Ulwaluko kwa Xhosa: young Xhosa men's lived experiences in the context of traditional male initiation
- Authors: Siswana, Anele
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3271 , http://hdl.handle.net/10962/d1020840
- Description: This thesis explores the lived experiences of young amaXhosa men in relation to U!walukokwa Xhosa (traditional male initiation [TMI]) and its impact on their sense of masculinity. The conceptual framework of this study is located within African epistemology focusing on indigenous knowledge systems (IKS) in South Africa. The study aimed at enabling young amaXhosa men who had undergone TMI to reflect on their first-hand, personal accounts of Ulwa/ukokwa Xhosa and manhood. Six semistructured interviews and a follow up focus group discussion were held with 23-27 years old amaXhosa men residing in Joza Township in Grahamstown, Eastern Cape. Participants were identified through purposive sampling. The thesis reports on the following findings: (a) the significance of the place/location of initiation, and the guise of modernity; (b) feelings of anticipation experienced by the young men; (c) the theme on ubudoda(manhood) affirmation Ndiyindoda!; (d) the theme on the concealment of pain (perseverance); (e) the theme on respect for self and others and ubuntu;(f) Uzimelegeqe (independence and autonomy) and (g) social role and responsibility. The paper argues for the relevance of TMI as a significantrite of passage from boyhood to manhood among amaXhosa men.
- Full Text:
- Date Issued: 2016
- Authors: Siswana, Anele
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3271 , http://hdl.handle.net/10962/d1020840
- Description: This thesis explores the lived experiences of young amaXhosa men in relation to U!walukokwa Xhosa (traditional male initiation [TMI]) and its impact on their sense of masculinity. The conceptual framework of this study is located within African epistemology focusing on indigenous knowledge systems (IKS) in South Africa. The study aimed at enabling young amaXhosa men who had undergone TMI to reflect on their first-hand, personal accounts of Ulwa/ukokwa Xhosa and manhood. Six semistructured interviews and a follow up focus group discussion were held with 23-27 years old amaXhosa men residing in Joza Township in Grahamstown, Eastern Cape. Participants were identified through purposive sampling. The thesis reports on the following findings: (a) the significance of the place/location of initiation, and the guise of modernity; (b) feelings of anticipation experienced by the young men; (c) the theme on ubudoda(manhood) affirmation Ndiyindoda!; (d) the theme on the concealment of pain (perseverance); (e) the theme on respect for self and others and ubuntu;(f) Uzimelegeqe (independence and autonomy) and (g) social role and responsibility. The paper argues for the relevance of TMI as a significantrite of passage from boyhood to manhood among amaXhosa men.
- Full Text:
- Date Issued: 2016
Investigating teachers’ experiences of using multiple representations to teach fractions for conceptual understanding in 'Grades 5-7': a Namibian case study
- Authors: Iiyambo,Julia
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1296 , vital:20044
- Description: This study investigated teachers’ experiences of using multiple representations to teach fractions for conceptual understanding in ‘grades 5 – 7’. Three teachers were involved in the study and the main goal was to explore how teachers might work with the additional tools of multiple representations to improve the teaching of fractions for conceptual understanding. Different types of multiple representations such as written mathematical symbols, descriptive written words, pictorial representations, manipulations, concrete reality, oral representations, and experience-based representations and videos or power point presentations were examined. This investigation was carried out through a focus group workshop developed by the researcher and though observations of fraction teaching which took place in schools. The research focused on the teachers working to develop their use of multiple representations to teach fractions and how they implemented what they learned in the workshop into their own classroom teaching. This study was conducted using a qualitative case study design and was oriented in the interpretive paradigm. The three participating teachers in the focus group workshop were observed and interviewed individually. The purpose of observing teaching before the workshop was to observe how the selected teachers taught fractions and in particular to observe which types of representations they used and how these were used to enhance the conceptual understanding of the learners. Post teaching took place after the focus group workshop and the different multiple representations which were used in different lessons were observed and analyzed. The purpose of the interview was to gain an understanding of the teachers’ views of using multiple representations when teaching fractions for conceptual understanding. The data showed that teachers who participated in the focus group workshop worked positively to develop their use of multiple representations to teach fractions. They made sense of fractions and were able to look at representations in different ways to develop the meaning and concepts of fractions. Teachers developed an understanding of working with multiple representations and were able to make connections among concepts and the use of concrete representations. Teachers also developed their lesson plans effectively to involve a variety of teaching methods and multiple representations, despite the limited time available to them. Moreover, teachers used different modes of representation to improve learner engagement in learning activities. Lastly, teachers used multiple representations to teach in ways that improved the learners’ conception of fractions. On the basis of this research, it can be concluded that in-service workshops for teachers on the integration of multiple representative tools in the teaching of ‘Grades 5 – 7’ fractions could provide a valuable contribution to further developing the teaching of fractions in schools.
- Full Text:
- Date Issued: 2016
- Authors: Iiyambo,Julia
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1296 , vital:20044
- Description: This study investigated teachers’ experiences of using multiple representations to teach fractions for conceptual understanding in ‘grades 5 – 7’. Three teachers were involved in the study and the main goal was to explore how teachers might work with the additional tools of multiple representations to improve the teaching of fractions for conceptual understanding. Different types of multiple representations such as written mathematical symbols, descriptive written words, pictorial representations, manipulations, concrete reality, oral representations, and experience-based representations and videos or power point presentations were examined. This investigation was carried out through a focus group workshop developed by the researcher and though observations of fraction teaching which took place in schools. The research focused on the teachers working to develop their use of multiple representations to teach fractions and how they implemented what they learned in the workshop into their own classroom teaching. This study was conducted using a qualitative case study design and was oriented in the interpretive paradigm. The three participating teachers in the focus group workshop were observed and interviewed individually. The purpose of observing teaching before the workshop was to observe how the selected teachers taught fractions and in particular to observe which types of representations they used and how these were used to enhance the conceptual understanding of the learners. Post teaching took place after the focus group workshop and the different multiple representations which were used in different lessons were observed and analyzed. The purpose of the interview was to gain an understanding of the teachers’ views of using multiple representations when teaching fractions for conceptual understanding. The data showed that teachers who participated in the focus group workshop worked positively to develop their use of multiple representations to teach fractions. They made sense of fractions and were able to look at representations in different ways to develop the meaning and concepts of fractions. Teachers developed an understanding of working with multiple representations and were able to make connections among concepts and the use of concrete representations. Teachers also developed their lesson plans effectively to involve a variety of teaching methods and multiple representations, despite the limited time available to them. Moreover, teachers used different modes of representation to improve learner engagement in learning activities. Lastly, teachers used multiple representations to teach in ways that improved the learners’ conception of fractions. On the basis of this research, it can be concluded that in-service workshops for teachers on the integration of multiple representative tools in the teaching of ‘Grades 5 – 7’ fractions could provide a valuable contribution to further developing the teaching of fractions in schools.
- Full Text:
- Date Issued: 2016
The challenges of German-English literary translation: an exploration of Franz Kafka's Das Urteil (The Judgment) and Die Verwandlung (The Metamorphosis)
- Authors: Thabane, Mathaabe
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3659 , http://hdl.handle.net/10962/d1021181
- Description: This thesis conducts a study of literary translation using selected texts by Franz Kafka as translated from German into English in the mid-twentieth century and in the early twenty-first century. This study entails a three-fold orientation, namely: to show the extent of the impact of socio-historical, political and cultural factors on both the translation process and translation product; secondly, it demonstrates the fact that a merging of theoretical principles and practical methods is necessary and possible for the study of literary translations; thirdly, it answers the questions of why the same literary works continue to be retranslated and why every generation of Kafka scholars and readers will need their own translations of his works. This research, furthermore, proposes that the position of literary translation should be elevated since this kind of translation can reveal more about the cultural and linguistic intricacies of the translation process. Seeking to contribute to the broader framework of the translation studies discipline, this thesis also makes a case for translators to reveal their translation process, in the form of notes or prefaces, in order to allow for informed studies of translations. Finally, the research at hand proposes some considerations for further study into literary translations and shows new trends in the sub-field of literary translation which will undoubtedly shift its current nature and call for theoretical and practical applications for more classes of languages.
- Full Text:
- Date Issued: 2016
- Authors: Thabane, Mathaabe
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3659 , http://hdl.handle.net/10962/d1021181
- Description: This thesis conducts a study of literary translation using selected texts by Franz Kafka as translated from German into English in the mid-twentieth century and in the early twenty-first century. This study entails a three-fold orientation, namely: to show the extent of the impact of socio-historical, political and cultural factors on both the translation process and translation product; secondly, it demonstrates the fact that a merging of theoretical principles and practical methods is necessary and possible for the study of literary translations; thirdly, it answers the questions of why the same literary works continue to be retranslated and why every generation of Kafka scholars and readers will need their own translations of his works. This research, furthermore, proposes that the position of literary translation should be elevated since this kind of translation can reveal more about the cultural and linguistic intricacies of the translation process. Seeking to contribute to the broader framework of the translation studies discipline, this thesis also makes a case for translators to reveal their translation process, in the form of notes or prefaces, in order to allow for informed studies of translations. Finally, the research at hand proposes some considerations for further study into literary translations and shows new trends in the sub-field of literary translation which will undoubtedly shift its current nature and call for theoretical and practical applications for more classes of languages.
- Full Text:
- Date Issued: 2016
A study on the role of the media in identity formation among isiXhosa speaking youth in Grahamstown with focus on SABC’s Yo TV
- Authors: Mabusela, Pumeza
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3661 , http://hdl.handle.net/10962/d1021302
- Description: This study explores the use of African languages, more specifically isiXhosa, in the South African Broadcasting Corporation (SABC). It does this by investigating the YO TV programme and its impact on identity formation amongst isiXhosa speaking youth. The research was conducted in Grahamstown which is located in the Eastern Cape province of South Africa. Young isiXhosa speakers were used as participants for questionnaires and focus group interviews. The location of the study within the Eastern Cape was driven by the fact that Grahamstown consists of mainly isiXhosa speakers, and young people are a big part of the population. Secondly, the participants were chosen in order to look at how isiXhosa and the Xhosa culture are represented in the YO TV programme through the lenses of young people who speak the language, and whether the representation of these two aspects plays a role in the formation of their identity. The goals of the research were to explore the relationship between language and youth identity, and the role of television in the construction of this identity. The research looked at the SABC’s YO TV which is a youth programme targeting South African youth who speak different languages and the role it plays in constructing the identity of isiXhosa speaking youth in relation to language and culture. It also examined for what purpose isiXhosa was used in the YO TV programme. The study further identified and critically analysed the already existing strategies used by the SABC to promote African languages in youth programs. The study made several findings, one of these being that there is a relationship that exists between language, culture and identity. As a result of this relationship, this study found that when one of these aspects is less represented on television, it affects the other(s). Thus, little representation of isiXhosa on YO TV has an impact on the identity formation of young isiXhosa speakers as they believe that language and culture are a part of who they are, their identity. This study also discovered that institutions of power such as the media play a key role in affirming the identity of young people. They play a role in influencing the way young people reason and do things. This study argues that television programmes such as the YO TV programme must use African languages, as well as English because the use of African languages adds value to how young people perceive them. The use of African languages on television will contribute to their growth and development. Moreover, the use of these languages in the media contributes in identity construction of young African language speakers.
