Analysis of technical efficiency of small-scale maize producers: a case study in Tsolo magisterial district in O.R Tambo district in the Eastern Cape of South Africa
- Authors: Avuletey, Richard
- Date: 2014
- Subjects: Corn -- Fertilizers -- South Africa -- Eastern Cape , Corn -- Economic aspects -- South Africa -- Eastern Cape , Entrepreneurship -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11210 , http://hdl.handle.net/10353/d1016191 , Corn -- Fertilizers -- South Africa -- Eastern Cape , Corn -- Economic aspects -- South Africa -- Eastern Cape , Entrepreneurship -- South Africa -- Eastern Cape
- Description: Maize is the most important cereal crop grown in South Africa. This crop is produced throughout the country under diverse conditions and in diverse environments. The study only focuses on technical efficiency because it is an important subject in developing agriculture where resources are limited, but high population growth is very common. In such a setting, increased output will depend more on efficiency improvements and assessing the scope for such efficiency improvements within the system is a crucial need. The objective of the study was to determine the level of technical efficiency and to identify the socio-economic and institutional characteristics as well as the entrepreneurial spirit that influence the technical efficiency of small-scale maize producers in the Tsolo magisterial district. Purposive and Snowball sampling techniques were used to collect primary data from 120 small-scale farmers. The stochastic frontier model was used to determine the level of technical efficiency. The Multivariate OLS was used to analyze the socio-economic factors and institutional characteristics that have influenced the technical efficiency of maize production. A similar linear regression model was used to estimate the influence of positive psychological capital and entrepreneurial spirit on the technical efficiency of maize production. The stochastic results revealed that small-scale farmers in Tsolo are technically efficient at 98 percent in maize production and experience increasing return to scale (1.37), which means that increase in the use of inputs, will as well increase their productivity and efficiency. The inefficiency model results indicated that age, years in farming, household size and extension contact significant and 3 variables, namely, as years in farming, extension contact and farm size are significant in the OLS model. Lastly the results of the linear regression indicated that, out of the 4 variables estimated in the entrepreneurial spirit, self-efficacy and resilience were significant with respect to its responsiveness to total maize output.
- Full Text:
- Date Issued: 2014
- Authors: Avuletey, Richard
- Date: 2014
- Subjects: Corn -- Fertilizers -- South Africa -- Eastern Cape , Corn -- Economic aspects -- South Africa -- Eastern Cape , Entrepreneurship -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11210 , http://hdl.handle.net/10353/d1016191 , Corn -- Fertilizers -- South Africa -- Eastern Cape , Corn -- Economic aspects -- South Africa -- Eastern Cape , Entrepreneurship -- South Africa -- Eastern Cape
- Description: Maize is the most important cereal crop grown in South Africa. This crop is produced throughout the country under diverse conditions and in diverse environments. The study only focuses on technical efficiency because it is an important subject in developing agriculture where resources are limited, but high population growth is very common. In such a setting, increased output will depend more on efficiency improvements and assessing the scope for such efficiency improvements within the system is a crucial need. The objective of the study was to determine the level of technical efficiency and to identify the socio-economic and institutional characteristics as well as the entrepreneurial spirit that influence the technical efficiency of small-scale maize producers in the Tsolo magisterial district. Purposive and Snowball sampling techniques were used to collect primary data from 120 small-scale farmers. The stochastic frontier model was used to determine the level of technical efficiency. The Multivariate OLS was used to analyze the socio-economic factors and institutional characteristics that have influenced the technical efficiency of maize production. A similar linear regression model was used to estimate the influence of positive psychological capital and entrepreneurial spirit on the technical efficiency of maize production. The stochastic results revealed that small-scale farmers in Tsolo are technically efficient at 98 percent in maize production and experience increasing return to scale (1.37), which means that increase in the use of inputs, will as well increase their productivity and efficiency. The inefficiency model results indicated that age, years in farming, household size and extension contact significant and 3 variables, namely, as years in farming, extension contact and farm size are significant in the OLS model. Lastly the results of the linear regression indicated that, out of the 4 variables estimated in the entrepreneurial spirit, self-efficacy and resilience were significant with respect to its responsiveness to total maize output.
- Full Text:
- Date Issued: 2014
Analysis of the interaction between recombinant human Beta2 integrin I-domains and CD23
- Authors: Sprong, Kaitlin
- Date: 2014
- Subjects: Immune response -- Regulation , Immunoglobulins , CD23 antigen
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10362 , http://hdl.handle.net/10948/d1021078
- Description: In order to further elucidate the interaction between CD23 and β2 integrins (CD11b/CD18) the following objectives were established: Expression and purification of CD11b I-domain as a GST-fusion protein using Escherichia coli; Cloning, synthesis and expression of CD18 I-Like domain.CD11b I-domain has previously been expressed as a GST-fusion protein (Daniels, 2010) and consequently led to comparable expression of CD18 I-like domain as a GST-fusion protein; Preparation of two site-directed mutants of CD18 I-Like domain in order to study the function of the serine residue involved in the S116P mutation. The serine was mutated to proline, as in LAD patients, as well as alanine, a non-polar alternative, in order to contrast and compare binding characteristics. Expression, refolding and purification of sCD23, and a double mutatedsCD23 (RKΔAA) from E. coli; This was performed according to the method described by Daniels et al. (2005); Investigation of the CD23-CD11b I-like domain interaction through surface plasmon resonance spectroscopy.
- Full Text:
- Date Issued: 2014
- Authors: Sprong, Kaitlin
- Date: 2014
- Subjects: Immune response -- Regulation , Immunoglobulins , CD23 antigen
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10362 , http://hdl.handle.net/10948/d1021078
- Description: In order to further elucidate the interaction between CD23 and β2 integrins (CD11b/CD18) the following objectives were established: Expression and purification of CD11b I-domain as a GST-fusion protein using Escherichia coli; Cloning, synthesis and expression of CD18 I-Like domain.CD11b I-domain has previously been expressed as a GST-fusion protein (Daniels, 2010) and consequently led to comparable expression of CD18 I-like domain as a GST-fusion protein; Preparation of two site-directed mutants of CD18 I-Like domain in order to study the function of the serine residue involved in the S116P mutation. The serine was mutated to proline, as in LAD patients, as well as alanine, a non-polar alternative, in order to contrast and compare binding characteristics. Expression, refolding and purification of sCD23, and a double mutatedsCD23 (RKΔAA) from E. coli; This was performed according to the method described by Daniels et al. (2005); Investigation of the CD23-CD11b I-like domain interaction through surface plasmon resonance spectroscopy.
- Full Text:
- Date Issued: 2014
Analysis of the interaction of Hsp90 with the extracellular matrix protein fibronectin (FN)
- Authors: Hunter, Morgan Campbell
- Date: 2014
- Subjects: Heat shock proteins , Fibronectins , Extracellular matrix proteins , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4170 , http://hdl.handle.net/10962/d1020960
- Description: Mounting evidence suggests that Hsp90 is present and functionally active in the extracellular space. The biological function of extracellular Hsp90 (eHsp90) remains relatively uncharacterized compared to that of intracellular Hsp90. eHsp90 has been shown to interact with a finite number of extracellular proteins, however, despite the identification of eHsp90 interacting proteins, the function of eHsp90 in these complexes is unknown. Several reports suggest a role for eHsp90α in cell migration and invasion. Reported targets for eHsp90 stimulated cell migration include MMPs, LRP-1, tyrosine kinase receptors and possible others unidentified. Limited studies report a role for eHsp90β. Recently, Hsp90α and Hsp90β were isolated in a complex containing fibronectin (FN) on the surface of MDA-MB-231 breast cancer cells. Herein, we report direct binding of Hsp90α and Hsp90β to FN using a solid phase binding assay and surface plasmon resonance (SPR) spectroscopy. SPR spectroscopy showed that Hsp90β bound the 70 kDa amino-terminal fragment of FN (FN70), but that binding of FN to Hsp90β was not limited to FN70. Confocal microscopy showed regions of colocalization of Hsp90 with extracellular FN matrix fibrils in Hs578T breast cancer cell lines. Treatment of Hs578T breast cancer cells with novobiocin (an Hsp90 inhibitor) and an LRP-1 blocking antibody resulted in a loss of FN matrix and FN endocytosis (novobiocin treated). Addition of exogenous Hsp90β was able to recover such effect after both treatments. FN was shown to colocalize with intracellular LRP-1 in novobiocin treated Hs578T cells. Immunoprecipitation of an LRP-1 containing complex showed the presence of Hsp90 and 70 and 120+ kDa FN fragments. Treatment of Hs578T cells with novobiocin increased the level of FN120+ bound in LRP-1 immunoprecipitate. Exogenous Hsp90β decreased the level of low and high molecular weight FN fragments in a complex with LRP-1, despite the fact that higher levels of lower molecular weight FN fragments were detected in this cell lysate compared to the other treatments. We report FN as a novel interacting protein of eHsp90. Taken together, we provide evidence for a direct role of eHsp90β in FN matrix remodeling. We suggest that Hsp90 plays a direct role in FN matrix dynamics through interaction with FN and LRP-1. The identification of FN as a novel interacting protein of eHsp90 suggests a role for Hsp90 in FN matrix remodeling, which is important for a number of fundamental cellular processes including cell migration and metastasis.
