A sociological understanding of contemporary child marriage in Mabvuku, Harare, Zimbabwe
- Authors: Madzivire, Shamso Christine
- Date: 2020
- Subjects: Child marriage -- Zimbabwe -- Mabvuku , Child marriage -- Zimbabwe -- Case studies , Shona (African people) -- Social life and customs , Marriage customs and rites -- Zimbabwe , Shona (African people) -- Marriage customs and rites , Marriage -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142566 , vital:38091
- Description: Child marriage is a phenomenon that has been increasingly recognised as a global problem since the late nineteenth century. Since then, scholars across many disciplines along with various agencies such as government bodies and non-governmental organisations have tirelessly engaged in research exploring the causes and consequences of this practice and in developing prevention and mitigation strategies. These research efforts have been concentrated in some parts of the world and not others, with the findings in many cases being generalised problematically across different geographical areas. This thesis stands as a response to the dearth of academic research on child marriage in present-day Zimbabwe and simultaneously highlights the significance of studying the specificities of child marriage under particular historical and spatial conditions. The main objective of this thesis is to explore and understand child marriage as a part of modernday marriage practices in Zimbabwe, through a case study of child marriage in Mabvuku in Harare. In addressing this objective, it is hoped that new ways of thinking around this phenomenon will become evident. In addressing this main objective, the thesis considers the experiences of child brides, the drivers and consequences of child and post-child marriage experiences. It does this seeking to understand child marriage with reference to the types of marital unions which exist amongst Shona people in pre-colonial times and in post-colonial Zimbabwe. The thesis adopts a qualitative research methodology which involved in-depth semistructured interviews with 25 women in Mabvuku who were married before the age of 18, along with focus group discussions with community workers and interviews with pertinent government and non-government representatives. Due to certain challenges with current theorising about child marriage, there is an attempt to build theory by drawing upon in particular the Zimbabwean notion and practice of hunhu. A key conclusion is that child marriage in present-day Zimbabwe is in part a result of family transitions which arose during the time of colonialism and continue to this day.
- Full Text:
- Date Issued: 2020
- Authors: Madzivire, Shamso Christine
- Date: 2020
- Subjects: Child marriage -- Zimbabwe -- Mabvuku , Child marriage -- Zimbabwe -- Case studies , Shona (African people) -- Social life and customs , Marriage customs and rites -- Zimbabwe , Shona (African people) -- Marriage customs and rites , Marriage -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142566 , vital:38091
- Description: Child marriage is a phenomenon that has been increasingly recognised as a global problem since the late nineteenth century. Since then, scholars across many disciplines along with various agencies such as government bodies and non-governmental organisations have tirelessly engaged in research exploring the causes and consequences of this practice and in developing prevention and mitigation strategies. These research efforts have been concentrated in some parts of the world and not others, with the findings in many cases being generalised problematically across different geographical areas. This thesis stands as a response to the dearth of academic research on child marriage in present-day Zimbabwe and simultaneously highlights the significance of studying the specificities of child marriage under particular historical and spatial conditions. The main objective of this thesis is to explore and understand child marriage as a part of modernday marriage practices in Zimbabwe, through a case study of child marriage in Mabvuku in Harare. In addressing this objective, it is hoped that new ways of thinking around this phenomenon will become evident. In addressing this main objective, the thesis considers the experiences of child brides, the drivers and consequences of child and post-child marriage experiences. It does this seeking to understand child marriage with reference to the types of marital unions which exist amongst Shona people in pre-colonial times and in post-colonial Zimbabwe. The thesis adopts a qualitative research methodology which involved in-depth semistructured interviews with 25 women in Mabvuku who were married before the age of 18, along with focus group discussions with community workers and interviews with pertinent government and non-government representatives. Due to certain challenges with current theorising about child marriage, there is an attempt to build theory by drawing upon in particular the Zimbabwean notion and practice of hunhu. A key conclusion is that child marriage in present-day Zimbabwe is in part a result of family transitions which arose during the time of colonialism and continue to this day.
- Full Text:
- Date Issued: 2020
An appraisal and critique of land redistribution approaches in South Africa
- Authors: Phiri, M C S
- Date: 2020
- Subjects: University of the Western Cape. Institute for Poverty, Land and Agrarian Studies , Land reform -- South Africa , Land reform -- Law and legislation -- South Africa , Agriculture and state -- South Africa , Reconstruction and Development Programme (South Africa) , Land reform beneficiaries -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994- , South Africa -- Economic policy , Land tenure -- Law and legislation -- South Africa , Black people -- South Africa -- Economic conditions , Black people -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/149161 , vital:38810
- Description: This paper is in response to the PLAAS Land Conference held in February 2019 which aimed at discovering an alternative to how to solve the land question. The conference came at a time where land and agrarian reform re-emerged in South African socio-policy discussion. After twenty-five years of democracy the three land reform programmes have failed to restructure apartheid’s economic segregation, exclusionary land ownership patterns and to restore dignity to poor black South Africans. This study offers a detailed examination of the discourse of South African land reform, specifically the redistribution component with a focus on the land redistribution approaches presented at the PLAAS conference. Ultimately, the study puts forward a synthesized land redistribution approach as a hybrid solution to the land and agrarian crisis.
- Full Text:
- Date Issued: 2020
- Authors: Phiri, M C S
- Date: 2020
- Subjects: University of the Western Cape. Institute for Poverty, Land and Agrarian Studies , Land reform -- South Africa , Land reform -- Law and legislation -- South Africa , Agriculture and state -- South Africa , Reconstruction and Development Programme (South Africa) , Land reform beneficiaries -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994- , South Africa -- Economic policy , Land tenure -- Law and legislation -- South Africa , Black people -- South Africa -- Economic conditions , Black people -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/149161 , vital:38810
- Description: This paper is in response to the PLAAS Land Conference held in February 2019 which aimed at discovering an alternative to how to solve the land question. The conference came at a time where land and agrarian reform re-emerged in South African socio-policy discussion. After twenty-five years of democracy the three land reform programmes have failed to restructure apartheid’s economic segregation, exclusionary land ownership patterns and to restore dignity to poor black South Africans. This study offers a detailed examination of the discourse of South African land reform, specifically the redistribution component with a focus on the land redistribution approaches presented at the PLAAS conference. Ultimately, the study puts forward a synthesized land redistribution approach as a hybrid solution to the land and agrarian crisis.
- Full Text:
- Date Issued: 2020
NFComms: A synchronous communication framework for the CPU-NFP heterogeneous system
- Authors: Pennefather, Sean
- Date: 2020
- Subjects: Network processors , Computer programming , Parallel processing (Electronic computers) , Netronome
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/144181 , vital:38318
- Description: This work explores the viability of using a Network Flow Processor (NFP), developed by Netronome, as a coprocessor for the construction of a CPU-NFP heterogeneous platform in the domain of general processing. When considering heterogeneous platforms involving architectures like the NFP, the communication framework provided is typically represented as virtual network interfaces and is thus not suitable for generic communication. To enable a CPU-NFP heterogeneous platform for use in the domain of general computing, a suitable generic communication framework is required. A feasibility study for a suitable communication medium between the two candidate architectures showed that a generic framework that conforms to the mechanisms dictated by Communicating Sequential Processes is achievable. The resulting NFComms framework, which facilitates inter- and intra-architecture communication through the use of synchronous message passing, supports up to 16 unidirectional channels and includes queuing mechanisms for transparently supporting concurrent streams exceeding the channel count. The framework has a minimum latency of between 15.5 μs and 18 μs per synchronous transaction and can sustain a peak throughput of up to 30 Gbit/s. The framework also supports a runtime for interacting with the Go programming language, allowing user-space processes to subscribe channels to the framework for interacting with processes executing on the NFP. The viability of utilising a heterogeneous CPU-NFP system for use in the domain of general and network computing was explored by introducing a set of problems or applications spanning general computing, and network processing. These were implemented on the heterogeneous architecture and benchmarked against equivalent CPU-only and CPU/GPU solutions. The results recorded were used to form an opinion on the viability of using an NFP for general processing. It is the author’s opinion that, beyond very specific use cases, it appears that the NFP-400 is not currently a viable solution as a coprocessor in the field of general computing. This does not mean that the proposed framework or the concept of a heterogeneous CPU-NFP system should be discarded as such a system does have acceptable use in the fields of network and stream processing. Additionally, when comparing the recorded limitations to those seen during the early stages of general purpose GPU development, it is clear that general processing on the NFP is currently in a similar state.
- Full Text:
- Date Issued: 2020
- Authors: Pennefather, Sean
- Date: 2020
- Subjects: Network processors , Computer programming , Parallel processing (Electronic computers) , Netronome
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/144181 , vital:38318
- Description: This work explores the viability of using a Network Flow Processor (NFP), developed by Netronome, as a coprocessor for the construction of a CPU-NFP heterogeneous platform in the domain of general processing. When considering heterogeneous platforms involving architectures like the NFP, the communication framework provided is typically represented as virtual network interfaces and is thus not suitable for generic communication. To enable a CPU-NFP heterogeneous platform for use in the domain of general computing, a suitable generic communication framework is required. A feasibility study for a suitable communication medium between the two candidate architectures showed that a generic framework that conforms to the mechanisms dictated by Communicating Sequential Processes is achievable. The resulting NFComms framework, which facilitates inter- and intra-architecture communication through the use of synchronous message passing, supports up to 16 unidirectional channels and includes queuing mechanisms for transparently supporting concurrent streams exceeding the channel count. The framework has a minimum latency of between 15.5 μs and 18 μs per synchronous transaction and can sustain a peak throughput of up to 30 Gbit/s. The framework also supports a runtime for interacting with the Go programming language, allowing user-space processes to subscribe channels to the framework for interacting with processes executing on the NFP. The viability of utilising a heterogeneous CPU-NFP system for use in the domain of general and network computing was explored by introducing a set of problems or applications spanning general computing, and network processing. These were implemented on the heterogeneous architecture and benchmarked against equivalent CPU-only and CPU/GPU solutions. The results recorded were used to form an opinion on the viability of using an NFP for general processing. It is the author’s opinion that, beyond very specific use cases, it appears that the NFP-400 is not currently a viable solution as a coprocessor in the field of general computing. This does not mean that the proposed framework or the concept of a heterogeneous CPU-NFP system should be discarded as such a system does have acceptable use in the fields of network and stream processing. Additionally, when comparing the recorded limitations to those seen during the early stages of general purpose GPU development, it is clear that general processing on the NFP is currently in a similar state.
