campaigns and arguments about tabloids and the public sphere. As text based research, the study employs critical discourse analysis as a qualitative procedure of textual analysis. It makes use of an eclectic approach to textual analysis that draws on linguistics, narrative and argumentation. The texts are analysed according to the categories of news texts contained which includes the Charter itself, signatory articles, testimonies, vox pops and letters to the editor. The overarching theme of nationhood projected in the editorials and other categories is also discussed as part of the analysis. The study concludes that the Daily Sun campaign might be a seemingly progressive action at first glance. However, it does not challenge the existing gender order but rather maintains and sustains patriarchal attitudes through the repeated representation of women as weak and in need of patronage and men as their protectors and providers. In some instances, women are constructed primarily as sexual beings as their physical attributes are emphasised, while men are constructed as working class citizens and rational beings. The study therefore proposes that the Daily Sun fails as an alternative public sphere that might make visible the concerns of women as a marginalised group in society. The campaign, it is argued, is self-serving in its promotion of the Daily Sun’s image as the “People’s Paper” rather than serious concerns about gender violence.
- Full Text:
- Date Issued: 2009
- Authors: Dewa, Nonhlanhla
- Date: 2009
- Subjects: Foucault, Michel, 1926-1984 -- Criticism and interpretation Daily Sun Women -- Violence against Mass media and women Abused women Tabloid newspapers Discourse analysis
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3426 , http://hdl.handle.net/10962/d1002879
- Description: The study seeks to interrogate the gender constructions in the Daily Sun’s “Charter for a Man” campaign which ran from 7 November to 7 December 2007. It coincided with the 16 Days of Activism against gender violence and was designed to lobby support for this campaign and discourage men from physically abusing women. The “Charter for a Man” listed nine principles that signatories were to abide by. It included a section to be signed by men to be submitted to and collected by the Daily Sun. The campaign was constructed as an intervention into the issue of gender violence. Consequently, the 30 news stories, four editorial pieces and 11 letters to the editor that were published during the campaign period make up the textual data analysed in the study. The news stories consisted of testimonies from abused women and some women abusers. In addition, celebrity signatories were selected to endorse the campaign and encourage other men to follow suit. In the editorials, the campaign was consistently flagged as a nation building initiative which all men were supposed to support. The letters to the editor consisted of readers who either supported or rejected the campaign. The study takes place against the context of a patriarchal society characterised by high levels of violence. Given this scenario, the study is informed by a concern with gender justice and therefore considers whether such a campaign, ostensibly aimed at eradicating gender violence, has the potential of being transformative of gender inequalities. The study set out to establish the kinds of masculinities and femininities that were variously constituted in the campaign as well as the gender discourses that were privileged. It is informed by the theories of feminist poststructuralism and Foucault’s conceptualisation of discourse. As the campaign is the initiative of a tabloid newspaper, it is also considered within the framework of newspaper campaigns and arguments about tabloids and the public sphere. As text based research, the study employs critical discourse analysis as a qualitative procedure of textual analysis. It makes use of an eclectic approach to textual analysis that draws on linguistics, narrative and argumentation. The texts are analysed according to the categories of news texts contained which includes the Charter itself, signatory articles, testimonies, vox pops and letters to the editor. The overarching theme of nationhood projected in the editorials and other categories is also discussed as part of the analysis. The study concludes that the Daily Sun campaign might be a seemingly progressive action at first glance. However, it does not challenge the existing gender order but rather maintains and sustains patriarchal attitudes through the repeated representation of women as weak and in need of patronage and men as their protectors and providers. In some instances, women are constructed primarily as sexual beings as their physical attributes are emphasised, while men are constructed as working class citizens and rational beings. The study therefore proposes that the Daily Sun fails as an alternative public sphere that might make visible the concerns of women as a marginalised group in society. The campaign, it is argued, is self-serving in its promotion of the Daily Sun’s image as the “People’s Paper” rather than serious concerns about gender violence.
