Goeie maniere en etiket
- Authors: Van Staden, Antoinique
- Date: 2016
- Language: Afrikaans , English
- Type: Thesis , Masters , MA
- Identifier: vital:6011 , http://hdl.handle.net/10962/d1021226
- Description: This bilingual collection of short stories combines the fairy tale form and the Bizarro genre to explore the value system ingrained in me at a very early age via my conservative Afrikaans upbringing. To my mind the four characteristics of the fairy tale form as identified by Kate Bernheimer (in her path-breaking essay “Fairy Tale is form, Form is Fairy Tale”) namely flatness, abstraction, intuitive logic and normalized magic, also apply to the Bizarro genre. This intersection is exemplified by some of Bernheimer's own fiction, as well as the fiction of Aimee Bender and Lucy Corin, among others, all of whom have influenced my writing. , Hierdie tweetalige versameling kortverhale kombineer sprokieselemente met die van die Bizarro-genre, om die waardesisteem wat van kleins af deur my konserwatiewe Afrikaanse opvoeding by my ingeprent is, te ondersoek. Die vier eienskappe van die sprokie word deur Kate Bernheimer in haar baanbrekende opstel Fairy tale is form, Form is fairy tale uitgelê as: ’n onbetrokke verteller, abstraksie, instinktiewe logika en genormaliseerde towerkuns. Na my mening is dié vier eienskappe ook op die Bizarro-genre van toepassing. Hierdie oorvleuling is sigbaar in Bernheimer se fiksie en ook onder andere Lucy Corin en Aimee Bender s'n – skrywers wat my werk beïnvloed het. , This thesis is presented in two parts: Afrikaans and English.
- Full Text:
- Date Issued: 2016
- Authors: Van Staden, Antoinique
- Date: 2016
- Language: Afrikaans , English
- Type: Thesis , Masters , MA
- Identifier: vital:6011 , http://hdl.handle.net/10962/d1021226
- Description: This bilingual collection of short stories combines the fairy tale form and the Bizarro genre to explore the value system ingrained in me at a very early age via my conservative Afrikaans upbringing. To my mind the four characteristics of the fairy tale form as identified by Kate Bernheimer (in her path-breaking essay “Fairy Tale is form, Form is Fairy Tale”) namely flatness, abstraction, intuitive logic and normalized magic, also apply to the Bizarro genre. This intersection is exemplified by some of Bernheimer's own fiction, as well as the fiction of Aimee Bender and Lucy Corin, among others, all of whom have influenced my writing. , Hierdie tweetalige versameling kortverhale kombineer sprokieselemente met die van die Bizarro-genre, om die waardesisteem wat van kleins af deur my konserwatiewe Afrikaanse opvoeding by my ingeprent is, te ondersoek. Die vier eienskappe van die sprokie word deur Kate Bernheimer in haar baanbrekende opstel Fairy tale is form, Form is fairy tale uitgelê as: ’n onbetrokke verteller, abstraksie, instinktiewe logika en genormaliseerde towerkuns. Na my mening is dié vier eienskappe ook op die Bizarro-genre van toepassing. Hierdie oorvleuling is sigbaar in Bernheimer se fiksie en ook onder andere Lucy Corin en Aimee Bender s'n – skrywers wat my werk beïnvloed het. , This thesis is presented in two parts: Afrikaans and English.
- Full Text:
- Date Issued: 2016
Nanocomposites of carbon nanomaterials and metallophthalocyanines : applications towards electrocatalysis
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Date Issued: 2016
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Date Issued: 2016
An evaluation of sampling and statistical methods for long-term monitoring of subtidal reef fishes : a case study of Tsitsikamma National Park marine protected area
- Authors: Parker, Denham
- Date: 2016
- Subjects: Reef fishes -- South Africa -- Monitoring , Tsitsikamma National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5385 , http://hdl.handle.net/10962/d1019991
- Description: Tsitsikamma National Park (TNP) possesses the oldest (established 1954), and one of the largest (350 km2) ‘no-take’ marine protected areas (MPA) in South Africa. A long-term monitoring (LTM) programme to observe the subtidal reef fishes in the TNP MPA was established in 2007. To date, 243 angling replicates have been completed, and a total of 2,751 fish belonging to 41 different species have been caught and released. In an era of unprecedented global biodiversity loss, data that can be used to monitor ecosystems and gauge changes in biodiversity through time are essential. This thesis aims to improve the methodological and statistical processes currently available for LTM of subtidal reef fish by providing an evaluation of the TNP MPA LTM programme. Angling data revealed definitive spatial structuring, in the form of spatial autocorrelation, and a shift in viewing spatial dependency as a statistical obstacle to a source of ecological information created a new avenue of data inference. Species-specific distribution maps identified localized habitat as the main predictor variable for species abundance, emphasizing the need for accurate a priori bathymetric information for subtidal monitoring. ‘Random forest’ analyses confirmed spatial variables are more important than temporal variables in predicting species abundance. The effectiveness of Generalized Linear Mixed Models (GAMMs) to account for spatial autocorrelation was highlighted, and evidence that disregarding spatial dependencies in temporal analyses can produce erroneous results was illustrated in the case of dageraad (Chrysoblephus cristiceps). Correlograms indicated that the current sampling strategy produced spatially redundant data and the sampling unit size (150 m2) could be doubled to optimize sampling. Temporal analyses demonstrated that after 50 years of ‘no take’ protection the TNP MPA ichthyofauna exhibits a high level of stability. Species-specific size structure was also found to be highly stable. Dageraad was the only species to exhibit a definitive temporal trend in their size structure, which was attributed to recruitment variation and the possibility that large individuals may migrate out of the study area. The inadequacy of angling as a method for monitoring a broad spectrum of the fish species was highlighted, particularly due to its selectivity towards large predators. As a result, a new sampling technique known as Stereo Baited Remote Underwater Videos (stereo-BRUVs) was introduced to the LTM programme in 2013. Stereo-BRUVs enabled sampling of 2640 fish belonging to 52 different species, from 57 samples collected in less than two years. A comparison of the sampling methods concluded that, compared to angling, stereo-BRUVs provide a superior technique that can survey a significantly larger proportion of the ichthyofauna with minimal length-selectivity biases. In addition, stereo-BRUVs possess a higher statistical power to detect changes in population abundance. However, a potential bias in the form of ‘hyperstability’ in sites with unusually high fish densities was identified as a possible flaw when using stereo-BRUVs. In an attempt to provide a more rigorous method evaluation, simulation testing was employed to assess the ability of angling and stereo-BRUVs to accurately describe a decreasing population. The advantage of this approach is that the simulated population abundances are known, so that each sampling method can be tested in terms of how well it tracks known abundance trends. The study established that stereo- BRUVs provided more accurate data when describing a distinct population decline of roman (Chrysoblephus laticeps) over 10- and 20-year periods. In addition, spawner-biomass was found to be a more accurate population estimate than relative abundance estimates (CPUE and MaxN) due to the inclusion of population size structure information, highlighting the importance of length-frequency data. The study illustrated that an evaluation framework that utilizes simulation testing has the potential to optimize LTM sampling procedures by addressing a number of methodological questions. This includes developing a procedure that aligns data collected from different sampling methods by applying correction factors, thus ensuring LTM programmes are able to adapt sampling strategies without losing data continuity.
- Full Text:
- Date Issued: 2016
- Authors: Parker, Denham
- Date: 2016
- Subjects: Reef fishes -- South Africa -- Monitoring , Tsitsikamma National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5385 , http://hdl.handle.net/10962/d1019991
- Description: Tsitsikamma National Park (TNP) possesses the oldest (established 1954), and one of the largest (350 km2) ‘no-take’ marine protected areas (MPA) in South Africa. A long-term monitoring (LTM) programme to observe the subtidal reef fishes in the TNP MPA was established in 2007. To date, 243 angling replicates have been completed, and a total of 2,751 fish belonging to 41 different species have been caught and released. In an era of unprecedented global biodiversity loss, data that can be used to monitor ecosystems and gauge changes in biodiversity through time are essential. This thesis aims to improve the methodological and statistical processes currently available for LTM of subtidal reef fish by providing an evaluation of the TNP MPA LTM programme. Angling data revealed definitive spatial structuring, in the form of spatial autocorrelation, and a shift in viewing spatial dependency as a statistical obstacle to a source of ecological information created a new avenue of data inference. Species-specific distribution maps identified localized habitat as the main predictor variable for species abundance, emphasizing the need for accurate a priori bathymetric information for subtidal monitoring. ‘Random forest’ analyses confirmed spatial variables are more important than temporal variables in predicting species abundance. The effectiveness of Generalized Linear Mixed Models (GAMMs) to account for spatial autocorrelation was highlighted, and evidence that disregarding spatial dependencies in temporal analyses can produce erroneous results was illustrated in the case of dageraad (Chrysoblephus cristiceps). Correlograms indicated that the current sampling strategy produced spatially redundant data and the sampling unit size (150 m2) could be doubled to optimize sampling. Temporal analyses demonstrated that after 50 years of ‘no take’ protection the TNP MPA ichthyofauna exhibits a high level of stability. Species-specific size structure was also found to be highly stable. Dageraad was the only species to exhibit a definitive temporal trend in their size structure, which was attributed to recruitment variation and the possibility that large individuals may migrate out of the study area. The inadequacy of angling as a method for monitoring a broad spectrum of the fish species was highlighted, particularly due to its selectivity towards large predators. As a result, a new sampling technique known as Stereo Baited Remote Underwater Videos (stereo-BRUVs) was introduced to the LTM programme in 2013. Stereo-BRUVs enabled sampling of 2640 fish belonging to 52 different species, from 57 samples collected in less than two years. A comparison of the sampling methods concluded that, compared to angling, stereo-BRUVs provide a superior technique that can survey a significantly larger proportion of the ichthyofauna with minimal length-selectivity biases. In addition, stereo-BRUVs possess a higher statistical power to detect changes in population abundance. However, a potential bias in the form of ‘hyperstability’ in sites with unusually high fish densities was identified as a possible flaw when using stereo-BRUVs. In an attempt to provide a more rigorous method evaluation, simulation testing was employed to assess the ability of angling and stereo-BRUVs to accurately describe a decreasing population. The advantage of this approach is that the simulated population abundances are known, so that each sampling method can be tested in terms of how well it tracks known abundance trends. The study established that stereo- BRUVs provided more accurate data when describing a distinct population decline of roman (Chrysoblephus laticeps) over 10- and 20-year periods. In addition, spawner-biomass was found to be a more accurate population estimate than relative abundance estimates (CPUE and MaxN) due to the inclusion of population size structure information, highlighting the importance of length-frequency data. The study illustrated that an evaluation framework that utilizes simulation testing has the potential to optimize LTM sampling procedures by addressing a number of methodological questions. This includes developing a procedure that aligns data collected from different sampling methods by applying correction factors, thus ensuring LTM programmes are able to adapt sampling strategies without losing data continuity.
- Full Text:
- Date Issued: 2016
Rhodes University Graduation Ceremony 2017
- Authors: Rhodes University
- Date: 2017
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/58067 , vital:27061
- Description: 2017 Graduation Ceremony, Umsitho Wothweso-Zidanga, Gradeplegtigheid [at] 1820 Settlers National Monument, Thursday, 20 April until Saturday, 22 April 2017.
- Full Text:
- Date Issued: 2017
- Authors: Rhodes University
- Date: 2017
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/58067 , vital:27061
- Description: 2017 Graduation Ceremony, Umsitho Wothweso-Zidanga, Gradeplegtigheid [at] 1820 Settlers National Monument, Thursday, 20 April until Saturday, 22 April 2017.