- Full Text:
- Date Issued: 2016
- Authors: Mabusela, Pumeza
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3661 , http://hdl.handle.net/10962/d1021302
- Description: This study explores the use of African languages, more specifically isiXhosa, in the South African Broadcasting Corporation (SABC). It does this by investigating the YO TV programme and its impact on identity formation amongst isiXhosa speaking youth. The research was conducted in Grahamstown which is located in the Eastern Cape province of South Africa. Young isiXhosa speakers were used as participants for questionnaires and focus group interviews. The location of the study within the Eastern Cape was driven by the fact that Grahamstown consists of mainly isiXhosa speakers, and young people are a big part of the population. Secondly, the participants were chosen in order to look at how isiXhosa and the Xhosa culture are represented in the YO TV programme through the lenses of young people who speak the language, and whether the representation of these two aspects plays a role in the formation of their identity. The goals of the research were to explore the relationship between language and youth identity, and the role of television in the construction of this identity. The research looked at the SABC’s YO TV which is a youth programme targeting South African youth who speak different languages and the role it plays in constructing the identity of isiXhosa speaking youth in relation to language and culture. It also examined for what purpose isiXhosa was used in the YO TV programme. The study further identified and critically analysed the already existing strategies used by the SABC to promote African languages in youth programs. The study made several findings, one of these being that there is a relationship that exists between language, culture and identity. As a result of this relationship, this study found that when one of these aspects is less represented on television, it affects the other(s). Thus, little representation of isiXhosa on YO TV has an impact on the identity formation of young isiXhosa speakers as they believe that language and culture are a part of who they are, their identity. This study also discovered that institutions of power such as the media play a key role in affirming the identity of young people. They play a role in influencing the way young people reason and do things. This study argues that television programmes such as the YO TV programme must use African languages, as well as English because the use of African languages adds value to how young people perceive them. The use of African languages on television will contribute to their growth and development. Moreover, the use of these languages in the media contributes in identity construction of young African language speakers.
- Full Text:
- Date Issued: 2016
The lived experience of the post-termination period of long-term psychotherapy
- Steenkamp, Jeanette Gwendoline
- Authors: Steenkamp, Jeanette Gwendoline
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3276 , http://hdl.handle.net/10962/d1021272
- Description: This study aimed to gain insight and understanding into adult clients’ personal lived experiences of the post-termination period of long-term psychotherapy. International research which examines the post-termination phase of psychotherapy has found that this particular lived experience can have both positive and negative consequences for clients’ psychosocial wellbeing. Few recent studies focusing on adult clients’ personal experiences of the post-termination phase could be located and none of these studies were conducted in a non-Western context. The study’s aim was to address this gap in the existing literature by using interpretative-phenomenological analysis (IPA) to explore the lived experience of the post-termination period of long-term psychotherapy for two South African adult clients. Data were collected via individual in-depth semi-structured interviews. Analysis of the data yielded the following themes: Therapy remembered as amazing, but hard work, Vivid memories of therapy retained post-termination, Seeing the therapist differently, Keeping the therapist alive, Being different after therapy, “I started losing all my ground I had gained”, and Resuming the external journey. These findings corroborated and expanded upon existing research in the area.
- Full Text:
- Date Issued: 2016
- Authors: Steenkamp, Jeanette Gwendoline
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3276 , http://hdl.handle.net/10962/d1021272
- Description: This study aimed to gain insight and understanding into adult clients’ personal lived experiences of the post-termination period of long-term psychotherapy. International research which examines the post-termination phase of psychotherapy has found that this particular lived experience can have both positive and negative consequences for clients’ psychosocial wellbeing. Few recent studies focusing on adult clients’ personal experiences of the post-termination phase could be located and none of these studies were conducted in a non-Western context. The study’s aim was to address this gap in the existing literature by using interpretative-phenomenological analysis (IPA) to explore the lived experience of the post-termination period of long-term psychotherapy for two South African adult clients. Data were collected via individual in-depth semi-structured interviews. Analysis of the data yielded the following themes: Therapy remembered as amazing, but hard work, Vivid memories of therapy retained post-termination, Seeing the therapist differently, Keeping the therapist alive, Being different after therapy, “I started losing all my ground I had gained”, and Resuming the external journey. These findings corroborated and expanded upon existing research in the area.
- Full Text:
- Date Issued: 2016
An ethnographic study of beginner mathematics teachers’ classroom practices in the first three years of their employment: Shaping of a Professional Identity
- Narayanan, Ajayagosh Ettappiriparambil
- Authors: Narayanan, Ajayagosh Ettappiriparambil
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2069 , http://hdl.handle.net/10962/d1020967
- Description: The main theme in this study examines how beginner mathematics teachers (BTs) shape their professional identity in their first three years of classroom practices in Lesotho. This study, which focuses particularly on BTs’ second and third year of employment, gathers data with an understanding that the notion of professional identity is multi-faceted. Professional identity embraces a host of other identities such as personal identity, teacher identity, mathematics identity and community of practice identity. This study is framed by social theories of learning. Learning occurs by active participation and practice. BTs’ peripheral participation assists them in making sense of the activities (situated learning) in which they are engaged, in the classrooms. The sense making processes eventually shape their professional identity. In line with situated meanings that BTs form, the key notion (professional identity) is further categorised into personal identity, teacher identity, mathematics identity and community of practice identity. These identities integrate to become the professional identity of a beginner mathematics teacher. Using a narrative ethnographic approach as the research method, I have made use of extensive classroom observations and interviews to gather data. In this study, six volunteer participant BTs were originally selected. These teachers were from two districts, Berea and Maseru in Lesotho. After being observed in the classrooms, these teachers were interviewed. In the third year of the study, one participant withdrew from the study. I used vertical (descriptive) analysis to narrate their classroom practice followed by horizontal analysis to understand how they shape their professional identity. The analytical model enables the researcher to analyse the data in order to establish how the BTs’ actions, their reflexive stories and their journey in becoming a mathematics teacher shape their professional identity. The recurring themes that emerged from the horizontal analysis are the ways BTs approach the classroom practice which is dominated by teacher-centred learning. This involves demonstrating an example and then students following this model to practice more examples. In this sense, their approach is the same though these BTs started understanding how their classroom approaches can bring changes in the learning of mathematics. I analysed the utterances from the BTs’ classroom activities by separating these into mathematizing and subjectifying. The subjectifying utterances were further analysed to understand how these created meaning. These, in my view, are also central features of a teacher’s practice that need interpretation in order to understand the shaping of a professional identity. The key finding is that their narrative helped them to understand how they shape their professional identity. The study highlights the importance of listening to BTs’ stories of how they become mathematics teachers. Their narratives can be the benchmark for stake-holders, policy makers and potential researchers as the study on BTs’ professional identity is relatively new in Lesotho.
- Full Text:
- Date Issued: 2016
- Authors: Narayanan, Ajayagosh Ettappiriparambil
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2069 , http://hdl.handle.net/10962/d1020967
- Description: The main theme in this study examines how beginner mathematics teachers (BTs) shape their professional identity in their first three years of classroom practices in Lesotho. This study, which focuses particularly on BTs’ second and third year of employment, gathers data with an understanding that the notion of professional identity is multi-faceted. Professional identity embraces a host of other identities such as personal identity, teacher identity, mathematics identity and community of practice identity. This study is framed by social theories of learning. Learning occurs by active participation and practice. BTs’ peripheral participation assists them in making sense of the activities (situated learning) in which they are engaged, in the classrooms. The sense making processes eventually shape their professional identity. In line with situated meanings that BTs form, the key notion (professional identity) is further categorised into personal identity, teacher identity, mathematics identity and community of practice identity. These identities integrate to become the professional identity of a beginner mathematics teacher. Using a narrative ethnographic approach as the research method, I have made use of extensive classroom observations and interviews to gather data. In this study, six volunteer participant BTs were originally selected. These teachers were from two districts, Berea and Maseru in Lesotho. After being observed in the classrooms, these teachers were interviewed. In the third year of the study, one participant withdrew from the study. I used vertical (descriptive) analysis to narrate their classroom practice followed by horizontal analysis to understand how they shape their professional identity. The analytical model enables the researcher to analyse the data in order to establish how the BTs’ actions, their reflexive stories and their journey in becoming a mathematics teacher shape their professional identity. The recurring themes that emerged from the horizontal analysis are the ways BTs approach the classroom practice which is dominated by teacher-centred learning. This involves demonstrating an example and then students following this model to practice more examples. In this sense, their approach is the same though these BTs started understanding how their classroom approaches can bring changes in the learning of mathematics. I analysed the utterances from the BTs’ classroom activities by separating these into mathematizing and subjectifying. The subjectifying utterances were further analysed to understand how these created meaning. These, in my view, are also central features of a teacher’s practice that need interpretation in order to understand the shaping of a professional identity. The key finding is that their narrative helped them to understand how they shape their professional identity. The study highlights the importance of listening to BTs’ stories of how they become mathematics teachers. Their narratives can be the benchmark for stake-holders, policy makers and potential researchers as the study on BTs’ professional identity is relatively new in Lesotho.