- Full Text:
- Date Issued: 2014
- Authors: Hunter, Morgan Campbell
- Date: 2014
- Subjects: Heat shock proteins , Fibronectins , Extracellular matrix proteins , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4170 , http://hdl.handle.net/10962/d1020960
- Description: Mounting evidence suggests that Hsp90 is present and functionally active in the extracellular space. The biological function of extracellular Hsp90 (eHsp90) remains relatively uncharacterized compared to that of intracellular Hsp90. eHsp90 has been shown to interact with a finite number of extracellular proteins, however, despite the identification of eHsp90 interacting proteins, the function of eHsp90 in these complexes is unknown. Several reports suggest a role for eHsp90α in cell migration and invasion. Reported targets for eHsp90 stimulated cell migration include MMPs, LRP-1, tyrosine kinase receptors and possible others unidentified. Limited studies report a role for eHsp90β. Recently, Hsp90α and Hsp90β were isolated in a complex containing fibronectin (FN) on the surface of MDA-MB-231 breast cancer cells. Herein, we report direct binding of Hsp90α and Hsp90β to FN using a solid phase binding assay and surface plasmon resonance (SPR) spectroscopy. SPR spectroscopy showed that Hsp90β bound the 70 kDa amino-terminal fragment of FN (FN70), but that binding of FN to Hsp90β was not limited to FN70. Confocal microscopy showed regions of colocalization of Hsp90 with extracellular FN matrix fibrils in Hs578T breast cancer cell lines. Treatment of Hs578T breast cancer cells with novobiocin (an Hsp90 inhibitor) and an LRP-1 blocking antibody resulted in a loss of FN matrix and FN endocytosis (novobiocin treated). Addition of exogenous Hsp90β was able to recover such effect after both treatments. FN was shown to colocalize with intracellular LRP-1 in novobiocin treated Hs578T cells. Immunoprecipitation of an LRP-1 containing complex showed the presence of Hsp90 and 70 and 120+ kDa FN fragments. Treatment of Hs578T cells with novobiocin increased the level of FN120+ bound in LRP-1 immunoprecipitate. Exogenous Hsp90β decreased the level of low and high molecular weight FN fragments in a complex with LRP-1, despite the fact that higher levels of lower molecular weight FN fragments were detected in this cell lysate compared to the other treatments. We report FN as a novel interacting protein of eHsp90. Taken together, we provide evidence for a direct role of eHsp90β in FN matrix remodeling. We suggest that Hsp90 plays a direct role in FN matrix dynamics through interaction with FN and LRP-1. The identification of FN as a novel interacting protein of eHsp90 suggests a role for Hsp90 in FN matrix remodeling, which is important for a number of fundamental cellular processes including cell migration and metastasis.
- Full Text:
- Date Issued: 2014
Analysis of the performance management system in the detective service of the Motherwell cluster in Port Elizabeth
- Authors: Saki, Nomachule Theodor
- Date: 2014
- Subjects: Performance -- Management , Employees -- Rating of -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8876 , http://hdl.handle.net/10948/d1020582
- Description: Performance management was implemented in the public service, including the South African Police Service, in 2001. The aim of implementing performance management in the public service was to improve the performance of all public servants. It was envisaged that the initiative for implementing performance management in the public service would entrench a culture of accountability, leading to improved service delivery. The effective utilisation of performance agreements, as a tool to align individual and organisational performance in the Motherwell Cluster Detective Service, was considered in this research. The contents of the individual detectives’ performance agreements and job descriptions in the Motherwell Cluster were analysed and compared with the contents of the SAPS Detective Service strategic objectives and performance indicators, as reflected in the SAPS Annual Performance Plan for 2012/2013. Interviews were conducted with Detective Service employees in the Motherwell Cluster, to determine whether the employees received training on the implementation of the Performance Enhancement Process, as the SAPS Performance Management and Development System. Research findings revealed that the contents of the respective individual detectives’ performance agreements and job descriptions were not aligned to the contents of the SAPS Detective Service strategic objectives and performance indicators. In areas where alignment was found, such alignment was so minimal that there was no meaningful correlation between an individual detective’s performance and organisational performance. The suggested recommendations are based on the findings of this study, which should be taken seriously if there is a desire to improve service delivery by the Detective Service. Apprehension, conviction, and sentencing of an offender can cause potential offenders to refrain from committing criminal acts for fear of apprehension and punishment.
- Full Text:
- Date Issued: 2014
- Authors: Saki, Nomachule Theodor
- Date: 2014
- Subjects: Performance -- Management , Employees -- Rating of -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8876 , http://hdl.handle.net/10948/d1020582
- Description: Performance management was implemented in the public service, including the South African Police Service, in 2001. The aim of implementing performance management in the public service was to improve the performance of all public servants. It was envisaged that the initiative for implementing performance management in the public service would entrench a culture of accountability, leading to improved service delivery. The effective utilisation of performance agreements, as a tool to align individual and organisational performance in the Motherwell Cluster Detective Service, was considered in this research. The contents of the individual detectives’ performance agreements and job descriptions in the Motherwell Cluster were analysed and compared with the contents of the SAPS Detective Service strategic objectives and performance indicators, as reflected in the SAPS Annual Performance Plan for 2012/2013. Interviews were conducted with Detective Service employees in the Motherwell Cluster, to determine whether the employees received training on the implementation of the Performance Enhancement Process, as the SAPS Performance Management and Development System. Research findings revealed that the contents of the respective individual detectives’ performance agreements and job descriptions were not aligned to the contents of the SAPS Detective Service strategic objectives and performance indicators. In areas where alignment was found, such alignment was so minimal that there was no meaningful correlation between an individual detective’s performance and organisational performance. The suggested recommendations are based on the findings of this study, which should be taken seriously if there is a desire to improve service delivery by the Detective Service. Apprehension, conviction, and sentencing of an offender can cause potential offenders to refrain from committing criminal acts for fear of apprehension and punishment.
- Full Text:
- Date Issued: 2014
Analysis of the tectonic and basin evolution of the seychelles microcontinent during the mesozoic to cenozoic, based on seismic and well data
- Authors: Mondon, Jean-Luc Andre
- Date: 2014
- Subjects: Sedimentation and deposition , Gondwana (Continent) , Sedimentary basins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/4386 , vital:20593
- Description: The Seychelles Microcontinent (SMc) is a fragment of continental lithosphere that experienced multiple phases of rifting and thermal subsidence during its isolation and submergence within the Indian Ocean. Originally part of central Gondwana, along with India and Madagascar, the SMc first emerged during Mesozoic fragmentation of Gondwana (ca. 220 – 180 Ma) along a complex rifted margin. Fragmentation involved three major rift phases, viz.: 1) Middle Triassic – Middle Jurassic (Rift I), associated with the “Karoo rifts” and break-up between [India-Madagascar-Seychelles] and East Africa; 2) Middle Jurassic – Early Cretaceous (Rift II), associated with the rifting and break-up of Madagascar from [India-Seychelles]; 3) Late Cretaceous (Rift III), associated with the rifting and final break-away of the SMc from India. In this study, the tectonic and sedimentary history of the SMc is analysed using 2D seismic reflection datasets and three exploration wells. Seismic to well-log correlations provide a chrono-stratigraphic framework that identifies seven sequences from the Middle Triassic to the Paleogene. This also identified horst and graben structures related to the extensional tectonics and thermal subsidence of this continental fragment. The latter is reflected also in changes of its litho-facies preserved on the SMc, from terrestrial to marine. The oldest sedimentary rocks identified on the SMc are Middle Triassic organic rich claystones (Sequence 7, Rift I), which grade upwards into alternating Upper Triassic sandstones and mudstones (Sequence 6, Rift I) followed by upward coarsening Lower Jurassic mudstones to sandstone units (Sequence 5, Rift I). These sequences are interpreted as lacustrine facies that evolved into fluvial channel migration facies and finally into progradational delta front facies. Sequence 5 is overlain by Middle Jurassic oolitic limestones that grade upwards into organic rich mudstones (Sequence 4, thermal subsidence after Rift I); the latter are interpreted as restricted-marginal marine deposits. Following Sequence 4, separated by a major break-up unconformity (BU), are the Upper Cretaceous open marine deposits comprising limestones, claystones and sandstones, and terminated with basaltic volcanics (ca. 66 Ma) prior to the separation of the SMc from India (Sequence 3, Rift III). This is overlain by the post-rift – thermal subsidence sequences comprising open marine claystones and shelf limestones (Sequence 2) followed by a sequence of shelf limestones (Sequence 1) that form the present carbonate platform, the Seychelles Plateau that lies approximately 200 m below the present sea-level. Backstripping and subsidence analysis quantifies 3 stages of subsidence; Phase A: Slow subsidence (ca. 5-20 m/Ma), from the Middle Jurassic to the Upper Cretaceous that terminated during a major marine transgression during ingression of the Tethys Sea between East Africa and [Madagascar-Seychelles-India]. This created marine conditions and the subsequent deposition of Sequences 4 and 3; Phase B: Accelerated subsidence (ca. 35-60 m/Ma) recorded throughout the Paleocene to the middle Eocene leading to deeper marine conditions and the subsequent deposition of Sequence 2; and Phase C: Reduced subsidence (ca. 10-30 m/Ma) following the interaction between the Carlsberg Ridge and the Reunion hotspot (ca. 55 Ma) that possibly introduced a reduction in subsidence and the subsequent deposition of Sequence 1 as the SMc drifted and thermally subsided to its submerged present location, and is now dominated mainly by marine carbonates. The effects of the Madagascar and Seychelles/India separation (ca. 84 Ma) are not observed in the subsidence analysis, possibly because it involved transcurrent-rotational movement between the two plates over a short period of time.