- Full Text:
- Date Issued: 2020
A critical analysis of the de-peasantisation process in Nepal with specific reference to the role of state land policies since the 1950s
- Authors: Basnet, Jagat
- Date: 2020
- Subjects: Land tenure -- Nepal , Land reform -- Law and legislation -- Nepal , Nepal -- Politics and government , Peasants -- Nepal -- Economic conditions , Panchayat -- Nepal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/138716 , vital:37667
- Description: The principal objective of this thesis is to offer a critical analysis of the process of de-peasantisation in Nepal since 1950, with a particular focus on the capitalist neo-liberal restructuring of the economy beginning in the early 1990s. The analysis begins by tracing the legacy of feudal land practices and landholdings from the pre-1950 Rana and Shah dynasties. It was under these feudal dynasties that economic and political institutions of extraction first emerged, leading to a landlord-peasant agrarian economy in which peasants (often as tenants/sharecroppers and smallholders) were subordinate to the power nexus between feudal landlords and the ruling dynasties. After 1950, a window of democratic opening was soon interrupted by the formation of the party-less Panchayat system, which lasted from 1960 to 1990. In 1964, a major land reform measure was enacted under the Lands Act, with the goal of enhancing the security and livelihood of the peasantry. However, this process was met with significant resistance by feudal landlords, and actually led to deepening insecurity and the loss of land by peasants, with farmers belonging to lower castes and indigenous groups experiencing this with a greater degree of intensity. The overall result of this period was the beginnings of what is referred to in this study as de-peasantisation. This line of analysis shows that the institutions of extraction remained firmly in place even after the reforms of this period. Finally, the neo-liberal period, which was marked by land titling, the marketisation of land, and the commercialisation of agriculture, represents the late entry of capitalism into Nepal. This period saw the deepening and widening of the process of de-peasantisation, including further loss of peasants’ access to land and a general turn to wage-labour. In this regard, despite propagating the slogan ‘land to the tillers’, the major political parties in Nepal (including the Maoist party) have failed to defend the interests of the peasantry. Some progressive civil society groups have recently sought to do better, but there is also evidence of peasant organisations themselves seeking to resist and oppose the de-peasantisation effects of neo-liberal restructuring. This thesis thus considers the form and extent of de-peasantisation in Nepal, and some responses to it, over an extended period. A broad Marxist-based political economy perspective has been adopted in pursuing the principal thesis objective, but one which argues that there is a symbiotic relationship between economic and political power, such that the latter is not reducible to the former. The thesis draws upon original fieldwork in twenty districts of Nepal, including through the use of a survey, interviews, observations, case studies, and focus group discussions, thus combining both quantitative and qualitative research methods. Based on this fieldwork, it becomes clear that (i) there are major social, economic, and political forces behind the processes of de-peasantisation in the studied districts (and in Nepal more broadly), and that (ii) the Nepali peasantry is becoming increasingly landless, or land-short, and subject to processes of proletarianisation.
- Full Text:
- Date Issued: 2020
- Authors: Basnet, Jagat
- Date: 2020
- Subjects: Land tenure -- Nepal , Land reform -- Law and legislation -- Nepal , Nepal -- Politics and government , Peasants -- Nepal -- Economic conditions , Panchayat -- Nepal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/138716 , vital:37667
- Description: The principal objective of this thesis is to offer a critical analysis of the process of de-peasantisation in Nepal since 1950, with a particular focus on the capitalist neo-liberal restructuring of the economy beginning in the early 1990s. The analysis begins by tracing the legacy of feudal land practices and landholdings from the pre-1950 Rana and Shah dynasties. It was under these feudal dynasties that economic and political institutions of extraction first emerged, leading to a landlord-peasant agrarian economy in which peasants (often as tenants/sharecroppers and smallholders) were subordinate to the power nexus between feudal landlords and the ruling dynasties. After 1950, a window of democratic opening was soon interrupted by the formation of the party-less Panchayat system, which lasted from 1960 to 1990. In 1964, a major land reform measure was enacted under the Lands Act, with the goal of enhancing the security and livelihood of the peasantry. However, this process was met with significant resistance by feudal landlords, and actually led to deepening insecurity and the loss of land by peasants, with farmers belonging to lower castes and indigenous groups experiencing this with a greater degree of intensity. The overall result of this period was the beginnings of what is referred to in this study as de-peasantisation. This line of analysis shows that the institutions of extraction remained firmly in place even after the reforms of this period. Finally, the neo-liberal period, which was marked by land titling, the marketisation of land, and the commercialisation of agriculture, represents the late entry of capitalism into Nepal. This period saw the deepening and widening of the process of de-peasantisation, including further loss of peasants’ access to land and a general turn to wage-labour. In this regard, despite propagating the slogan ‘land to the tillers’, the major political parties in Nepal (including the Maoist party) have failed to defend the interests of the peasantry. Some progressive civil society groups have recently sought to do better, but there is also evidence of peasant organisations themselves seeking to resist and oppose the de-peasantisation effects of neo-liberal restructuring. This thesis thus considers the form and extent of de-peasantisation in Nepal, and some responses to it, over an extended period. A broad Marxist-based political economy perspective has been adopted in pursuing the principal thesis objective, but one which argues that there is a symbiotic relationship between economic and political power, such that the latter is not reducible to the former. The thesis draws upon original fieldwork in twenty districts of Nepal, including through the use of a survey, interviews, observations, case studies, and focus group discussions, thus combining both quantitative and qualitative research methods. Based on this fieldwork, it becomes clear that (i) there are major social, economic, and political forces behind the processes of de-peasantisation in the studied districts (and in Nepal more broadly), and that (ii) the Nepali peasantry is becoming increasingly landless, or land-short, and subject to processes of proletarianisation.
- Full Text:
- Date Issued: 2020
Dynamics of stimulated luminescence in natural quartz: Thermoluminescence and phototransferred thermoluminescence
- Authors: Folley, Damilola Esther
- Date: 2020
- Subjects: Thermoluminescence , Quartz
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146255 , vital:38509
- Description: Natural quartz has remained an important mineral that is of topical interest in luminescence and dosimetry-related research. We investigate the dynamics of stimulated luminescence on this material through thermoluminescence (TL) and phototransferred thermoluminescence (PTTL). Measurements were made on unannealed natural quartz as well as quartz annealed at 800 and 1000̊C. The samples were annealed for 10 minutes and for 1 hour. The material, in its un- and annealed state has its main peak between 68 and 72̊C when measured at 1Cs ̃1 after a dose of 50 Gy. A study of dosimetric features and kinetic analysis was carried out on two prominent peaks, peak I and III for all the samples. The peaks show a sublinear dose response for irradiation doses between 10 and 300 Gy. Kinetic analysis shows that peak I is a first-order peak and peak III a general-order peak. Interestingly, we observe for peak I for the sample annealed at 800̊C for 1 hour an inverse thermal quenching behaviour. We demonstrate that a peak affected with an inverse thermal quenching-like behaviour can still show effect of thermal quenching when the dose the sample is irradiated to is significantly reduced. We ascribe the apparent dependence of thermal quenching on dose to competition between radiative and non-radiative transitions at the recombination centre. Peaks I, II, and III for all the samples were reproduced under phototransfer when the peaks, initially removed by preheating to a certain temperature are exposed to 470 and 525 nm light. The infuence of duration of illumination on the PTTL intensity of these peaks corresponding to various preheating temperatures is modelled using coupled first-order dfferential equations. The model is based on systems of acceptors and donors whose number and role depends on preheating temperature
- Full Text:
- Date Issued: 2020
- Authors: Folley, Damilola Esther
- Date: 2020
- Subjects: Thermoluminescence , Quartz
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146255 , vital:38509
- Description: Natural quartz has remained an important mineral that is of topical interest in luminescence and dosimetry-related research. We investigate the dynamics of stimulated luminescence on this material through thermoluminescence (TL) and phototransferred thermoluminescence (PTTL). Measurements were made on unannealed natural quartz as well as quartz annealed at 800 and 1000̊C. The samples were annealed for 10 minutes and for 1 hour. The material, in its un- and annealed state has its main peak between 68 and 72̊C when measured at 1Cs ̃1 after a dose of 50 Gy. A study of dosimetric features and kinetic analysis was carried out on two prominent peaks, peak I and III for all the samples. The peaks show a sublinear dose response for irradiation doses between 10 and 300 Gy. Kinetic analysis shows that peak I is a first-order peak and peak III a general-order peak. Interestingly, we observe for peak I for the sample annealed at 800̊C for 1 hour an inverse thermal quenching behaviour. We demonstrate that a peak affected with an inverse thermal quenching-like behaviour can still show effect of thermal quenching when the dose the sample is irradiated to is significantly reduced. We ascribe the apparent dependence of thermal quenching on dose to competition between radiative and non-radiative transitions at the recombination centre. Peaks I, II, and III for all the samples were reproduced under phototransfer when the peaks, initially removed by preheating to a certain temperature are exposed to 470 and 525 nm light. The infuence of duration of illumination on the PTTL intensity of these peaks corresponding to various preheating temperatures is modelled using coupled first-order dfferential equations. The model is based on systems of acceptors and donors whose number and role depends on preheating temperature
- Full Text:
- Date Issued: 2020
Assessing community structure and trophic interrelationships in three differently impacted headwater streams in the AmatholeWinterberg freshwater ecoregion, South Africa
- Authors: Matomela, Nonjabulo Happy
- Date: 2020
- Subjects: Stream ecology -- South Africa -- Eastern Cape , Freshwater animals -- Ecology -- South Africa -- Eastern Cape , Kat River (South Africa) -- , Lushington River (South Africa) , Elands River (South Africa) , Eyre River (South Africa) , Food chains (Ecology) -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/147653 , vital:38658
- Description: Afromontane regions represent some of the highly threatened ecosystems on the planet as they harbour endemic and often relic freshwater fauna. These ecologically sensitive ecosystems have been altered by multiple impacts, including invasion by non-native fishes, replacement of diverse indigenous vegetation with monoculture plantations, agricultural and mining activities, hydrological modifications, and degradation of instream habitats, with potential detrimental effects on aquatic community structures and food web dynamics. The aim of the present study was to compare spatio-temporal patterns of macroinvertebrate and fish communities as well as food web dynamics in three differently impacted headwater tributaries of the Kat River in the Amathole-Winterberg freshwater ecoregion in the Eastern Cape Province of South Africa. The upper Kat River catchment was the ideal model for purposes of the present study as it contains streams with varying degrees of human impact. The streams considered in the present study were (i) the Eyre River which was considered to closely represent near-natural conditions as it is the least impacted stream in this catchment, with the riparian zone dominated by relatively intact and diverse native woody vegetation, (ii) the Elands River whose catchment has been altered by agricultural activities, and (iii) the Lushington River, whose riparian zone has been heavily invaded by black wattle. The three headwater streams were generally distinguished based on the physical-chemical variables. The Elands River was characterised by high conductivity and total dissolved solids (TDS). In addition, the Elands River was more alkaline and relatively warmer than the other two rivers. This suggested the negative influence of agriculture activities on the water quality in the Elands River. In general, the Lushington and Eyre rivers had comparable physical and chemical variables. However, the Lushington River was generally characterised by low streamflow, likely as a consequent of black wattle which is known for altering hydrological regimes of streams .The Eyre River and Lushington River were comparable in terms of macroinvertebrate richness and diversity, whereas the Elands River was characterised by low macroinvertebrate diversity and richness. Redundancy analysis indicated that the macroinvertebrate communities were mostly influenced by seasonality, with land-use accounting for a small but significant difference in community composition. In comparison, the generalised linear mixed-effects models (GLMMs) showed that chubbyhead barb abundance was significantly influenced by land-use patterns. Evaluation of food web dynamics using stable isotope analysis revealed that the food web structure in the three rivers differed substantially as a result of land-use. Specifically, the Eyre River was characterised by less variation in stable isotope values of basal food sources and consequently, the consumer groups had a narrow isotopic breadth. In contrast, the Elands River was characterised by a wide variation in basal food sources and therefore, a wider isotopic breadth for consumers. The Lushington River was spatially variable in terms of basal sources and isotopic breadth for consumers. The study concluded that food webs and trophic interrelationships were a more informative indicator of land-use than community structure was in evaluating the impact of land-use patterns on aquatic communities. In addition, future studies should seek to investigate food webs interrelationships in addition to community structure to infer a more conclusive river assessment.