- Full Text:
- Date Issued: 2017
Understanding how the incorporation of indigenous knowledge (IK) enables or constrains the teaching and learning of alcoholic fermentation in Life Sciences in Grade 11
- Authors: Mutanho, Chrispen
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1264 , vital:20041
- Description: There is growing interest in the role of indigenous knowledge (IK) in science education in many parts of the world. In South Africa, this comes against the backdrop of a long history of cultural alienation, neglect and suppression of the IK of the indigenous people by colonial governments. Hence, the first post-independence National Curriculum Policy Statement (Curriculum, 2005) and its subsequent modified versions emphasised the need to redress the imbalances of the past so as to make science accessible to learners from diverse cultural backgrounds. However, literature reveals that the efforts to implement an IK-based curriculum are constrained by the lack of clarity, knowledge and skills on how to effectively make use of IK in the classroom situation so as to bring about effective teaching and learning. Against this background, this study sought to understand how the incorporation of IK enables or constrains the teaching and learning of alcoholic fermentation. Underpinned by an interpretive paradigm, a qualitative case study was conducted at a high school in Mthatha District in the Eastern Cape Province of South Africa. The study comprised of a sample of ten Life Sciences teachers from four neighbouring high schools, two Grade 11 Life Sciences teachers and their classes and two focus groups of six learners from each class. Convenience and purposive sampling were used to select the participants and the research site. The study made use of a questionnaire, document analysis, lesson observation, stimulated recall interviews and focus group interviews to generate data. The questionnaire sought to get an overview of Life Sciences teachers’ attitudes, opinions and experiences on incorporating IK in science teaching. The data gathered were then used as baseline information to inform the main study. The lesson observations, stimulated recall interviews and the focus group interviews sought to understand how the incorporation of IK enables or constrains the teaching and learning of alcoholic fermentation. Document analysis, lesson observation, stimulated recall interviews and focus group interviews were conducted to understand the experience of incorporating IK in a real life classroom situation. The study was informed by Vygotsky’s socio-cultural constructivism and Shulman’s pedagogical content knowledge (PCK) theory. From Vygotsky’s theory I borrowed the idea of mediated learning, scaffolding (Bruner, 1986), zone of proximal development (ZPD), as well as the use of language and cultural artefacts as tools of analysis of the classroom interaction between the teacher and the learners during the teaching-learning process. Shulman’s theory of PCK was also used to analyse how teachers apply IK in teaching Science. The data obtained were coded inductively and presented in tables, graphs and thick descriptive texts to make it easy to understand. The findings of this research show that incorporating IK improved the teaching-learning process by arousing learners’ interest in science, increasing learners’ participation and motivation, meaning making, language use, questioning and engagement in the learning process. Teaching became learner-centred, for it was directed by learners’ questions. Collaborative learning through group discussions, debates, arguments and brainstorming emerged to be an effective way of engaging learners in learning. The teachers used probing to encourage critical thinking before scaffolding learners. However, even though teachers generally accept IK as valuable in their teaching they lack the pedagogical content knowledge to effectively incorporate it into meaningful teaching and learning. Furthermore, teachers viewed cultural diversity as a constraint to their efforts to incorporate IK in teaching science. On the contrary, their learners held the view that having cultural diversity in classrooms created an opportunity to learn from other people’s cultures. Variables such as experience and difference in the cultural background of learners and teachers alike, tended to affect the teachers’ ability to incorporate IK.
- Full Text:
- Date Issued: 2016
- Authors: Mutanho, Chrispen
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1264 , vital:20041
- Description: There is growing interest in the role of indigenous knowledge (IK) in science education in many parts of the world. In South Africa, this comes against the backdrop of a long history of cultural alienation, neglect and suppression of the IK of the indigenous people by colonial governments. Hence, the first post-independence National Curriculum Policy Statement (Curriculum, 2005) and its subsequent modified versions emphasised the need to redress the imbalances of the past so as to make science accessible to learners from diverse cultural backgrounds. However, literature reveals that the efforts to implement an IK-based curriculum are constrained by the lack of clarity, knowledge and skills on how to effectively make use of IK in the classroom situation so as to bring about effective teaching and learning. Against this background, this study sought to understand how the incorporation of IK enables or constrains the teaching and learning of alcoholic fermentation. Underpinned by an interpretive paradigm, a qualitative case study was conducted at a high school in Mthatha District in the Eastern Cape Province of South Africa. The study comprised of a sample of ten Life Sciences teachers from four neighbouring high schools, two Grade 11 Life Sciences teachers and their classes and two focus groups of six learners from each class. Convenience and purposive sampling were used to select the participants and the research site. The study made use of a questionnaire, document analysis, lesson observation, stimulated recall interviews and focus group interviews to generate data. The questionnaire sought to get an overview of Life Sciences teachers’ attitudes, opinions and experiences on incorporating IK in science teaching. The data gathered were then used as baseline information to inform the main study. The lesson observations, stimulated recall interviews and the focus group interviews sought to understand how the incorporation of IK enables or constrains the teaching and learning of alcoholic fermentation. Document analysis, lesson observation, stimulated recall interviews and focus group interviews were conducted to understand the experience of incorporating IK in a real life classroom situation. The study was informed by Vygotsky’s socio-cultural constructivism and Shulman’s pedagogical content knowledge (PCK) theory. From Vygotsky’s theory I borrowed the idea of mediated learning, scaffolding (Bruner, 1986), zone of proximal development (ZPD), as well as the use of language and cultural artefacts as tools of analysis of the classroom interaction between the teacher and the learners during the teaching-learning process. Shulman’s theory of PCK was also used to analyse how teachers apply IK in teaching Science. The data obtained were coded inductively and presented in tables, graphs and thick descriptive texts to make it easy to understand. The findings of this research show that incorporating IK improved the teaching-learning process by arousing learners’ interest in science, increasing learners’ participation and motivation, meaning making, language use, questioning and engagement in the learning process. Teaching became learner-centred, for it was directed by learners’ questions. Collaborative learning through group discussions, debates, arguments and brainstorming emerged to be an effective way of engaging learners in learning. The teachers used probing to encourage critical thinking before scaffolding learners. However, even though teachers generally accept IK as valuable in their teaching they lack the pedagogical content knowledge to effectively incorporate it into meaningful teaching and learning. Furthermore, teachers viewed cultural diversity as a constraint to their efforts to incorporate IK in teaching science. On the contrary, their learners held the view that having cultural diversity in classrooms created an opportunity to learn from other people’s cultures. Variables such as experience and difference in the cultural background of learners and teachers alike, tended to affect the teachers’ ability to incorporate IK.
- Full Text:
- Date Issued: 2016
Representations of the ‘other’: a comparison between Roman descriptions of Britons, Gauls and Germans pre-AD 300 and Sir Harry Smith’s portrayal of the Xhosa 1830s – 1850s
- Authors: Van Wezel, Amy Hester
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4223 , vital:20634
- Description: Stereotypical representations of an ‘ethnically’ or ‘racially’ different ‘other’ in ancient texts would seem to reappear throughout history. By comparing Roman views of Britons, Gauls and Germans, with Sir Harry Smith’s views of the Xhosa, this study seeks to explore the extent to which these stereotypical images were employed and for what reasons. Through close textual analyses, the descriptions of these peoples are examined and compared, taking into consideration the different authors’ context and agendas. By highlighting Caesar’s views of the abilities of the ‘other’ and Tacitus’ judgements of the moral character of the ‘other’, compared with Smith’s view of the same, the study aims to draw out the role of the author’s ‘self’ in complex and contradictory representations of the ‘other’, while arguing that various overwhelmingly negative images served to justify imperial conquest and rule. The extent to which the ‘other’ was perceived as remote and different from themselves, epitomised in the dichotomy between the ‘barbarism’ and ‘civilisation’, is examined, comparing a variety of Roman authors with Smith. The similar idea of ‘civilising missions’ are discussed, while acknowledging the differences between the policies of the Roman and British Empires toward the ‘other’. The connections between how the ‘other’ was portrayed in relation to ‘Empire’ and the ways in which they were treated is also explored stressing even further the different approaches taken by Roman and British authorities to include these peoples within their Empires. While certain stereotypes are shown to have persisted from Roman times, reappearing in the writing of Sir Harry Smith, summed up in the archetypal ‘barbarian’, I argue that the use of these images was varied, inconsistent and reflected more the motives and personalities of the writers themselves, whofor the most part ascribed to imperial ideologies.
- Full Text:
- Date Issued: 2016
- Authors: Van Wezel, Amy Hester
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4223 , vital:20634
- Description: Stereotypical representations of an ‘ethnically’ or ‘racially’ different ‘other’ in ancient texts would seem to reappear throughout history. By comparing Roman views of Britons, Gauls and Germans, with Sir Harry Smith’s views of the Xhosa, this study seeks to explore the extent to which these stereotypical images were employed and for what reasons. Through close textual analyses, the descriptions of these peoples are examined and compared, taking into consideration the different authors’ context and agendas. By highlighting Caesar’s views of the abilities of the ‘other’ and Tacitus’ judgements of the moral character of the ‘other’, compared with Smith’s view of the same, the study aims to draw out the role of the author’s ‘self’ in complex and contradictory representations of the ‘other’, while arguing that various overwhelmingly negative images served to justify imperial conquest and rule. The extent to which the ‘other’ was perceived as remote and different from themselves, epitomised in the dichotomy between the ‘barbarism’ and ‘civilisation’, is examined, comparing a variety of Roman authors with Smith. The similar idea of ‘civilising missions’ are discussed, while acknowledging the differences between the policies of the Roman and British Empires toward the ‘other’. The connections between how the ‘other’ was portrayed in relation to ‘Empire’ and the ways in which they were treated is also explored stressing even further the different approaches taken by Roman and British authorities to include these peoples within their Empires. While certain stereotypes are shown to have persisted from Roman times, reappearing in the writing of Sir Harry Smith, summed up in the archetypal ‘barbarian’, I argue that the use of these images was varied, inconsistent and reflected more the motives and personalities of the writers themselves, whofor the most part ascribed to imperial ideologies.
- Full Text:
- Date Issued: 2016
In silico analysis of the effects of non-synonymous single nucleotide polymorphisms on the human macrophage migration inhibitory factor gene and their possible role in human African trypanosomiasis susceptibility
- Authors: Kimuda, Magambo Philip
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3047 , vital:20355
- Description: Human African trypanosomiasis (HAT) is a public health problem in sub-Saharan Africa, with approximately 10,000 cases being reported per year. The Macrophage Migration Inhibitory Factor (MIF) which is encoded by a functionally polymorphic gene is important in both innate andadaptive immune responses, and has been implicated in affecting the outcome and processes of several inflammatory conditions. A recent study in mice to that effect showed that MIF deficient and anti-MIF antibody treated mice showed lowered inflammatory responses, liver damage and anaemia than the wild type mice when experimentally challenged with Trypanosomes. These findings could mean that the transcript levels and/or polymorphisms in this gene can possibly affect individual risk to trypanosomiasis. This is especially of interest because there have been reports of spontaneous recovery i.e self-cure/resistance in some HAT cases in West Africa. Prior to this discovery the general paradigm was that trypanosomiasis is fatal if left untreated. The aim of this study was to gain insights into how human genetic variation in forms of nonsynonymous SNPs affects the MIF structure and function and possibly HAT susceptibility. NsSNPs in the mif gene were obtained from dbSNP. Through homology modeling, SNP prediction tools, protein interface analysis, alanine scanning, changes in free energy of folding, protein interactions calculator (PIC), and molecular dynamics simulations, SNP effects on the protein structure and function were studied. The study cohort comprised of human genome sequence data from 50 North Western Uganda Lugbara endemic individuals of whom 20 were cases (previous HAT patients) and 30 were controls (HAT free individuals). None of the 26 nsSNPs retrieved from dbSNP (July 2015) were present in the mif gene region in the study cohort. Out of the eight variants called in the mif coding region there was only one missense variant rs36065127 whose clinical significance is unknown. It was not possible to test for association of this variant with HAT due to its low global MAF that was less than 0.05. Alanine scanning provided a fast and computationally cheap means of quickly assessing nsSNPs of importance. NsSNPs that were interface residues were more likely to be hotspots (important in protein stability). Assessment of possible compensatory mutations using PIC analysis showed that some nsSNP sites were interacting with others, but this requires further experimentation. Analysis of changes in free energy using FOLDX was not enough to predict which nsSNPs would adversely affect protein structure, function and kinetics. The MD simulations were unfortunately too short to glean any meaningful inferences. This was the first genetic study carried out on the people of Lugbara ethnicity from North Western Uganda.