- Full Text:
- Date Issued: 2009
The protein and energy requirements of the South African abalone, Haliotis midae
- Authors: Green, Alistair John
- Date: 2009
- Subjects: Haliotis midae -- South Africa Abalone culture -- South Africa Abalones -- Nutrition Abalones -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5352 , http://hdl.handle.net/10962/d1008261
- Description: The abalone (Haliotis midae) culture industry in South Africa is becoming increasingly dependent on the use of formulated feeds, due to limitations in the supply of kelp. The bulk of the feeds that are currently available were developed based on the requirements of juvenile abalone cultured within the optimal temperature range for growth (18 - 20 °C). However, most abalone farming facilities are land-based pump ashore operations and are thus mostly exposed to temperatures outside of this range. In addition, these feeds have been found to be unsuitable for abalone cultured at elevated water temperatures (> 20°C). The aim of the study was to develop size and temperature specific diets for H midoe through optimisation of dietary protein, energy and lipid levels. Abalone were cultured under farm-like conditions in three partially recirculating temperature controlled systems at either 18, 22 or 24°C and fed formulated diets containing graded levels of protein (18,22 and 26 %) and energy (11.6, 13.5 and 16.2 MJ.kg·I ). Abalone were stocked into baskets at 5 % of available of surface area (n=36) and each diet (n=9) was fed to four baskets of abalone at each of the three temperature regimes for ten weeks. Abalone growth was temperature dependent, with growth declining from 4.33 g.month-I for abalone cultured at 18°C to 0.77 g.month-I at 24°C. Dietary protein could be reduced from 26 to 18 % provided dietary energy levels were maintained at 13.5 MJ.kg- l • A dietary energy level of 11.6 MJ.kg-1 was insufficient to meet the energetic requirements of H midae regardless of the protein content of the diet. The effects of water temperature and body size on the protein requirements of H midae were investigated by culturing abalone at temperatures within the optimal range for abalone farming (i.e. 14, 16 and 18°C). Three size classes of abalone (15, 50 and 80 mm) were fed formulated feed containing graded levels of dietary protein (20, 26, 32, 38 and 44 %) under controlled laboratory conditions for 12 weeks, and, in a separate experiment, under commercial farm conditions for 24 weeks. It was not possible to convincingly define the optimal protein levels for abalone of different sizes in this experiment because growth rates fell below average commercial growth rates obtained on farms. Growth was temperature dependent in the laboratory trial, with the rate of weight gain of the 15 mm (ANOV A: p=0.002) and 50 mm abalone (ANOV A: p=0.02) increasing significantly with an increase in temperature from 14 to 18°C. In the farm trial, dietary protein content did not affect the growth rate of the 10-15 or 80 mm abalone (ANOVA: p>0.05), however, the 50 mm abalone displayed significantly higher weight gain on the 32 % (4.72±0.20 g.month-I ) and 38 % (5.01±0.34 g.month-I ) protein diets compared to those fed the 20 % protein diet (3.75±0.13 g.month-I ) (ANOVA: p=O.OI). Although definition of optimal dietary protein levels were not possible, the effects of dietary protein content and water temperature on the growth of H midae were independent signifying that the protein requirements of abalone are temperature independent. In addition, there was no evidence to indicate that abalone of the different sizes tested here had different dietary protein requirements. The size specific dietary lipid and protein requirements of H midae were investigated by feeding two size classes of abalone (30 and 60 mm initial shell length) diets containing graded levels of dietary lipid (4, 7, 10, 13 and 16 %) and protein (34 - 39 %) for 12 weeks. The 30 and 60 mm abalone were stocked at 7 (n=200) and 9 % (n=36) of the available basket surface area respectively and each diet was fed to four baskets of abalone of each size class. The protein requirements of H. midae are influenced by the amount of available dietary energy and thus it is possible that the ability of abalone to utilise lipids as a source of energy differs in the presence of varying levels of dietary protein. High levels of dietary lipid negatively affected the growth, condition factor and soft tissue glycogen content of both size classes of abalone. This negative effect was greater in the 30 mm size class compared to the 60 mm abalone. The corresponding increase in feed consumption and feed conversion ratio in response to increasing levels of dietary protein also provides evidence that abalone are unable to utilise dietary lipids as an energy source and high levels of dietary lipid probably inhibit the uptake of carbohydrates and protein. High dietary lipid levels did however appear to promote gonad maturation. It was possible to reduce dietary protein from 34 to 20 % without negatively affecting growth through the maintenance of dietary energy levels and thus it is recommended that future experiments on the energy content of formulated feeds should focus on the improved use of carbohydrates. Reductions in the protein portion of formulated feeds for H. midae are possible provided the diet contains sufficient levels of energy supplied from carbohydrates. As the ability of abalone to utilise dietary lipid is limited, lipids are unlikely to play a significant role as an energy source in abalone feeds. Further investigations should focus on the utilisation of various carbohydrate sources in abalone feeds.