- Full Text:
- Date Issued: 2016
Developing an attractant for monitoring fruit-feeding moths in citrus orchards
- Authors: Goddard, Mathew Keith
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2981 , vital:20349
- Description: Fruit-piercing moths are a sporadic pest of citrus, especially in the Eastern Cape Province of South Africa, where the adults can cause significant damage in outbreak years. Currently the only way in which to successfully control fruit-feeding moths within the orchards is the use of repellent lights. However, growers confuse fruit-piercing moths with fruit-sucking moths that don‘t cause primary damage, and there is no way of monitoring which moth species are attacking the fruit in the orchards during the night. In a previous study, banana was shown to be the most attractive bait for a variety of fruit-feeding moth species. Therefore the aim of this study was to determine the population dynamics of fruit-feeding moths develop a cost-effective alternative to the use of fresh banana as a bait for fruit-piercing moths. Fresh banana was compared to nine alternative synthetic attractants, frozen banana and a control under field conditions in several orchards in the Eastern Cape Province. Once again, banana was shown to be the most attractive bait. Some 23 species of fruit-feeding moth species were sampled in the traps, but there was only two fruit-piercing species, Serrodes partita (Fabricius) (Lepidoptera: Noctuidae) and Eudocima sp. Surprisingly S. partita, which was thought to be the main pest, comprised only 6.9% of trap catches. Serrodes partita, is a sporadic pest, only becoming problematic every five to 10 years after good rainfall in the Little Karoo region that causes flushes of their larval host, wild plum, Pappea capensis (Ecklon and Zeyher). During these outbreaks, damage to fruit can range from 70 to 90% and this is especially so for soft skinned citrus. A study on the morphology of the proboscis confirmed that only two species of fruit-piercing moths were present. Trap catches over three citrus growing seasons was linked to fruit damage found within several orchards. Once again fruit-piercing moth damage was relatively low in comparison to other types of damage such as mechanical and undefined damage. There was a very weak correlation between S. partita trap catches and damage, but generally damage was recorded two to three weeks after a peak in S. partita trap catches. Climatic conditions were also recorded and compared to weekly trap catches of S. partita, and while temperature and wind direction had no influence on moth populations, precipitation in the orchards was weakly correlated with trap catches. This study has shown that in non-outbreak seasons, the main fruit-piercing moth, S. partita comprises a small percentage of fruit-feeding moths in citrus orchards, but that growers are unable to determine the difference between fruit-piercing species and the harmless fruit-sucking species. Further fresh banana remains the best method for attracting fruit-piecing moths to traps, but this is not cost effective and thus a commercially viable protocol for monitoring these species remains elusive.
- Full Text:
- Date Issued: 2016
- Authors: Goddard, Mathew Keith
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2981 , vital:20349
- Description: Fruit-piercing moths are a sporadic pest of citrus, especially in the Eastern Cape Province of South Africa, where the adults can cause significant damage in outbreak years. Currently the only way in which to successfully control fruit-feeding moths within the orchards is the use of repellent lights. However, growers confuse fruit-piercing moths with fruit-sucking moths that don‘t cause primary damage, and there is no way of monitoring which moth species are attacking the fruit in the orchards during the night. In a previous study, banana was shown to be the most attractive bait for a variety of fruit-feeding moth species. Therefore the aim of this study was to determine the population dynamics of fruit-feeding moths develop a cost-effective alternative to the use of fresh banana as a bait for fruit-piercing moths. Fresh banana was compared to nine alternative synthetic attractants, frozen banana and a control under field conditions in several orchards in the Eastern Cape Province. Once again, banana was shown to be the most attractive bait. Some 23 species of fruit-feeding moth species were sampled in the traps, but there was only two fruit-piercing species, Serrodes partita (Fabricius) (Lepidoptera: Noctuidae) and Eudocima sp. Surprisingly S. partita, which was thought to be the main pest, comprised only 6.9% of trap catches. Serrodes partita, is a sporadic pest, only becoming problematic every five to 10 years after good rainfall in the Little Karoo region that causes flushes of their larval host, wild plum, Pappea capensis (Ecklon and Zeyher). During these outbreaks, damage to fruit can range from 70 to 90% and this is especially so for soft skinned citrus. A study on the morphology of the proboscis confirmed that only two species of fruit-piercing moths were present. Trap catches over three citrus growing seasons was linked to fruit damage found within several orchards. Once again fruit-piercing moth damage was relatively low in comparison to other types of damage such as mechanical and undefined damage. There was a very weak correlation between S. partita trap catches and damage, but generally damage was recorded two to three weeks after a peak in S. partita trap catches. Climatic conditions were also recorded and compared to weekly trap catches of S. partita, and while temperature and wind direction had no influence on moth populations, precipitation in the orchards was weakly correlated with trap catches. This study has shown that in non-outbreak seasons, the main fruit-piercing moth, S. partita comprises a small percentage of fruit-feeding moths in citrus orchards, but that growers are unable to determine the difference between fruit-piercing species and the harmless fruit-sucking species. Further fresh banana remains the best method for attracting fruit-piecing moths to traps, but this is not cost effective and thus a commercially viable protocol for monitoring these species remains elusive.
- Full Text:
- Date Issued: 2016
Assessment of fluctuating asymmetry as an indicator of water quality stress in South Africa
- Authors: Holland, Alexandra Jennifer
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/430 , vital:19958
- Description: South Africa’s freshwater resources are facing numerous water quality challenges and need to be protected from degradation and pollution by appropriate management strategies as they are a limited and shared resource. The South African Scoring System (SASS5), which assesses macroinvertebrate communities at family level, is used in routine monitoring of riverine ecosystems in South Africa. Assessing the condition of these ecosystems is limited as SASS5 does not allow for changes at lower levels of biological organisation to be detected. Fluctuating asymmetry (FA) - small random deviations from perfect symmetry - is considered a direct measure of developmental instability. This phenotypical response results from numerous internal and external factors and has a low level of heritability. FA is based on sound scientific principles, easy to measure, biologically robust and cost-effective. It reflects synergistic interactions between stressors and provides an integrated measure of several anthropogenic stresses, which strengthens the assertion that FA is an environmental indicator of water quality stress, and can potentially be used to detect stress in populations before irreversible effects manifest. FA responses were investigated by (1) exposing freshwater shrimp to increasing concentrations of cadmium chloride in a long-term experiment and (2) comparing FA responses to water quality changes and macroinvertebrate community responses in two case studies (Kwazulu-Natal and Limpopo Province) in South Africa. Although no consistent concentration-response curve could be established, this study suggests that FA responses can be used as a sublethal endpoint in exposure experiments. Determining water quality parameters causing FA responses was not possible in field collected freshwater shrimp in either case study. Although FA did not specifically respond to any of the measured water quality parameters identified in the case studies, it has potential as a general indicator of water quality stress in freshwater shrimp. This study shows that FA responses are potentially more sensitive than macroinvertebrate community responses to pollution since it is not affected by habitat. Since FA has the potential to be a general indicator of population quality, particularly where there are natural habitat differences, it can be useful at the level of biomonitoring required for routine basic river status assessments in South Africa. However, in order for FA to become a robust tool that can be used routinely in conjunction with SASS5 more research is required.
- Full Text:
- Date Issued: 2016
- Authors: Holland, Alexandra Jennifer
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/430 , vital:19958
- Description: South Africa’s freshwater resources are facing numerous water quality challenges and need to be protected from degradation and pollution by appropriate management strategies as they are a limited and shared resource. The South African Scoring System (SASS5), which assesses macroinvertebrate communities at family level, is used in routine monitoring of riverine ecosystems in South Africa. Assessing the condition of these ecosystems is limited as SASS5 does not allow for changes at lower levels of biological organisation to be detected. Fluctuating asymmetry (FA) - small random deviations from perfect symmetry - is considered a direct measure of developmental instability. This phenotypical response results from numerous internal and external factors and has a low level of heritability. FA is based on sound scientific principles, easy to measure, biologically robust and cost-effective. It reflects synergistic interactions between stressors and provides an integrated measure of several anthropogenic stresses, which strengthens the assertion that FA is an environmental indicator of water quality stress, and can potentially be used to detect stress in populations before irreversible effects manifest. FA responses were investigated by (1) exposing freshwater shrimp to increasing concentrations of cadmium chloride in a long-term experiment and (2) comparing FA responses to water quality changes and macroinvertebrate community responses in two case studies (Kwazulu-Natal and Limpopo Province) in South Africa. Although no consistent concentration-response curve could be established, this study suggests that FA responses can be used as a sublethal endpoint in exposure experiments. Determining water quality parameters causing FA responses was not possible in field collected freshwater shrimp in either case study. Although FA did not specifically respond to any of the measured water quality parameters identified in the case studies, it has potential as a general indicator of water quality stress in freshwater shrimp. This study shows that FA responses are potentially more sensitive than macroinvertebrate community responses to pollution since it is not affected by habitat. Since FA has the potential to be a general indicator of population quality, particularly where there are natural habitat differences, it can be useful at the level of biomonitoring required for routine basic river status assessments in South Africa. However, in order for FA to become a robust tool that can be used routinely in conjunction with SASS5 more research is required.
- Full Text:
- Date Issued: 2016
A psychobiographical study of Charlize Theron
- Authors: Prenter, Tracey
- Date: 2016
- Subjects: Theron, Charlize -- Psychology , Motion picture actors and actresses -- South Africa -- Biography , Motion picture actors and actresses -- United States -- Biography , Psychology -- Biographical methods
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3272 , http://hdl.handle.net/10962/d1020843
- Description: Psychobiographers study the lives of extraordinary, prominent, and enigmatic individuals. Psychobiographical research advances our insight into the uniqueness and complexity of the human personality and therefore makes a substantial contribution towards one of the major objectives of the field of psychology. Purposive sampling was employed to select Charlize Theron as the subject of this psychobiographical study. As the only South African who has won an Oscar, Theron is an exceptional individual who demonstrates tenacity and a will to succeed despite significant traumatic events in her childhood. The case study data was organised and analysed according to the general analytic approach developed by Huberman and Miles (2002) and one of Alexander’s (1990) strategies, namely questioning the data. Erikson’s psychosocial theory (1950, 1963, 1995) was selected to guide this study because it recognises the impact of socio-cultural influences on developmental processes and provides a comprehensive, staged framework for studying Theron’s personality development. This study contributes to the development of psychobiographical research in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Prenter, Tracey
- Date: 2016
- Subjects: Theron, Charlize -- Psychology , Motion picture actors and actresses -- South Africa -- Biography , Motion picture actors and actresses -- United States -- Biography , Psychology -- Biographical methods
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3272 , http://hdl.handle.net/10962/d1020843
- Description: Psychobiographers study the lives of extraordinary, prominent, and enigmatic individuals. Psychobiographical research advances our insight into the uniqueness and complexity of the human personality and therefore makes a substantial contribution towards one of the major objectives of the field of psychology. Purposive sampling was employed to select Charlize Theron as the subject of this psychobiographical study. As the only South African who has won an Oscar, Theron is an exceptional individual who demonstrates tenacity and a will to succeed despite significant traumatic events in her childhood. The case study data was organised and analysed according to the general analytic approach developed by Huberman and Miles (2002) and one of Alexander’s (1990) strategies, namely questioning the data. Erikson’s psychosocial theory (1950, 1963, 1995) was selected to guide this study because it recognises the impact of socio-cultural influences on developmental processes and provides a comprehensive, staged framework for studying Theron’s personality development. This study contributes to the development of psychobiographical research in South Africa.