- Full Text:
- Date Issued: 2016
- Authors: Kimuda, Magambo Philip
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3047 , vital:20355
- Description: Human African trypanosomiasis (HAT) is a public health problem in sub-Saharan Africa, with approximately 10,000 cases being reported per year. The Macrophage Migration Inhibitory Factor (MIF) which is encoded by a functionally polymorphic gene is important in both innate andadaptive immune responses, and has been implicated in affecting the outcome and processes of several inflammatory conditions. A recent study in mice to that effect showed that MIF deficient and anti-MIF antibody treated mice showed lowered inflammatory responses, liver damage and anaemia than the wild type mice when experimentally challenged with Trypanosomes. These findings could mean that the transcript levels and/or polymorphisms in this gene can possibly affect individual risk to trypanosomiasis. This is especially of interest because there have been reports of spontaneous recovery i.e self-cure/resistance in some HAT cases in West Africa. Prior to this discovery the general paradigm was that trypanosomiasis is fatal if left untreated. The aim of this study was to gain insights into how human genetic variation in forms of nonsynonymous SNPs affects the MIF structure and function and possibly HAT susceptibility. NsSNPs in the mif gene were obtained from dbSNP. Through homology modeling, SNP prediction tools, protein interface analysis, alanine scanning, changes in free energy of folding, protein interactions calculator (PIC), and molecular dynamics simulations, SNP effects on the protein structure and function were studied. The study cohort comprised of human genome sequence data from 50 North Western Uganda Lugbara endemic individuals of whom 20 were cases (previous HAT patients) and 30 were controls (HAT free individuals). None of the 26 nsSNPs retrieved from dbSNP (July 2015) were present in the mif gene region in the study cohort. Out of the eight variants called in the mif coding region there was only one missense variant rs36065127 whose clinical significance is unknown. It was not possible to test for association of this variant with HAT due to its low global MAF that was less than 0.05. Alanine scanning provided a fast and computationally cheap means of quickly assessing nsSNPs of importance. NsSNPs that were interface residues were more likely to be hotspots (important in protein stability). Assessment of possible compensatory mutations using PIC analysis showed that some nsSNP sites were interacting with others, but this requires further experimentation. Analysis of changes in free energy using FOLDX was not enough to predict which nsSNPs would adversely affect protein structure, function and kinetics. The MD simulations were unfortunately too short to glean any meaningful inferences. This was the first genetic study carried out on the people of Lugbara ethnicity from North Western Uganda.
- Full Text:
- Date Issued: 2016
The efficacy of a community based eccentric hamstring strengthening program in peri-urban Black South African soccer players
- Authors: Ryan, Bennett
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3573 , vital:20526
- Description: Introduction: Hamstring injury prevalence in soccer remains a major concern. Research in this context has focused on Caucasian populations with little attention given to other ethnic groups. The compatibility and applicability of such research to the South African context, particularly at an amateur level, may be minimal due to fundamental differences in physical characteristics, as well as complexities with regards to implementation. The aim of this investigation was therefore twofold. 1) Identify the lower extremity strength and performance profile of Peri-urban Amateur South African Players, and 2) Assess the efficacy of a community based intervention through the use of the Nordic Hamstring Exercise. Methods: 19 Black male Eastern Cape amateur players participated in a 12 week randomly controlled trial (9 = Control, 10 = Intervention). All participants completed regular training, while the intervention group, in addition, performed the Nordic Hamstring exercise post warm up. The incremental program design was taken from Mjolsnes et al. (2004), with a progressive increase in both sets and repetitions. Compliance was defined as completion of the required exercises for that session. Isokinetic strength evaluations (at 60°.s-1 and 180°.s-1) including assessment of peak torque and total work, as well as performance measures of countermovement and squat jump, were completed pre and post intervention, with the profile of the Peri-urban player the combined responses of both groups at baseline. Additionally, both the functional ratio (Eccentric Hamstrings/Concentric Quadriceps) and eccentric utilization ratio (Countermovement Jump/Squat Jump) were calculated. Results: Concentric quadriceps peak torque at baseline reported values of 195 (±22) Nm and 141 (±21) Nm at 60°.s-1 and 180°.s-1. Values of 162 (±21) Nm were observed for peak torque of the eccentric hamstrings at 60°.s-1, while 157 (±18) Nm was indicated at 180°.s-1. Mean functional ratio responses were observed as 0.83 (±0.11) and 1.12 (±0.16) for 60°.s-1 and 180°.s-1 respectively. Additionally, the eccentric utilization ratio responses were recorded as 1.04 (±0.08). Regarding the intervention, concentric quadriceps total work of the dominant limb significantly improved over the time course of experimentation within the intervention group. Other quadriceps variables, concentric hamstrings, squat jump capability and performance measures all reported no significant changes (p>0.05) over the course of assessment when compared to the control. Eccentric hamstrings peak torque observed significant improvements (p<0.05) of between 5.72 and 12.82 % within the intervention group, while the countermovement jump indicated a significant 15.59 % increase (p<0.05). Additionally, the functional ratio and the eccentric utilization ratio both indicated no significant changes (p>0.05), with a 2.48-7.66 % and 5.33 % improvement noted following completion of assessment. Conclusion: Isokinetic responses at baseline observed decreased quadriceps strength, and increased hamstring strength when compared to both amateur and professional populations examined in previous studies, for both isokinetic testing speeds. Additionally, performance measures indicated similar responses to other amateur populations. Regarding the intervention, significant improvements in eccentric hamstring peak torque and countermovement jump indicate the partial success of the present intervention. Additionally, while the functional ratio and eccentric utilization ratio reported no significant changes, improvements were noted within the intervention group while the control noted no change. The Nordic hamstring lower therefore resulted in strength improvements within the eccentric hamstrings, reported as a significant factor for injury risk, however, such changes were not sufficient to significantly impact the functional ratio. It can be concluded that community based programs within South Africa have the potential to be effective; however, there are many barriers to implementation, including, language, ethnic and cultural differences, while a lack of resources and infrastructure play a significant role in a lack of development. More research of this nature is required to provide scientific support for structures and guidelines for the peri-urban community based South African player, to ensure the efficacy of internationally successful interventions such as the Nordic exercise.
- Full Text:
- Date Issued: 2016
- Authors: Ryan, Bennett
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3573 , vital:20526
- Description: Introduction: Hamstring injury prevalence in soccer remains a major concern. Research in this context has focused on Caucasian populations with little attention given to other ethnic groups. The compatibility and applicability of such research to the South African context, particularly at an amateur level, may be minimal due to fundamental differences in physical characteristics, as well as complexities with regards to implementation. The aim of this investigation was therefore twofold. 1) Identify the lower extremity strength and performance profile of Peri-urban Amateur South African Players, and 2) Assess the efficacy of a community based intervention through the use of the Nordic Hamstring Exercise. Methods: 19 Black male Eastern Cape amateur players participated in a 12 week randomly controlled trial (9 = Control, 10 = Intervention). All participants completed regular training, while the intervention group, in addition, performed the Nordic Hamstring exercise post warm up. The incremental program design was taken from Mjolsnes et al. (2004), with a progressive increase in both sets and repetitions. Compliance was defined as completion of the required exercises for that session. Isokinetic strength evaluations (at 60°.s-1 and 180°.s-1) including assessment of peak torque and total work, as well as performance measures of countermovement and squat jump, were completed pre and post intervention, with the profile of the Peri-urban player the combined responses of both groups at baseline. Additionally, both the functional ratio (Eccentric Hamstrings/Concentric Quadriceps) and eccentric utilization ratio (Countermovement Jump/Squat Jump) were calculated. Results: Concentric quadriceps peak torque at baseline reported values of 195 (±22) Nm and 141 (±21) Nm at 60°.s-1 and 180°.s-1. Values of 162 (±21) Nm were observed for peak torque of the eccentric hamstrings at 60°.s-1, while 157 (±18) Nm was indicated at 180°.s-1. Mean functional ratio responses were observed as 0.83 (±0.11) and 1.12 (±0.16) for 60°.s-1 and 180°.s-1 respectively. Additionally, the eccentric utilization ratio responses were recorded as 1.04 (±0.08). Regarding the intervention, concentric quadriceps total work of the dominant limb significantly improved over the time course of experimentation within the intervention group. Other quadriceps variables, concentric hamstrings, squat jump capability and performance measures all reported no significant changes (p>0.05) over the course of assessment when compared to the control. Eccentric hamstrings peak torque observed significant improvements (p<0.05) of between 5.72 and 12.82 % within the intervention group, while the countermovement jump indicated a significant 15.59 % increase (p<0.05). Additionally, the functional ratio and the eccentric utilization ratio both indicated no significant changes (p>0.05), with a 2.48-7.66 % and 5.33 % improvement noted following completion of assessment. Conclusion: Isokinetic responses at baseline observed decreased quadriceps strength, and increased hamstring strength when compared to both amateur and professional populations examined in previous studies, for both isokinetic testing speeds. Additionally, performance measures indicated similar responses to other amateur populations. Regarding the intervention, significant improvements in eccentric hamstring peak torque and countermovement jump indicate the partial success of the present intervention. Additionally, while the functional ratio and eccentric utilization ratio reported no significant changes, improvements were noted within the intervention group while the control noted no change. The Nordic hamstring lower therefore resulted in strength improvements within the eccentric hamstrings, reported as a significant factor for injury risk, however, such changes were not sufficient to significantly impact the functional ratio. It can be concluded that community based programs within South Africa have the potential to be effective; however, there are many barriers to implementation, including, language, ethnic and cultural differences, while a lack of resources and infrastructure play a significant role in a lack of development. More research of this nature is required to provide scientific support for structures and guidelines for the peri-urban community based South African player, to ensure the efficacy of internationally successful interventions such as the Nordic exercise.
- Full Text:
- Date Issued: 2016
Toward an automated botnet analysis framework: a darkcomet case-study
- Authors: du Bruyn, Jeremy Cecil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2937 , vital:20344
- Full Text:
- Date Issued: 2016
- Authors: du Bruyn, Jeremy Cecil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2937 , vital:20344
- Full Text:
- Date Issued: 2016
A comparative study of syllables and morphemes as literacy processing units in word recognition: IsiXhosa and SeTswana
- Authors: Probert, Tracy Nicole
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3266 , vital:20415
- Description: Word recognition is a core foundation of reading (Invenizzi and Hayes 2010) and involves interactions of language skills, metalinguistic skills and orthography. The extent of the interaction with one another in reading has yet to be fully explored, especially in the Southern-Bantu languages. This comparative study of isiXhosa and Setswana explores this three-way interaction between language skills (effect of Language of Learning and Teaching (LoLT)), metalinguistic skills (Phonological and Morphological Awareness) and orthography (conjunctivism vs. disjunctivism). This thesis is novel in three respects, (a) a set of linguistic-informed reading measures were developed in isiXhosa and Setswana for the first-time, (b) to my knowledge, the comparisons made and study of Morphological Awareness in the Southern-Bantu languages have never been done, and (c) the use of d-prime as a way of testing for grain size in reading is an innovative approach. Grade 3 and Grade 4 learners were tested on four independent linguistic tasks: an open-ended decomposition task, a Phonological Awareness task, a Morphological Awareness task and an independent reading measure. These tasks were administered to determine the grain size unit (Ziegler and Goswami 2005, Ziegler et al. 2001) which learners use in word recognition, with the grain sizes of syllables and morphemes being studied. Results showed that syllables were the dominant grain size in both isiXhosa and Setswana, with morphemes as secondary grains in isiXhosa. Grain size differed slightly between the two orthographies. These results are reflected in the scores on the metalinguistic tasks. LoLT was not shown to have a significant impact on word recognition in first-language reading. The Psycholinguistic Grain Size Theory (PGST) was found to be the most applicable model of word recognition to the Southern- Bantu languages, as opposed to the Dual-Route Cascade Model and Orthographic Depth Hypothesis. This thesis concludes with suggested adaptations to this theory in order to allow for morpheme grain size to be included. This study has implications for teaching practice and curriculum design, and contributes to a broader understanding of literacy in the foundation phase in the Southern-Bantu languages.