- Full Text:
- Date Issued: 2014
- Authors: Mondon, Jean-Luc Andre
- Date: 2014
- Subjects: Sedimentation and deposition , Gondwana (Continent) , Sedimentary basins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/4386 , vital:20593
- Description: The Seychelles Microcontinent (SMc) is a fragment of continental lithosphere that experienced multiple phases of rifting and thermal subsidence during its isolation and submergence within the Indian Ocean. Originally part of central Gondwana, along with India and Madagascar, the SMc first emerged during Mesozoic fragmentation of Gondwana (ca. 220 – 180 Ma) along a complex rifted margin. Fragmentation involved three major rift phases, viz.: 1) Middle Triassic – Middle Jurassic (Rift I), associated with the “Karoo rifts” and break-up between [India-Madagascar-Seychelles] and East Africa; 2) Middle Jurassic – Early Cretaceous (Rift II), associated with the rifting and break-up of Madagascar from [India-Seychelles]; 3) Late Cretaceous (Rift III), associated with the rifting and final break-away of the SMc from India. In this study, the tectonic and sedimentary history of the SMc is analysed using 2D seismic reflection datasets and three exploration wells. Seismic to well-log correlations provide a chrono-stratigraphic framework that identifies seven sequences from the Middle Triassic to the Paleogene. This also identified horst and graben structures related to the extensional tectonics and thermal subsidence of this continental fragment. The latter is reflected also in changes of its litho-facies preserved on the SMc, from terrestrial to marine. The oldest sedimentary rocks identified on the SMc are Middle Triassic organic rich claystones (Sequence 7, Rift I), which grade upwards into alternating Upper Triassic sandstones and mudstones (Sequence 6, Rift I) followed by upward coarsening Lower Jurassic mudstones to sandstone units (Sequence 5, Rift I). These sequences are interpreted as lacustrine facies that evolved into fluvial channel migration facies and finally into progradational delta front facies. Sequence 5 is overlain by Middle Jurassic oolitic limestones that grade upwards into organic rich mudstones (Sequence 4, thermal subsidence after Rift I); the latter are interpreted as restricted-marginal marine deposits. Following Sequence 4, separated by a major break-up unconformity (BU), are the Upper Cretaceous open marine deposits comprising limestones, claystones and sandstones, and terminated with basaltic volcanics (ca. 66 Ma) prior to the separation of the SMc from India (Sequence 3, Rift III). This is overlain by the post-rift – thermal subsidence sequences comprising open marine claystones and shelf limestones (Sequence 2) followed by a sequence of shelf limestones (Sequence 1) that form the present carbonate platform, the Seychelles Plateau that lies approximately 200 m below the present sea-level. Backstripping and subsidence analysis quantifies 3 stages of subsidence; Phase A: Slow subsidence (ca. 5-20 m/Ma), from the Middle Jurassic to the Upper Cretaceous that terminated during a major marine transgression during ingression of the Tethys Sea between East Africa and [Madagascar-Seychelles-India]. This created marine conditions and the subsequent deposition of Sequences 4 and 3; Phase B: Accelerated subsidence (ca. 35-60 m/Ma) recorded throughout the Paleocene to the middle Eocene leading to deeper marine conditions and the subsequent deposition of Sequence 2; and Phase C: Reduced subsidence (ca. 10-30 m/Ma) following the interaction between the Carlsberg Ridge and the Reunion hotspot (ca. 55 Ma) that possibly introduced a reduction in subsidence and the subsequent deposition of Sequence 1 as the SMc drifted and thermally subsided to its submerged present location, and is now dominated mainly by marine carbonates. The effects of the Madagascar and Seychelles/India separation (ca. 84 Ma) are not observed in the subsidence analysis, possibly because it involved transcurrent-rotational movement between the two plates over a short period of time.
- Full Text:
- Date Issued: 2014
Analysis of transcription factor binding specificity using ChIP-seq data.
- Authors: Kibet, Caleb Kipkurui
- Date: 2014
- Subjects: Transcription factors , Chronic myeloid leukemia , Antioncogenes , Cancer cells -- Growth -- Regulation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4115 , http://hdl.handle.net/10962/d1013131
- Description: Transcription factors (TFs) are key regulators of gene expression whose failure has been implicated in many diseases, including cancer. They bind at various sites at different specificity depending on the prevailing cellular conditions, disease, development stage or environmental conditions of the cell. TF binding specificity is how well a TF distinguishes functional sites from potential non-functional sites to form a useful regulatory network. Owing to its role in diseases, various techniques have been used to determine TF binding specificity in vitro and in vivo, including chromatin immuno-precipitation followed by massively parallel sequencing (ChIP-seq). ChIP-seq is an in vivo technique that considers how the chromatin landscape affects TF binding. Motif enrichment analysis (MEA) tools are used to identify motifs that are over-represented in ChIP-seq peak regions. One such tool, CentriMo, finds over-represented motifs at the center since peak calling software are biased to declaring binding regions centered at the TF binding site. In this study, we investigate the use of CentriMo and other MEA tools to determine the difference in motif enrichment attributed presence of Chronic Myeloid leukemia (CML)), treatment with Interferon (IFN) and Dexamethasone (DEX) compared to control based on Fisher’s exact test; using uniform peaks ChIP-seq data generated by the ENCODE consortium. CentriMo proved to be capable. We observed differential motif enrichment of TFs with tumor promoter activity: YY1, CEBPA, Egr1, Cmyc family, Gata1 and JunD in K562 while Stat1, Irf1, and Runx1 in Gm12878. Enrichment of CTCF in Gm12878 with YY1 as the immuno-precipitated (ChIP-ed) factor and the presence of significant spacing (SpaMo analysis) of CTCF and YY1 in Gm12878 but not in K562 could show that CTCF, as a repressor, helps in maintaining the required YY1 level in a normal cell line. IFN might reduce Cmyc and the Jun family of TFs binding via the repressive action of CTCF and E2f2. We also show that the concentration of DEX treatment affects motif enrichment with 50nm being an optimum concentration for Gr binding by maintaining open chromatin via AP1 TF. This study has demonstrated the usefulness of CentriMo for TF binding specificity analysis.
- Full Text:
- Date Issued: 2014
- Authors: Kibet, Caleb Kipkurui
- Date: 2014
- Subjects: Transcription factors , Chronic myeloid leukemia , Antioncogenes , Cancer cells -- Growth -- Regulation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4115 , http://hdl.handle.net/10962/d1013131
- Description: Transcription factors (TFs) are key regulators of gene expression whose failure has been implicated in many diseases, including cancer. They bind at various sites at different specificity depending on the prevailing cellular conditions, disease, development stage or environmental conditions of the cell. TF binding specificity is how well a TF distinguishes functional sites from potential non-functional sites to form a useful regulatory network. Owing to its role in diseases, various techniques have been used to determine TF binding specificity in vitro and in vivo, including chromatin immuno-precipitation followed by massively parallel sequencing (ChIP-seq). ChIP-seq is an in vivo technique that considers how the chromatin landscape affects TF binding. Motif enrichment analysis (MEA) tools are used to identify motifs that are over-represented in ChIP-seq peak regions. One such tool, CentriMo, finds over-represented motifs at the center since peak calling software are biased to declaring binding regions centered at the TF binding site. In this study, we investigate the use of CentriMo and other MEA tools to determine the difference in motif enrichment attributed presence of Chronic Myeloid leukemia (CML)), treatment with Interferon (IFN) and Dexamethasone (DEX) compared to control based on Fisher’s exact test; using uniform peaks ChIP-seq data generated by the ENCODE consortium. CentriMo proved to be capable. We observed differential motif enrichment of TFs with tumor promoter activity: YY1, CEBPA, Egr1, Cmyc family, Gata1 and JunD in K562 while Stat1, Irf1, and Runx1 in Gm12878. Enrichment of CTCF in Gm12878 with YY1 as the immuno-precipitated (ChIP-ed) factor and the presence of significant spacing (SpaMo analysis) of CTCF and YY1 in Gm12878 but not in K562 could show that CTCF, as a repressor, helps in maintaining the required YY1 level in a normal cell line. IFN might reduce Cmyc and the Jun family of TFs binding via the repressive action of CTCF and E2f2. We also show that the concentration of DEX treatment affects motif enrichment with 50nm being an optimum concentration for Gr binding by maintaining open chromatin via AP1 TF. This study has demonstrated the usefulness of CentriMo for TF binding specificity analysis.