- Full Text:
- Date Issued: 2016
Rhodes University Graduation Ceremony 2016
- Authors: Rhodes University
- Date: 2016
- Language: English
- Type: text
- Identifier: vital:8150 , http://hdl.handle.net/10962/d1021288
- Description: Rhodes University Graduation Ceremonies 2016 [at] 1820 Settlers National Monument Thursday, 31 March at 10.00 & 17:00 [and] Friday, 1 April at 10:00; 14:30 & 18:30 [and] Saturday, 2 April at 10:00
- Full Text:
- Date Issued: 2016
- Authors: Rhodes University
- Date: 2016
- Language: English
- Type: text
- Identifier: vital:8150 , http://hdl.handle.net/10962/d1021288
- Description: Rhodes University Graduation Ceremonies 2016 [at] 1820 Settlers National Monument Thursday, 31 March at 10.00 & 17:00 [and] Friday, 1 April at 10:00; 14:30 & 18:30 [and] Saturday, 2 April at 10:00
- Full Text:
- Date Issued: 2016
Eye of a needle
- Authors: Fick, Cornelia
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6003 , http://hdl.handle.net/10962/d1021210
- Description: Most of my stories are about interpersonal relationships between the sexes, as well as intrapersonal processes, such as growing old. I have a deep connection to such themes because of my background as a general nurse and midwife; meeting too many abused women in hospitals, and the broader community. Because patterns of abuse tend to become invisible, I use experimental forms of storytelling as well as sharp, ironic and dark humour as a way to make this side of life more visible. My reading has shown me how experimental forms can render seemingly timeless or ageless topics in a fresh, vital way.
- Full Text:
- Date Issued: 2016
- Authors: Fick, Cornelia
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6003 , http://hdl.handle.net/10962/d1021210
- Description: Most of my stories are about interpersonal relationships between the sexes, as well as intrapersonal processes, such as growing old. I have a deep connection to such themes because of my background as a general nurse and midwife; meeting too many abused women in hospitals, and the broader community. Because patterns of abuse tend to become invisible, I use experimental forms of storytelling as well as sharp, ironic and dark humour as a way to make this side of life more visible. My reading has shown me how experimental forms can render seemingly timeless or ageless topics in a fresh, vital way.
- Full Text:
- Date Issued: 2016
Rural livelihood strategies of female headed households in former Bantustans of post-apartheid South Africa: The case of Cala, Eastern Cape Province.
- Authors: Chirau, Takunda John
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3410 , http://hdl.handle.net/10962/d1021301
- Description: Communal areas in contemporary South Africa (that is, the former Bantustans of apartheid South Africa) continue to bear and endure, albeit in new forms, socio-economic and political vulnerabilities which are negatively affecting household livelihoods. Current studies on rural livelihoods have failed to keep pace in exploring and analysing the lived experiences and ever-changing challenges faced by these rural households. This thesis provides an understanding and explanation of the livelihood activities of specifically de facto and de jure female-headed households in the former Transkei Bantustan, with a specific focus on villages in Cala. This is framed analytically by feminist theories with their emphasis on systems of patriarchy and by a rural livelihoods framework. It uses a multiplicity of research methods, including focus group discussions, in-depth interviews, life histories and survey questionnaires. The major findings of the thesis show that the female-headed households in Cala depend upon agricultural-based activities and non-agriculturally-based activities and income (including social grants) but that they exist under conditions of extreme vulnerability which are subject to fluctuation. In the end, the livelihoods of female-headed households are precarious and unstable as they live under circumstances of poverty. However, the female heads are not mere passive victims of the rural crisis in post-apartheid South Africa, as they demonstrate qualities of ingenuity and resourcefulness including through a range of coping mechanisms. At the same time, rural communities continue to be marked by patriarchal norms and practices, including systems of chieftainship, which disempower women (including female heads), though this affects de jure heads and de facto heads differently. The thesis contributes to an understanding of rural livelihoods in communal areas (or former Bantustans) of present-day South Africa by way of ‘thick descriptions’ of the everyday lives of female heads in Cala. Further, in examining rural livelihoods, it highlights the importance of bringing to bear on the livelihoods framework a feminist perspective in pinpointing the additional livelihood burdens carried by rural women.
- Full Text:
- Date Issued: 2016
- Authors: Chirau, Takunda John
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3410 , http://hdl.handle.net/10962/d1021301
- Description: Communal areas in contemporary South Africa (that is, the former Bantustans of apartheid South Africa) continue to bear and endure, albeit in new forms, socio-economic and political vulnerabilities which are negatively affecting household livelihoods. Current studies on rural livelihoods have failed to keep pace in exploring and analysing the lived experiences and ever-changing challenges faced by these rural households. This thesis provides an understanding and explanation of the livelihood activities of specifically de facto and de jure female-headed households in the former Transkei Bantustan, with a specific focus on villages in Cala. This is framed analytically by feminist theories with their emphasis on systems of patriarchy and by a rural livelihoods framework. It uses a multiplicity of research methods, including focus group discussions, in-depth interviews, life histories and survey questionnaires. The major findings of the thesis show that the female-headed households in Cala depend upon agricultural-based activities and non-agriculturally-based activities and income (including social grants) but that they exist under conditions of extreme vulnerability which are subject to fluctuation. In the end, the livelihoods of female-headed households are precarious and unstable as they live under circumstances of poverty. However, the female heads are not mere passive victims of the rural crisis in post-apartheid South Africa, as they demonstrate qualities of ingenuity and resourcefulness including through a range of coping mechanisms. At the same time, rural communities continue to be marked by patriarchal norms and practices, including systems of chieftainship, which disempower women (including female heads), though this affects de jure heads and de facto heads differently. The thesis contributes to an understanding of rural livelihoods in communal areas (or former Bantustans) of present-day South Africa by way of ‘thick descriptions’ of the everyday lives of female heads in Cala. Further, in examining rural livelihoods, it highlights the importance of bringing to bear on the livelihoods framework a feminist perspective in pinpointing the additional livelihood burdens carried by rural women.
- Full Text:
- Date Issued: 2016
Notebook of unremembered poems
- Authors: McKeown, Jean Wallace
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6013 , http://hdl.handle.net/10962/d1021233
- Description: My poems contain narrative elements and explore themes of identity, motherhood, sexuality, and fear of relinquishing control. Sharon Olds, in her book Stag’s Leap, sums up my intention: “and I saw again how blessed my life has been, / first, to have been able to love, / then, to have the parting now behind me.” My collection chronicles a path towards acceptance of self from childhood onwards, and, more than that, a pleasure and pride in self, and I have tried to find the forms which will reflect this path in the reader’s own experience. Most of the poems are written in a conversational voice and a free-form style which gives me creative licence to explore transition and transformation.
- Full Text:
- Date Issued: 2016
- Authors: McKeown, Jean Wallace
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6013 , http://hdl.handle.net/10962/d1021233
- Description: My poems contain narrative elements and explore themes of identity, motherhood, sexuality, and fear of relinquishing control. Sharon Olds, in her book Stag’s Leap, sums up my intention: “and I saw again how blessed my life has been, / first, to have been able to love, / then, to have the parting now behind me.” My collection chronicles a path towards acceptance of self from childhood onwards, and, more than that, a pleasure and pride in self, and I have tried to find the forms which will reflect this path in the reader’s own experience. Most of the poems are written in a conversational voice and a free-form style which gives me creative licence to explore transition and transformation.