- Full Text:
- Date Issued: 2009
- Authors: Green, Alistair John
- Date: 2009
- Subjects: Haliotis midae -- South Africa Abalone culture -- South Africa Abalones -- Nutrition Abalones -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5352 , http://hdl.handle.net/10962/d1008261
- Description: The abalone (Haliotis midae) culture industry in South Africa is becoming increasingly dependent on the use of formulated feeds, due to limitations in the supply of kelp. The bulk of the feeds that are currently available were developed based on the requirements of juvenile abalone cultured within the optimal temperature range for growth (18 - 20 °C). However, most abalone farming facilities are land-based pump ashore operations and are thus mostly exposed to temperatures outside of this range. In addition, these feeds have been found to be unsuitable for abalone cultured at elevated water temperatures (> 20°C). The aim of the study was to develop size and temperature specific diets for H midoe through optimisation of dietary protein, energy and lipid levels. Abalone were cultured under farm-like conditions in three partially recirculating temperature controlled systems at either 18, 22 or 24°C and fed formulated diets containing graded levels of protein (18,22 and 26 %) and energy (11.6, 13.5 and 16.2 MJ.kg·I ). Abalone were stocked into baskets at 5 % of available of surface area (n=36) and each diet (n=9) was fed to four baskets of abalone at each of the three temperature regimes for ten weeks. Abalone growth was temperature dependent, with growth declining from 4.33 g.month-I for abalone cultured at 18°C to 0.77 g.month-I at 24°C. Dietary protein could be reduced from 26 to 18 % provided dietary energy levels were maintained at 13.5 MJ.kg- l • A dietary energy level of 11.6 MJ.kg-1 was insufficient to meet the energetic requirements of H midae regardless of the protein content of the diet. The effects of water temperature and body size on the protein requirements of H midae were investigated by culturing abalone at temperatures within the optimal range for abalone farming (i.e. 14, 16 and 18°C). Three size classes of abalone (15, 50 and 80 mm) were fed formulated feed containing graded levels of dietary protein (20, 26, 32, 38 and 44 %) under controlled laboratory conditions for 12 weeks, and, in a separate experiment, under commercial farm conditions for 24 weeks. It was not possible to convincingly define the optimal protein levels for abalone of different sizes in this experiment because growth rates fell below average commercial growth rates obtained on farms. Growth was temperature dependent in the laboratory trial, with the rate of weight gain of the 15 mm (ANOV A: p=0.002) and 50 mm abalone (ANOV A: p=0.02) increasing significantly with an increase in temperature from 14 to 18°C. In the farm trial, dietary protein content did not affect the growth rate of the 10-15 or 80 mm abalone (ANOVA: p>0.05), however, the 50 mm abalone displayed significantly higher weight gain on the 32 % (4.72±0.20 g.month-I ) and 38 % (5.01±0.34 g.month-I ) protein diets compared to those fed the 20 % protein diet (3.75±0.13 g.month-I ) (ANOVA: p=O.OI). Although definition of optimal dietary protein levels were not possible, the effects of dietary protein content and water temperature on the growth of H midae were independent signifying that the protein requirements of abalone are temperature independent. In addition, there was no evidence to indicate that abalone of the different sizes tested here had different dietary protein requirements. The size specific dietary lipid and protein requirements of H midae were investigated by feeding two size classes of abalone (30 and 60 mm initial shell length) diets containing graded levels of dietary lipid (4, 7, 10, 13 and 16 %) and protein (34 - 39 %) for 12 weeks. The 30 and 60 mm abalone were stocked