- Full Text:
- Date Issued: 2014
Antecedents to sustainability of small consulting engineering businesses within the Amathole district municipality
- Authors: Silinga, Nyaniso Sandisiwe
- Date: 2014
- Subjects: Small business -- Environmental aspects , Sustainable development , Social responsibility of business
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/5184 , vital:20819
- Description: The South African consulting engineering industry faces a challenge of relevance, particularly in the wake of government infrastructure investment through the planned National Development Plan and other current infrastructure plans. This challenge is even more so for small consulting engineering businesses within the industry who experienced a decline in earnings by ten percent in the first six months of 2013 as compared to the last six months of 2012 (Consulting Engineers South Africa, 2013:38). Government, as a job creator, has a duty to ensure that the conditions that these businesses operate in are favourable to them in order for the businesses to remain sustainable. Factors that contribute to the sustainability of small consulting engineering businesses need to be identified. Amathole District Municipality (ADM) situated in the Eastern Cape Province and which is the second largest province in South Africa but the second poorest (Eastern Cape Socio Economic Council (ECSECC), 2011:15 cited in Mtshibe, 2013:1) is one of those job creators. According to the Amathole District Municipality (ADM) (2013:38), the district, which comprises of seven local municipalities, is the 3rd largest economy in the province after the Nelson Mandela Bay Metropolitan Municipality and Buffalo City Metropolitan Municipality, contributing twelve percent to the provincial economy. Figures published in the Division of Revenue Bill, 2014 (RSA, 2014:236) indicate infrastructure development allocations totalling R1.34 billion budgeted to the ADM for the next three years. This translates to job opportunities for the consulting engineering industry of this region. However, the latest ADM SMME procurement data reveals that in the past five years, only a small percentage of tenders awarded were to small consulting engineering businesses with a majority going to medium to large well-established enterprises (ADM, 2014). These results pose a serious challenge for policy makers who have a duty to ensure that work opportunities do not disadvantage emerging small businesses. The main objective of this study was to gain an understanding of the antecedents that impact on the sustainability of small consulting engineering businesses within the Amathole District Municipality. This was done by identifying antecedents to sustainability of small consulting engineering businesses through a detailed literature review. This literature review identified the competitive environment, regulatory environment and policy environment (independent variables) as being antecedents to sustainability of small consulting engineering businesses (dependant variable). In testing the above research objective, the researcher used statistical analysis methods to reach a conclusion with regard to these antecedents. The positivistic research paradigm (quantitative method) was selected in testing this research objective through the use of hypothesis testing. Data was collected using self-administered questionnaires distributed to 100 small consulting engineering businesses using the databases of both the Amathole District Municipality and Consulting Engineers South Africa (CESA). Out of the selected sample of 100 small consulting engineering businesses, only 81 responses were received, thus representing an eighty-one percent response rate which is considered adequate. The collected data was then analysed using inferential and confirmatory statistical analysis methods. The analysis was presented in the form of graphs and tables. The results of the empirical survey identified rival competitor influence, the competitive environment and policy environment as being antecedents to sustainability of small consulting engineering businesses within the Amathole District Municipality. Based on these findings, recommendations were made to the management of the Amathole District Municipality in an endeavour to make the environment within which small consulting engineering businesses operate more favourable for the businesses to be sustainable. Suggestions for future research were also made as a way to help in addressing some of the challenges that are faced by the engineering industry.
- Full Text:
- Date Issued: 2014
- Authors: Silinga, Nyaniso Sandisiwe
- Date: 2014
- Subjects: Small business -- Environmental aspects , Sustainable development , Social responsibility of business
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/5184 , vital:20819
- Description: The South African consulting engineering industry faces a challenge of relevance, particularly in the wake of government infrastructure investment through the planned National Development Plan and other current infrastructure plans. This challenge is even more so for small consulting engineering businesses within the industry who experienced a decline in earnings by ten percent in the first six months of 2013 as compared to the last six months of 2012 (Consulting Engineers South Africa, 2013:38). Government, as a job creator, has a duty to ensure that the conditions that these businesses operate in are favourable to them in order for the businesses to remain sustainable. Factors that contribute to the sustainability of small consulting engineering businesses need to be identified. Amathole District Municipality (ADM) situated in the Eastern Cape Province and which is the second largest province in South Africa but the second poorest (Eastern Cape Socio Economic Council (ECSECC), 2011:15 cited in Mtshibe, 2013:1) is one of those job creators. According to the Amathole District Municipality (ADM) (2013:38), the district, which comprises of seven local municipalities, is the 3rd largest economy in the province after the Nelson Mandela Bay Metropolitan Municipality and Buffalo City Metropolitan Municipality, contributing twelve percent to the provincial economy. Figures published in the Division of Revenue Bill, 2014 (RSA, 2014:236) indicate infrastructure development allocations totalling R1.34 billion budgeted to the ADM for the next three years. This translates to job opportunities for the consulting engineering industry of this region. However, the latest ADM SMME procurement data reveals that in the past five years, only a small percentage of tenders awarded were to small consulting engineering businesses with a majority going to medium to large well-established enterprises (ADM, 2014). These results pose a serious challenge for policy makers who have a duty to ensure that work opportunities do not disadvantage emerging small businesses. The main objective of this study was to gain an understanding of the antecedents that impact on the sustainability of small consulting engineering businesses within the Amathole District Municipality. This was done by identifying antecedents to sustainability of small consulting engineering businesses through a detailed literature review. This literature review identified the competitive environment, regulatory environment and policy environment (independent variables) as being antecedents to sustainability of small consulting engineering businesses (dependant variable). In testing the above research objective, the researcher used statistical analysis methods to reach a conclusion with regard to these antecedents. The positivistic research paradigm (quantitative method) was selected in testing this research objective through the use of hypothesis testing. Data was collected using self-administered questionnaires distributed to 100 small consulting engineering businesses using the databases of both the Amathole District Municipality and Consulting Engineers South Africa (CESA). Out of the selected sample of 100 small consulting engineering businesses, only 81 responses were received, thus representing an eighty-one percent response rate which is considered adequate. The collected data was then analysed using inferential and confirmatory statistical analysis methods. The analysis was presented in the form of graphs and tables. The results of the empirical survey identified rival competitor influence, the competitive environment and policy environment as being antecedents to sustainability of small consulting engineering businesses within the Amathole District Municipality. Based on these findings, recommendations were made to the management of the Amathole District Municipality in an endeavour to make the environment within which small consulting engineering businesses operate more favourable for the businesses to be sustainable. Suggestions for future research were also made as a way to help in addressing some of the challenges that are faced by the engineering industry.
- Full Text:
- Date Issued: 2014
Anti-staphylococcal, anti-HIV and cytotoxicity studies of four South African medicinal plants and isolation of bioactive compounds from Cassine transvaalensis (Burtt. Davy) codd
- Mthethwa, Ningy S, Oyedeji, Bola A O, Obi, Larry C, Aiyegoro, Olayinka A
- Authors: Mthethwa, Ningy S , Oyedeji, Bola A O , Obi, Larry C , Aiyegoro, Olayinka A
- Date: 2014
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/722 , vital:29661
- Description: Background: Medicinal plants represent an important opportunity to rural communities in Africa, as a source of affordable medicine and as a source of income. Increased patient awareness about safe usage is important as well as more training with regards to traditional medicine. The aim of this study was to evaluate the ethnomedicinal prowess of some indigenous South African plants commonly used in Eastern Cape Province of South Africa for the treatment of skin and respiratory tract infections, HIV and their toxicity potential. Methods: Cassine transvaalensis, Vangueria infausta, Croton gratissimus and Vitex ferruginea were tested for antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis using Kirby-Bauer disk diffusion and minimum inhibition concentration (MIC). Cytotoxic and anti-HIV-1 activities of plants were tested using MTT Assay (3- (Dimethylthiozole-2-yl-2,5-diphenyltetrazolium bromide)) and anti- HIV-1iib assay. In search of bioactive lead compounds, Cassine transvaalensis which was found to be the most active plant extract against the two Staphylocoous bacteria was subjected to various chromatographic. Thin layer chromatography, Column chromatography and Nuclear Magnetic Resonance (NMR), (1H-1H, 13C-13C, in DMSO_d6, Bruker 600 MHz) were used to isolate and characterize 3-Oxo-28-hydroxylbetuli-20(29)-ene and 3,28-dihydroxylbetuli-20(29)-ene bioactive compounds from C. transvaalensis. Results: The four plants studied exhibited bioactive properties against the test isolates. The zones of inhibition rangedbetween 16 mm to 31 mm for multi-drug resistant staphylococci species. MIC values varied between 0.6 and 0.02 μg/ml. C. gratissimus and C. transvaalensis exhibited the abilities to inhibit HIV-1iib. Two bioactive compounds were isolated from C. transvaalensis. Conclusion: Data from this study reveals the use of these plant by traditional healers in the Eastern Cape. Furthermore, C. transvaalensis and C. gratissimus were found to be more active as against HIV-1iib. While C. transvaalensis was most active against the two Staphylococcus bacteria.
- Full Text:
- Date Issued: 2014
- Authors: Mthethwa, Ningy S , Oyedeji, Bola A O , Obi, Larry C , Aiyegoro, Olayinka A
- Date: 2014
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/722 , vital:29661
- Description: Background: Medicinal plants represent an important opportunity to rural communities in Africa, as a source of affordable medicine and as a source of income. Increased patient awareness about safe usage is important as well as more training with regards to traditional medicine. The aim of this study was to evaluate the ethnomedicinal prowess of some indigenous South African plants commonly used in Eastern Cape Province of South Africa for the treatment of skin and respiratory tract infections, HIV and their toxicity potential. Methods: Cassine transvaalensis, Vangueria infausta, Croton gratissimus and Vitex ferruginea were tested for antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis using Kirby-Bauer disk diffusion and minimum inhibition concentration (MIC). Cytotoxic and anti-HIV-1 activities of plants were tested using MTT Assay (3- (Dimethylthiozole-2-yl-2,5-diphenyltetrazolium bromide)) and anti- HIV-1iib assay. In search of bioactive lead compounds, Cassine transvaalensis which was found to be the most active plant extract against the two Staphylocoous bacteria was subjected to various chromatographic. Thin layer chromatography, Column chromatography and Nuclear Magnetic Resonance (NMR), (1H-1H, 13C-13C, in DMSO_d6, Bruker 600 MHz) were used to isolate and characterize 3-Oxo-28-hydroxylbetuli-20(29)-ene and 3,28-dihydroxylbetuli-20(29)-ene bioactive compounds from C. transvaalensis. Results: The four plants studied exhibited bioactive properties against the test isolates. The zones of inhibition rangedbetween 16 mm to 31 mm for multi-drug resistant staphylococci species. MIC values varied between 0.6 and 0.02 μg/ml. C. gratissimus and C. transvaalensis exhibited the abilities to inhibit HIV-1iib. Two bioactive compounds were isolated from C. transvaalensis. Conclusion: Data from this study reveals the use of these plant by traditional healers in the Eastern Cape. Furthermore, C. transvaalensis and C. gratissimus were found to be more active as against HIV-1iib. While C. transvaalensis was most active against the two Staphylococcus bacteria.