- Full Text:
- Date Issued: 2016
Aquatic–terrestrial trophic linkages via riverine invertebrates in a South African catchment
- Authors: Moyo, Sydney
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54427 , vital:26564
- Description: Rivers play a vital role in human livelihoods and are likely to undergo substantial alteration due to climate and land use changes from an increasing human population. Mitigating the pressures facing rivers in the world requires scientists and environmental managers to understand the ecological mechanisms, and ultimately the strength, of connections between ecosystems. This understanding of connections between adjacent habitats will enable environmental managers to predict the consequences of perturbing these linkages in the future. In this thesis, aquatic-terrestrial linkages in rivers were investigated using ecologically meaningful variables including abundances, biomasses, stable isotopes and fatty acids. This study is part of a larger project entitled “Connectivity through allochthony: reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa”, in which a team of researchers assessed a variety of pathways connecting riverine and estuarine systems to land within a catchment in the Eastern Cape, South Africa. I conceptualised the flow of energy within a temperate southern hemisphere river (the Kowie River) within theoretical models of energy flow such as the River Continuum Concept (RCC; presents lotic systems as being longitudinally linked with food webs in shaded headwaters being principally driven by allochthonous energy, with the addition of autochthonous food as a minor carbon source in the lower reaches) and the Riverine Productivity Model (RPM; proposes consumers derive most of their energy from local production of phytoplankton, benthic algae and aquatic plants, as well as directly from riparian zones via terrestrial leaf litter). Using the RCC as a starting point, I collected macroinvertebrates (September 2012 to May 2013) along a longitudinal gradient and grouped them into functional feeding groups (FFGs). The results revealed that gatherers and filterers dominated in the Kowie River, and together represented 50 – 83% of the invertebrate assemblages. There was a general paucity of shredders (relative abundance was ≤ 10% across all sites and seasons). The changes in relative abundances of different FFGs did not follow predictions of the RCC along the longitudinal gradient, as there were no correlations of community structure with some physical attributes (stream width, canopy cover, distance of river) that changed along the river continuum. However, FFG abundances were related to water velocity, total dissolved solids and canopy cover. Broadly, the Kowie River data showed that changes in relative abundances of FFGs along the river continuum could not be explained by changes in physical attributes alone, and may be highly influenced by the availability of food and the chemistry of the stream. Analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes was used to estimate the contributions of algal and land-based production to consumers over space (six sites) and time (November 2012 to September 2013). Carbon contributions determined by the use of mixing models (Stable Isotope Analysis in R) revealed that consumers in the headwater assimilated mainly terrestrially-derived organic matter, with consumers in the middle and lower reaches assimilating autochthonous basal resources (macrophytes and algae). The findings from this river supported aspects of the RCC (at the headwaters; terrestrial organic matter made up 41% of consumer diets), but overall the data supported the predictions of the RPM (local production made the highest contributions of 50 – 86% to all FFGs across all seasons). The carbon isotopes of consumers and their food sources changed substantially every season, indicating that samples of food sources and consumers should be analysed many times throughout the year to capture that variability and to ensure that ephemeral components of the food web are not missed. To validate the findings from the isotope data, fatty acids were used as complementary tracers to determine the contributions of algal versus terrestrial organic matter to the consumers. Fatty acid tracers for terrestrial (Ʃω3/Ʃω6; 18:2ω6; 18:3ω3) vs aquatic (Ʃω3/Ʃω6; 20:5ω3) sources corroborated the findings from the isotope data set, as the mean ratio of Ʃω3/Ʃω6 in consumers was less than one at the headwaters (indicating allochthony), while middle and lower reaches were associated with Ʃω3/Ʃω6 > 1 (indicating autochthony). In addition to the tracer and FFG analyses for examining trophic connections between land and river, the bidirectional exchange of organisms between the riparian zone and the river was assessed using floating pyramidal traps (to measure emergence) and pan traps (for infalling invertebrates) placed at different sites in the river and the biomass in each trap was determined. The exchanges were variable over space and time, with emergence peaking in summer (169 to 1402 mg m-2 day-1) and declining in winter (3 to 28 mg m-2 day-1). Similarly, infalling invertebrates increased in summer (413 to 679 mg m-2 day-1) and declined in winter (11 to 220 mg m-2 day-1). Biomass measurements are indications of quantity that ignore nutritional quality, so I determined the bidirectional flow of invertebrates using absolute concentrations of physiologically important biochemical compounds (essential and polyunsaturated fatty acids). The fluxes of emergent and infalling arthropods peaked in summer (emergence = 0.3 to 18 mg m-2 day-1 and terrestrial infall = 0.3 to 3 mg m-2 day-1) and declined in winter (emergence = 0.01 to 0.51 mg m-2 day-1 and terrestrial infall = 0.01 to 0.03 mg m-2 day-1). However, during some seasons, no significant differences in polyunsaturated fatty acid flux in either direction were observed; this finding indicated the balance of reciprocal subsidisation via reciprocal flows of animals. Factors such as air temperature and algal productivity affected the reciprocal flows between adjacent habitats, with algal productivity being positively related to emergence while air temperature was positively correlated to infalling terrestrial invertebrates. This research enhances the growing body of literature on the function of riverine systems and offers some invaluable information on the flow of energy and the role played by invertebrates in translocating nutrients from terrestrial systems to aquatic systems and vice versa. This study unifies the concepts of the RCC and RPM and shows that these concepts are not limited only to large rivers, but are applicable to small southern temperate rivers too. However, some tenets of the theoretical models were challenged. For example, it challenges the proposition by the RCC that the fine particulate organic matter leaked from upstream breakdown of coarse particulate organic matter is predominantly allochthonous. Additionally, this study showed that in the headwaters, the RPM underestimated the role of autochthony. Overall, the results showed that the Kowie River and its riparian area are intrinsically connected. Once we understand the mechanisms controlling connections and subsidies across ecotones, we can then start to predict the consequences of disruptions to these connections by climate change and/or land use changes. To make predictions about future perturbations to rivers and riparian zones, studies like this, which considers the form and magnitude of subsidies, are needed to provide baseline information. Algal resources (e.g. epiphyton), macrophytes, riparian plants, terrestrial organisms and aquatic organisms all contributed to aquatic and terrestrial linkages in the Kowie River; therefore, it is important to conserve the different components of these ecosystems.
- Full Text:
- Date Issued: 2016
- Authors: Moyo, Sydney
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54427 , vital:26564
- Description: Rivers play a vital role in human livelihoods and are likely to undergo substantial alteration due to climate and land use changes from an increasing human population. Mitigating the pressures facing rivers in the world requires scientists and environmental managers to understand the ecological mechanisms, and ultimately the strength, of connections between ecosystems. This understanding of connections between adjacent habitats will enable environmental managers to predict the consequences of perturbing these linkages in the future. In this thesis, aquatic-terrestrial linkages in rivers were investigated using ecologically meaningful variables including abundances, biomasses, stable isotopes and fatty acids. This study is part of a larger project entitled “Connectivity through allochthony: reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa”, in which a team of researchers assessed a variety of pathways connecting riverine and estuarine systems to land within a catchment in the Eastern Cape, South Africa. I conceptualised the flow of energy within a temperate southern hemisphere river (the Kowie River) within theoretical models of energy flow such as the River Continuum Concept (RCC; presents lotic systems as being longitudinally linked with food webs in shaded headwaters being principally driven by allochthonous energy, with the addition of autochthonous food as a minor carbon source in the lower reaches) and the Riverine Productivity Model (RPM; proposes consumers derive most of their energy from local production of phytoplankton, benthic algae and aquatic plants, as well as directly from riparian zones via terrestrial leaf litter). Using the RCC as a starting point, I collected macroinvertebrates (September 2012 to May 2013) along a longitudinal gradient and grouped them into functional feeding groups (FFGs). The results revealed that gatherers and filterers dominated in the Kowie River, and together represented 50 – 83% of the invertebrate assemblages. There was a general paucity of shredders (relative abundance was ≤ 10% across all sites and seasons). The changes in relative abundances of different FFGs did not follow predictions of the RCC along the longitudinal gradient, as there were no correlations of community structure with some physical attributes (stream width, canopy cover, distance of river) that changed along the river continuum. However, FFG abundances were related to water velocity, total dissolved solids and canopy cover. Broadly, the Kowie River data showed that changes in relative abundances of FFGs along the river continuum could not be explained by changes in physical attributes alone, and may be highly influenced by the availability of food and the chemistry of the stream. Analysis of stable carbon (δ13C) and nitrogen (δ15N) isotopes was used to estimate the contributions of algal and land-based production to consumers over space (six sites) and time (November 2012 to September 2013). Carbon contributions determined by the use of mixing models (Stable Isotope Analysis in R) revealed that consumers in the headwater assimilated mainly terrestrially-derived organic matter, with consumers in the middle and lower reaches assimilating autochthonous basal resources (macrophytes and algae). The findings from this river supported aspects of the RCC (at the headwaters; terrestrial organic matter made up 41% of consumer diets), but overall the data supported the predictions of the RPM (local production made the highest contributions of 50 – 86% to all FFGs across all seasons). The carbon isotopes of consumers and their food sources changed substantially every season, indicating that samples of food sources and consumers should be analysed many times throughout the year to capture that variability and to ensure that ephemeral components of the food web are not missed. To validate the findings from the isotope data, fatty acids were used as complementary tracers to determine the contributions of algal versus terrestrial organic matter to the consumers. Fatty acid tracers for terrestrial (Ʃω3/Ʃω6; 18:2ω6; 18:3ω3) vs aquatic (Ʃω3/Ʃω6; 20:5ω3) sources corroborated the findings from the isotope data set, as the mean ratio of Ʃω3/Ʃω6 in consumers was less than one at the headwaters (indicating allochthony), while middle and lower reaches were associated with Ʃω3/Ʃω6 > 1 (indicating autochthony). In addition to the tracer and FFG analyses for examining trophic connections between land and river, the bidirectional exchange of organisms between the riparian zone and the river was assessed using floating pyramidal traps (to measure emergence) and pan traps (for infalling invertebrates) placed at different sites in the river and the biomass in each trap was determined. The exchanges were variable over space and time, with emergence peaking in summer (169 to 1402 mg m-2 day-1) and declining in winter (3 to 28 mg m-2 day-1). Similarly, infalling invertebrates increased in summer (413 to 679 mg m-2 day-1) and declined in winter (11 to 220 mg m-2 day-1). Biomass measurements are indications of quantity that ignore nutritional quality, so I determined the bidirectional flow of invertebrates using absolute concentrations of physiologically important biochemical compounds (essential and polyunsaturated fatty acids). The fluxes of emergent and infalling arthropods peaked in summer (emergence = 0.3 to 18 mg m-2 day-1 and terrestrial infall = 0.3 to 3 mg m-2 day-1) and declined in winter (emergence = 0.01 to 0.51 mg m-2 day-1 and terrestrial infall = 0.01 to 0.03 mg m-2 day-1). However, during some seasons, no significant differences in polyunsaturated fatty acid flux in either direction were observed; this finding indicated the balance of reciprocal subsidisation via reciprocal flows of animals. Factors such as air temperature and algal productivity affected the reciprocal flows between adjacent habitats, with algal productivity being positively related to emergence while air temperature was positively correlated to infalling terrestrial invertebrates. This research enhances the growing body of literature on the function of riverine systems and offers some invaluable information on the flow of energy and the role played by invertebrates in translocating nutrients from terrestrial systems to aquatic systems and vice versa. This study unifies the concepts of the RCC and RPM and shows that these concepts are not limited only to large rivers, but are applicable to small southern temperate rivers too. However, some tenets of the theoretical models were challenged. For example, it challenges the proposition by the RCC that the fine particulate organic matter leaked from upstream breakdown of coarse particulate organic matter is predominantly allochthonous. Additionally, this study showed that in the headwaters, the RPM underestimated the role of autochthony. Overall, the results showed that the Kowie River and its riparian area are intrinsically connected. Once we understand the mechanisms controlling connections and subsidies across ecotones, we can then start to predict the consequences of disruptions to these connections by climate change and/or land use changes. To make predictions about future perturbations to rivers and riparian zones, studies like this, which considers the form and magnitude of subsidies, are needed to provide baseline information. Algal resources (e.g. epiphyton), macrophytes, riparian plants, terrestrial organisms and aquatic organisms all contributed to aquatic and terrestrial linkages in the Kowie River; therefore, it is important to conserve the different components of these ecosystems.
- Full Text:
- Date Issued: 2016
An erosion and sediment delivery model for semi-arid catchments
- Authors: Bryson, Louise Kay
- Date: 2016
- Subjects: Sedimentation and deposition , Erosion , Watershed management -- South Africa , Water-supply -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6056 , http://hdl.handle.net/10962/d1020331
- Description: Sedimentation has become a significant environmental threat in South Africa as it intensifies water management problems in the water-scarce semi-arid regions of the country. As South Africa already allocates 98% of available water, the loss of storage capacity in reservoirs and degraded water quality has meant that a reliable water supply is compromised. The overall aim of this thesis was to develop a catchment scale model that represents the sediment dynamics of semi-arid regions of South Africa as a simple and practically applicable tool for water resource managers. Development of a conceptual framework for the model relied on an understanding of both the sediment dynamics of South African catchments and applicable modelling techniques. Scale was an issue in both cases as most of our understanding of the physical processes of runoff generation and sediment transport has been derived from plot scale studies. By identifying defining properties of semi-arid catchments it was possible to consider how temporal and spatial properties at higher levels emerged from properties at lower levels. These properties were effectively represented by using the Pitman rainfall-runoff model disaggregated to a daily timescale, the Modified Universal Soil Loss Equation (MUSLE) model incorporating probability function theory and through the representation of sediment storages across a semi-distributed catchment. The model was tested on two small and one large study catchment in the Karoo, South Africa, with limited observed data. Limitations to the model were found to be the large parameter data set and the dominance of structural constraints with an increase in catchment size. The next steps in model development will require a reduction of the parameter data set and an inclusion of an in-stream component for sub-catchments at a larger spatial scale. The model is applicable in areas such as South Africa where water resource managers need a simple model at the catchment scale in order to make decisions. This type of model provides a simple representation of the stochastic nature of erosion and sediment delivery over large spatial and temporal scales.