- Full Text:
- Date Issued: 2020
- Authors: Matomela, Nonjabulo Happy
- Date: 2020
- Subjects: Stream ecology -- South Africa -- Eastern Cape , Freshwater animals -- Ecology -- South Africa -- Eastern Cape , Kat River (South Africa) -- , Lushington River (South Africa) , Elands River (South Africa) , Eyre River (South Africa) , Food chains (Ecology) -- South Africa -- Eastern Cape , Water quality -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/147653 , vital:38658
- Description: Afromontane regions represent some of the highly threatened ecosystems on the planet as they harbour endemic and often relic freshwater fauna. These ecologically sensitive ecosystems have been altered by multiple impacts, including invasion by non-native fishes, replacement of diverse indigenous vegetation with monoculture plantations, agricultural and mining activities, hydrological modifications, and degradation of instream habitats, with potential detrimental effects on aquatic community structures and food web dynamics. The aim of the present study was to compare spatio-temporal patterns of macroinvertebrate and fish communities as well as food web dynamics in three differently impacted headwater tributaries of the Kat River in the Amathole-Winterberg freshwater ecoregion in the Eastern Cape Province of South Africa. The upper Kat River catchment was the ideal model for purposes of the present study as it contains streams with varying degrees of human impact. The streams considered in the present study were (i) the Eyre River which was considered to closely represent near-natural conditions as it is the least impacted stream in this catchment, with the riparian zone dominated by relatively intact and diverse native woody vegetation, (ii) the Elands River whose catchment has been altered by agricultural activities, and (iii) the Lushington River, whose riparian zone has been heavily invaded by black wattle. The three headwater streams were generally distinguished based on the physical-chemical variables. The Elands River was characterised by high conductivity and total dissolved solids (TDS). In addition, the Elands River was more alkaline and relatively warmer than the other two rivers. This suggested the negative influence of agriculture activities on the water quality in the Elands River. In general, the Lushington and Eyre rivers had comparable physical and chemical variables. However, the Lushington River was generally characterised by low streamflow, likely as a consequent of black wattle which is known for altering hydrological regimes of streams .The Eyre River and Lushington River were comparable in terms of macroinvertebrate richness and diversity, whereas the Elands River was characterised by low macroinvertebrate diversity and richness. Redundancy analysis indicated that the macroinvertebrate communities were mostly influenced by seasonality, with land-use accounting for a small but significant difference in community composition. In comparison, the generalised linear mixed-effects models (GLMMs) showed that chubbyhead barb abundance was significantly influenced by land-use patterns. Evaluation of food web dynamics using stable isotope analysis revealed that the food web structure in the three rivers differed substantially as a result of land-use. Specifically, the Eyre River was characterised by less variation in stable isotope values of basal food sources and consequently, the consumer groups had a narrow isotopic breadth. In contrast, the Elands River was characterised by a wide variation in basal food sources and therefore, a wider isotopic breadth for consumers. The Lushington River was spatially variable in terms of basal sources and isotopic breadth for consumers. The study concluded that food webs and trophic interrelationships were a more informative indicator of land-use than community structure was in evaluating the impact of land-use patterns on aquatic communities. In addition, future studies should seek to investigate food webs interrelationships in addition to community structure to infer a more conclusive river assessment.
- Full Text:
- Date Issued: 2020
Zundiqondisise!: investigating voice, visibility and agency in the work of Xhosa women crafters who work in community art centres in the Eastern Cape
- Authors: Tutani, Zodwa
- Date: 2020
- Subjects: Art centers -- Eastern Cape , Community arts projects -- Eastern Cape , Women artists, Black -- Eastern Cape , Ethnic art -- Eastern Cape , Agent (Philosophy) , Art and society -- Eastern Cape , Voice (Philosophy) , Critical discourse analysis , Postcolonialism and the arts , Feminism and art , Curatorship -- Eastern Cape , Art, Xhosa -- Conservation and restoration , Gompo Community Art Centre , Nomzamo Old Age Centre
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/146546 , vital:38535
- Description: A curatorial practice, Zundiqondisise! Reclaiming Our Voice is a twofold study comprised of curatorial practice and a written thesis, both of which are interdependent, examining the significance of space, agency, voice, and visibility in the works of Xhosa women crafters from the Eastern Cape. The study explores ways of reading and displaying indigenous art, as well as the archiving and inserting of these essential but neglected creative works of black women into the discourse of South African contemporary visual arts. This scholarship takes into account the social, cultural, and labour conditions that give rise to the perceived voicelessness in the ‘craft’ work of Xhosa women who work from community art centres. Through collaborating with two groups of women from two Eastern Cape art centres, namely Gompo Community Art Centre in East London and Nomzamo Old Age Centre in Ilitha Township, the study undertakes to locate, highlight and authorise these women’s voices and agency. This undertaking is carried out through a textual inquiry and curated exhibition, two interdependent components of this study, working with black feminist and postcolonial theories that enable me to formulate a critical discourse and practice towards a reflective scholarship on black women’s ‘craft’ work. It is a scholarship whose various chapters and curatorial interventions are tailored to excavate ancient Xhosa wisdom found in folklore and cultural practices of the everyday. This scholarship also provides new understandings that demonstrate and appreciate the fertile and significant though marginalised indigenous ways of creative expressions and knowledge production.
- Full Text:
- Date Issued: 2020
- Authors: Tutani, Zodwa
- Date: 2020
- Subjects: Art centers -- Eastern Cape , Community arts projects -- Eastern Cape , Women artists, Black -- Eastern Cape , Ethnic art -- Eastern Cape , Agent (Philosophy) , Art and society -- Eastern Cape , Voice (Philosophy) , Critical discourse analysis , Postcolonialism and the arts , Feminism and art , Curatorship -- Eastern Cape , Art, Xhosa -- Conservation and restoration , Gompo Community Art Centre , Nomzamo Old Age Centre
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/146546 , vital:38535
- Description: A curatorial practice, Zundiqondisise! Reclaiming Our Voice is a twofold study comprised of curatorial practice and a written thesis, both of which are interdependent, examining the significance of space, agency, voice, and visibility in the works of Xhosa women crafters from the Eastern Cape. The study explores ways of reading and displaying indigenous art, as well as the archiving and inserting of these essential but neglected creative works of black women into the discourse of South African contemporary visual arts. This scholarship takes into account the social, cultural, and labour conditions that give rise to the perceived voicelessness in the ‘craft’ work of Xhosa women who work from community art centres. Through collaborating with two groups of women from two Eastern Cape art centres, namely Gompo Community Art Centre in East London and Nomzamo Old Age Centre in Ilitha Township, the study undertakes to locate, highlight and authorise these women’s voices and agency. This undertaking is carried out through a textual inquiry and curated exhibition, two interdependent components of this study, working with black feminist and postcolonial theories that enable me to formulate a critical discourse and practice towards a reflective scholarship on black women’s ‘craft’ work. It is a scholarship whose various chapters and curatorial interventions are tailored to excavate ancient Xhosa wisdom found in folklore and cultural practices of the everyday. This scholarship also provides new understandings that demonstrate and appreciate the fertile and significant though marginalised indigenous ways of creative expressions and knowledge production.