- Full Text:
- Date Issued: 2014
Antibiogram profiling of Escherichia coli pathotypes isolated from Kat River and Fort Beaufort abstraction water
- Authors: Nontongana, Nolonwabo
- Date: 2014
- Subjects: Escherichia coli infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11289 , http://hdl.handle.net/10353/d1019820 , Escherichia coli infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape
- Description: Escherichia coli (E. coli) is a widespread species that includes a broad variety of strains, ranging from highly pathogenic strains causing worldwide outbreaks of severe disease to virulent isolates which are part of the normal intestinal flora or which are well characterized and safe laboratory strains. The pathogenicity of a given E. coli strain is mainly determined by specific virulence factors which include adhesins, invasins, toxins and capsule. The aim of this study was to evaluate the prevalence and antibiogram profiles of E. coli pathotypes previously isolated from Kat River and Fort Beaufort abstraction water. A total of 171 E. coli isolates showed at least one pathogenic determinant among the isolated 278 E. coli. The other 107 isolates were negative for the tested virulence genes. All 278 presumptive isolates tested positive for the UidA gene, and were therefore classified as non-categorized pathogenic E. coli. The 171 pathogenic isolates had at least one characteristic gene of pathogenic E. coli and were identified and classified as enteropathogenic E. coli (6%), enterotoxigenicE. coli (131), uropathogenic E. coli (6), neonatal meningitis E. coli (14), diffusely adherent E. coli (1) and enterohaemrrhagic E. coli (1). Interestingly, no virulence genes were detected for the enteroinvasive E. coli and the enteroaggregative E. coli. The antibiotic resistance profiles for all isolates that were identified as E. coli showed 100% resistance to penicillin G, 98% resistance to ampicillin, 38% resistance to trimethoprim-sulphamethoxazole and 8% resistance to streptomycin. Multiple antibacterial resistance (MAR) was also observed, where 44% of the isolates were resistant to three antibiotics and 8% resistant to four antibiotics. The results of this study showed the Kat River and Fort Beaufort abstraction water are reservoirs of pathogenic strains of E. coli which harbour antibiotic resistance determinants that can cause serious health risks to the people in the surrounding communities.
- Full Text:
- Date Issued: 2014
- Authors: Nontongana, Nolonwabo
- Date: 2014
- Subjects: Escherichia coli infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11289 , http://hdl.handle.net/10353/d1019820 , Escherichia coli infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape
- Description: Escherichia coli (E. coli) is a widespread species that includes a broad variety of strains, ranging from highly pathogenic strains causing worldwide outbreaks of severe disease to virulent isolates which are part of the normal intestinal flora or which are well characterized and safe laboratory strains. The pathogenicity of a given E. coli strain is mainly determined by specific virulence factors which include adhesins, invasins, toxins and capsule. The aim of this study was to evaluate the prevalence and antibiogram profiles of E. coli pathotypes previously isolated from Kat River and Fort Beaufort abstraction water. A total of 171 E. coli isolates showed at least one pathogenic determinant among the isolated 278 E. coli. The other 107 isolates were negative for the tested virulence genes. All 278 presumptive isolates tested positive for the UidA gene, and were therefore classified as non-categorized pathogenic E. coli. The 171 pathogenic isolates had at least one characteristic gene of pathogenic E. coli and were identified and classified as enteropathogenic E. coli (6%), enterotoxigenicE. coli (131), uropathogenic E. coli (6), neonatal meningitis E. coli (14), diffusely adherent E. coli (1) and enterohaemrrhagic E. coli (1). Interestingly, no virulence genes were detected for the enteroinvasive E. coli and the enteroaggregative E. coli. The antibiotic resistance profiles for all isolates that were identified as E. coli showed 100% resistance to penicillin G, 98% resistance to ampicillin, 38% resistance to trimethoprim-sulphamethoxazole and 8% resistance to streptomycin. Multiple antibacterial resistance (MAR) was also observed, where 44% of the isolates were resistant to three antibiotics and 8% resistant to four antibiotics. The results of this study showed the Kat River and Fort Beaufort abstraction water are reservoirs of pathogenic strains of E. coli which harbour antibiotic resistance determinants that can cause serious health risks to the people in the surrounding communities.
- Full Text:
- Date Issued: 2014
Antimicrobial properties and isotope investigations of South African honey
- Khan, F, Hill, Jaclyn M, Kaehler, Sven, Allsopp, M, van Vuuren, S
- Authors: Khan, F , Hill, Jaclyn M , Kaehler, Sven , Allsopp, M , van Vuuren, S
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444539 , vital:74249 , https://doi.org/10.1111/jam.12533
- Description: The therapeutic potential of honey for the treatment of wound infections is well documented. However, South African (SA) honey has been poorly explored as an antimicrobial agent and given the well‐established antimicrobial properties of the indigenous plant species from SA, there is the potential that honey from this geographical region may exhibit noteworthy anti‐infective properties. In this study, the antimicrobial properties of 42 SA honey samples were determined.
- Full Text:
- Date Issued: 2014
- Authors: Khan, F , Hill, Jaclyn M , Kaehler, Sven , Allsopp, M , van Vuuren, S
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444539 , vital:74249 , https://doi.org/10.1111/jam.12533
- Description: The therapeutic potential of honey for the treatment of wound infections is well documented. However, South African (SA) honey has been poorly explored as an antimicrobial agent and given the well‐established antimicrobial properties of the indigenous plant species from SA, there is the potential that honey from this geographical region may exhibit noteworthy anti‐infective properties. In this study, the antimicrobial properties of 42 SA honey samples were determined.
- Full Text:
- Date Issued: 2014
Application of carbon black and iron phthalocyanine composites in bioelectricity production at a brewery wastewater fed microbial fuel cell
- Mshoperi, Edith, Fogel, Ronen, Limson, Janice
- Authors: Mshoperi, Edith , Fogel, Ronen , Limson, Janice
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431050 , vital:72740 , xlink:href="https://doi.org/10.1016/j.electacta.2013.11.01"
- Description: Aerobic cathode microbial fuel cells (MFCs) have been widely researched to provide bioremediation of wastewaters, coupled to sustainable energy production. In order to effectively accomplish this aim, suitable catalysts and catalyst supports for oxygen reduction reaction (ORR) are required. While iron phthaloycanine (FePc), supported on multi-walled carbon nanotubes has previously been studied for this function, cost of industrial production may hinder this. Importantly, this study examines the use of several available grades of carbon black for their relative suitability to perform as supports for FePc in MFC formats. Voltammetric studies showed that the different grades of carbon black provided varying lowering of the ORR overpotential, between ∼160 and ∼270 mV relative to unmodified GCEs, and an optimum grade (N326) was selected for further study. Carbon black/FePC composite electrodes exhibited comparable lowering of the ORR overpotential (606 mV) to potentials previously reported to nanotube/FePc composites (620 mV), as well as lowered charge-transfer resistance compared to electrodes solely modified with FePc. When applied as cathode modifiers in dual chambered MFCs utilising Enterobacter cloacae, the combined use of carbon black and FePc provided greater power densities than either alone; composite electrodes obtaining ∼400% power density, compared to unmodified electrodes. Modification of the anode with carbon black further increased power density, generating power densities an order of magnitude larger than those obtained at unmodified electrodes. The ability of beer brewery waste water (BBWW) to generate power at these modified surfaces yielded permissible power densities (∼40% that of reinforced clostridial media). Differences observed, in particular under agitation, are attributed to variations in nutrient content and nutrient complexity, between the two fuel substrates.
- Full Text:
- Date Issued: 2014
- Authors: Mshoperi, Edith , Fogel, Ronen , Limson, Janice
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431050 , vital:72740 , xlink:href="https://doi.org/10.1016/j.electacta.2013.11.01"
- Description: Aerobic cathode microbial fuel cells (MFCs) have been widely researched to provide bioremediation of wastewaters, coupled to sustainable energy production. In order to effectively accomplish this aim, suitable catalysts and catalyst supports for oxygen reduction reaction (ORR) are required. While iron phthaloycanine (FePc), supported on multi-walled carbon nanotubes has previously been studied for this function, cost of industrial production may hinder this. Importantly, this study examines the use of several available grades of carbon black for their relative suitability to perform as supports for FePc in MFC formats. Voltammetric studies showed that the different grades of carbon black provided varying lowering of the ORR overpotential, between ∼160 and ∼270 mV relative to unmodified GCEs, and an optimum grade (N326) was selected for further study. Carbon black/FePC composite electrodes exhibited comparable lowering of the ORR overpotential (606 mV) to potentials previously reported to nanotube/FePc composites (620 mV), as well as lowered charge-transfer resistance compared to electrodes solely modified with FePc. When applied as cathode modifiers in dual chambered MFCs utilising Enterobacter cloacae, the combined use of carbon black and FePc provided greater power densities than either alone; composite electrodes obtaining ∼400% power density, compared to unmodified electrodes. Modification of the anode with carbon black further increased power density, generating power densities an order of magnitude larger than those obtained at unmodified electrodes. The ability of beer brewery waste water (BBWW) to generate power at these modified surfaces yielded permissible power densities (∼40% that of reinforced clostridial media). Differences observed, in particular under agitation, are attributed to variations in nutrient content and nutrient complexity, between the two fuel substrates.