- Full Text:
- Date Issued: 2016
- Authors: Probert, Tracy Nicole
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3266 , vital:20415
- Description: Word recognition is a core foundation of reading (Invenizzi and Hayes 2010) and involves interactions of language skills, metalinguistic skills and orthography. The extent of the interaction with one another in reading has yet to be fully explored, especially in the Southern-Bantu languages. This comparative study of isiXhosa and Setswana explores this three-way interaction between language skills (effect of Language of Learning and Teaching (LoLT)), metalinguistic skills (Phonological and Morphological Awareness) and orthography (conjunctivism vs. disjunctivism). This thesis is novel in three respects, (a) a set of linguistic-informed reading measures were developed in isiXhosa and Setswana for the first-time, (b) to my knowledge, the comparisons made and study of Morphological Awareness in the Southern-Bantu languages have never been done, and (c) the use of d-prime as a way of testing for grain size in reading is an innovative approach. Grade 3 and Grade 4 learners were tested on four independent linguistic tasks: an open-ended decomposition task, a Phonological Awareness task, a Morphological Awareness task and an independent reading measure. These tasks were administered to determine the grain size unit (Ziegler and Goswami 2005, Ziegler et al. 2001) which learners use in word recognition, with the grain sizes of syllables and morphemes being studied. Results showed that syllables were the dominant grain size in both isiXhosa and Setswana, with morphemes as secondary grains in isiXhosa. Grain size differed slightly between the two orthographies. These results are reflected in the scores on the metalinguistic tasks. LoLT was not shown to have a significant impact on word recognition in first-language reading. The Psycholinguistic Grain Size Theory (PGST) was found to be the most applicable model of word recognition to the Southern- Bantu languages, as opposed to the Dual-Route Cascade Model and Orthographic Depth Hypothesis. This thesis concludes with suggested adaptations to this theory in order to allow for morpheme grain size to be included. This study has implications for teaching practice and curriculum design, and contributes to a broader understanding of literacy in the foundation phase in the Southern-Bantu languages.
- Full Text:
- Date Issued: 2016
An investigation on the effect of Russian wheat aphid (Diuraphis noxia Kurdjumov) population growth and feeding damage on selected barley (Hordeum vulgare L.) cultivars under ambient and elevated CO2
- Authors: Sacranie, Sattar Farouk
- Date: 2016
- Subjects: Russian wheat aphid -- Research -- South Africa Barley -- Disease and pest resistance -- South Africa Callose Aphids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50311 , vital:25975
- Description: The Russian wheat aphid (RWA) (Diuraphis noxia Kurdjumov) is a major pest of cultivated small grains. It is particularly devastating because of is high reproductive rate which results in the growth of large populations which become damaging to its host plants. Development of resistant barley (Hordeum vulgare L.) cultivars is complicated as resistance is polygenic. As a result, the industry remains at risk now that the RWA has spread throughout South Africa. It has, as recently as, 2013, been identified in the SW Cape, which was previously geographically isolated. This is South Africa‟s principle barley growing region. Now a potentially huge problem exists. Therefore, it is imperative that an alternative to pesticide use is found. Testing potential innate resistance in barley cultivars is thus, critical. In this thesis, I present data on four barely cultivars where I have examined their resistance/ lack of resistance to three known RWA biotypes, RWASA1, RWASA2 and RWASA3. The barley varieties used were two economically important South African malt barley cultivars (S5 and SSG 564) along with two potentially RWA resistant Afghan accessions (CIho 4125 and CIho 4159). The RWA biotype population growth rates on each of the plants were determined over a 14 day period. The aim was to establish baseline data of the effects of RWA population growth on the host plants under ambient CO2 (380 – 400 ppm) conditions. The extent of RWA feeding damage was investigated at the cell level by examining saliva deposition and cell disruption using Transmission Electron Microscopy; at the tissue/vascular level using fluorescence microscopy, to determine the extent of callose formation; at a whole leaf level by recording percent chlorosis and leaf roll; and finally, at a whole plant level by measuring biomass loss.The experiments were repeated under elevated CO2 (450 ppm) to model any changes in RWA/plant interaction with respect to future climate change. The effects of an elevated CO2 environment and RWA feeding on host plant foliar N and C:N ratio were compared to ambient CO2 conditions, to provide a clearer picture of the potential nutrient drain that a feeding RWA colony exacts on its host. Of the varieties tested, the CIho accessions performed better than the two SA barley cultivars as the CIho accessions appeared to express a mild antibiosis resistance response as RWA populations, particularly those of RWASA1, were smaller than those observed on either S5 or SSG 564. In addition, less damage was evident in the two CIho accessions due to RWA feeding. II RWASA2 was the most virulent of the three RWA biotypes tested, followed by RWASA3 while RWASA1 was the least virulent. Under elevated CO2 conditions, RWA feeding damage was exacerbated but the trend of biotype virulence remained the same. Higher aphid population sizes were recorded under elevated CO2, meant that even the more resistant CIho accessions were overcome by the increased demand made by the larger aphid colonies on the host plants. The % foliar N data showed that under elevated CO2 aphid-free control plants had increased N levels in their leaves. Increased “food” supply (as shown by the increased N levels) therefore allowed significantly larger aphid populations to develop on the plants exposed to elevated CO2, due to improved nutrient status of the phloem sap taken up by RWA. The knock-on effect of a higher aphid population was increased cell disruption as a result of extensive probing, extensive formations of wound callose, with the result that phloem damage impeded nutrient flow through the vascular tissues which contributed to chlorosis and (eventually plant) death. The major conclusion from this study is that even a mild CO2 elevation resulted in an increase aphid population which may pose a severe and very real threat to a barley crop. Therefore, without effort to identify and deploy resistant barley cultivars, it could well be possible that future barley cultivation in South Africa may no longer be viable.
- Full Text:
- Date Issued: 2016
- Authors: Sacranie, Sattar Farouk
- Date: 2016
- Subjects: Russian wheat aphid -- Research -- South Africa Barley -- Disease and pest resistance -- South Africa Callose Aphids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50311 , vital:25975
- Description: The Russian wheat aphid (RWA) (Diuraphis noxia Kurdjumov) is a major pest of cultivated small grains. It is particularly devastating because of is high reproductive rate which results in the growth of large populations which become damaging to its host plants. Development of resistant barley (Hordeum vulgare L.) cultivars is complicated as resistance is polygenic. As a result, the industry remains at risk now that the RWA has spread throughout South Africa. It has, as recently as, 2013, been identified in the SW Cape, which was previously geographically isolated. This is South Africa‟s principle barley growing region. Now a potentially huge problem exists. Therefore, it is imperative that an alternative to pesticide use is found. Testing potential innate resistance in barley cultivars is thus, critical. In this thesis, I present data on four barely cultivars where I have examined their resistance/ lack of resistance to three known RWA biotypes, RWASA1, RWASA2 and RWASA3. The barley varieties used were two economically important South African malt barley cultivars (S5 and SSG 564) along with two potentially RWA resistant Afghan accessions (CIho 4125 and CIho 4159). The RWA biotype population growth rates on each of the plants were determined over a 14 day period. The aim was to establish baseline data of the effects of RWA population growth on the host plants under ambient CO2 (380 – 400 ppm) conditions. The extent of RWA feeding damage was investigated at the cell level by examining saliva deposition and cell disruption using Transmission Electron Microscopy; at the tissue/vascular level using fluorescence microscopy, to determine the extent of callose formation; at a whole leaf level by recording percent chlorosis and leaf roll; and finally, at a whole plant level by measuring biomass loss.The experiments were repeated under elevated CO2 (450 ppm) to model any changes in RWA/plant interaction with respect to future climate change. The effects of an elevated CO2 environment and RWA feeding on host plant foliar N and C:N ratio were compared to ambient CO2 conditions, to provide a clearer picture of the potential nutrient drain that a feeding RWA colony exacts on its host. Of the varieties tested, the CIho accessions performed better than the two SA barley cultivars as the CIho accessions appeared to express a mild antibiosis resistance response as RWA populations, particularly those of RWASA1, were smaller than those observed on either S5 or SSG 564. In addition, less damage was evident in the two CIho accessions due to RWA feeding. II RWASA2 was the most virulent of the three RWA biotypes tested, followed by RWASA3 while RWASA1 was the least virulent. Under elevated CO2 conditions, RWA feeding damage was exacerbated but the trend of biotype virulence remained the same. Higher aphid population sizes were recorded under elevated CO2, meant that even the more resistant CIho accessions were overcome by the increased demand made by the larger aphid colonies on the host plants. The % foliar N data showed that under elevated CO2 aphid-free control plants had increased N levels in their leaves. Increased “food” supply (as shown by the increased N levels) therefore allowed significantly larger aphid populations to develop on the plants exposed to elevated CO2, due to improved nutrient status of the phloem sap taken up by RWA. The knock-on effect of a higher aphid population was increased cell disruption as a result of extensive probing, extensive formations of wound callose, with the result that phloem damage impeded nutrient flow through the vascular tissues which contributed to chlorosis and (eventually plant) death. The major conclusion from this study is that even a mild CO2 elevation resulted in an increase aphid population which may pose a severe and very real threat to a barley crop. Therefore, without effort to identify and deploy resistant barley cultivars, it could well be possible that future barley cultivation in South Africa may no longer be viable.
- Full Text:
- Date Issued: 2016
A critical analysis of the relationship between the South African Defence Force and the South African media from 1975-83
- Authors: Kirsten, Frederik Fouche
- Date: 2016
- Subjects: South Africa -- South African Defence Force , Mass media -- Political aspects -- South Africa , Freedom of information -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2626 , http://hdl.handle.net/10962/d1020841
- Description: The main focus of this thesis is to show the nature of the relationship between the South African Defence Force and the local media from 1975-83. The thesis will analyse issues specifically relating to the nature of the relationship and show how and why they are relevant to understanding the authoritarianism of the apartheid state. The nature of the relationship will be conceptualised by way of the analogy of a marriage. The thesis will show that for the SADF the relationship was “a marriage of convenience” whereas for the media it was a “marriage of necessity”. This relationship operated within the context of a highly militarised society that has been termed a “Garrison State”. The apartheid government introduced legislation governing reporting of defence matters and the media (namely the South African Defence Act 1957 including amendments made up until 1980) that imposed legal constraints within which defence correspondents had to operate. Moreover, the MID’s secret monitoring of the local media reveals the extent to which the military distrusted the media. A sampling of the coverage of defence matters in a selection of newspapers will reveal how their editorial staffs and reporters operated in a situation where the flow of information was controlled by the military. This will also show that certain defence correspondents cultivated close relations with SADF personnel to ensure that they were kept informed. The thesis will also show how the SADF reacted to the international media exposure of Operation Savannah and Operation Reindeer and how the SADF sought to limit the damage to its reputation by clamping down on the local media. The creation of two media commissions both headed by Justice MT Steyn, set out to investigate the manner in which local media reported on security issues in an environment in which the media and the public were confronted by the “Total Strategy” discourse of the apartheid government. The working relationship between the SADF and the media encapsulated in the thesis can be described as highly complex and the use of the “marriage” analogy assists in understanding this relationship.