- Full Text:
- Date Issued: 2020
A multimodal analysis of the representations of gender in contemporary South African children’s picture books produced by Book Dash
- Authors: Heydenrych, Ellen Frances
- Date: 2020
- Subjects: Book Dash (South Africa) , Picture books for children -- South Africa , Sex role in literature , Patriarchy in literature , Children's literature, South African (English) -- 21st century -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/164284 , vital:41106
- Description: In response to a demand for quality children’s picture books written and published by South Africans for local children, Book Dash – a South African non-profit organisation – has devised a publishing model in which they produce high quality children’s picture books in a twelve-hour period. Their aim is to publish books that represent a diverse range of South African children. However, while their objective is to create books that are representative of many races, this representation happens through gendered characters. In this thesis, I explore the representation of gender in Book Dash’s picture books. I use a combination of visual social semiotics, narrative theory, and critical discourse analysis, specifically focusing on the gendered ways in which the characters are represented. My analysis of these books shows how complex it can be to contest regimes of representation that work to fix patriarchal discourses and gender inequality. My findings reveal a paradox in the representation of gender norms in female characters, as some girl child characters are represented in roles that challenge gender norms, while female adult characters are consistently represented as conforming to the patriarchal feminine ideal. There is also a notable lack of father figures in these books. Such portrayals may contribute to the perpetuation of patriarchal discourses and gender inequality, particularly if these books are held up as examples of equality.
- Full Text:
- Date Issued: 2020
- Authors: Heydenrych, Ellen Frances
- Date: 2020
- Subjects: Book Dash (South Africa) , Picture books for children -- South Africa , Sex role in literature , Patriarchy in literature , Children's literature, South African (English) -- 21st century -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/164284 , vital:41106
- Description: In response to a demand for quality children’s picture books written and published by South Africans for local children, Book Dash – a South African non-profit organisation – has devised a publishing model in which they produce high quality children’s picture books in a twelve-hour period. Their aim is to publish books that represent a diverse range of South African children. However, while their objective is to create books that are representative of many races, this representation happens through gendered characters. In this thesis, I explore the representation of gender in Book Dash’s picture books. I use a combination of visual social semiotics, narrative theory, and critical discourse analysis, specifically focusing on the gendered ways in which the characters are represented. My analysis of these books shows how complex it can be to contest regimes of representation that work to fix patriarchal discourses and gender inequality. My findings reveal a paradox in the representation of gender norms in female characters, as some girl child characters are represented in roles that challenge gender norms, while female adult characters are consistently represented as conforming to the patriarchal feminine ideal. There is also a notable lack of father figures in these books. Such portrayals may contribute to the perpetuation of patriarchal discourses and gender inequality, particularly if these books are held up as examples of equality.
- Full Text:
- Date Issued: 2020
The taxonomy of the topminnows (Teleostei: Cyprinodontiformes) (Procatopodidae: Procatopodinae) of southern Africa
- Authors: Van Zeeventer, Ryan Matthew
- Date: 2020
- Subjects: Cyprinodontiformes -- Africa, Southern , Killifishes -- Africa, Southern
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145559 , vital:38449
- Description: Taxonomy is a tool that plays a crucial role in the implementation of effective management assessments, the ability to identify different fish species and their life stages, and create effective conservation strategies. Recent years have seen an increase in the discovery of cryptic species which could have an effect on how we implement conservation strategies, increasing the importance of accurate taxonomic assessments. The southern African topminnows of the genera Micropanchax and Lacustricola (Family Procatopodidae) include several species of egg-laying fishes that live in the marginal areas of rivers and lakes throughout the river systems of southern Africa in separated and connected populations. It was recently discovered that these populations showed subtle differences in their morphology and colouration, which led to the belief that new and cryptic species may be present. Previous studies of the Procatopodidae relied heavily on phylogenetic analyses that drew on morphological traits without reliance on molecular methods of analysis. A few of the taxonomic issues were resolved through these limited studies but ultimately the taxonomic status of the Procatopodidae remained poorly understood. Furthermore, these studies had not been updated in recent years and hence the benefits of new technology had not been brought to bear on the issues. A multi-gene analysis using standard phylogenetic methods and five molecular markers (mitochondrial cytochrome C oxidase (COI), mitochondrial cytochrome b (cytb), mitochondrial 16S ribosomal RNA (16S rRNA), nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial Tyrosine Kinase (X-src) (TyrK)) allowed phylogenetic trees to be made which demonstrated clear relationships within Micropanchax and Lacustricola of southern Africa and the out-groups used in the analysis. The inference trees showed that Micropanchax johnstoni was represented by three clades and was shown to be polyphyletic while Micropanchax hutereaui, which was represented by two clades, and Micropanchax katangae, which was represented by one clade, were monophyletic. The two species of Lacustricola, L. myaposae and L. macrurus showed very close relationships to Micropanchax and it is suggested that these two species be transferred to Micropanchax, leaving Lacustricola to only be found in central Africa.
- Full Text:
- Date Issued: 2020
- Authors: Van Zeeventer, Ryan Matthew
- Date: 2020
- Subjects: Cyprinodontiformes -- Africa, Southern , Killifishes -- Africa, Southern
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145559 , vital:38449
- Description: Taxonomy is a tool that plays a crucial role in the implementation of effective management assessments, the ability to identify different fish species and their life stages, and create effective conservation strategies. Recent years have seen an increase in the discovery of cryptic species which could have an effect on how we implement conservation strategies, increasing the importance of accurate taxonomic assessments. The southern African topminnows of the genera Micropanchax and Lacustricola (Family Procatopodidae) include several species of egg-laying fishes that live in the marginal areas of rivers and lakes throughout the river systems of southern Africa in separated and connected populations. It was recently discovered that these populations showed subtle differences in their morphology and colouration, which led to the belief that new and cryptic species may be present. Previous studies of the Procatopodidae relied heavily on phylogenetic analyses that drew on morphological traits without reliance on molecular methods of analysis. A few of the taxonomic issues were resolved through these limited studies but ultimately the taxonomic status of the Procatopodidae remained poorly understood. Furthermore, these studies had not been updated in recent years and hence the benefits of new technology had not been brought to bear on the issues. A multi-gene analysis using standard phylogenetic methods and five molecular markers (mitochondrial cytochrome C oxidase (COI), mitochondrial cytochrome b (cytb), mitochondrial 16S ribosomal RNA (16S rRNA), nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial Tyrosine Kinase (X-src) (TyrK)) allowed phylogenetic trees to be made which demonstrated clear relationships within Micropanchax and Lacustricola of southern Africa and the out-groups used in the analysis. The inference trees showed that Micropanchax johnstoni was represented by three clades and was shown to be polyphyletic while Micropanchax hutereaui, which was represented by two clades, and Micropanchax katangae, which was represented by one clade, were monophyletic. The two species of Lacustricola, L. myaposae and L. macrurus showed very close relationships to Micropanchax and it is suggested that these two species be transferred to Micropanchax, leaving Lacustricola to only be found in central Africa.
- Full Text:
- Date Issued: 2020
An investigation into the knowledge a Grade one teacher uses to develop the number sense of learners with mathematics learning difficulties
- Authors: Fleming, Kirsty Ann
- Date: 2020
- Subjects: Learning disabled children -- Education -- South Africa , Mathematics -- Study and teching (Elementary) -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/141533 , vital:37983
- Description: Learners in South Africa continue to underperform in the international and national mathematics benchmarking tests. In the primary school, poor performance in mathematics is viewed as an indicator of limited number sense. Since the end of Apartheid, there has been a proliferation of classroom-based research that attempts to explain why learners are underperforming and find solutions to the problem. Research that seeks to explain learner underperformance attributes poor learner performance to social-economic issues, teachers’ poor content and pedagogical knowledge, the complexity of the Language of Learning and Teaching, and insufficient support for learners with Mathematics Learning Difficulties (MLD). With regards to the latter, research suggests that Foundation Phase teachers are not equipped to assist learners with MLD develop their number sense. This qualitative case study aims to investigate the knowledge that an expert Foundation Phase teacher draws on, in the process of teaching, to assist learners with MLD develop their number sense. Data generated from observations and interviews with a Grade One teacher was analysed using Rowland, Turner and Thwaites’ (2013) Knowledge Quartet. The study found that the participant Grade One teacher employed all four categories of the Knowledge Quartet when developing her learners’ number sense. In particular, she placed strong emphasis on vocabulary development as a means of circumnavigating MLD when developing number sense in a Grade One mathematics lesson. She demonstrated knowledge of: the importance of vocabulary in learning mathematics; how to develop the learners’ understanding of mathematics vocabulary (and concepts); and how to adapt her approach to support the number sense development of learners with MLD. This research has value for teacher education programmes, both pre- and in-service, as it highlights the knowledge that a Grade One teacher draws on as she develops the number sense of all her learners, including those with MLD.
- Full Text:
- Date Issued: 2020
- Authors: Fleming, Kirsty Ann
- Date: 2020
- Subjects: Learning disabled children -- Education -- South Africa , Mathematics -- Study and teching (Elementary) -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/141533 , vital:37983
- Description: Learners in South Africa continue to underperform in the international and national mathematics benchmarking tests. In the primary school, poor performance in mathematics is viewed as an indicator of limited number sense. Since the end of Apartheid, there has been a proliferation of classroom-based research that attempts to explain why learners are underperforming and find solutions to the problem. Research that seeks to explain learner underperformance attributes poor learner performance to social-economic issues, teachers’ poor content and pedagogical knowledge, the complexity of the Language of Learning and Teaching, and insufficient support for learners with Mathematics Learning Difficulties (MLD). With regards to the latter, research suggests that Foundation Phase teachers are not equipped to assist learners with MLD develop their number sense. This qualitative case study aims to investigate the knowledge that an expert Foundation Phase teacher draws on, in the process of teaching, to assist learners with MLD develop their number sense. Data generated from observations and interviews with a Grade One teacher was analysed using Rowland, Turner and Thwaites’ (2013) Knowledge Quartet. The study found that the participant Grade One teacher employed all four categories of the Knowledge Quartet when developing her learners’ number sense. In particular, she placed strong emphasis on vocabulary development as a means of circumnavigating MLD when developing number sense in a Grade One mathematics lesson. She demonstrated knowledge of: the importance of vocabulary in learning mathematics; how to develop the learners’ understanding of mathematics vocabulary (and concepts); and how to adapt her approach to support the number sense development of learners with MLD. This research has value for teacher education programmes, both pre- and in-service, as it highlights the knowledge that a Grade One teacher draws on as she develops the number sense of all her learners, including those with MLD.