- Full Text:
- Date Issued: 2014
Application of section 139 of the constitution of the Republic of South Africa, 1996
- Authors: Moleli, Thanduxolo
- Date: 2014
- Subjects: Municipal government -- South Africa , Local government -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/8397 , vital:26353
- Description: This research investigated the application of section 139 of the Constitution of Republic of Republic of South Africa, 1996. Koukamma, Sundays River Valley and Mnquma Local Municipalities are the case studies for this research as provincial interventions to these municipalities will be analysed. The study was conducted within the legal and legislative framework of local government which clearly defines how municipalities should be governed. Furthermore, it explains the procedural and substantive requirements for intervention should a municipality fail to deliver on its constitutional mandate as stipulated in Section 152 of the Constitution. A descriptive approach was used in the study, with data collection coming from primary and secondary sources such as textbooks, minutes of meetings of the Eastern Cape Department of Local Government and Traditional Affairs, National Council of Provinces and reports by administrators appointed by Member of the Executive Council (MEC) responsible for local government in the respective province. Several recommendations were provided in the final chapter. Should these be implemented properly, it could result in effective local government, and thereby reduce or eliminate the need for the application of section 139 of the Constitution.
- Full Text:
- Date Issued: 2014
- Authors: Moleli, Thanduxolo
- Date: 2014
- Subjects: Municipal government -- South Africa , Local government -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/8397 , vital:26353
- Description: This research investigated the application of section 139 of the Constitution of Republic of Republic of South Africa, 1996. Koukamma, Sundays River Valley and Mnquma Local Municipalities are the case studies for this research as provincial interventions to these municipalities will be analysed. The study was conducted within the legal and legislative framework of local government which clearly defines how municipalities should be governed. Furthermore, it explains the procedural and substantive requirements for intervention should a municipality fail to deliver on its constitutional mandate as stipulated in Section 152 of the Constitution. A descriptive approach was used in the study, with data collection coming from primary and secondary sources such as textbooks, minutes of meetings of the Eastern Cape Department of Local Government and Traditional Affairs, National Council of Provinces and reports by administrators appointed by Member of the Executive Council (MEC) responsible for local government in the respective province. Several recommendations were provided in the final chapter. Should these be implemented properly, it could result in effective local government, and thereby reduce or eliminate the need for the application of section 139 of the Constitution.
- Full Text:
- Date Issued: 2014
Applications of lead phthalocyanines embedded in electrospun fibers for the photoinactivation of Escherichia coli in water
- Osifeko, Olawale L, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189898 , vital:44945 , xlink:href="https://doi.org/10.1016/j.dyepig.2014.05.010"
- Description: Lead (II) pyridyloxyphthalocyanine (PbTpyPc) and its quaternized form (PbTepyPc) were synthesized and the photophysical behavior examined. Low fluorescence quantum yields (ΦF) of 0.01 and 0.02 were observed for PbTepyPc and PbTpyPc, respectively. The singlet oxygen quantum yields (ΦΔ) were 0.60 and 0.68, for PbTepyPc and PbTpyPc, respectively using DPBF as a quencher in DMF. Singlet oxygen production of the embedded sensitizers in electrospun fiber were quantified using ADMA and were found to be ΦΔ = 0.41 and ΦΔ = 0.21 for PbTepyPc and PbTpyPc, respectively. Photodynamic inactivation of Escherichia coli (E. coli) with the quaternized photosensitizer at 5 μM, totally inactivated the E. coli (with log CFU = 10 decrease). Only 0.4 log CFU decrease was obtained with PbTpyPc. The embedded non-quaternized photosensitizer (PbTpyPc) was less active on the gram negative bacteria but the quaternized photosensitizer (PbTepyPc) was effective towards inactivation of E. coli.
- Full Text:
- Date Issued: 2014
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189898 , vital:44945 , xlink:href="https://doi.org/10.1016/j.dyepig.2014.05.010"
- Description: Lead (II) pyridyloxyphthalocyanine (PbTpyPc) and its quaternized form (PbTepyPc) were synthesized and the photophysical behavior examined. Low fluorescence quantum yields (ΦF) of 0.01 and 0.02 were observed for PbTepyPc and PbTpyPc, respectively. The singlet oxygen quantum yields (ΦΔ) were 0.60 and 0.68, for PbTepyPc and PbTpyPc, respectively using DPBF as a quencher in DMF. Singlet oxygen production of the embedded sensitizers in electrospun fiber were quantified using ADMA and were found to be ΦΔ = 0.41 and ΦΔ = 0.21 for PbTepyPc and PbTpyPc, respectively. Photodynamic inactivation of Escherichia coli (E. coli) with the quaternized photosensitizer at 5 μM, totally inactivated the E. coli (with log CFU = 10 decrease). Only 0.4 log CFU decrease was obtained with PbTpyPc. The embedded non-quaternized photosensitizer (PbTpyPc) was less active on the gram negative bacteria but the quaternized photosensitizer (PbTepyPc) was effective towards inactivation of E. coli.
- Full Text:
- Date Issued: 2014
Applications of lead phthalocyanines embedded in electrospun fibers for the photoinactivation of Escherichia coli in water
- Osifeko, Olawale L, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:7304 , http://hdl.handle.net/10962/d1020381
- Description: Lead (II) pyridyloxyphthalocyanine (PbTpyPc) and its quaternized form (PbTepyPc) were synthesized and the photophysical behavior examined. Low fluorescence quantum yields (ΦF) of 0.01 and 0.02 were observed for PbTepyPc and PbTpyPc, respectively. The singlet oxygen quantum yields (ΦΔ) were 0.60 and 0.68, for PbTepyPc and PbTpyPc, respectively using DPBF as a quencher in DMF. Singlet oxygen production of the embedded sensitizers in electrospun fiber were quantified using ADMA and were found to be ΦΔ = 0.41 and ΦΔ = 0.21 for PbTepyPc and PbTpyPc, respectively. Photodynamic inactivation of Escherichia coli (E. coli) with the quaternized photosensitizer at 5 μM, totally inactivated the E. coli (with log CFU = 10 decrease). Only 0.4 log CFU decrease was obtained with PbTpyPc. The embedded non-quaternized photosensitizer (PbTpyPc) was less active on the gram negative bacteria but the quaternized photosensitizer (PbTepyPc) was effective towards inactivation of E. coli. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2014.05.010
- Full Text: false
- Date Issued: 2014
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:7304 , http://hdl.handle.net/10962/d1020381
- Description: Lead (II) pyridyloxyphthalocyanine (PbTpyPc) and its quaternized form (PbTepyPc) were synthesized and the photophysical behavior examined. Low fluorescence quantum yields (ΦF) of 0.01 and 0.02 were observed for PbTepyPc and PbTpyPc, respectively. The singlet oxygen quantum yields (ΦΔ) were 0.60 and 0.68, for PbTepyPc and PbTpyPc, respectively using DPBF as a quencher in DMF. Singlet oxygen production of the embedded sensitizers in electrospun fiber were quantified using ADMA and were found to be ΦΔ = 0.41 and ΦΔ = 0.21 for PbTepyPc and PbTpyPc, respectively. Photodynamic inactivation of Escherichia coli (E. coli) with the quaternized photosensitizer at 5 μM, totally inactivated the E. coli (with log CFU = 10 decrease). Only 0.4 log CFU decrease was obtained with PbTpyPc. The embedded non-quaternized photosensitizer (PbTpyPc) was less active on the gram negative bacteria but the quaternized photosensitizer (PbTepyPc) was effective towards inactivation of E. coli. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2014.05.010
- Full Text: false
- Date Issued: 2014
Apprehension of bias and the spectacle of the fair-minded observer: a survey of recent commonwealth and South African decisions on pre-judgment
- Okpaluba, Chuks, Juma, Laurence
- Authors: Okpaluba, Chuks , Juma, Laurence
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126107 , vital:35850 , http://specjuris.ufh.ac.za/apprehension-bias-and-spectacle-fair-minded-observer-survey-recent-commonwealth-and-south-african
- Description: A perusal of contemporary Commonwealth case law reveals that allegations of bias or apprehension of bias tend to revolve around the pecuniary or other interests of the Judge arising from kinship, previous relationship, or association with party or counsel.1Apparent bias could also be inferred from the judge‘s conduct or utterances, especially, his/her criticisms or cumulative criticisms of a party during proceedings or in adjudication.2In other instances, a judge‘s previous knowledge or association with the case in court, or of an important witness, may disqualify him/her from sitting or passing judgment in the case.3
- Full Text:
- Date Issued: 2014
- Authors: Okpaluba, Chuks , Juma, Laurence
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126107 , vital:35850 , http://specjuris.ufh.ac.za/apprehension-bias-and-spectacle-fair-minded-observer-survey-recent-commonwealth-and-south-african
- Description: A perusal of contemporary Commonwealth case law reveals that allegations of bias or apprehension of bias tend to revolve around the pecuniary or other interests of the Judge arising from kinship, previous relationship, or association with party or counsel.1Apparent bias could also be inferred from the judge‘s conduct or utterances, especially, his/her criticisms or cumulative criticisms of a party during proceedings or in adjudication.2In other instances, a judge‘s previous knowledge or association with the case in court, or of an important witness, may disqualify him/her from sitting or passing judgment in the case.3
- Full Text:
- Date Issued: 2014
Appropriateness of municipal workers' job behaviour and performance at the Buffalo City Metropolitan Municipality
- Authors: Twalo, Thembinkosi Gladden
- Date: 2014
- Subjects: Education -- Employees , Employees -- Attitudes , Employees -- Rating of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9587 , http://hdl.handle.net/10948/d1020997