at 7 (n=200) and 9 % (n=36) of the available basket surface area respectively and each diet was fed to four baskets of abalone of each size class. The protein requirements of H. midae are influenced by the amount of available dietary energy and thus it is possible that the ability of abalone to utilise lipids as a source of energy differs in the presence of varying levels of dietary protein. High levels of dietary lipid negatively affected the growth, condition factor and soft tissue glycogen content of both size classes of abalone. This negative effect was greater in the 30 mm size class compared to the 60 mm abalone. The corresponding increase in feed consumption and feed conversion ratio in response to increasing levels of dietary protein also provides evidence that abalone are unable to utilise dietary lipids as an energy source and high levels of dietary lipid probably inhibit the uptake of carbohydrates and protein. High dietary lipid levels did however appear to promote gonad maturation. It was possible to reduce dietary protein from 34 to 20 % without negatively affecting growth through the maintenance of dietary energy levels and thus it is recommended that future experiments on the energy content of formulated feeds should focus on the improved use of carbohydrates. Reductions in the protein portion of formulated feeds for H. midae are possible provided the diet contains sufficient levels of energy supplied from carbohydrates. As the ability of abalone to utilise dietary lipid is limited, lipids are unlikely to play a significant role as an energy source in abalone feeds. Further investigations should focus on the utilisation of various carbohydrate sources in abalone feeds.
- Full Text:
- Date Issued: 2009
Protein secondary structure prediction using neural networks and support vector machines
- Authors: Tsilo, Lipontseng Cecilia
- Date: 2009
- Subjects: Neural networks (Computer science) , Support vector machines , Proteins -- Structure -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5569 , http://hdl.handle.net/10962/d1002809 , Neural networks (Computer science) , Support vector machines , Proteins -- Structure -- Mathematical models
- Description: Predicting the secondary structure of proteins is important in biochemistry because the 3D structure can be determined from the local folds that are found in secondary structures. Moreover, knowing the tertiary structure of proteins can assist in determining their functions. The objective of this thesis is to compare the performance of Neural Networks (NN) and Support Vector Machines (SVM) in predicting the secondary structure of 62 globular proteins from their primary sequence. For each NN and SVM, we created six binary classifiers to distinguish between the classes’ helices (H) strand (E), and coil (C). For NN we use Resilient Backpropagation training with and without early stopping. We use NN with either no hidden layer or with one hidden layer with 1,2,...,40 hidden neurons. For SVM we use a Gaussian kernel with parameter fixed at = 0.1 and varying cost parameters C in the range [0.1,5]. 10- fold cross-validation is used to obtain overall estimates for the probability of making a correct prediction. Our experiments indicate for NN and SVM that the different binary classifiers have varying accuracies: from 69% correct predictions for coils vs. non-coil up to 80% correct predictions for stand vs. non-strand. It is further demonstrated that NN with no hidden layer or not more than 2 hidden neurons in the hidden layer are sufficient for better predictions. For SVM we show that the estimated accuracies do not depend on the value of the cost parameter. As a major result, we will demonstrate that the accuracy estimates of NN and SVM binary classifiers cannot distinguish. This contradicts a modern belief in bioinformatics that SVM outperforms other predictors.