- Full Text:
- Date Issued: 2020
A social-ecological investigation into urban domestic gardens and avifauna in medium-sized towns of the Eastern Cape, South Africa
- Authors: Tricam, Shayla
- Date: 2020
- Subjects: Urban ecology (Biology) -- South Africa , Biotic communites -- South Africa , Gardens -- South Africa -- Managemenet , Birds – Ecology – South Africa , Gardening to attract birds -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145314 , vital:38427
- Description: Urban domestic gardens are an often overlooked component of urban green infrastructure, despite their potential to contribute to the preservation of urban biodiversity. As opposed to public greenspaces, private gardens are individually owned and managed, thus act as social-ecological systems, where the cumulative actions of urban residents can scale up to influence ecological patterns and processes on a larger scale. The diversity of fauna and flora within urban gardens provide a range of ecosystem goods and services, as well as less tangible benefits in the form of recreation, education and culture. However, little is known about the contribution of urban domestic gardens to urban biodiversity and its potential conservation value in South Africa. This study investigated urban domestic gardens along a socio-economic gradient in two medium-sized towns, Grahamstown and Port Alfred in the Eastern Cape, South Africa. This study found distinct differences among urban resident garden management practices as well as the avifauna which were seen within the gardens across the socio-economic gradient. The Garden Management Intensity index was higher within affluent households compared to other socio-economic levels, with subsequent management scores not differing statistically along the gradient. While there was variation within garden management practices, as well as the number of residents who participated in supplementary bird feeding, little variation was seen in the activities which were enjoyed by the residents, indicating numerous benefits the garden environment provides for all urban residents. The bird community composition along the socio-economic gradient displayed patterns directly reflecting the “luxury effect”, where households with a higher socio-economic status had harbour gardens with greater levels of biodiversity. This study showed that affluent gardens displayed far greater diversity, richness and abundance of urban birds. Multivariate analyses confirmed the patterns by highlighting a distinct bird community in the affluent zone, compared to other two socio-economic zones, which housed a second bird community. Furthermore, the main driver of the bird community composition was dominated by vegetation complexity, most notably tree cover within the gardens. Therefore, this study highlighted that patterns of ecological inequality are highly evident in medium-sized towns in South Africa, where older, affluent suburbs households display greater diversity and abundance of birdlife, compared to subsequent socio-economic zones within the study. Prioritisation with regards to the benefits a garden environment brings to urban residents in terms of a connection to nature, access to urban greenery, and relationship to urban wildlife is vital and should be promoted and planned for across all socio-economic zones.
- Full Text:
- Date Issued: 2020
- Authors: Tricam, Shayla
- Date: 2020
- Subjects: Urban ecology (Biology) -- South Africa , Biotic communites -- South Africa , Gardens -- South Africa -- Managemenet , Birds – Ecology – South Africa , Gardening to attract birds -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145314 , vital:38427
- Description: Urban domestic gardens are an often overlooked component of urban green infrastructure, despite their potential to contribute to the preservation of urban biodiversity. As opposed to public greenspaces, private gardens are individually owned and managed, thus act as social-ecological systems, where the cumulative actions of urban residents can scale up to influence ecological patterns and processes on a larger scale. The diversity of fauna and flora within urban gardens provide a range of ecosystem goods and services, as well as less tangible benefits in the form of recreation, education and culture. However, little is known about the contribution of urban domestic gardens to urban biodiversity and its potential conservation value in South Africa. This study investigated urban domestic gardens along a socio-economic gradient in two medium-sized towns, Grahamstown and Port Alfred in the Eastern Cape, South Africa. This study found distinct differences among urban resident garden management practices as well as the avifauna which were seen within the gardens across the socio-economic gradient. The Garden Management Intensity index was higher within affluent households compared to other socio-economic levels, with subsequent management scores not differing statistically along the gradient. While there was variation within garden management practices, as well as the number of residents who participated in supplementary bird feeding, little variation was seen in the activities which were enjoyed by the residents, indicating numerous benefits the garden environment provides for all urban residents. The bird community composition along the socio-economic gradient displayed patterns directly reflecting the “luxury effect”, where households with a higher socio-economic status had harbour gardens with greater levels of biodiversity. This study showed that affluent gardens displayed far greater diversity, richness and abundance of urban birds. Multivariate analyses confirmed the patterns by highlighting a distinct bird community in the affluent zone, compared to other two socio-economic zones, which housed a second bird community. Furthermore, the main driver of the bird community composition was dominated by vegetation complexity, most notably tree cover within the gardens. Therefore, this study highlighted that patterns of ecological inequality are highly evident in medium-sized towns in South Africa, where older, affluent suburbs households display greater diversity and abundance of birdlife, compared to subsequent socio-economic zones within the study. Prioritisation with regards to the benefits a garden environment brings to urban residents in terms of a connection to nature, access to urban greenery, and relationship to urban wildlife is vital and should be promoted and planned for across all socio-economic zones.
- Full Text:
- Date Issued: 2020
Activity of diverse chalcones against several targets: statistical analysis of a high-throughput virtual screen of a custom chalcone library
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
Seasonal trends of rainfall intensity, ground cover and sediment dynamics in the Little Pot River and Gqukunqa River catchments, South Africa
- Authors: Herd-Hoare, Sean
- Date: 2020
- Subjects: Land degradation -- Control -- South Africa -- Eastern Cape , Vegetation mapping -- South Africa -- Eastern Cape , Rain and rainfall -- South Africa -- Eastern Cape , Gqukunqa River catchment (South Africa) , Little Pot River catchment (South Africa) , Tsitsa River catchment (South Africa)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146288 , vital:38512
- Description: Natural rangelands provide a variety of ecosystem services including livestock production which occurs on land under freehold land tenure and on land under communal tenure. There is an ongoing debate around the extent to which land degradation is occurring on these rangelands under different land management and land tenure systems and what the main degradation drivers are. Over-grazing, rainfall and soil type are key drivers of rangeland dynamics and the resultant sediment yield in the river systems, however, over-grazing is an outcome of land management while rainfall and soil type are natural drivers. This study explores the relationship between rainfall and daily sediment flux as well as the seasonal trends of vegetation cover and the study is part of a greater research effort called the Tsitsa Project which is based in the Tsitsa River catchment (near Maclear, Eastern Cape, South Africa). The Tsitsa Project aims at developing and managing both land and water in a sustainable way by improving the land, water and lives of people living in the Tsitsa River catchment. The restoration efforts of the Tstisa Project will aid in extending the lifespan of both the proposed dams on the Tsitsa River. The Tsitsa River catchment is characterised by grasslands, steep topography, highly erodible soils with many large gullies present and a very high sediment yield in the Tsitsa River which allowed for the exploration of some of the system drivers of sediment yield in this catchment. The study involved two sub-catchments of the Upper Tsitsa River catchment of different land management strategies: one dominated by commercial livestock farms (Little Pot River catchment) and one dominated by communal rangelands (Gqukunqa River catchment). The aim of this study was to determine the seasonal trends of rainfall intensity, ground cover and sediment dynamics in the Little Pot River and Gqukunqa River catchments. The purpose of the findings was to improve management strategies in degraded areas and catchments. In order to achieve this aim a variety of field and desktop methods were used. Field methods involved measuring variables including: vegetation biomass, vegetation cover, soil surface hardness, biocrust cover and slope angle for a range of Normalized Difference Vegetation Index (NDVI) values from the Sentinel-2A sensor. The study assessed the system response of the field variables in both catchments over one rainfall season (2018-2019). Desktop methods included various NDVI analyses as well as analyses of trends and relationships between vegetation dynamics, rainfall and sediment. The relationship between erosive rainfall events, daily rainfall, antecedent rainfall and daily sediment flux was explored over the time period of January 2016 to January 2019 and October 2015 to January 2019 for the Little Pot River catchment and the Gqukunqa River catchment respectively. NDVI was explored as a proxy for vegetation cover to extrapolate across the catchments and monitoring period. NDVI was found to have a weak positive relationship with vegetation cover and biomass (R2 values ranged from 0,04 to 0,525). Mean monthly catchment NDVI values, biomass and vegetation cover increased throughout the wet season of 2018-2019 in both catchments. Mean monthly NDVI values increased from 0,26 to 0,55 in the Little Pot River catchment and from 0,29 to 0,53 in the Gqukunqa River catchment over the course of the 2018-2019 wet season. NDVI, biomass and vegetation cover was found to be higher on south-facing slopes than north-facing slopes in both catchments for the majority of the wet season. The Gqukunqa River has significantly higher daily sediment fluxes than the Little Pot River despite similar NDVI and rainfall intensities which is owed to the dispersive soils in the Gqukunqa River catchment. Soil surface hardness results were inconclusive due to rainfall before or during every field trip which changed the properties of the soil. The largest erosive rainfall, daily rainfall and daily sediment events occurred from January to March each wet season in both catchments. Rainfall intensity and sediment fluxes were found to have a weak relationship, however, there was a stronger relationship found between antecedent rainfall and sediment flux. The larger daily sediment fluxes in each catchment often did not result from an erosive rainfall event on the same day but rather from multiple days of rainfall which can result in saturated soils and runoff leading to surface and sub-surface erosion. The possibility of sub-surface erosion via chemical processes contributing to the larger sediment events was also explored to explain the stronger relationship between antecedent rainfall and daily sediment flux.