- Description: The Buffalo City Metropolitan Municipality (BCMM) has been experiencing inappropriate job behaviour and performance from some of its workers. These inappropriate practices have been widely reported in the media, audit reports, parliamentary discussions, reports to parliament, municipal reports, and departmental reports. They include misappropriation of municipal resources, maladministration, mismanagement, lack of service delivery, fraud, and corruption. Since many BCMM workers have various levels of formal education, such practices are not expected, because the structural-functionalist assumption is that formal education is a solution to societal challenges. At the BCMM, however, formal education seemed to also serve a different purpose, that of realising the principle that says “[k]now the rules well, so you can break them effectively” (Dalai Lama 2013, 2). This study therefore hypothesises that the perpetual inappropriate job behaviour and performance at the BCMM is due to the paucity of broad skills. The concept of broad skills includes the various dimensions of knowledge (know that, know why, know how) as well as attitudes, ethics and values. Inappropriate job behaviour and performance practices thus indicate that current levels of broad skills are insufficient. This study acknowledges that labour (ability to work) is a product of multifarious forms of capital, hence this study amalgamates four forms of capital - human capital, social capital, cultural capital, and reputation capital – into a theoretical framework in order to get a broader explanation of the workers’ job behaviour and performance. The various forms of capital contribute to the formation of skill, hence the notion of broad skills. How workers discharge their responsibilities is determined by numerous factors such as cultural capital (the workers’ family background, race, ethnicity, personality, and geographical area) (Bourdieu 1977); reputation capital (the workers’ brand, public perceptions of trustworthiness, popularity, authority in the field, ethics, integrity and reputation) (Ingbretsen 2011); social capital (the workers’ social development, social relations, and social networks) (Blackmore 1997); and human capital (schooling) (Becker 1964). The value of adopting the broad skills approach lies in gaining a broader perspective on job performance as opposed to the dominant use of the human capital model alone which predominantly uses schooling to explain job performance. In practice, the human capital model is characterised by its association of job performance problems with lack of skills. However, investigation of the role of attitudes, ethics and values in the labour process reveals that the lack of will also contributes to job performance problems. In fact, the adoption of multiple perspectives for investigating the paradoxical co-existence of inappropriate job behaviour and performance with formal education reveals several factors that make this phenomenon possible, besides lack of skills. These include the job environment, ineffective performance management systems, compromised municipal effectiveness and efficiency due to the politicisation of municipal management, and manipulation of the labour process to suit the interests of the workers who want to engage in inappropriate practices.
- Full Text:
- Date Issued: 2014
- Authors: Twalo, Thembinkosi Gladden
- Date: 2014
- Subjects: Education -- Employees , Employees -- Attitudes , Employees -- Rating of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9587 , http://hdl.handle.net/10948/d1020997
- Description: The Buffalo City Metropolitan Municipality (BCMM) has been experiencing inappropriate job behaviour and performance from some of its workers. These inappropriate practices have been widely reported in the media, audit reports, parliamentary discussions, reports to parliament, municipal reports, and departmental reports. They include misappropriation of municipal resources, maladministration, mismanagement, lack of service delivery, fraud, and corruption. Since many BCMM workers have various levels of formal education, such practices are not expected, because the structural-functionalist assumption is that formal education is a solution to societal challenges. At the BCMM, however, formal education seemed to also serve a different purpose, that of realising the principle that says “[k]now the rules well, so you can break them effectively” (Dalai Lama 2013, 2). This study therefore hypothesises that the perpetual inappropriate job behaviour and performance at the BCMM is due to the paucity of broad skills. The concept of broad skills includes the various dimensions of knowledge (know that, know why, know how) as well as attitudes, ethics and values. Inappropriate job behaviour and performance practices thus indicate that current levels of broad skills are insufficient. This study acknowledges that labour (ability to work) is a product of multifarious forms of capital, hence this study amalgamates four forms of capital - human capital, social capital, cultural capital, and reputation capital – into a theoretical framework in order to get a broader explanation of the workers’ job behaviour and performance. The various forms of capital contribute to the formation of skill, hence the notion of broad skills. How workers discharge their responsibilities is determined by numerous factors such as cultural capital (the workers’ family background, race, ethnicity, personality, and geographical area) (Bourdieu 1977); reputation capital (the workers’ brand, public perceptions of trustworthiness, popularity, authority in the field, ethics, integrity and reputation) (Ingbretsen 2011); social capital (the workers’ social development, social relations, and social networks) (Blackmore 1997); and human capital (schooling) (Becker 1964). The value of adopting the broad skills approach lies in gaining a broader perspective on job performance as opposed to the dominant use of the human capital model alone which predominantly uses schooling to explain job performance. In practice, the human capital model is characterised by its association of job performance problems with lack of skills. However, investigation of the role of attitudes, ethics and values in the labour process reveals that the lack of will also contributes to job performance problems. In fact, the adoption of multiple perspectives for investigating the paradoxical co-existence of inappropriate job behaviour and performance with formal education reveals several factors that make this phenomenon possible, besides lack of skills. These include the job environment, ineffective performance management systems, compromised municipal effectiveness and efficiency due to the politicisation of municipal management, and manipulation of the labour process to suit the interests of the workers who want to engage in inappropriate practices.
- Full Text:
- Date Issued: 2014
Architectural design interventions toward improvement of construction health, safety, and ergonomics in South Africa
- Authors: Goldswain, Craig Colin
- Date: 2014
- Subjects: Construction industry -- Safety measures , Construction industry -- Accidents -- South Africa , Architectural design -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9717 , http://hdl.handle.net/10948/d1021060
- Description: The construction industry produces a high rate of accident statistics. Constructors are exposed to a range of construction hazards and risks which manifest themselves in accidents and lead to a high incidence of illnesses, injuries and fatalities. Despite evidence that up to 50 percent of construction accidents can be avoided through mitigation of hazards and risks in the design phase of construction projects, architectural designers do not adequately engage in designing for construction health, safety, and ergonomics. The research localises the problem in the context of South Africa and sets out to develop an architectural design oriented model toward a reduction of construction hazards and risks, which can be engendered through optimisation of tertiary architectural education and through continuing professional development (CPD) programmes. The ultimate aim is to realise a paradigm shift in architectural design relative to construction health, safety, and ergonomics as architectural designers in South Africa still view it as the constructor’s responsibility. The research intertwined a range of secondary data with four provisional studies undertaken in the Eastern Cape Province considered representative of South Africa. This involved both quantitative and qualitative methodologies and were directed at architectural designers registered with the South African Council for the Architectural Profession (SACAP). The provisional studies were published in international conference proceedings and served to gradually provide local insight, and ultimately provided a line of structured questions for use in the main study. The main study was positioned in the action research (AR) paradigm and used focus group (FG) methodology to solicit a vast richness of qualitative data from SACAP registered architectural designers who participated in the FG proceedings. Synthesis of data with literature and the provisional studies gave rise to a provisional model comprising six main model components and a range of sub-components. The provisional model was validated and refined while simultaneously testing the research hypotheses by means of questionnaires directed at the SACAP registered FG participants. The evolved model includes a core model embedded in a greater process model, and implementation and use of the core model relies on appropriate knowledge of architectural designers. It is ultimately recommended that tertiary architectural education institutions and those involved in architectural CPD programmes take ‘upstream design ownership’ and use the model as a basis for designing and implementing appropriate tertiary architectural programmes and architectural CPD offerings. Ultimately the model is not considered as a complete means to an end, and further investigation is needed in order to design and implement the recommended programmes. Only then can we begin to realise a paradigm shift in architectural thinking and practice.