- Full Text:
- Date Issued: 2016
- Authors: Bryson, Louise Kay
- Date: 2016
- Subjects: Sedimentation and deposition , Erosion , Watershed management -- South Africa , Water-supply -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6056 , http://hdl.handle.net/10962/d1020331
- Description: Sedimentation has become a significant environmental threat in South Africa as it intensifies water management problems in the water-scarce semi-arid regions of the country. As South Africa already allocates 98% of available water, the loss of storage capacity in reservoirs and degraded water quality has meant that a reliable water supply is compromised. The overall aim of this thesis was to develop a catchment scale model that represents the sediment dynamics of semi-arid regions of South Africa as a simple and practically applicable tool for water resource managers. Development of a conceptual framework for the model relied on an understanding of both the sediment dynamics of South African catchments and applicable modelling techniques. Scale was an issue in both cases as most of our understanding of the physical processes of runoff generation and sediment transport has been derived from plot scale studies. By identifying defining properties of semi-arid catchments it was possible to consider how temporal and spatial properties at higher levels emerged from properties at lower levels. These properties were effectively represented by using the Pitman rainfall-runoff model disaggregated to a daily timescale, the Modified Universal Soil Loss Equation (MUSLE) model incorporating probability function theory and through the representation of sediment storages across a semi-distributed catchment. The model was tested on two small and one large study catchment in the Karoo, South Africa, with limited observed data. Limitations to the model were found to be the large parameter data set and the dominance of structural constraints with an increase in catchment size. The next steps in model development will require a reduction of the parameter data set and an inclusion of an in-stream component for sub-catchments at a larger spatial scale. The model is applicable in areas such as South Africa where water resource managers need a simple model at the catchment scale in order to make decisions. This type of model provides a simple representation of the stochastic nature of erosion and sediment delivery over large spatial and temporal scales.
- Full Text:
- Date Issued: 2016
Genetic and biological characterisation of a novel South African Cydia pomonella granulovirus (CpGV-SA) isolate
- Motsoeneng, Boitumelo Madika
- Authors: Motsoeneng, Boitumelo Madika
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20503 , http://hdl.handle.net/10962/d1021266
- Description: The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the primary pest of pome fruit cultivated worldwide. The control of this insect pest has been dependent on the frequent use of broad-spectrum chemical pesticides, which has led to the development of resistance in pest populations and negative effects on human health and the environment. The Betabaculovirus of C. pomonella has successfully been applied as a biological control agent in integrated pest management (IPM) programmes for the suppression of pest populations worldwide. Previously, all Cydia pomonella granulovirus (CpGV) biopesticides were based on a Mexican isolate (CpGV-M) and although these products are highly efficient at controlling C. pomonella, resistance cases have been reported across Europe. The identification of novel CpGV isolates as additional or alternative control agents to manage resistance is therefore necessary. This study aimed to genetically and biologically characterise a novel South African C. pomonella granulovirus isolate and to test its virulence against neonate larvae. Based on the morphology of the occlusion bodies observed using transmission electron microscopy, granuloviruses were recovered from diseased and dead larvae collected from an orchard in South Africa where no virus applications had been made. DNA was extracted and the identification of the isolated granulovirus was achieved through the PCR amplification and sequencing of the lef-8, lef-9, granulin and egt genes. Submission of the gene sequences to BLAST revealed high percentage identities to sequences from various CpGV isolates, resulting in the naming of the isolate in this study as the South African Cydia pomonella granulovirus (CpGV-SA) isolate. Phylogenetic analysis based on the single nucleotide polymorphisms (SNPs) detected in the lef-8, lef-9 and granulin nucleotide sequences grouped the South African isolate with CpGV-E2 (genome type B) and CpGV-S (genome type E). The CpGV-SA isolate was further genetically characterised by restriction endonuclease analysis and complete sequencing of the genomic DNA. Differences were observed for the BamHI, EcoRI, PstI and XhoI profiles of CpGV-SA in comparison to the respective profiles generated for CpGV-M extracted from a biopesticide, Carpovirusine® (Arysta Lifescience, France). Several genetic variations between the complete genome sequence of CpGV-SA and the reference isolate, CpGV-M1, as well as a recent genome submission of CpGV-M, both representing genome type A were observed. The complete genome analysis confirmed that CpGV-SA is genetically different from the Mexican CpGV isolate, used in thedevelopment of most biopesticides. In silico restriction profiles of the genome sequence obtained for CpGV-SA and genome sequences of genetically different CpGV isolates originating from Mexico (M1 and M), England (E2), Canada (S) and Iran (I12 and I07), available on the NCBI’s GenBank database confirmed that CpGV-SA is of mixed genotypes. Furthermore, the South African isolate shared the single common difference found in the pe38 gene of resistance overcoming isolates, which was the absence of an internal 24 nucleotide repeat present in CpGV-M1. In addition to the common difference, SNPs detected in the pe38 gene grouped the isolate with the CpGV-S isolate, suggesting that the CpGV-SA isolate is predominantly of genome type E. To determine the biological activity of CpGV-SA against neonate C. pomonella larvae, surface bioassays were conducted alongside CpGV-M (Carpovirusine®) bioassays. The LC50 and LC90 values for the South African isolate were 1.6 × 103 and 1.2 × 105 OBs/ml respectively. The LT50 was determined to be 135 hours. These values were similar to the values obtained for CpGV-M (Carpovirusine®). The results in this study suggest that a novel South African CpGV isolate of mixed genotypes, potentially able to overcome resistance in C. pomonella, with biological activity similar to CpGV-M (Carpovirusine®) and important for the control of C. pomonella was recovered. The CpGV-SA isolate could therefore potentially be developed into a biopesticide for use in resistance management strategies against C. pomonella populations in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Motsoeneng, Boitumelo Madika
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20503 , http://hdl.handle.net/10962/d1021266
- Description: The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the primary pest of pome fruit cultivated worldwide. The control of this insect pest has been dependent on the frequent use of broad-spectrum chemical pesticides, which has led to the development of resistance in pest populations and negative effects on human health and the environment. The Betabaculovirus of C. pomonella has successfully been applied as a biological control agent in integrated pest management (IPM) programmes for the suppression of pest populations worldwide. Previously, all Cydia pomonella granulovirus (CpGV) biopesticides were based on a Mexican isolate (CpGV-M) and although these products are highly efficient at controlling C. pomonella, resistance cases have been reported across Europe. The identification of novel CpGV isolates as additional or alternative control agents to manage resistance is therefore necessary. This study aimed to genetically and biologically characterise a novel South African C. pomonella granulovirus isolate and to test its virulence against neonate larvae. Based on the morphology of the occlusion bodies observed using transmission electron microscopy, granuloviruses were recovered from diseased and dead larvae collected from an orchard in South Africa where no virus applications had been made. DNA was extracted and the identification of the isolated granulovirus was achieved through the PCR amplification and sequencing of the lef-8, lef-9, granulin and egt genes. Submission of the gene sequences to BLAST revealed high percentage identities to sequences from various CpGV isolates, resulting in the naming of the isolate in this study as the South African Cydia pomonella granulovirus (CpGV-SA) isolate. Phylogenetic analysis based on the single nucleotide polymorphisms (SNPs) detected in the lef-8, lef-9 and granulin nucleotide sequences grouped the South African isolate with CpGV-E2 (genome type B) and CpGV-S (genome type E). The CpGV-SA isolate was further genetically characterised by restriction endonuclease analysis and complete sequencing of the genomic DNA. Differences were observed for the BamHI, EcoRI, PstI and XhoI profiles of CpGV-SA in comparison to the respective profiles generated for CpGV-M extracted from a biopesticide, Carpovirusine® (Arysta Lifescience, France). Several genetic variations between the complete genome sequence of CpGV-SA and the reference isolate, CpGV-M1, as well as a recent genome submission of CpGV-M, both representing genome type A were observed. The complete genome analysis confirmed that CpGV-SA is genetically different from the Mexican CpGV isolate, used in thedevelopment of most biopesticides. In silico restriction profiles of the genome sequence obtained for CpGV-SA and genome sequences of genetically different CpGV isolates originating from Mexico (M1 and M), England (E2), Canada (S) and Iran (I12 and I07), available on the NCBI’s GenBank database confirmed that CpGV-SA is of mixed genotypes. Furthermore, the South African isolate shared the single common difference found in the pe38 gene of resistance overcoming isolates, which was the absence of an internal 24 nucleotide repeat present in CpGV-M1. In addition to the common difference, SNPs detected in the pe38 gene grouped the isolate with the CpGV-S isolate, suggesting that the CpGV-SA isolate is predominantly of genome type E. To determine the biological activity of CpGV-SA against neonate C. pomonella larvae, surface bioassays were conducted alongside CpGV-M (Carpovirusine®) bioassays. The LC50 and LC90 values for the South African isolate were 1.6 × 103 and 1.2 × 105 OBs/ml respectively. The LT50 was determined to be 135 hours. These values were similar to the values obtained for CpGV-M (Carpovirusine®). The results in this study suggest that a novel South African CpGV isolate of mixed genotypes, potentially able to overcome resistance in C. pomonella, with biological activity similar to CpGV-M (Carpovirusine®) and important for the control of C. pomonella was recovered. The CpGV-SA isolate could therefore potentially be developed into a biopesticide for use in resistance management strategies against C. pomonella populations in South Africa.