- Full Text:
- Date Issued: 2020
- Authors: Herd-Hoare, Sean
- Date: 2020
- Subjects: Land degradation -- Control -- South Africa -- Eastern Cape , Vegetation mapping -- South Africa -- Eastern Cape , Rain and rainfall -- South Africa -- Eastern Cape , Gqukunqa River catchment (South Africa) , Little Pot River catchment (South Africa) , Tsitsa River catchment (South Africa)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146288 , vital:38512
- Description: Natural rangelands provide a variety of ecosystem services including livestock production which occurs on land under freehold land tenure and on land under communal tenure. There is an ongoing debate around the extent to which land degradation is occurring on these rangelands under different land management and land tenure systems and what the main degradation drivers are. Over-grazing, rainfall and soil type are key drivers of rangeland dynamics and the resultant sediment yield in the river systems, however, over-grazing is an outcome of land management while rainfall and soil type are natural drivers. This study explores the relationship between rainfall and daily sediment flux as well as the seasonal trends of vegetation cover and the study is part of a greater research effort called the Tsitsa Project which is based in the Tsitsa River catchment (near Maclear, Eastern Cape, South Africa). The Tsitsa Project aims at developing and managing both land and water in a sustainable way by improving the land, water and lives of people living in the Tsitsa River catchment. The restoration efforts of the Tstisa Project will aid in extending the lifespan of both the proposed dams on the Tsitsa River. The Tsitsa River catchment is characterised by grasslands, steep topography, highly erodible soils with many large gullies present and a very high sediment yield in the Tsitsa River which allowed for the exploration of some of the system drivers of sediment yield in this catchment. The study involved two sub-catchments of the Upper Tsitsa River catchment of different land management strategies: one dominated by commercial livestock farms (Little Pot River catchment) and one dominated by communal rangelands (Gqukunqa River catchment). The aim of this study was to determine the seasonal trends of rainfall intensity, ground cover and sediment dynamics in the Little Pot River and Gqukunqa River catchments. The purpose of the findings was to improve management strategies in degraded areas and catchments. In order to achieve this aim a variety of field and desktop methods were used. Field methods involved measuring variables including: vegetation biomass, vegetation cover, soil surface hardness, biocrust cover and slope angle for a range of Normalized Difference Vegetation Index (NDVI) values from the Sentinel-2A sensor. The study assessed the system response of the field variables in both catchments over one rainfall season (2018-2019). Desktop methods included various NDVI analyses as well as analyses of trends and relationships between vegetation dynamics, rainfall and sediment. The relationship between erosive rainfall events, daily rainfall, antecedent rainfall and daily sediment flux was explored over the time period of January 2016 to January 2019 and October 2015 to January 2019 for the Little Pot River catchment and the Gqukunqa River catchment respectively. NDVI was explored as a proxy for vegetation cover to extrapolate across the catchments and monitoring period. NDVI was found to have a weak positive relationship with vegetation cover and biomass (R2 values ranged from 0,04 to 0,525). Mean monthly catchment NDVI values, biomass and vegetation cover increased throughout the wet season of 2018-2019 in both catchments. Mean monthly NDVI values increased from 0,26 to 0,55 in the Little Pot River catchment and from 0,29 to 0,53 in the Gqukunqa River catchment over the course of the 2018-2019 wet season. NDVI, biomass and vegetation cover was found to be higher on south-facing slopes than north-facing slopes in both catchments for the majority of the wet season. The Gqukunqa River has significantly higher daily sediment fluxes than the Little Pot River despite similar NDVI and rainfall intensities which is owed to the dispersive soils in the Gqukunqa River catchment. Soil surface hardness results were inconclusive due to rainfall before or during every field trip which changed the properties of the soil. The largest erosive rainfall, daily rainfall and daily sediment events occurred from January to March each wet season in both catchments. Rainfall intensity and sediment fluxes were found to have a weak relationship, however, there was a stronger relationship found between antecedent rainfall and sediment flux. The larger daily sediment fluxes in each catchment often did not result from an erosive rainfall event on the same day but rather from multiple days of rainfall which can result in saturated soils and runoff leading to surface and sub-surface erosion. The possibility of sub-surface erosion via chemical processes contributing to the larger sediment events was also explored to explain the stronger relationship between antecedent rainfall and daily sediment flux.
- Full Text:
- Date Issued: 2020
An ideological analysis of the construction of the young female action hero as feminist hero in The Hunger Games film franchise
- Authors: Mathurine, Kim Elizabeth
- Date: 2020
- Subjects: Everdeen, Katniss (Fictitious character) , Women superheroes in motion pictures , Hunger Games films , Feminist film criticism , Feminism and motion pictures , Women in motion pictures
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/142900 , vital:38174
- Description: Young female action heroes have recently stepped into the limelight as commercial celebrations of Girl Power in Hollywood action-adventure films. Feminist films studies however have shown that these independent, tough female heroes claimed as feminist, are still constrained in various ways through stereotypical gender roles within the action-adventure genre. This thesis examines these claims through the ideological analysis of the young female action hero Katniss in The Hunger Games film franchise. Building on existing research on female action heroes, the research asks: ‘to what degree can the claim of Katniss as boundary-breaking, feminist hero be validated’? This question is addressed through a textual analysis of the four films of The Hunger Games film franchise, employing conventions of action-adventure genre, narrative analysis, mise-en-scène and cinematography to unmask the characterisation of the female hero. The discussion of the findings, utilising the themes of Love, Violence and Power, reveal both progressive and regressive elements present in the characterisation of Katniss. The findings indicate that while female action heroes can be celebrated for displaying progressive moments of liberated action, they remain constrained within dominant heteronormative gender roles in commercial Hollywood films, undergoing various acts of transformation and recuperation as a means of containing the threat of their transgressive behaviour.
- Full Text:
- Date Issued: 2020
- Authors: Mathurine, Kim Elizabeth
- Date: 2020
- Subjects: Everdeen, Katniss (Fictitious character) , Women superheroes in motion pictures , Hunger Games films , Feminist film criticism , Feminism and motion pictures , Women in motion pictures
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/142900 , vital:38174
- Description: Young female action heroes have recently stepped into the limelight as commercial celebrations of Girl Power in Hollywood action-adventure films. Feminist films studies however have shown that these independent, tough female heroes claimed as feminist, are still constrained in various ways through stereotypical gender roles within the action-adventure genre. This thesis examines these claims through the ideological analysis of the young female action hero Katniss in The Hunger Games film franchise. Building on existing research on female action heroes, the research asks: ‘to what degree can the claim of Katniss as boundary-breaking, feminist hero be validated’? This question is addressed through a textual analysis of the four films of The Hunger Games film franchise, employing conventions of action-adventure genre, narrative analysis, mise-en-scène and cinematography to unmask the characterisation of the female hero. The discussion of the findings, utilising the themes of Love, Violence and Power, reveal both progressive and regressive elements present in the characterisation of Katniss. The findings indicate that while female action heroes can be celebrated for displaying progressive moments of liberated action, they remain constrained within dominant heteronormative gender roles in commercial Hollywood films, undergoing various acts of transformation and recuperation as a means of containing the threat of their transgressive behaviour.
- Full Text:
- Date Issued: 2020
History on trial: a study of the Salem commonage land claim
- Authors: Bezuidenhout, GJW
- Date: 2020
- Subjects: South Africa. Restitution of Land Rights Act, 1994 , Salem (South Africa) -- History , Land tenure -- Law and legilstion -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146647 , vital:38545
- Description: This thesis critically examines the Salem commonage claim, a dispute that has shaken the hamlet of Salem to its core. On ground level it has caused racialized fault lines to reopen, while suspicion and distrust has also grown between the black Africans of the area as well. On a national level, the Constitutional Court judgement has potentially set a precedent with regards to its jurisprudential approach in determining the validity of land claims in South Africa. Its interpretation of the law was determined by the restorative justice jurisprudence enshrined in the Restitution of Land Rights Act 22 of 1994 (the Act). It based its own understanding of the history of the commonage on this jurisprudence. In a bold step towards realising the aims and purposes of the Act, the Constitutional Court found that both the black African claimants as well as the white landowners have equal rights to the land. One of the reasons why the decision of the Constitutional Court is ground-breaking is that the dispute involves a former commonage – land used for common purpose. The Constitutional Court emphasised that the Act was an “extraordinary piece of legislation” and had to be interpreted in such a way so as to address the injustices of the past. This included provisions of the Act which dealt with how oral testimonies from claimants would be dealt with. Another interesting feature was the heavy reliance by all parties on expert witnesses in the persons of eminent historians, Professors Martin Legassick and Herman Giliomee. This case gave much-needed clarification as to what the appropriate role of an expert historian witness may be in a land claim. The success or failure of land claims often depend on the weight of the evidence supplied by the expert historian witness. But the historian must also take cognisance of the fact that the evidence s/he gives is appropriate according to the scope of law. This case also dismisses the assumption that colonial instruments of land assignation are beyond reproach. These instruments which grant rights to land may also be scrutinised in a court of law, just like when oral testimony is tested for its credibility. This is important to note, especially when balancing land rights of the claimants against those of the landowners. This thesis agrees with the decision taken by the Constitutional Court in this instance. However, it also cautions that such softly-softly approaches may appear as a suitable compromise on paper, but the feeling on the ground may not be as receptive to reconciliation as what the courts would have hoped for. To the jurist, this judgement accurately encapsulates the purpose and aims of the Act. However, such a judgement may not seem satisfactory to the people of Salem. The decisions of the Salem commonage case are sure to inform the discourse of land claims in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Bezuidenhout, GJW
- Date: 2020
- Subjects: South Africa. Restitution of Land Rights Act, 1994 , Salem (South Africa) -- History , Land tenure -- Law and legilstion -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146647 , vital:38545
- Description: This thesis critically examines the Salem commonage claim, a dispute that has shaken the hamlet of Salem to its core. On ground level it has caused racialized fault lines to reopen, while suspicion and distrust has also grown between the black Africans of the area as well. On a national level, the Constitutional Court judgement has potentially set a precedent with regards to its jurisprudential approach in determining the validity of land claims in South Africa. Its interpretation of the law was determined by the restorative justice jurisprudence enshrined in the Restitution of Land Rights Act 22 of 1994 (the Act). It based its own understanding of the history of the commonage on this jurisprudence. In a bold step towards realising the aims and purposes of the Act, the Constitutional Court found that both the black African claimants as well as the white landowners have equal rights to the land. One of the reasons why the decision of the Constitutional Court is ground-breaking is that the dispute involves a former commonage – land used for common purpose. The Constitutional Court emphasised that the Act was an “extraordinary piece of legislation” and had to be interpreted in such a way so as to address the injustices of the past. This included provisions of the Act which dealt with how oral testimonies from claimants would be dealt with. Another interesting feature was the heavy reliance by all parties on expert witnesses in the persons of eminent historians, Professors Martin Legassick and Herman Giliomee. This case gave much-needed clarification as to what the appropriate role of an expert historian witness may be in a land claim. The success or failure of land claims often depend on the weight of the evidence supplied by the expert historian witness. But the historian must also take cognisance of the fact that the evidence s/he gives is appropriate according to the scope of law. This case also dismisses the assumption that colonial instruments of land assignation are beyond reproach. These instruments which grant rights to land may also be scrutinised in a court of law, just like when oral testimony is tested for its credibility. This is important to note, especially when balancing land rights of the claimants against those of the landowners. This thesis agrees with the decision taken by the Constitutional Court in this instance. However, it also cautions that such softly-softly approaches may appear as a suitable compromise on paper, but the feeling on the ground may not be as receptive to reconciliation as what the courts would have hoped for. To the jurist, this judgement accurately encapsulates the purpose and aims of the Act. However, such a judgement may not seem satisfactory to the people of Salem. The decisions of the Salem commonage case are sure to inform the discourse of land claims in South Africa.