- Full Text:
- Date Issued: 2016
- Authors: Kirsten, Frederik Fouche
- Date: 2016
- Subjects: South Africa -- South African Defence Force , Mass media -- Political aspects -- South Africa , Freedom of information -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2626 , http://hdl.handle.net/10962/d1020841
- Description: The main focus of this thesis is to show the nature of the relationship between the South African Defence Force and the local media from 1975-83. The thesis will analyse issues specifically relating to the nature of the relationship and show how and why they are relevant to understanding the authoritarianism of the apartheid state. The nature of the relationship will be conceptualised by way of the analogy of a marriage. The thesis will show that for the SADF the relationship was “a marriage of convenience” whereas for the media it was a “marriage of necessity”. This relationship operated within the context of a highly militarised society that has been termed a “Garrison State”. The apartheid government introduced legislation governing reporting of defence matters and the media (namely the South African Defence Act 1957 including amendments made up until 1980) that imposed legal constraints within which defence correspondents had to operate. Moreover, the MID’s secret monitoring of the local media reveals the extent to which the military distrusted the media. A sampling of the coverage of defence matters in a selection of newspapers will reveal how their editorial staffs and reporters operated in a situation where the flow of information was controlled by the military. This will also show that certain defence correspondents cultivated close relations with SADF personnel to ensure that they were kept informed. The thesis will also show how the SADF reacted to the international media exposure of Operation Savannah and Operation Reindeer and how the SADF sought to limit the damage to its reputation by clamping down on the local media. The creation of two media commissions both headed by Justice MT Steyn, set out to investigate the manner in which local media reported on security issues in an environment in which the media and the public were confronted by the “Total Strategy” discourse of the apartheid government. The working relationship between the SADF and the media encapsulated in the thesis can be described as highly complex and the use of the “marriage” analogy assists in understanding this relationship.
- Full Text:
- Date Issued: 2016
How do editors' attitudes and their perceptions of readers' interests combine with other factors to influence the publication of articles on the natural sciences in the Daily Dispatch?
- Authors: Lang, Steven
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3893 , vital:20553
- Description: This half-thesis examines how editorial values and perceptions determine the quantity and nature of science articles published in the Daily Dispatch, a newspaper distributed through large parts of the Eastern Cape in South Africa. It was predicated on the notion that South African media in general does not cover the natural sciences adequately. In order to test this assumption I decided to investigate the production and publication of science content at the Daily Dispatch as a test case. This study‘s theoretical framework draws on the normative roles of the media in a democracy developed by Christians et al. (2009) and the models of science journalism described by Secko et al. (2012) to demonstrate how two parallel conceptions of democracy set diverse journalistic objectives and engender different types of science content. Having applied an essentially political framework, this thesis uses the Hierarchy of Influences Model devised by Reese and Shoemaker‘s (2014) to explore how an array of forces acting inside and outside the news organisation can shape the publication of science articles. A quantitative content analysis is used to ascertain the number of science articles published in the first six months of 2014. It investigates which science fields received the most coverage, and how prominently the articles are positioned. As the Daily Dispatch does not have any staff dedicated to the science beat, the analysis finds out who produces the science articles that are published. The second phase of this research is a series of interviews with senior editorial staff members aimed at probing the editorial thought processes that determine when and whether specific science stories should be covered. The personal views and biases of the editorial leadership are pivotal to this research because although the newspaper commissioned surveys to determine readership preferences, there were no questions about the sciences. Senior reporters were adamant that they worked for a political newspaper and that as a significant proportion of their readership lived in socio-economically deprived circumstances, they were bound to give priority to articles aimed at improving the lot of their readers. The third phase is a qualitative content analysis of selected articles designed to reveal how science articles are constructed. The final element of this thesis, which ultimately provides an answer to the research question, draws together conclusions from the previous phases to demonstrate the linkage between editorial values and the production of science content.
- Full Text:
- Date Issued: 2016
- Authors: Lang, Steven
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3893 , vital:20553
- Description: This half-thesis examines how editorial values and perceptions determine the quantity and nature of science articles published in the Daily Dispatch, a newspaper distributed through large parts of the Eastern Cape in South Africa. It was predicated on the notion that South African media in general does not cover the natural sciences adequately. In order to test this assumption I decided to investigate the production and publication of science content at the Daily Dispatch as a test case. This study‘s theoretical framework draws on the normative roles of the media in a democracy developed by Christians et al. (2009) and the models of science journalism described by Secko et al. (2012) to demonstrate how two parallel conceptions of democracy set diverse journalistic objectives and engender different types of science content. Having applied an essentially political framework, this thesis uses the Hierarchy of Influences Model devised by Reese and Shoemaker‘s (2014) to explore how an array of forces acting inside and outside the news organisation can shape the publication of science articles. A quantitative content analysis is used to ascertain the number of science articles published in the first six months of 2014. It investigates which science fields received the most coverage, and how prominently the articles are positioned. As the Daily Dispatch does not have any staff dedicated to the science beat, the analysis finds out who produces the science articles that are published. The second phase of this research is a series of interviews with senior editorial staff members aimed at probing the editorial thought processes that determine when and whether specific science stories should be covered. The personal views and biases of the editorial leadership are pivotal to this research because although the newspaper commissioned surveys to determine readership preferences, there were no questions about the sciences. Senior reporters were adamant that they worked for a political newspaper and that as a significant proportion of their readership lived in socio-economically deprived circumstances, they were bound to give priority to articles aimed at improving the lot of their readers. The third phase is a qualitative content analysis of selected articles designed to reveal how science articles are constructed. The final element of this thesis, which ultimately provides an answer to the research question, draws together conclusions from the previous phases to demonstrate the linkage between editorial values and the production of science content.
- Full Text:
- Date Issued: 2016
Report containing learning, reflection and evaluation based on social learning:
- Burt, Jane C, Wilson, Jessica, Copteros, Athina, Lotz-Sisitka, Heila, Pereira, Taryn, Mokoena, Samson, Munnik, Victor, Ngcozela, Thabang, Lusithi, Thabo
- Authors: Burt, Jane C , Wilson, Jessica , Copteros, Athina , Lotz-Sisitka, Heila , Pereira, Taryn , Mokoena, Samson , Munnik, Victor , Ngcozela, Thabang , Lusithi, Thabo
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142005 , vital:38023 , ISBN WRC Report no K5/2313 Deliverable 7
- Description: This report forms the seventh deliverable in the NWRS2 citizen monitoring project and builds on the previous 6 deliverables, which include methodology for the project (Del 1), an assessment of civil society involvement in water policy (Del 2), an overview of the social learning approach and introduction to the case studies (Del 3), draft citizen monitoring guidelines (Del 4), an update on social learning to-date, including action plans (Del 5) and a report on a description and assessment of the case studies (Del 6). This report describes the last social learning module of the ‘Changing Practice’ course and highlights preliminary reflections on the learning that has taken place during this course. The report also describes the plans that were taken at the follow up research meeting. Finally we present the approach towards evaluating the role of social learning in the project as a whole.
- Full Text:
- Date Issued: 2016
- Authors: Burt, Jane C , Wilson, Jessica , Copteros, Athina , Lotz-Sisitka, Heila , Pereira, Taryn , Mokoena, Samson , Munnik, Victor , Ngcozela, Thabang , Lusithi, Thabo
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142005 , vital:38023 , ISBN WRC Report no K5/2313 Deliverable 7
- Description: This report forms the seventh deliverable in the NWRS2 citizen monitoring project and builds on the previous 6 deliverables, which include methodology for the project (Del 1), an assessment of civil society involvement in water policy (Del 2), an overview of the social learning approach and introduction to the case studies (Del 3), draft citizen monitoring guidelines (Del 4), an update on social learning to-date, including action plans (Del 5) and a report on a description and assessment of the case studies (Del 6). This report describes the last social learning module of the ‘Changing Practice’ course and highlights preliminary reflections on the learning that has taken place during this course. The report also describes the plans that were taken at the follow up research meeting. Finally we present the approach towards evaluating the role of social learning in the project as a whole.
- Full Text:
- Date Issued: 2016
Geology, regional diamond exploration and diamond provenance of the proterozoic diamondiferous Umkondo conglomerates, Umkondo group, eastern Zimbabwe
- Authors: Zhou, Takawira
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3598 , vital:20528
- Description: The Umkondo Sedimentary Basin in eastern Zimbabwe has been studied by various individuals and organizations since 1901. Their interest had been in finding limestone and beryl and base metal deposits, especially copper, iron and uranium, but these occurrences had proved to be of no economic value (Watson, 1969). The recent discovery of placer diamonds within the Proterozoic basal conglomerates of the Umkondo Sedimentary Basin has now attracted worldwide interest in the basin’s diamond economic potential, in understanding of the geology, and the diamond provenance of the Umkondo conglomerates. The Umkondo Sedimentary Basin basal conglomerate placer deposit might narrowly be defined as a mega-placer because of its sheer large size and high grades, especially on the 70,000 hectare western margin diamond dispersion halo where alluvial diamonds are being mined. Bluck, et al., (2005, pp 213) defines a diamond mega-placer as: . . . a number of linked deposits that are a result of one or a continuous process of transportation and deposition and holds or have held at least >= 50 million carats at >= 95% gem quality, for example, the Orange-Vaal dispersal, off the Kaapvaal craton in South Africa. On craton placers are residual, and transient placers are eroded and deposited into the exit drainage, while terminal placers, the final depositories of diamonds with the highest chances of being mega-placers are deposited into terminal basins like oceans and foreland basins. Though data is limited at the moment, the Umkondo conglomerates caratage is likely to run into hundreds of millions of carats, with a diamond gem content of between twenty and twenty-five percent, as is indicated from recent diamond production data. The greater part of the Umkondo diamonds are likely to be lodged beneath the deep gravels of the Middle and Lower Save River basin, because small remnant tilted mountain blocks and inselbergs forming the caps of hills are what remains of the host conglomerate on the western margin of the Umkondo Basin. Areas to be examined in this document will be the geology; the mode of formation of the Umkondo basin and its sedimentary system; the regional kimberlite exploration around the basin; and diamond production in the Marange diamond field, in order to come up with indications of the provenance of the diamonds within the Umkondo conglomerates. The kimberlite clusters in and around the Umkondo sedimentary basin have all proved to be barren or only nominally diamondiferous and that the kimberlites are between 200Ma and 500Ma and thus much younger than the greater than 1.1Ga Umkondo diamondiferous conglomerates. Studies so far undertaken have not managed to point to the origin, or provenance, of the Umkondo or Marange diamonds, which were discovered on the western edge of the Umkondo Basin and in the east of the basin below the Chimanimani Mountains along the Haroni River. This paper is an attempt to clear up some of the misconceptions surrounding the Marange diamond deposit and to raise interest in the urgent rquirement to study and understand the Umkondo Basin and the origin of its diamonds. The only meaningful studies on diamond occurrence and diamond exploration of the basin were undertaken from 1996 to 2006 by Kimberlitic Searches Zimbabwe (Pvt) Ltd, the then Zimbabwe kimberlite exploration arm of De Beers, Zimbabwe, in their quest to find kimberlites, which were thought to be related to the Umkondo alluvial diamond deposit. As will be shown in the following chapters, many of the discovered kimberlites range from very low grade to non-diamondiferous, and are much younger than the Umkondo conglomerates, whose diamonds are in turn a great deal older. Thus the basic question concerning the origin or provenance of the Umkondo placer diamonds still remains unresolved. Because of the sheer size of the basin, modern, wide-area-coverage, geophysical exploration methods become appropriate to effectively generate diamond potential targets for further examination. This document will attempt to collate various data available to paint a true picture of the state of exploration within the Umkondo Basin.