- Full Text:
- Date Issued: 2009
- Authors: Tsilo, Lipontseng Cecilia
- Date: 2009
- Subjects: Neural networks (Computer science) , Support vector machines , Proteins -- Structure -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5569 , http://hdl.handle.net/10962/d1002809 , Neural networks (Computer science) , Support vector machines , Proteins -- Structure -- Mathematical models
- Description: Predicting the secondary structure of proteins is important in biochemistry because the 3D structure can be determined from the local folds that are found in secondary structures. Moreover, knowing the tertiary structure of proteins can assist in determining their functions. The objective of this thesis is to compare the performance of Neural Networks (NN) and Support Vector Machines (SVM) in predicting the secondary structure of 62 globular proteins from their primary sequence. For each NN and SVM, we created six binary classifiers to distinguish between the classes’ helices (H) strand (E), and coil (C). For NN we use Resilient Backpropagation training with and without early stopping. We use NN with either no hidden layer or with one hidden layer with 1,2,...,40 hidden neurons. For SVM we use a Gaussian kernel with parameter fixed at = 0.1 and varying cost parameters C in the range [0.1,5]. 10- fold cross-validation is used to obtain overall estimates for the probability of making a correct prediction. Our experiments indicate for NN and SVM that the different binary classifiers have varying accuracies: from 69% correct predictions for coils vs. non-coil up to 80% correct predictions for stand vs. non-strand. It is further demonstrated that NN with no hidden layer or not more than 2 hidden neurons in the hidden layer are sufficient for better predictions. For SVM we show that the estimated accuracies do not depend on the value of the cost parameter. As a major result, we will demonstrate that the accuracy estimates of NN and SVM binary classifiers cannot distinguish. This contradicts a modern belief in bioinformatics that SVM outperforms other predictors.
- Full Text:
- Date Issued: 2009
The spatial ecology and activity patterns of leopards (Panthera pardus) in the Baviaanskloof and Greater Addo Elephant National Park (GAENP), Eastern Cape Province, South Africa
- Authors: McManus, Jeannine Stephanie
- Date: 2009
- Subjects: Leopard -- South Africa -- Eastern Cape , Leopard -- Monitoring -- South Africa -- Eastern Cape , Leopard -- Conservation -- South Africa -- Eastern Cape , Leopard -- Ecology -- South Africa -- Eastern Cape , Spatial ecology -- South Africa -- Eastern Cape , Wildlife monitoring -- South Africa -- Eastern Cape , Animal populations -- South Africa -- Eastern Cape , Wildlife conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5823 , http://hdl.handle.net/10962/d1007601 , Leopard -- South Africa -- Eastern Cape , Leopard -- Monitoring -- South Africa -- Eastern Cape , Leopard -- Conservation -- South Africa -- Eastern Cape , Leopard -- Ecology -- South Africa -- Eastern Cape , Spatial ecology -- South Africa -- Eastern Cape , Wildlife monitoring -- South Africa -- Eastern Cape , Animal populations -- South Africa -- Eastern Cape , Wildlife conservation -- South Africa -- Eastern Cape
- Description: The conservation of leopards in the Eastern Cape Province requires a holistic approach that considers both predator-human interactions as well as the biology of the carnivore. Numerous studies have been conducted on leopards within protected areas; however more information regarding the species is needed outside these areas to facilitate effective management of predators. The spatial ecology of the leopard (Panthera pardus) were studied in the Baviaanskloof and GAENP in the Eastern Cape. The Baviaanskloof is an extensive area of mountainous terrain (approximately 2665km²) which has a mosaic of land uses, and leopards move from conservation areas to farmland where they come into contact and conflict with farmers. This study examined the spatial ecology of leopards living on farmlands adjacent to protected land. The space utilization and activity patterns of six leopards were analysed. These animals were caught and released on farmlands in the Baviaanskloof (n=4) or translocated (n=2) when not possible to release on site. The animals were caught by means of fall-door, walk-in traps and fitted with Vectronic GPS collars that facilitated the collection of high quality GPS fixes from each animal. Data was collected using VHF and UHF telemetry to download data. An understanding of spatial requirements in areas with different land use, and the extent of overlap of space use with other leopards allow, for the first time in the region, the calculation of possible maximum population size. Analysis of range size was carried out using two methods: minimum convex polygon, and Kernel Utilization Distribution. Finally, a key predictor of space use is prey availability. I assessed the prey base using a grid of camera traps. The studied leopards revealed large range utilization with minimal overlap. The activity patterns suggest there is no preference between diurnal and nocturnal activity patterns and the population density was estimated between 0.3 - 1.3 leopards per 100km². Large home range sizes and low population densities suggest that leopards require large areas of suitable habitat, and that conservation efforts need to be extended beyond protected areas to ensure the long-term viability of leopard populations in such areas.