- Full Text:
- Date Issued: 2020
Design, formulation and evalauation of liposomes co-loaded with human serum Albumin and Rifampicin
- Authors: Bapolisi, Alain Murhimalika
- Date: 2020
- Subjects: Liposomes , Serum albumin , Rifampin , Mycobacterium tuberculosis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/161780 , vital:40670
- Description: Tuberculosis (TB) is a devastating infectious disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious agent. The high morbidity and mortality rates of TB are partly due to factors such as the lengthy regimen (of 6–24 months), the development of drug resistance, and the pathogen location within the macrophages. These, with poor physiochemical properties of existing drugs hamper the effectiveness of the treatment despite the existence of potent antibiotics such as Rifampicin (Rif). Hydrophobicity plagues many drugs, including Rif, which are then particularly affected due to inherently poor intracellular availability. Novel drug delivery approaches are therefore needed in order to optimize the cytotoxic potential of said antitubercular drugs. To improve the bioavailability of hydrophobic drugs, numerous delivery strategies have been developed. Amongst these, the coordination of cytotoxic drugs to therapeutic proteins have shown some success for improved efficacy in the management of illnesses including infectious diseases. Of therapeutic proteins, Human Serum Albumin (HSA) is an attractive drug carrier with interestingbenefits such as low immunogenicity, antioxidant properties and improving cellular uptake ofdrugs through HSA-specific binding sites which are expressed on most cells including macrophages, where M. tuberculosis often resides. Hence, combination of Rif to HSA (Rif-HSA)seems a promising approach for improved intracellular delivery of Rif. However, the in vivo stability of colloidal protein-based therapeutics is mostly challenging and an effective vehicle is needed to control the biological fate of such conjugates.Liposomes seem to be appropriate carriers for the Rif-HSA complex due to their reputable applicability for encapsulating diverse materials (i.e., hydrophobic and hydrophilic compounds or small and complex molecules) and preventing chemical and biological degradation of the cargo. Therefore, the main objective of this study was to simultaneously encapsulate Rif and HSA in liposomes, which, to the best of our knowledge, has not been done before. The dual liposomes (Rif-HSA-lip) were made by a modified “Reverse Phase Evaporation” method (REV), following a Design of Experiments (DOE) approach to determine which factors impact the formulation. In addition, liposomes were made from crude soybean lecithin (CSL), rather than expensive and highly purified lipids. The liposomes were fully characterised, and the encapsulation efficiency (î) was monitored using high-performance liquid chromatography (HPLC). The results were correlated with factors such as organic and aqueous phase composition, as well as the in vitro release profile of Rif. Transmission electron microscopy (TEM) results confirmed the formation of spherical dual liposomes nanoparticles of roughly 200 nm. Dynamic light scattering (DLS) and Zeta potential measurements showed a negative charge (<–45 mV) and with satisfactory polydispersity (PDI<0.5). HSA dramatically improved the aqueous solubility of Rif (from1.9 mg/ml in water to around 4.3 mg/ml in HSA 10% solution) mainly due to Rif-HSA hydrophobic interactions. This resulted in a good î of almost 60% for Rif, despite the presence of bulky HSA in the lipid bilayer. These details were confirmed using proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). Furthermore, energy dispersive X-ray (EDX) and DLS data suggested the presence of HSA poking out on the surface of liposomes, which is encouraging for potential targeted delivery in the future. The in vitro release studies also depicted a substantial improvement in the diffusion of Rif in dual liposomes versus free Rif, from 65% after 12 hours for free Rif to 95% after only 5 hours for Rif- HSA-lip. Finally, stability studies conducted over 30 days at room temperature, showed that the freeze-dried formulations of Rif-HSA-lip exhibited good shelf stability over liposomes with no HSA. This study represents an illustrative example of co-loading of antibiotics and proteins into liposomes, which could encourage further development of novel nanoparticulate tools for the effective management of both drug-susceptible and -resistant infectious diseases such as TB.
- Full Text:
- Date Issued: 2020
- Authors: Bapolisi, Alain Murhimalika
- Date: 2020
- Subjects: Liposomes , Serum albumin , Rifampin , Mycobacterium tuberculosis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/161780 , vital:40670
- Description: Tuberculosis (TB) is a devastating infectious disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious agent. The high morbidity and mortality rates of TB are partly due to factors such as the lengthy regimen (of 6–24 months), the development of drug resistance, and the pathogen location within the macrophages. These, with poor physiochemical properties of existing drugs hamper the effectiveness of the treatment despite the existence of potent antibiotics such as Rifampicin (Rif). Hydrophobicity plagues many drugs, including Rif, which are then particularly affected due to inherently poor intracellular availability. Novel drug delivery approaches are therefore needed in order to optimize the cytotoxic potential of said antitubercular drugs. To improve the bioavailability of hydrophobic drugs, numerous delivery strategies have been developed. Amongst these, the coordination of cytotoxic drugs to therapeutic proteins have shown some success for improved efficacy in the management of illnesses including infectious diseases. Of therapeutic proteins, Human Serum Albumin (HSA) is an attractive drug carrier with interestingbenefits such as low immunogenicity, antioxidant properties and improving cellular uptake ofdrugs through HSA-specific binding sites which are expressed on most cells including macrophages, where M. tuberculosis often resides. Hence, combination of Rif to HSA (Rif-HSA)seems a promising approach for improved intracellular delivery of Rif. However, the in vivo stability of colloidal protein-based therapeutics is mostly challenging and an effective vehicle is needed to control the biological fate of such conjugates.Liposomes seem to be appropriate carriers for the Rif-HSA complex due to their reputable applicability for encapsulating diverse materials (i.e., hydrophobic and hydrophilic compounds or small and complex molecules) and preventing chemical and biological degradation of the cargo. Therefore, the main objective of this study was to simultaneously encapsulate Rif and HSA in liposomes, which, to the best of our knowledge, has not been done before. The dual liposomes (Rif-HSA-lip) were made by a modified “Reverse Phase Evaporation” method (REV), following a Design of Experiments (DOE) approach to determine which factors impact the formulation. In addition, liposomes were made from crude soybean lecithin (CSL), rather than expensive and highly purified lipids. The liposomes were fully characterised, and the encapsulation efficiency (î) was monitored using high-performance liquid chromatography (HPLC). The results were correlated with factors such as organic and aqueous phase composition, as well as the in vitro release profile of Rif. Transmission electron microscopy (TEM) results confirmed the formation of spherical dual liposomes nanoparticles of roughly 200 nm. Dynamic light scattering (DLS) and Zeta potential measurements showed a negative charge (<–45 mV) and with satisfactory polydispersity (PDI<0.5). HSA dramatically improved the aqueous solubility of Rif (from1.9 mg/ml in water to around 4.3 mg/ml in HSA 10% solution) mainly due to Rif-HSA hydrophobic interactions. This resulted in a good î of almost 60% for Rif, despite the presence of bulky HSA in the lipid bilayer. These details were confirmed using proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). Furthermore, energy dispersive X-ray (EDX) and DLS data suggested the presence of HSA poking out on the surface of liposomes, which is encouraging for potential targeted delivery in the future. The in vitro release studies also depicted a substantial improvement in the diffusion of Rif in dual liposomes versus free Rif, from 65% after 12 hours for free Rif to 95% after only 5 hours for Rif- HSA-lip. Finally, stability studies conducted over 30 days at room temperature, showed that the freeze-dried formulations of Rif-HSA-lip exhibited good shelf stability over liposomes with no HSA. This study represents an illustrative example of co-loading of antibiotics and proteins into liposomes, which could encourage further development of novel nanoparticulate tools for the effective management of both drug-susceptible and -resistant infectious diseases such as TB.
- Full Text:
- Date Issued: 2020
A 150 MHz all sky survey with the Precision Array to Probe the Epoch of Reionization
- Authors: Chege, James Kariuki
- Date: 2020
- Subjects: Epoch of reionization -- Research , Astronomy -- Observations , Radio interferometers
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117733 , vital:34556
- Description: The Precision Array to Probe the Epoch of Reionization (PAPER) was built to measure the redshifted 21 cm line of hydrogen from cosmic reionization. Such low frequency observations promise to be the best means of understanding the cosmic dawn; when the first galaxies in the universe formed, and also the Epoch of Reionization; when the intergalactic medium changed from neutral to ionized. The major challenges to these observations is the presence of astrophysical foregrounds that are much brighter than the cosmological signal. Here, I present an all-sky survey at 150 MHz obtained from the analysis of 300 hours of PAPER observations. Particular focus is given to the calibration and imaging techniques that need to deal with the wide field of view of a non-tracking instrument. The survey covers ~ 7000 square degrees of the southern sky. From a sky area of 4400 square degrees out of the total survey area, I extract a catalogue of sources brighter than 4 Jy whose accuracy was tested against the published GLEAM catalogue, leading to a fractional difference rms better than 20%. The catalogue provides an all-sky accurate model of the extragalactic foreground to be used for the calibration of future Epoch of Reionization observations and to be subtracted from the PAPER observations themselves in order to mitigate the foreground contamination.