- Full Text:
- Date Issued: 2016
- Authors: Zhou, Takawira
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3598 , vital:20528
- Description: The Umkondo Sedimentary Basin in eastern Zimbabwe has been studied by various individuals and organizations since 1901. Their interest had been in finding limestone and beryl and base metal deposits, especially copper, iron and uranium, but these occurrences had proved to be of no economic value (Watson, 1969). The recent discovery of placer diamonds within the Proterozoic basal conglomerates of the Umkondo Sedimentary Basin has now attracted worldwide interest in the basin’s diamond economic potential, in understanding of the geology, and the diamond provenance of the Umkondo conglomerates. The Umkondo Sedimentary Basin basal conglomerate placer deposit might narrowly be defined as a mega-placer because of its sheer large size and high grades, especially on the 70,000 hectare western margin diamond dispersion halo where alluvial diamonds are being mined. Bluck, et al., (2005, pp 213) defines a diamond mega-placer as: . . . a number of linked deposits that are a result of one or a continuous process of transportation and deposition and holds or have held at least >= 50 million carats at >= 95% gem quality, for example, the Orange-Vaal dispersal, off the Kaapvaal craton in South Africa. On craton placers are residual, and transient placers are eroded and deposited into the exit drainage, while terminal placers, the final depositories of diamonds with the highest chances of being mega-placers are deposited into terminal basins like oceans and foreland basins. Though data is limited at the moment, the Umkondo conglomerates caratage is likely to run into hundreds of millions of carats, with a diamond gem content of between twenty and twenty-five percent, as is indicated from recent diamond production data. The greater part of the Umkondo diamonds are likely to be lodged beneath the deep gravels of the Middle and Lower Save River basin, because small remnant tilted mountain blocks and inselbergs forming the caps of hills are what remains of the host conglomerate on the western margin of the Umkondo Basin. Areas to be examined in this document will be the geology; the mode of formation of the Umkondo basin and its sedimentary system; the regional kimberlite exploration around the basin; and diamond production in the Marange diamond field, in order to come up with indications of the provenance of the diamonds within the Umkondo conglomerates. The kimberlite clusters in and around the Umkondo sedimentary basin have all proved to be barren or only nominally diamondiferous and that the kimberlites are between 200Ma and 500Ma and thus much younger than the greater than 1.1Ga Umkondo diamondiferous conglomerates. Studies so far undertaken have not managed to point to the origin, or provenance, of the Umkondo or Marange diamonds, which were discovered on the western edge of the Umkondo Basin and in the east of the basin below the Chimanimani Mountains along the Haroni River. This paper is an attempt to clear up some of the misconceptions surrounding the Marange diamond deposit and to raise interest in the urgent rquirement to study and understand the Umkondo Basin and the origin of its diamonds. The only meaningful studies on diamond occurrence and diamond exploration of the basin were undertaken from 1996 to 2006 by Kimberlitic Searches Zimbabwe (Pvt) Ltd, the then Zimbabwe kimberlite exploration arm of De Beers, Zimbabwe, in their quest to find kimberlites, which were thought to be related to the Umkondo alluvial diamond deposit. As will be shown in the following chapters, many of the discovered kimberlites range from very low grade to non-diamondiferous, and are much younger than the Umkondo conglomerates, whose diamonds are in turn a great deal older. Thus the basic question concerning the origin or provenance of the Umkondo placer diamonds still remains unresolved. Because of the sheer size of the basin, modern, wide-area-coverage, geophysical exploration methods become appropriate to effectively generate diamond potential targets for further examination. This document will attempt to collate various data available to paint a true picture of the state of exploration within the Umkondo Basin.
- Full Text:
- Date Issued: 2016
The past in the present: race, gender and transnationalism in Zoë Wicomb’s October and Chimamanda Ngozi Adichie’s Americanah
- Authors: Nthunya, Manosa
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3939 , vital:20559
- Description: This thesis will interrogate the ways in which the most recent novels of Zoë Wicomb and Chimamanda Ngozi Adichie (namely October and Americanah) explore race, gender and transnational issues. Wicomb and Adichie share an interest in representing the lives of people who have been historically marginalised by racial and gender classifications. This thesis will argue that historical and stereotypical ways of looking at people, particularly African people, are still prevalent in the twenty-first century. Wicomb’s interest is in the coloured community and the impact that apartheid ideology has had on it. She shows, as this thesis will argue, that notions of shame and respectability still influence the coloured community, post-1994, in the same ways they did under apartheid. Furthermore, the thesis will show that religion, which was used to justify apartheid, has been instrumental in maintaining racist and sexist norms in the coloured community in post-apartheid South Africa. Adichie’s novel, on the other hand, shows the impact of gender norms in Nigeria on her female characters. Unlike characters in Wicomb’s novel, Adichie’s mostly experience racial bias when they move to Western countries. This thesis will argue that many Western countries, which were the main beneficiaries of colonialism, continue to ‘other’ Africans, in spite of their claims to respect all human beings. Wicomb’s and Adichie’s novels depict characters that are moving between different continents, along with the impact that this has on them. In the twenty-first century, more people are moving between different spaces and, as a result, interacting with different cultures. These migrations, as this thesis will show, give rise to paradoxical circumstances: people are still being judged according to their race and gender, in spite of the freedom that these moves are supposed to lead to. Of central importance to both novels then is the question of home and belonging. Since people are moving between different continents, is it still possible to belong to one place? Is it in fact possible to belong at all? These are some of the questions that will be raised and answered in this thesis. Lastly, the thesis will look at the thematic representations of reading and writing in the novels under consideration. This is most evident in Adichie’s novel where her main character starts blogging as a way to express her dissatisfaction with the racist and sexist environment she encounters in the United States of America. The thesis will explore how Adichie examines blogging as a mode of communication that is unique to the twenty-first century. It will argue that it is perhaps through new media that historically subjugated subjects, such as African people and women, will be able to express themselves. Less hackneyed modes of communication might provide the necessary channels for those who have historically been denied voice to finally find it.
- Full Text:
- Date Issued: 2016
- Authors: Nthunya, Manosa
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3939 , vital:20559
- Description: This thesis will interrogate the ways in which the most recent novels of Zoë Wicomb and Chimamanda Ngozi Adichie (namely October and Americanah) explore race, gender and transnational issues. Wicomb and Adichie share an interest in representing the lives of people who have been historically marginalised by racial and gender classifications. This thesis will argue that historical and stereotypical ways of looking at people, particularly African people, are still prevalent in the twenty-first century. Wicomb’s interest is in the coloured community and the impact that apartheid ideology has had on it. She shows, as this thesis will argue, that notions of shame and respectability still influence the coloured community, post-1994, in the same ways they did under apartheid. Furthermore, the thesis will show that religion, which was used to justify apartheid, has been instrumental in maintaining racist and sexist norms in the coloured community in post-apartheid South Africa. Adichie’s novel, on the other hand, shows the impact of gender norms in Nigeria on her female characters. Unlike characters in Wicomb’s novel, Adichie’s mostly experience racial bias when they move to Western countries. This thesis will argue that many Western countries, which were the main beneficiaries of colonialism, continue to ‘other’ Africans, in spite of their claims to respect all human beings. Wicomb’s and Adichie’s novels depict characters that are moving between different continents, along with the impact that this has on them. In the twenty-first century, more people are moving between different spaces and, as a result, interacting with different cultures. These migrations, as this thesis will show, give rise to paradoxical circumstances: people are still being judged according to their race and gender, in spite of the freedom that these moves are supposed to lead to. Of central importance to both novels then is the question of home and belonging. Since people are moving between different continents, is it still possible to belong to one place? Is it in fact possible to belong at all? These are some of the questions that will be raised and answered in this thesis. Lastly, the thesis will look at the thematic representations of reading and writing in the novels under consideration. This is most evident in Adichie’s novel where her main character starts blogging as a way to express her dissatisfaction with the racist and sexist environment she encounters in the United States of America. The thesis will explore how Adichie examines blogging as a mode of communication that is unique to the twenty-first century. It will argue that it is perhaps through new media that historically subjugated subjects, such as African people and women, will be able to express themselves. Less hackneyed modes of communication might provide the necessary channels for those who have historically been denied voice to finally find it.
- Full Text:
- Date Issued: 2016
Street tree composition, distribution and urban residents’ perceptions within and between Eastern Cape towns
- Authors: Gwedla, Nanamhla
- Date: 2016
- Subjects: Urbanization -- South Africa -- Eastern Cape , Urban ecology (Sociology) -- South Africa -- Eastern Cape , Tree planting -- South Africa -- Eastern Cape , Trees in cities -- Environmental aspects -- South Africa -- Eastern Cape , Urban forestry -- Law and legislation -- South Africa -- Eastern Cape , Low-income housing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4702 , vital:20714
- Description: Promoting urban sustainability is vital in the face of rapid human and urban population growth. A core tenet of urban sustainability, urban forestry, is poised to “go global” with the intent of mitigating the negative environmental and social effects of urbanisation through green infrastructure, spaces and trees. Amongst these, the planting of street trees has become a major strategy. The public functions of street trees as demonstrated through the provision of ecosystem services are highly dependent on the structure, composition and diversity of tree species within the urban forest. The bulk of available literature on the composition, diversity and perceptions of residents regarding street trees has largely focused on the developed world, while the few in the developing world have been conducted at only one or two sites. The aim of this study was to investigate the composition, diversity and density of urban street trees in relation to the perceptions of local residents and horticulturists, across a range of ecological and social contexts. To do this, the species composition, diversity and dominance of street trees planted in 10 randomly selected Eastern Cape towns was assessed. Within each town ten replicate 200 m transects were located in three different suburbs. Perceptions and appreciation of street trees were assessed by 1 200 household questionnaires, as well as key informant interviews with personnel responsible for street tree planting and maintenance. Sixty-nine out of 300 sampled transects had street trees, with 888 trees enumerated, spanning ninety-seven species. Alien tree species accounted for 71 % of all the enumerated trees while indigenous trees species accounted for 12 %. The non-former homeland towns had a significantly higher (5.8±1.6 trees) mean street tree density per transect than the former homeland towns (0.6±03). There were no significant relationships between street tree density or richness to mean annual rainfall or the background biome in which the town was situated. However, density strongly was related to size of the town. RDP and township suburbs had fewer street trees and low species richness relative to the affluent suburbs. In selecting street trees, root system of the prospective tree, the eventual size or shape of the species, whether an alien or indigenous species, and the species’ adaptability to the climate of the respective town are considered before planting. The biggest identified threats to street trees were the deliberate vandalism of trees by people and animals, and lack of education and awareness regarding the importance of street trees among urban residents and municipal officials. More than half of the respondents prefer that trees be planted both on the street and in their yards while a few do not want trees at all. The majority of respondents with this preference do so because they want shade and abundant fruit, and to have beautiful yards and streets. Those who do not want trees at all do so because they just do not like trees, there is no space for trees, or they fear that criminals hide behind trees. The presence of trees in peoples’ yards correlated with a positive preference for trees in the street. The majority of respondents were neither satisfied with the general appearance of their street nor with the number of trees on their street. Residents from the RDP suburbs were the least satisfied with both the appearance and number of trees on their streets, while those from the affluent suburbs were the most satisfied. Street trees were seen as greatly important to have by the majority of people. The more educated people were more appreciative of the importance of street trees. Local municipalities were identified by the majority of respondents as the stakeholders responsible for the planting and maintenance of street trees, although a considerable proportion of respondents reported a willingness to volunteer to help plant and maintain trees on their streets. Municipalities were seen as doing very little to provide and maintain trees in the various suburbs by the majority of respondents. The majority of respondents also reported that they had never been consulted about tree planting activities in their suburbs before, and would like to have been consulted.