- Full Text:
- Date Issued: 2016
A narrative-discursive analysis of abortion decision-making in Zimbabwe
- Authors: Chiweshe, Malvern Tatenda
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/496 , vital:19964
- Description: Most research on abortion decision-making has looked at the factors or influences that are seen to affect abortion decision-making and thus take a health determinants approach. However, this approach is rarely able to account for the complex, multi-faceted nature of abortion decision-making, and it is often not located within a framework that can unpick the complex array of power relations that underpins the process of abortion decision-making. Research on abortion decision-making has rarely examined how women who undergo a termination of pregnancy (TOP) construct micro-narratives of the decision to terminate the pregnancy and also how these women are positioned by the service providers who interact with them. Using a Foucauldian postcolonial feminist approach and narrative-discursive analysis, this study explores abortion decision-making narratives in a Zimbabwean context where abortion laws are restrictive. In this study I elicited the narratives of women who had undergone an abortion about how they came to make the decision and proceeded to terminate the pregnancy. I highlight the discourses employed in constructing these narratives and how women position themselves in these narratives and discourses. These are then compared to the subject positions enabled in health service providers’ narratives on the same topic. These narratives are then linked to the social discourses and power relations that work to enable or constrain reproductive justice. The data were collected from three sites in Harare, Zimbabwe. The three sites were Harare Hospital, Epworth and Mufakose. An adapted version of Wengraf’s (2001) narrative interview was used to elicit narratives from 18 women who had terminated pregnancies (six at each site). Semi-structured interviews were conducted with six service providers (two nurses at Harare Hospital, two village health workers in Epworth and two nurses in Mufakose). All the service providers interviewed have experience working with women who have terminated pregnancies. In narrating their stories about their abortions, the women employed discursive resources around shame, stigma, religion, health and culture. These discursive resources were drawn upon in the construction of the women’s micro-narratives. The women spoke in a socially sanctioned manner where stories were enabled and constrained by particular religious, cultural and gendered discursive resources. In these stories, cultural constructions, gendered understandings of motherhood and femininity constrained reproductive justice for women who have terminated pregnancies. Comparisons of the way women positioned themselves and how they were positioned by health service providers point to the existence of social discourses and power relations that work to constrain reproductive justice. While the women saw themselves as having ‘unsupportable pregnancies’, the service providers positioned them as being evil, selfish and irresponsible. The negative positions deployed by the service providers point to the vilification and blaming of women who have undergone a termination of pregnancy. In these positions, the woman is at fault and there is silence on the role of men in abortion decision-making. In the women’s narratives and the health service providers positioning of the women a ‘reproductive rights’ discourse was absent. This was significant as much of the activism around abortion has centred on the woman’s rights to her body. Where rights were mentioned, it was in reference to foetal rights (using cultural, moralistic religious understandings of abortion as killing). The missing ‘reproductive rights’ discourse points to a need to move from a reproductive rights framework to a reproductive justice framework that can be applied through local understandings of hunhu/ubuntu. By doing this, abortion is not seen as a ‘choice’ that a woman makes but rather as involving broader social and environmental circumstances that make a pregnancy ‘unsupportable’.
- Full Text:
- Date Issued: 2016
- Authors: Chiweshe, Malvern Tatenda
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/496 , vital:19964
- Description: Most research on abortion decision-making has looked at the factors or influences that are seen to affect abortion decision-making and thus take a health determinants approach. However, this approach is rarely able to account for the complex, multi-faceted nature of abortion decision-making, and it is often not located within a framework that can unpick the complex array of power relations that underpins the process of abortion decision-making. Research on abortion decision-making has rarely examined how women who undergo a termination of pregnancy (TOP) construct micro-narratives of the decision to terminate the pregnancy and also how these women are positioned by the service providers who interact with them. Using a Foucauldian postcolonial feminist approach and narrative-discursive analysis, this study explores abortion decision-making narratives in a Zimbabwean context where abortion laws are restrictive. In this study I elicited the narratives of women who had undergone an abortion about how they came to make the decision and proceeded to terminate the pregnancy. I highlight the discourses employed in constructing these narratives and how women position themselves in these narratives and discourses. These are then compared to the subject positions enabled in health service providers’ narratives on the same topic. These narratives are then linked to the social discourses and power relations that work to enable or constrain reproductive justice. The data were collected from three sites in Harare, Zimbabwe. The three sites were Harare Hospital, Epworth and Mufakose. An adapted version of Wengraf’s (2001) narrative interview was used to elicit narratives from 18 women who had terminated pregnancies (six at each site). Semi-structured interviews were conducted with six service providers (two nurses at Harare Hospital, two village health workers in Epworth and two nurses in Mufakose). All the service providers interviewed have experience working with women who have terminated pregnancies. In narrating their stories about their abortions, the women employed discursive resources around shame, stigma, religion, health and culture. These discursive resources were drawn upon in the construction of the women’s micro-narratives. The women spoke in a socially sanctioned manner where stories were enabled and constrained by particular religious, cultural and gendered discursive resources. In these stories, cultural constructions, gendered understandings of motherhood and femininity constrained reproductive justice for women who have terminated pregnancies. Comparisons of the way women positioned themselves and how they were positioned by health service providers point to the existence of social discourses and power relations that work to constrain reproductive justice. While the women saw themselves as having ‘unsupportable pregnancies’, the service providers positioned them as being evil, selfish and irresponsible. The negative positions deployed by the service providers point to the vilification and blaming of women who have undergone a termination of pregnancy. In these positions, the woman is at fault and there is silence on the role of men in abortion decision-making. In the women’s narratives and the health service providers positioning of the women a ‘reproductive rights’ discourse was absent. This was significant as much of the activism around abortion has centred on the woman’s rights to her body. Where rights were mentioned, it was in reference to foetal rights (using cultural, moralistic religious understandings of abortion as killing). The missing ‘reproductive rights’ discourse points to a need to move from a reproductive rights framework to a reproductive justice framework that can be applied through local understandings of hunhu/ubuntu. By doing this, abortion is not seen as a ‘choice’ that a woman makes but rather as involving broader social and environmental circumstances that make a pregnancy ‘unsupportable’.
- Full Text:
- Date Issued: 2016
Assessing the impact of climate change on mangrove crabs: the role of ontogenetic macrophysiology and settlement in the persistence of central and marginal populations
- Authors: Mostert, Bruce Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/826 , vital:19994
- Description: After a brief respite in the mid to late 20th century, macro physiology has come to the fore in elucidating large scale ecological patterns and processes as physiological assumptions often form the backbone of many predictive theories associated with species distributions. Critically, macro physiological patterns are valuable in explaining physiological variation across multiple scales and provide insights into the effects of climate change on populations spanning a wide range of latitudes. This can assist in predicting possible distribution expansions, contractions or shifts in light of current climate change scenarios. From this perspective, investigating intra- and inter-specific physiological responses to environmental stress may contribute to better understanding and predicting the effects of climate change on geographical ranges. Further, investigating the physiological effects to environmental stresses across ontogenetic stages allows for the identification of weak links within the lifecycle of a species. Additionally, determining settlement characteristics along a latitudinal cline provides integrated indications of the sustainability of populations, highlighting vulnerable regions in terms of repopulation of viable habitats. In this context, the present study aimed at establishing how temperature, in a physiological context, may affect reproductive biology of two species of mangrove crab, Perisesarma guttatum and Uca urvillei at the centre (Kenya) and edge (South Africa) of their distributional range along the east coast of Africa and highlight possible consequences for range distributions. A third species, Neosarmatium africanum, only in South Africa, was included to provide additional interspecies comparisons. Furthermore, settlement characteristics of brachyuran populations at the centre and edge of their distributional range were considered in order to determine how settlement may contribute to population persistence. Physiological investigations at the centre and edge of distributional range and across ontogenetic stages (larvae, stage 2 and 4 embryos, non-gravid and gravid females) under the concept of oxygen and capacity limitation of thermal tolerance (OCLTT), revealed that, for both species, populations at the centre of their distribution (Kenya) were generally more robust to increasing temperatures and generally displayed greater physiological stability with increasing temperatures compared to their conspecifics in South Africa. Variability in physiological robustness between regions, did however, differ among ontogenetic stages and species but, overall, were evident throughout. Within and between regions, adaptation to oxygen extraction in both milieus (air or water) was displayed for present temperature conditions but aerial respiration largely alleviated increased thermal stress due to overcoming the limitations of reduced oxygen availability and diffusiveness in water for all bimodal ontogenetic stages. Brooding eggs proved to be a physiologically critical process with either heighted oxygen consumption for gravid females or collapse of physiological processes demonstrated by supressed oxygen consumption. The physiological cost of brooding eggs, referred to as maternal costs, was reflected in in both Perisesarma guttatum and Uca urvillei where, in most cases, maternal costs were negative. Again, aerial respiration was able to alleviated increased thermal stress, as shown by positive maternal costs indicating sustained maternal care, but this mechanism was species and regionally specific. Settlement patterns differed between the edge and centre of distribution of the species studied. This difference was predominantly driven by zonal preference within the mangal and/or effects of new and full moon (lunar phase). Overall, settlement dynamics were more widely variable in South Africa, both spatially and temporally, than in Kenya. Finally, empirical physiological data from ontogenetic stages present during the reproductive process (early and late stage embryos) and from non-gravid and gravid females were used in conjunction with data mined from the existing literature to parameterise an individual based model designed to simulate reproductive output at the centre and edge of distribution of Perisesarma guttatum. Physiological data indicate that, in terms of reproductive output across increasing temperatures, populations based at the centre of their distribution presently outperform their counterparts at the edge of the species’ distribution, but reproductive output stagnated as temperature rose. Edge of distribution populations consistently increased reproductive output with increasing temperatures to eventually outperform centre of distribution populations at higher simulated temperatures. Overall, results of the physiological and settlement studies suggest that with increased climate change there may be a contraction of distributional range of the study species from high latitudes to low latitudes, contrary to general poleward shifts/migrations seen in most species, with possible contractions of the entire ecosystem mirroring the disappearance of keystone mangrove macrofauna.