- Full Text:
- Date Issued: 2020
- Authors: Chege, James Kariuki
- Date: 2020
- Subjects: Epoch of reionization -- Research , Astronomy -- Observations , Radio interferometers
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117733 , vital:34556
- Description: The Precision Array to Probe the Epoch of Reionization (PAPER) was built to measure the redshifted 21 cm line of hydrogen from cosmic reionization. Such low frequency observations promise to be the best means of understanding the cosmic dawn; when the first galaxies in the universe formed, and also the Epoch of Reionization; when the intergalactic medium changed from neutral to ionized. The major challenges to these observations is the presence of astrophysical foregrounds that are much brighter than the cosmological signal. Here, I present an all-sky survey at 150 MHz obtained from the analysis of 300 hours of PAPER observations. Particular focus is given to the calibration and imaging techniques that need to deal with the wide field of view of a non-tracking instrument. The survey covers ~ 7000 square degrees of the southern sky. From a sky area of 4400 square degrees out of the total survey area, I extract a catalogue of sources brighter than 4 Jy whose accuracy was tested against the published GLEAM catalogue, leading to a fractional difference rms better than 20%. The catalogue provides an all-sky accurate model of the extragalactic foreground to be used for the calibration of future Epoch of Reionization observations and to be subtracted from the PAPER observations themselves in order to mitigate the foreground contamination.
- Full Text:
- Date Issued: 2020
Petits récits: creative perspectives of Chinese encounters in Zambia
- Authors: Mwaba, Stary
- Date: 2020
- Subjects: Personal narratives , Lyotard, Jean-François, 1924-1998 , Art and society -- Zambia , Social practice (Art) -- Zambia , Art and globalization -- Zambia , China -- Relations -- Zambia , Storytelling in art , Colonization in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/146355 , vital:38518
- Description: This mini-thesis, which supports my MFA exhibition Black Mountain, articulates on-the- ground creative perspectives of the Zambia-China discourse, through the representation of little narratives - les petits récits - connected to personal experiences. Through my creative production as an artist, I respond to perceptions of the Chinese presence in Africa. I utilize historical and contemporary personal narratives to complicate existing perceptions of Chinese presence in my home context of Zambia. “Petit récits”, or “little narratives”, in Francois Lyotard’s term, refers to personal stories of individuals that subvert dominant master-narratives and their legitimization in social-cultural structure. In the case of China’s presence in Zambia, I refer to the dichotomized narratives in the media as metanarratives which pay little attention to the people on the ground and propose the approach of “little narratives” to foreground the lived experiences of Zambians who have individual encounters with Chinese in various social spaces. By employing the narratives of my family members through installations, paintings, and drawings, I intervene in a broader China-Africa discourse that is often driven by economics and politics, and I attach importance to the little narratives. In my thesis I divide my material into three chapters; each chapter grows out of an encounter with the presence of China (and Chinese people) in Zambia in relation to the very personal narratives of family members - Zoë my daughter, my grandma, and Ngolo my cousin. The first chapter focuses on my work Chinese Cabbage as my entry point to this topic, which is based on a school experiment I did with my daughter Zoë. In this chapter I also discuss the current discourses around China’s presence. Chapter two revisits the Zambian-Chinese historical encounters in memory of my grandma’s insaka stories about the construction of TAZARA Railway, and thus my works discussed in this chapter attach importance to the individual engagements from a historical perspective. Chapter three discusses in particular the controversial issues around Black Mountain and the works inspired by my cousin Ngolo’s stories of mining in Black Mountain and dealing with the Chinese traders.
- Full Text:
- Date Issued: 2020
- Authors: Mwaba, Stary
- Date: 2020
- Subjects: Personal narratives , Lyotard, Jean-François, 1924-1998 , Art and society -- Zambia , Social practice (Art) -- Zambia , Art and globalization -- Zambia , China -- Relations -- Zambia , Storytelling in art , Colonization in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/146355 , vital:38518
- Description: This mini-thesis, which supports my MFA exhibition Black Mountain, articulates on-the- ground creative perspectives of the Zambia-China discourse, through the representation of little narratives - les petits récits - connected to personal experiences. Through my creative production as an artist, I respond to perceptions of the Chinese presence in Africa. I utilize historical and contemporary personal narratives to complicate existing perceptions of Chinese presence in my home context of Zambia. “Petit récits”, or “little narratives”, in Francois Lyotard’s term, refers to personal stories of individuals that subvert dominant master-narratives and their legitimization in social-cultural structure. In the case of China’s presence in Zambia, I refer to the dichotomized narratives in the media as metanarratives which pay little attention to the people on the ground and propose the approach of “little narratives” to foreground the lived experiences of Zambians who have individual encounters with Chinese in various social spaces. By employing the narratives of my family members through installations, paintings, and drawings, I intervene in a broader China-Africa discourse that is often driven by economics and politics, and I attach importance to the little narratives. In my thesis I divide my material into three chapters; each chapter grows out of an encounter with the presence of China (and Chinese people) in Zambia in relation to the very personal narratives of family members - Zoë my daughter, my grandma, and Ngolo my cousin. The first chapter focuses on my work Chinese Cabbage as my entry point to this topic, which is based on a school experiment I did with my daughter Zoë. In this chapter I also discuss the current discourses around China’s presence. Chapter two revisits the Zambian-Chinese historical encounters in memory of my grandma’s insaka stories about the construction of TAZARA Railway, and thus my works discussed in this chapter attach importance to the individual engagements from a historical perspective. Chapter three discusses in particular the controversial issues around Black Mountain and the works inspired by my cousin Ngolo’s stories of mining in Black Mountain and dealing with the Chinese traders.
- Full Text:
- Date Issued: 2020
Nine stories
- Authors: Dukas, Graham
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147124 , vital:38595
- Description: Creative work portfolio.
- Full Text:
- Date Issued: 2020
- Authors: Dukas, Graham
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147124 , vital:38595
- Description: Creative work portfolio.
- Full Text:
- Date Issued: 2020
Sectoral co-integration and portfolio diversification benefits: a business cycle examination of South African equity sectors
- Authors: Hofisi, Tinashe S
- Date: 2020
- Subjects: Portfolio management -- South Africa , Investments -- South Africa , Investments, South African , Stocks -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146379 , vital:38521
- Description: The onset of globalisation and simultaneous changes in financial technology and financial reforms dissipated hurdles once faced in financial transactions among stock markets. Hence, stock markets around the world became increasingly integrated because there was a free flow of cross border investments. Consequently, international diversification diminished thereby undermining the ability of investors to diversify investments across borders. For that reason, recent literature on portfolio diversification is urging investors to shift their focus to domestic portfolio diversification as an alternative. On that account, this study aims to examine the co-integration and dynamic causalities between South African equity market sectors in order to ascertain the sectoral diversification opportunities available to domestic investors over time. The study was examined over the different phases of the business cycle as well as the full sample, i.e. 2004 – 2018, with a view to shedding light on the inter-sectoral diversification opportunities of domestic investors over the South African business cycle. The phases of the business cycle applied are a| expansion and boom; b| recession and recovery phase and c| stagnation phase. The Johansen co-integration and Granger-causality tests were employed. The hypothesis of the study is that, if sectors are not cointegrated, then diversification benefits can be reaped by constructing a portfolio that combines stocks from the respective sectors. On the whole, the findings of this study show that there are both long-run and short-run diversification opportunities across the different phases of the South African business cycle as well as the full sample. However, there are lesser diversification opportunities in the recession and recovery phase over both the long-run and short-run. These results indicate that domestic sectoral portfolio diversification is least effective when it is needed the most (i.e. in a period of heightened volatility such as recession and recovery phase). This study will contribute to the existing literature in two ways; firstly, to investors who intend to diversify their portfolios domestically rather than internationally and, secondly, after reasonably thorough research it was evident that there is scant literature on domestic sectoral diversification in South Africa. As a result, the study attempts to address this gap. Additionally, the essence of the business cycle in this study is to make investors aware of potential diversification opportunities when positioning their portfolios for the next shift in the business cycle.
- Full Text:
- Date Issued: 2020
- Authors: Hofisi, Tinashe S
- Date: 2020
- Subjects: Portfolio management -- South Africa , Investments -- South Africa , Investments, South African , Stocks -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146379 , vital:38521
- Description: The onset of globalisation and simultaneous changes in financial technology and financial reforms dissipated hurdles once faced in financial transactions among stock markets. Hence, stock markets around the world became increasingly integrated because there was a free flow of cross border investments. Consequently, international diversification diminished thereby undermining the ability of investors to diversify investments across borders. For that reason, recent literature on portfolio diversification is urging investors to shift their focus to domestic portfolio diversification as an alternative. On that account, this study aims to examine the co-integration and dynamic causalities between South African equity market sectors in order to ascertain the sectoral diversification opportunities available to domestic investors over time. The study was examined over the different phases of the business cycle as well as the full sample, i.e. 2004 – 2018, with a view to shedding light on the inter-sectoral diversification opportunities of domestic investors over the South African business cycle. The phases of the business cycle applied are a| expansion and boom; b| recession and recovery phase and c| stagnation phase. The Johansen co-integration and Granger-causality tests were employed. The hypothesis of the study is that, if sectors are not cointegrated, then diversification benefits can be reaped by constructing a portfolio that combines stocks from the respective sectors. On the whole, the findings of this study show that there are both long-run and short-run diversification opportunities across the different phases of the South African business cycle as well as the full sample. However, there are lesser diversification opportunities in the recession and recovery phase over both the long-run and short-run. These results indicate that domestic sectoral portfolio diversification is least effective when it is needed the most (i.e. in a period of heightened volatility such as recession and recovery phase). This study will contribute to the existing literature in two ways; firstly, to investors who intend to diversify their portfolios domestically rather than internationally and, secondly, after reasonably thorough research it was evident that there is scant literature on domestic sectoral diversification in South Africa. As a result, the study attempts to address this gap. Additionally, the essence of the business cycle in this study is to make investors aware of potential diversification opportunities when positioning their portfolios for the next shift in the business cycle.
- Full Text:
- Date Issued: 2020