- Full Text:
- Date Issued: 2016
- Authors: Gwedla, Nanamhla
- Date: 2016
- Subjects: Urbanization -- South Africa -- Eastern Cape , Urban ecology (Sociology) -- South Africa -- Eastern Cape , Tree planting -- South Africa -- Eastern Cape , Trees in cities -- Environmental aspects -- South Africa -- Eastern Cape , Urban forestry -- Law and legislation -- South Africa -- Eastern Cape , Low-income housing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4702 , vital:20714
- Description: Promoting urban sustainability is vital in the face of rapid human and urban population growth. A core tenet of urban sustainability, urban forestry, is poised to “go global” with the intent of mitigating the negative environmental and social effects of urbanisation through green infrastructure, spaces and trees. Amongst these, the planting of street trees has become a major strategy. The public functions of street trees as demonstrated through the provision of ecosystem services are highly dependent on the structure, composition and diversity of tree species within the urban forest. The bulk of available literature on the composition, diversity and perceptions of residents regarding street trees has largely focused on the developed world, while the few in the developing world have been conducted at only one or two sites. The aim of this study was to investigate the composition, diversity and density of urban street trees in relation to the perceptions of local residents and horticulturists, across a range of ecological and social contexts. To do this, the species composition, diversity and dominance of street trees planted in 10 randomly selected Eastern Cape towns was assessed. Within each town ten replicate 200 m transects were located in three different suburbs. Perceptions and appreciation of street trees were assessed by 1 200 household questionnaires, as well as key informant interviews with personnel responsible for street tree planting and maintenance. Sixty-nine out of 300 sampled transects had street trees, with 888 trees enumerated, spanning ninety-seven species. Alien tree species accounted for 71 % of all the enumerated trees while indigenous trees species accounted for 12 %. The non-former homeland towns had a significantly higher (5.8±1.6 trees) mean street tree density per transect than the former homeland towns (0.6±03). There were no significant relationships between street tree density or richness to mean annual rainfall or the background biome in which the town was situated. However, density strongly was related to size of the town. RDP and township suburbs had fewer street trees and low species richness relative to the affluent suburbs. In selecting street trees, root system of the prospective tree, the eventual size or shape of the species, whether an alien or indigenous species, and the species’ adaptability to the climate of the respective town are considered before planting. The biggest identified threats to street trees were the deliberate vandalism of trees by people and animals, and lack of education and awareness regarding the importance of street trees among urban residents and municipal officials. More than half of the respondents prefer that trees be planted both on the street and in their yards while a few do not want trees at all. The majority of respondents with this preference do so because they want shade and abundant fruit, and to have beautiful yards and streets. Those who do not want trees at all do so because they just do not like trees, there is no space for trees, or they fear that criminals hide behind trees. The presence of trees in peoples’ yards correlated with a positive preference for trees in the street. The majority of respondents were neither satisfied with the general appearance of their street nor with the number of trees on their street. Residents from the RDP suburbs were the least satisfied with both the appearance and number of trees on their streets, while those from the affluent suburbs were the most satisfied. Street trees were seen as greatly important to have by the majority of people. The more educated people were more appreciative of the importance of street trees. Local municipalities were identified by the majority of respondents as the stakeholders responsible for the planting and maintenance of street trees, although a considerable proportion of respondents reported a willingness to volunteer to help plant and maintain trees on their streets. Municipalities were seen as doing very little to provide and maintain trees in the various suburbs by the majority of respondents. The majority of respondents also reported that they had never been consulted about tree planting activities in their suburbs before, and would like to have been consulted.
- Full Text:
- Date Issued: 2016
Testing the effectiveness and cost-efficiency of livestock guarding dogs in Botswana
- Authors: Horgan, Jane Elizabeth
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5951 , http://hdl.handle.net/10962/d1021300
- Description: Livestock guarding dogs (LSGDs) have been used for centuries to reduce depredation on livestock and more recently, to facilitate the conservation of threatened predator species. Conservation NGOs (non-government organisations) in southern Africa promote the use of Anatolian Shepherds as LSGDs. However, livestock farmers in Botswana have been using a variety of different breeds for this purpose, including the local mixed-breed “Tswana” dogs. Postal, telephonic and face-to-face interview questionnaires were administered to 108 livestock farmers in Botswana to gauge how their LSGDs were being used, in order to determine what factors contributed to the success and affordability of these dogs. Eighty-three percent of farmers had LSGDs which equaled or decreased livestock depredations on their farms, with an average reduction in livestock depredation of 75% per year. This equated to an average saving of US$2,017 annually per farm. The costs of purchasing (average US$27) and maintaining the 198 LSGDs in my study (average US$169/LSGD/year) were very low compared to other countries and helped contribute to the high profits obtained by farmers (average US$1,497/farm or US$789/LSGD). A unique investigation of different breeds was possible due to the diverse array of breeds in the sample (Anatolian Shepherds, Cross Breeds, Tswana dogs, Greyhounds and Pitbulls), with the crossbreed dogs (Crosses and Tswana LSGDs) performing the best. LSGDs that reduced depredation and had minimal behavioural problems were the most likely to incite positive changes in their owners in regards to attitudes towards predators. Sixtysix percent of farmers stated that they were more tolerant of predators since obtaining a LSGD, and 51% reported that they were less likely to kill predators since obtaining a LSGD. My results indicate that successful, well-behaved LSGDs are a cost-effective tool that has the ability to increase farm productivity and improve predator-farmer conflicts in Botswana. The methods recommended in my thesis, in particular the benefits of using local breeds of dog as LSGDs, can be implemented on farming practices the world over to assist farming productivity and to promote conservation efforts.
- Full Text:
- Date Issued: 2016
- Authors: Horgan, Jane Elizabeth
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5951 , http://hdl.handle.net/10962/d1021300
- Description: Livestock guarding dogs (LSGDs) have been used for centuries to reduce depredation on livestock and more recently, to facilitate the conservation of threatened predator species. Conservation NGOs (non-government organisations) in southern Africa promote the use of Anatolian Shepherds as LSGDs. However, livestock farmers in Botswana have been using a variety of different breeds for this purpose, including the local mixed-breed “Tswana” dogs. Postal, telephonic and face-to-face interview questionnaires were administered to 108 livestock farmers in Botswana to gauge how their LSGDs were being used, in order to determine what factors contributed to the success and affordability of these dogs. Eighty-three percent of farmers had LSGDs which equaled or decreased livestock depredations on their farms, with an average reduction in livestock depredation of 75% per year. This equated to an average saving of US$2,017 annually per farm. The costs of purchasing (average US$27) and maintaining the 198 LSGDs in my study (average US$169/LSGD/year) were very low compared to other countries and helped contribute to the high profits obtained by farmers (average US$1,497/farm or US$789/LSGD). A unique investigation of different breeds was possible due to the diverse array of breeds in the sample (Anatolian Shepherds, Cross Breeds, Tswana dogs, Greyhounds and Pitbulls), with the crossbreed dogs (Crosses and Tswana LSGDs) performing the best. LSGDs that reduced depredation and had minimal behavioural problems were the most likely to incite positive changes in their owners in regards to attitudes towards predators. Sixtysix percent of farmers stated that they were more tolerant of predators since obtaining a LSGD, and 51% reported that they were less likely to kill predators since obtaining a LSGD. My results indicate that successful, well-behaved LSGDs are a cost-effective tool that has the ability to increase farm productivity and improve predator-farmer conflicts in Botswana. The methods recommended in my thesis, in particular the benefits of using local breeds of dog as LSGDs, can be implemented on farming practices the world over to assist farming productivity and to promote conservation efforts.
- Full Text:
- Date Issued: 2016
The Contribution of fruit from trees to improve household nutritional security in the context of deforestation in Cameroon
- Tata epse Ngome, Precillia Ijang
- Authors: Tata epse Ngome, Precillia Ijang
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/793 , vital:19991
- Description: Cameroon needs healthy citizens to archive emergence by 2035. Malnutrition and undernourishment is the highest burden in the World in recent times and a silent crisis facing most rural communities in forest areas of Cameroon. Its abstruseness makes extremely fragile political, social and economic planning to foster development in such areas. Therefore, it is time we bring appropriate understanding and new strategies on unpacking the complexities of food and nutritional security and define practical solutions to food insecurity. Working in the context of increasing deforestation, this thesis brings evidence on the situation of household food insecurity (FIS) access experience in forest areas which is not reported in current discussions at the national level. It further investigates the knowledge and awareness of households on the availability, accessibility, utilisation, vulnerability and consumption of nutrient rich food items using the example of fruits from trees. Thus, the aim of this research was to investigate strategies for addressing household FIS through increased domestic supply and consumption of fruits from trees in the context of deforestation in Cameroon. Data were collected through four rounds of structured interviews completed between August 2013 and October 2014. Analysis was done using simple citations and ordering, Principal Component Analysis (PCA), Likert scale, χ2-test of association and Cramer's V coefficient to test the strength of the association and means and ANOVA. The HFIAS approach used to determine household FIS. Only 1% of the population were food secure and the moderately deforested zone showed the worst trends in food insecurity. Therefore, the effect of deforestation was nuanced. Diverse fruit trees were registered. Households said they required fruits only 2.4 ± 1.5 times per week. Recently, the intake of 400 g of fruit per person per day for good health was announced as a priority of international recognition. However, households were not aware of the importance and frequency of fruit consumption with less than 50% of households eating fruits daily during the harvesting season. Fruit tree nurseries where scarce and seeds where obtained from local sources. Fruit tree diseases where rampant and up to 50% harvest lost was registered for some fruits species. This study has shown that food availability does not necessarily mean adequate food intake. Three opinions about fruit trees and the prevalence of food insecurity in Cameroon has been raised in this thesis. First, there is ineffectiveness in the eradication of FIS because even in agricultural conducive environments, hunger and food insecurity are still prevalent at high rates. Therefore, effective and efficient targeting of food insecured groups need to be promoted in all clusters of the population. Secondly, the national nutrition program is neglecting sensitisation on food consumption patterns and therefore people are not making use of nutrient rich foods even when this maybe found around their environments - taking the case of fruits from trees. Thus, very few people ate fruits and at irregular frequencies of consumption. Thus, there is need to design special campaign programs to promote the consumption of fruits from trees. Thirdly, the word-of-mouth or neighbour-to-neighbour dissemination approach on fruit trees planting has not been efficient across communities. As such nurseries where scarce and people obtained fruit trees plants from natural regeneration or found them on the field when establishing the field. Therefore, in this research, it is postulated that no matter the nature of efforts and level of intervention, what is certain is that addressing FIS requires effective targeting of the vulnerable population and the implementation of novel and practical approaches on promoting access to and consumption of fruits in the right frequencies. This research further revealed that poor eating habits was a problem and lack of knowledge about the frequency and intake of nutrient rich food was serious. For instance, people were not aware on the recommended frequency of fruit consumption and people ate infested fruit while reserving the healthy ones for sale. This is the trap of the food insecurity problem in some regions – knowledge about foods and ways of food utilisation. This is neither a problem of availability nor accessibility, but rather a problem of lack of knowledge and lack of sensitisation. From FAO reports on the state of food insecurity in the world and other studies of food intake in most developing nation, poor food consumption is a global problem in most poor regions and even in rich areas affected by obesity. Thus, there is a need to establish a high level policy framework maybe in the form of a convention or an intergovernmental panel at the level of the United Nations and/or the African Union on ‘reducing malnutrition in all its forms (rates, drivers and consequences on human health and the environment)’. This structure will promote setting priorities, strategies, monitoring on peoples eating habits, setting nutritional standards, and principles and indicators for observing under nutrition, over nutrition and associated problems within all population strata.