- Full Text:
- Date Issued: 2009
- Authors: McManus, Jeannine Stephanie
- Date: 2009
- Subjects: Leopard -- South Africa -- Eastern Cape , Leopard -- Monitoring -- South Africa -- Eastern Cape , Leopard -- Conservation -- South Africa -- Eastern Cape , Leopard -- Ecology -- South Africa -- Eastern Cape , Spatial ecology -- South Africa -- Eastern Cape , Wildlife monitoring -- South Africa -- Eastern Cape , Animal populations -- South Africa -- Eastern Cape , Wildlife conservation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5823 , http://hdl.handle.net/10962/d1007601 , Leopard -- South Africa -- Eastern Cape , Leopard -- Monitoring -- South Africa -- Eastern Cape , Leopard -- Conservation -- South Africa -- Eastern Cape , Leopard -- Ecology -- South Africa -- Eastern Cape , Spatial ecology -- South Africa -- Eastern Cape , Wildlife monitoring -- South Africa -- Eastern Cape , Animal populations -- South Africa -- Eastern Cape , Wildlife conservation -- South Africa -- Eastern Cape
- Description: The conservation of leopards in the Eastern Cape Province requires a holistic approach that considers both predator-human interactions as well as the biology of the carnivore. Numerous studies have been conducted on leopards within protected areas; however more information regarding the species is needed outside these areas to facilitate effective management of predators. The spatial ecology of the leopard (Panthera pardus) were studied in the Baviaanskloof and GAENP in the Eastern Cape. The Baviaanskloof is an extensive area of mountainous terrain (approximately 2665km²) which has a mosaic of land uses, and leopards move from conservation areas to farmland where they come into contact and conflict with farmers. This study examined the spatial ecology of leopards living on farmlands adjacent to protected land. The space utilization and activity patterns of six leopards were analysed. These animals were caught and released on farmlands in the Baviaanskloof (n=4) or translocated (n=2) when not possible to release on site. The animals were caught by means of fall-door, walk-in traps and fitted with Vectronic GPS collars that facilitated the collection of high quality GPS fixes from each animal. Data was collected using VHF and UHF telemetry to download data. An understanding of spatial requirements in areas with different land use, and the extent of overlap of space use with other leopards allow, for the first time in the region, the calculation of possible maximum population size. Analysis of range size was carried out using two methods: minimum convex polygon, and Kernel Utilization Distribution. Finally, a key predictor of space use is prey availability. I assessed the prey base using a grid of camera traps. The studied leopards revealed large range utilization with minimal overlap. The activity patterns suggest there is no preference between diurnal and nocturnal activity patterns and the population density was estimated between 0.3 - 1.3 leopards per 100km². Large home range sizes and low population densities suggest that leopards require large areas of suitable habitat, and that conservation efforts need to be extended beyond protected areas to ensure the long-term viability of leopard populations in such areas.
- Full Text:
- Date Issued: 2009