- Full Text:
- Date Issued: 2016
- Authors: Mostert, Bruce Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/826 , vital:19994
- Description: After a brief respite in the mid to late 20th century, macro physiology has come to the fore in elucidating large scale ecological patterns and processes as physiological assumptions often form the backbone of many predictive theories associated with species distributions. Critically, macro physiological patterns are valuable in explaining physiological variation across multiple scales and provide insights into the effects of climate change on populations spanning a wide range of latitudes. This can assist in predicting possible distribution expansions, contractions or shifts in light of current climate change scenarios. From this perspective, investigating intra- and inter-specific physiological responses to environmental stress may contribute to better understanding and predicting the effects of climate change on geographical ranges. Further, investigating the physiological effects to environmental stresses across ontogenetic stages allows for the identification of weak links within the lifecycle of a species. Additionally, determining settlement characteristics along a latitudinal cline provides integrated indications of the sustainability of populations, highlighting vulnerable regions in terms of repopulation of viable habitats. In this context, the present study aimed at establishing how temperature, in a physiological context, may affect reproductive biology of two species of mangrove crab, Perisesarma guttatum and Uca urvillei at the centre (Kenya) and edge (South Africa) of their distributional range along the east coast of Africa and highlight possible consequences for range distributions. A third species, Neosarmatium africanum, only in South Africa, was included to provide additional interspecies comparisons. Furthermore, settlement characteristics of brachyuran populations at the centre and edge of their distributional range were considered in order to determine how settlement may contribute to population persistence. Physiological investigations at the centre and edge of distributional range and across ontogenetic stages (larvae, stage 2 and 4 embryos, non-gravid and gravid females) under the concept of oxygen and capacity limitation of thermal tolerance (OCLTT), revealed that, for both species, populations at the centre of their distribution (Kenya) were generally more robust to increasing temperatures and generally displayed greater physiological stability with increasing temperatures compared to their conspecifics in South Africa. Variability in physiological robustness between regions, did however, differ among ontogenetic stages and species but, overall, were evident throughout. Within and between regions, adaptation to oxygen extraction in both milieus (air or water) was displayed for present temperature conditions but aerial respiration largely alleviated increased thermal stress due to overcoming the limitations of reduced oxygen availability and diffusiveness in water for all bimodal ontogenetic stages. Brooding eggs proved to be a physiologically critical process with either heighted oxygen consumption for gravid females or collapse of physiological processes demonstrated by supressed oxygen consumption. The physiological cost of brooding eggs, referred to as maternal costs, was reflected in in both Perisesarma guttatum and Uca urvillei where, in most cases, maternal costs were negative. Again, aerial respiration was able to alleviated increased thermal stress, as shown by positive maternal costs indicating sustained maternal care, but this mechanism was species and regionally specific. Settlement patterns differed between the edge and centre of distribution of the species studied. This difference was predominantly driven by zonal preference within the mangal and/or effects of new and full moon (lunar phase). Overall, settlement dynamics were more widely variable in South Africa, both spatially and temporally, than in Kenya. Finally, empirical physiological data from ontogenetic stages present during the reproductive process (early and late stage embryos) and from non-gravid and gravid females were used in conjunction with data mined from the existing literature to parameterise an individual based model designed to simulate reproductive output at the centre and edge of distribution of Perisesarma guttatum. Physiological data indicate that, in terms of reproductive output across increasing temperatures, populations based at the centre of their distribution presently outperform their counterparts at the edge of the species’ distribution, but reproductive output stagnated as temperature rose. Edge of distribution populations consistently increased reproductive output with increasing temperatures to eventually outperform centre of distribution populations at higher simulated temperatures. Overall, results of the physiological and settlement studies suggest that with increased climate change there may be a contraction of distributional range of the study species from high latitudes to low latitudes, contrary to general poleward shifts/migrations seen in most species, with possible contractions of the entire ecosystem mirroring the disappearance of keystone mangrove macrofauna.
- Full Text:
- Date Issued: 2016
Investigating a mathematics recovery program for assessment and intervention with groups of Grade 4 learners
- Authors: Wasserman, Anelia
- Date: 2016
- Subjects: Mathematics -- Study and teaching (Primary) , Mathematics -- Evaluation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2065 , http://hdl.handle.net/10962/d1020340
- Description: This study reports on the findings of my research, which was based on an intervention focused on recovery of early arithmetic strategies with one Grade 4 class of learners in a township school in Port Elizabeth in the Eastern Cape. Learners came from poor socio-economic backgrounds and initial evaluations showed that the majority of learners still relied on concrete methods, like tally counting, to perform addition and subtraction calculations even with numbers less than 10. This is not uncommon in the South African context especially with learners in low Socio-economic Status (SES) schools. The results of numerous assessments including the Department of Education’s Annual National Assessments point to a crisis in primary mathematics education where intermediate phase learners are generally operating several grade levels below the grade they are in. A large drop in mathematics performance is seen in the ANA results in grade 4 learners (the first grade of the transition from foundation phase to intermediate phase). Within this context, and my background in learning support for students, my research aimed to understand the possibilities and constraints of the implementation of a recovery program adapted from the widely implemented work of Wright et al. (2006, 2012). The primary adaptation made to the MR program involved administering the assessments and intervention with groups of (rather than individual) learners. Within the context of the many low SES under-resourced schools in SA, individualised interview based assessments and recovery is not seen as a possible remediation strategy. Drawing on a socio- constructivist perspective, my study used action research with one class of 23 learners and found that adaptation of the MR program for a group, based on eight recovery sessions, was useful for enabling some progress for all learners in terms of their early arithmetic strategies and conceptual place value. Although the need for a longer recovery period is acknowledged, the adapted program enabled some progress in levels and stages of conceptual knowledge (as conceptualized by Wright et al.’s (2006) Learning Framework in Number) for these two domains. The study concludes with some reflections and recommendations for the future.
- Full Text:
- Date Issued: 2016
- Authors: Wasserman, Anelia
- Date: 2016
- Subjects: Mathematics -- Study and teaching (Primary) , Mathematics -- Evaluation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2065 , http://hdl.handle.net/10962/d1020340
- Description: This study reports on the findings of my research, which was based on an intervention focused on recovery of early arithmetic strategies with one Grade 4 class of learners in a township school in Port Elizabeth in the Eastern Cape. Learners came from poor socio-economic backgrounds and initial evaluations showed that the majority of learners still relied on concrete methods, like tally counting, to perform addition and subtraction calculations even with numbers less than 10. This is not uncommon in the South African context especially with learners in low Socio-economic Status (SES) schools. The results of numerous assessments including the Department of Education’s Annual National Assessments point to a crisis in primary mathematics education where intermediate phase learners are generally operating several grade levels below the grade they are in. A large drop in mathematics performance is seen in the ANA results in grade 4 learners (the first grade of the transition from foundation phase to intermediate phase). Within this context, and my background in learning support for students, my research aimed to understand the possibilities and constraints of the implementation of a recovery program adapted from the widely implemented work of Wright et al. (2006, 2012). The primary adaptation made to the MR program involved administering the assessments and intervention with groups of (rather than individual) learners. Within the context of the many low SES under-resourced schools in SA, individualised interview based assessments and recovery is not seen as a possible remediation strategy. Drawing on a socio- constructivist perspective, my study used action research with one class of 23 learners and found that adaptation of the MR program for a group, based on eight recovery sessions, was useful for enabling some progress for all learners in terms of their early arithmetic strategies and conceptual place value. Although the need for a longer recovery period is acknowledged, the adapted program enabled some progress in levels and stages of conceptual knowledge (as conceptualized by Wright et al.’s (2006) Learning Framework in Number) for these two domains. The study concludes with some reflections and recommendations for the future.
- Full Text:
- Date Issued: 2016
Exploration, monetization, disillusion: a history of upstream oil development in the onshore Algoa basin
- Authors: James, Jonathan Scott
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3870 , vital:20551
- Description: The onshore Algoa basin has, since the mid-1960s, been an area of interest for oil and gas exploration. Despite the general lack of knowledge and publicly available information on the topic, a large amount of geological and geophysical data has been collected on the region owing to the oil and gas exploration. The intended aim of this thesis is to compile and construct a historical narrative of the oil and gas exploration that took place within the onshore Algoa basin, and to then contextualize that localized narrative within the greater macro-narrative of the global oil and gas industry. This thesis is primarily concerned with the time period beginning in the early 1960s up to mid-2014, however reference is also made to events pre-1960. For the purposes of compartmentalizing the various areas of research covered, the thesis has been divided into three broad areas of interest: the geology of the onshore Algoa basin, the global oil market and its impact on exploration therein, and the attempts to monetize the leases that came to be purchased post-exploration. The narrative on the geology of the onshore Algoa basin is aimed at providing a summarized account of the most important details pertaining to the search for petroleum systems in simplified, yet accurate, language. The aspects of the geology which command the most attention are those which are necessary in functioning petroleum systems such as suitable permeabilities, porosities, reservoir rocks, trapping mechanisms and cap rocks. The global oil and gas market is also used to contextualize the search for oil and gas within the onshore Algoa basin and is explained against the backdrop of the global oil trade and the sanctions imposed on the apartheid state. Furthermore, the analysis of the attempts to monetize leases within the onshore Algoa basin will provide a financial reference point to the shortcomings of the exploration and monetization efforts. The purpose of this thesis is to construct a historical narrative of the onshore Algoa basin which not only gives an accurate portrayal of the exploration efforts that have taken place thus far, but to also provide a enough detail of those exploration efforts to indicate the future of the onshore Algoa basin as an exploration play.
- Full Text:
- Date Issued: 2016
- Authors: James, Jonathan Scott
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3870 , vital:20551
- Description: The onshore Algoa basin has, since the mid-1960s, been an area of interest for oil and gas exploration. Despite the general lack of knowledge and publicly available information on the topic, a large amount of geological and geophysical data has been collected on the region owing to the oil and gas exploration. The intended aim of this thesis is to compile and construct a historical narrative of the oil and gas exploration that took place within the onshore Algoa basin, and to then contextualize that localized narrative within the greater macro-narrative of the global oil and gas industry. This thesis is primarily concerned with the time period beginning in the early 1960s up to mid-2014, however reference is also made to events pre-1960. For the purposes of compartmentalizing the various areas of research covered, the thesis has been divided into three broad areas of interest: the geology of the onshore Algoa basin, the global oil market and its impact on exploration therein, and the attempts to monetize the leases that came to be purchased post-exploration. The narrative on the geology of the onshore Algoa basin is aimed at providing a summarized account of the most important details pertaining to the search for petroleum systems in simplified, yet accurate, language. The aspects of the geology which command the most attention are those which are necessary in functioning petroleum systems such as suitable permeabilities, porosities, reservoir rocks, trapping mechanisms and cap rocks. The global oil and gas market is also used to contextualize the search for oil and gas within the onshore Algoa basin and is explained against the backdrop of the global oil trade and the sanctions imposed on the apartheid state. Furthermore, the analysis of the attempts to monetize leases within the onshore Algoa basin will provide a financial reference point to the shortcomings of the exploration and monetization efforts. The purpose of this thesis is to construct a historical narrative of the onshore Algoa basin which not only gives an accurate portrayal of the exploration efforts that have taken place thus far, but to also provide a enough detail of those exploration efforts to indicate the future of the onshore Algoa basin as an exploration play.
- Full Text:
- Date Issued: 2016