- Full Text:
- Date Issued: 2016
- Authors: Tata epse Ngome, Precillia Ijang
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/793 , vital:19991
- Description: Cameroon needs healthy citizens to archive emergence by 2035. Malnutrition and undernourishment is the highest burden in the World in recent times and a silent crisis facing most rural communities in forest areas of Cameroon. Its abstruseness makes extremely fragile political, social and economic planning to foster development in such areas. Therefore, it is time we bring appropriate understanding and new strategies on unpacking the complexities of food and nutritional security and define practical solutions to food insecurity. Working in the context of increasing deforestation, this thesis brings evidence on the situation of household food insecurity (FIS) access experience in forest areas which is not reported in current discussions at the national level. It further investigates the knowledge and awareness of households on the availability, accessibility, utilisation, vulnerability and consumption of nutrient rich food items using the example of fruits from trees. Thus, the aim of this research was to investigate strategies for addressing household FIS through increased domestic supply and consumption of fruits from trees in the context of deforestation in Cameroon. Data were collected through four rounds of structured interviews completed between August 2013 and October 2014. Analysis was done using simple citations and ordering, Principal Component Analysis (PCA), Likert scale, χ2-test of association and Cramer's V coefficient to test the strength of the association and means and ANOVA. The HFIAS approach used to determine household FIS. Only 1% of the population were food secure and the moderately deforested zone showed the worst trends in food insecurity. Therefore, the effect of deforestation was nuanced. Diverse fruit trees were registered. Households said they required fruits only 2.4 ± 1.5 times per week. Recently, the intake of 400 g of fruit per person per day for good health was announced as a priority of international recognition. However, households were not aware of the importance and frequency of fruit consumption with less than 50% of households eating fruits daily during the harvesting season. Fruit tree nurseries where scarce and seeds where obtained from local sources. Fruit tree diseases where rampant and up to 50% harvest lost was registered for some fruits species. This study has shown that food availability does not necessarily mean adequate food intake. Three opinions about fruit trees and the prevalence of food insecurity in Cameroon has been raised in this thesis. First, there is ineffectiveness in the eradication of FIS because even in agricultural conducive environments, hunger and food insecurity are still prevalent at high rates. Therefore, effective and efficient targeting of food insecured groups need to be promoted in all clusters of the population. Secondly, the national nutrition program is neglecting sensitisation on food consumption patterns and therefore people are not making use of nutrient rich foods even when this maybe found around their environments - taking the case of fruits from trees. Thus, very few people ate fruits and at irregular frequencies of consumption. Thus, there is need to design special campaign programs to promote the consumption of fruits from trees. Thirdly, the word-of-mouth or neighbour-to-neighbour dissemination approach on fruit trees planting has not been efficient across communities. As such nurseries where scarce and people obtained fruit trees plants from natural regeneration or found them on the field when establishing the field. Therefore, in this research, it is postulated that no matter the nature of efforts and level of intervention, what is certain is that addressing FIS requires effective targeting of the vulnerable population and the implementation of novel and practical approaches on promoting access to and consumption of fruits in the right frequencies. This research further revealed that poor eating habits was a problem and lack of knowledge about the frequency and intake of nutrient rich food was serious. For instance, people were not aware on the recommended frequency of fruit consumption and people ate infested fruit while reserving the healthy ones for sale. This is the trap of the food insecurity problem in some regions – knowledge about foods and ways of food utilisation. This is neither a problem of availability nor accessibility, but rather a problem of lack of knowledge and lack of sensitisation. From FAO reports on the state of food insecurity in the world and other studies of food intake in most developing nation, poor food consumption is a global problem in most poor regions and even in rich areas affected by obesity. Thus, there is a need to establish a high level policy framework maybe in the form of a convention or an intergovernmental panel at the level of the United Nations and/or the African Union on ‘reducing malnutrition in all its forms (rates, drivers and consequences on human health and the environment)’. This structure will promote setting priorities, strategies, monitoring on peoples eating habits, setting nutritional standards, and principles and indicators for observing under nutrition, over nutrition and associated problems within all population strata.
- Full Text:
- Date Issued: 2016
Life history of the maritime platygastrid Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae: Scelioninae)
- Authors: Owen, Candice Ann
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/837 , vital:19995 , 10.21504/10962/837
- Description: Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae, Scelioninae) is an intertidal parasitoid wasp that uses the eggs of the maritime spider, Desis formidabilis O.P. Cambridge 1890 (Araneae: Desidae), as a host. This species is one of only three known maritime parasitoids globally, and is the only known spider egg parasitoid that attacks its host within the intertidal region in southern Africa. Originally described from ‘The Island’, Kommetjie (Western Cape, South Africa), this shore was the only known locality of the species at the commencement of this thesis. Furthermore, the extent of the parasitism pressure the wasp exerts on D. formidabilis was largely unknown, along with its basic biology (drivers of its broad-scale and fine-scale distribution patterns; parasitism incidence; and sex ratios) and morphological and physiological adaptations for living within the frequently saltwater-inundated environment. This thesis unravelled these aspects, as well as experimentally provided data for many components of the life history of E. lamorali that had only been hypothesized by other authors, at a variety of scales, from the country-wide ecosystem, to single shores, and finally to the scale of the individual. While the distribution of E. lamorali was found to be much wider than previously thought, it remained restricted to the shores of the Cape Peninsula (Western Cape, South Africa). The host spiders were located throughout a much wider distributional range than the wasp, from East London in the east to the Peninsula, but some behavioural and morphological differences were found between those within and outside of the range of the parasitoid, suggesting range-limitation imposed by the host on E. lamorali. This limitation may be strengthened by the general lack of suitable shore types within the close vicinity of the Peninsula. Modelling using macro-climatic conditions suggested that maximum temperatures and humidities were also largely limiting to E. lamorali, although these patterns were not observable in the micro-climates in which the species survives. The wasp populations and spiders within the range of E. lamorali as identified in Chapter 2 were assessed to determine any preferences for local conditions, including location along the Peninsula, nesting sites and intertidal zones within single shores, using AICc modelling, which detected parasitism patterns in D. formidabilis and E. lamorali populations, as well as the sex ratios in the latter species. The models showed that the spider population size and distribution was more influenced by bottom-up factors such as abiotic components of the shore than by parasitism, which only showed density dependence with the host at certain scales. Both host and parasitoid populations illustrated a preference for the middle zone on single shores. Observed spider nest characteristics suggested opportunistic nesting behaviour in the species, although preference was shown for construction along an east-west orientation and in locations with low sun exposure. Along with larger population sizes on the west coast over the east coast (not reflected by E. lamorali), these observations suggest that D. formidabilis prefers cooler environments. Spider brood success was 50% in unparasitized egg-sacs, but this figure halved when E. lamorali gained access to the eggs (of which 100% within a single compartment were parasitized each time). Encapsulation of the embryo was found to be positively correlated with parasitism, indicating some form of host resistance. Resultant parasitoid broods illustrated a strong female bias in the species, as is common for this group of insects. The life history of E. lamorali was then assessed at a smaller scale, that of the individual. Scanning electron microscopy of whole E. lamorali specimens and light microscopy of sectioned specimens demonstrated no morphological adaptations in the trachea and spiracles to cope with saltwater inundation. On the other hand, respirometry experiments categorically demonstrated that the species copes with inundation through the formation of a physical gill over the full habitus, and the induction of a state of torpor to reduce metabolic needs, when submerged. This precludes the need for any further morphological adaptations. Determination of the wasp’s critical thermal tolerance illustrated a wide temperature range with a particularly cold lower limit of -1.1ºC ± 0.16, suggesting the presence of related genera or ancestors in much colder environments. With a much broader distribution than previously thought, and the inclusion of the distributional range of E. lamorali within the Table Mountain National Park, this species is being effectively conserved and managed through the umbrella-conservation of the park. Links to the host proved to vary at differing scales, proving the need for scale considerations to be included in other similar biological and ecological studies. Finally, the species showed physiological adaptation to its intertidal existence. Echthrodesis lamorali, the only discovered maritime spider egg parasitoid in Southern Africa, displayed unusual characteristics at every scale of its life history and as such, warrants further investigation.
- Full Text:
- Date Issued: 2016
- Authors: Owen, Candice Ann
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/837 , vital:19995 , 10.21504/10962/837
- Description: Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae, Scelioninae) is an intertidal parasitoid wasp that uses the eggs of the maritime spider, Desis formidabilis O.P. Cambridge 1890 (Araneae: Desidae), as a host. This species is one of only three known maritime parasitoids globally, and is the only known spider egg parasitoid that attacks its host within the intertidal region in southern Africa. Originally described from ‘The Island’, Kommetjie (Western Cape, South Africa), this shore was the only known locality of the species at the commencement of this thesis. Furthermore, the extent of the parasitism pressure the wasp exerts on D. formidabilis was largely unknown, along with its basic biology (drivers of its broad-scale and fine-scale distribution patterns; parasitism incidence; and sex ratios) and morphological and physiological adaptations for living within the frequently saltwater-inundated environment. This thesis unravelled these aspects, as well as experimentally provided data for many components of the life history of E. lamorali that had only been hypothesized by other authors, at a variety of scales, from the country-wide ecosystem, to single shores, and finally to the scale of the individual. While the distribution of E. lamorali was found to be much wider than previously thought, it remained restricted to the shores of the Cape Peninsula (Western Cape, South Africa). The host spiders were located throughout a much wider distributional range than the wasp, from East London in the east to the Peninsula, but some behavioural and morphological differences were found between those within and outside of the range of the parasitoid, suggesting range-limitation imposed by the host on E. lamorali. This limitation may be strengthened by the general lack of suitable shore types within the close vicinity of the Peninsula. Modelling using macro-climatic conditions suggested that maximum temperatures and humidities were also largely limiting to E. lamorali, although these patterns were not observable in the micro-climates in which the species survives. The wasp populations and spiders within the range of E. lamorali as identified in Chapter 2 were assessed to determine any preferences for local conditions, including location along the Peninsula, nesting sites and intertidal zones within single shores, using AICc modelling, which detected parasitism patterns in D. formidabilis and E. lamorali populations, as well as the sex ratios in the latter species. The models showed that the spider population size and distribution was more influenced by bottom-up factors such as abiotic components of the shore than by parasitism, which only showed density dependence with the host at certain scales. Both host and parasitoid populations illustrated a preference for the middle zone on single shores. Observed spider nest characteristics suggested opportunistic nesting behaviour in the species, although preference was shown for construction along an east-west orientation and in locations with low sun exposure. Along with larger population sizes on the west coast over the east coast (not reflected by E. lamorali), these observations suggest that D. formidabilis prefers cooler environments. Spider brood success was 50% in unparasitized egg-sacs, but this figure halved when E. lamorali gained access to the eggs (of which 100% within a single compartment were parasitized each time). Encapsulation of the embryo was found to be positively correlated with parasitism, indicating some form of host resistance. Resultant parasitoid broods illustrated a strong female bias in the species, as is common for this group of insects. The life history of E. lamorali was then assessed at a smaller scale, that of the individual. Scanning electron microscopy of whole E. lamorali specimens and light microscopy of sectioned specimens demonstrated no morphological adaptations in the trachea and spiracles to cope with saltwater inundation. On the other hand, respirometry experiments categorically demonstrated that the species copes with inundation through the formation of a physical gill over the full habitus, and the induction of a state of torpor to reduce metabolic needs, when submerged. This precludes the need for any further morphological adaptations. Determination of the wasp’s critical thermal tolerance illustrated a wide temperature range with a particularly cold lower limit of -1.1ºC ± 0.16, suggesting the presence of related genera or ancestors in much colder environments. With a much broader distribution than previously thought, and the inclusion of the distributional range of E. lamorali within the Table Mountain National Park, this species is being effectively conserved and managed through the umbrella-conservation of the park. Links to the host proved to vary at differing scales, proving the need for scale considerations to be included in other similar biological and ecological studies. Finally, the species showed physiological adaptation to its intertidal existence. Echthrodesis lamorali, the only discovered maritime spider egg parasitoid in Southern Africa, displayed unusual characteristics at every scale of its life history and as such, warrants further investigation.
- Full Text:
- Date Issued: 2016