- Full Text:
- Date Issued: 2014
- Authors: Goldswain, Craig Colin
- Date: 2014
- Subjects: Construction industry -- Safety measures , Construction industry -- Accidents -- South Africa , Architectural design -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9717 , http://hdl.handle.net/10948/d1021060
- Description: The construction industry produces a high rate of accident statistics. Constructors are exposed to a range of construction hazards and risks which manifest themselves in accidents and lead to a high incidence of illnesses, injuries and fatalities. Despite evidence that up to 50 percent of construction accidents can be avoided through mitigation of hazards and risks in the design phase of construction projects, architectural designers do not adequately engage in designing for construction health, safety, and ergonomics. The research localises the problem in the context of South Africa and sets out to develop an architectural design oriented model toward a reduction of construction hazards and risks, which can be engendered through optimisation of tertiary architectural education and through continuing professional development (CPD) programmes. The ultimate aim is to realise a paradigm shift in architectural design relative to construction health, safety, and ergonomics as architectural designers in South Africa still view it as the constructor’s responsibility. The research intertwined a range of secondary data with four provisional studies undertaken in the Eastern Cape Province considered representative of South Africa. This involved both quantitative and qualitative methodologies and were directed at architectural designers registered with the South African Council for the Architectural Profession (SACAP). The provisional studies were published in international conference proceedings and served to gradually provide local insight, and ultimately provided a line of structured questions for use in the main study. The main study was positioned in the action research (AR) paradigm and used focus group (FG) methodology to solicit a vast richness of qualitative data from SACAP registered architectural designers who participated in the FG proceedings. Synthesis of data with literature and the provisional studies gave rise to a provisional model comprising six main model components and a range of sub-components. The provisional model was validated and refined while simultaneously testing the research hypotheses by means of questionnaires directed at the SACAP registered FG participants. The evolved model includes a core model embedded in a greater process model, and implementation and use of the core model relies on appropriate knowledge of architectural designers. It is ultimately recommended that tertiary architectural education institutions and those involved in architectural CPD programmes take ‘upstream design ownership’ and use the model as a basis for designing and implementing appropriate tertiary architectural programmes and architectural CPD offerings. Ultimately the model is not considered as a complete means to an end, and further investigation is needed in order to design and implement the recommended programmes. Only then can we begin to realise a paradigm shift in architectural thinking and practice.
- Full Text:
- Date Issued: 2014
Argumentative and trustworthy scholars
- McKenna, Sioux, Boughey, Chrissie
- Authors: McKenna, Sioux , Boughey, Chrissie
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187216 , vital:44580 , xlink:href="https://doi.org/10.1080/13562517.2014.934351"
- Description: Research-intensive universities, such as the Russell Group in the UK, the Ivy League Colleges in the USA and the Sandstone Universities in Australia, enjoy particular status in the higher education landscape. They are, however, also often associated with social elitism and selectivity, and this has led to critique as higher education systems seek to widen access. This article looks at how academic staff are discursively constructed in five such institutions in South Africa through an analysis of documentation submitted as part of a national review. Three interrelated discourses are identified: a discourse of ‘staff as scholars’ whereby research is privileged over teaching, a discourse of ‘academic argumentation’ whereby a critical disposition is valued and is called upon by academics to resist development initiatives and a discourse of ‘trust’ whereby it is assumed that academics share a value system and should thus be trusted to undertake quality teaching without interference.
- Full Text:
- Date Issued: 2014
- Authors: McKenna, Sioux , Boughey, Chrissie
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187216 , vital:44580 , xlink:href="https://doi.org/10.1080/13562517.2014.934351"
- Description: Research-intensive universities, such as the Russell Group in the UK, the Ivy League Colleges in the USA and the Sandstone Universities in Australia, enjoy particular status in the higher education landscape. They are, however, also often associated with social elitism and selectivity, and this has led to critique as higher education systems seek to widen access. This article looks at how academic staff are discursively constructed in five such institutions in South Africa through an analysis of documentation submitted as part of a national review. Three interrelated discourses are identified: a discourse of ‘staff as scholars’ whereby research is privileged over teaching, a discourse of ‘academic argumentation’ whereby a critical disposition is valued and is called upon by academics to resist development initiatives and a discourse of ‘trust’ whereby it is assumed that academics share a value system and should thus be trusted to undertake quality teaching without interference.
- Full Text:
- Date Issued: 2014
ARTERIAL TONE IN BLACK WOMEN WITH PREECLAMPSIA FROM TRANSKEI REGION OF SOUTH AFRICA
- Authors: AMBROSE VINCENT NAMUGOWA
- Date: 2014
- Language: English
- Type: PhD Manuscript
- Identifier: http://hdl.handle.net/11260/2016 , vital:40802 , DOCTOR OF PHILOSOPHY (Ph.D) (In Health Sciences, Physiology)
- Description: Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The mechanisms which mediate this heightened risk are poorly understood; it was long believed that pre-eclampsia was cured by delivery of the foetus. But it is now apparent that the risks of complications persist for some time after delivery. The aim of the study was to establish the presence and pattern of endothelial dysfunction during gestation and postpartum among women who develop preeclampsia in the Transkei region of South Africa. This was a two parts study: part one was a cross-sectional experimental study, which involved 85 women with established pre-eclampsia (PE) and 112 pregnant controls (PC); part two was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC). Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperaemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperaemia index (RHI) as a measure of endothelial function. In part one, the measurements were adjusted for maternal age, heart rate, mean arterial pressure, and aortic time to wave reflection and expressed as multiples of the median (MoM) of the pregnant control group.PE group compared with pregnant controls, PE had higher median pulse wave velocity [1.2 inter-quartile range (IQR) 1.08-1.35 MoM vs. 0.97, IQR 8.6-1.09 MoM; p=0.0000].In contrast, there were no ii significant differences between the two groups median of central augmentation index (1.0, IQR -0.4 -1.7 MoM vs. 0.9, IQR 0.69-1.36 MoM; p=0.765). RHI was higher in PE than controls (1.16, IQR 1-1.33 MoM vs. 1, IQR 0.9- 1.18 MoM; p=0.0000). Early-onset pre-eclampsia had higher median brachial blood pressure (87.5, IQR 79-101 vs. 82, IQR 65-88 mmHg; p=0.02), higher mean arterial pressure (110, IQR97-120 vs.101 IQR 88-110 mmHg; p=0.04) and higher central diastolic blood pressure (90, IQR 80-103 vs.84, IQR 67-90 mmHg; p=0.017) than the lateonset pre-eclampsia. Pulse wave velocity (carotid-femoral) was increased in pregnant women with preeclampsia during the third trimester. Reactive hyperaemia index, a measure of endothelial function, was higher in pregnant women with pre-eclampsia than pregnant controls. This suggests that regional (aortic) arterial stiffness is increased, but endothelial function, as assessed by ENDOPAT 2000 device, was not compromised in rural African women with pre-eclampsia. Pulse wave reflection, as assessed by augmentation index adjusted to heart rate of 75 beats/min, was increased in women who had early-onset pre-eclampsia more than those with late-onset pre-eclampsia. Brachial diastolic blood pressure was higher in early-onset pre-eclampsia which resulted in lower brachial pulse pressure than in the late-onset pre-eclampsia. Furthermore, the mean arterial pressure was higher in early-onset than late onset pre-eclampsia. This suggests that early onset pre-eclampsia is more severe condition than the late-onset pre-eclampsia. In part two, pulse wave velocity remained significantly higher in previously preeclamptic women than non-pregnant controls up to three months after delivery iii (p<0.05).Then it reduced to non significant values. Regional (aortic) arterial stiffness, though it persists for some time after delivery, it is transitory in previously pre-eclamptic women from the rural Africa setting. All blood pressure indices (central and brachial pressures), were increased in women who previously had pre-eclampsia as compared to non pregnant controls up to one year postpartum. Although pulse wave velocity and augmentation decrease to low values with time after delivery increased blood pressure is an indication of compromised arterial compliance in women with previously pre-eclampsia.
- Full Text:
- Authors: AMBROSE VINCENT NAMUGOWA
- Date: 2014
- Language: English
- Type: PhD Manuscript
- Identifier: http://hdl.handle.net/11260/2016 , vital:40802 , DOCTOR OF PHILOSOPHY (Ph.D) (In Health Sciences, Physiology)
- Description: Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The mechanisms which mediate this heightened risk are poorly understood; it was long believed that pre-eclampsia was cured by delivery of the foetus. But it is now apparent that the risks of complications persist for some time after delivery. The aim of the study was to establish the presence and pattern of endothelial dysfunction during gestation and postpartum among women who develop preeclampsia in the Transkei region of South Africa. This was a two parts study: part one was a cross-sectional experimental study, which involved 85 women with established pre-eclampsia (PE) and 112 pregnant controls (PC); part two was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC). Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperaemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperaemia index (RHI) as a measure of endothelial function. In part one, the measurements were adjusted for maternal age, heart rate, mean arterial pressure, and aortic time to wave reflection and expressed as multiples of the median (MoM) of the pregnant control group.PE group compared with pregnant controls, PE had higher median pulse wave velocity [1.2 inter-quartile range (IQR) 1.08-1.35 MoM vs. 0.97, IQR 8.6-1.09 MoM; p=0.0000].In contrast, there were no ii significant differences between the two groups median of central augmentation index (1.0, IQR -0.4 -1.7 MoM vs. 0.9, IQR 0.69-1.36 MoM; p=0.765). RHI was higher in PE than controls (1.16, IQR 1-1.33 MoM vs. 1, IQR 0.9- 1.18 MoM; p=0.0000). Early-onset pre-eclampsia had higher median brachial blood pressure (87.5, IQR 79-101 vs. 82, IQR 65-88 mmHg; p=0.02), higher mean arterial pressure (110, IQR97-120 vs.101 IQR 88-110 mmHg; p=0.04) and higher central diastolic blood pressure (90, IQR 80-103 vs.84, IQR 67-90 mmHg; p=0.017) than the lateonset pre-eclampsia. Pulse wave velocity (carotid-femoral) was increased in pregnant women with preeclampsia during the third trimester. Reactive hyperaemia index, a measure of endothelial function, was higher in pregnant women with pre-eclampsia than pregnant controls. This suggests that regional (aortic) arterial stiffness is increased, but endothelial function, as assessed by ENDOPAT 2000 device, was not compromised in rural African women with pre-eclampsia. Pulse wave reflection, as assessed by augmentation index adjusted to heart rate of 75 beats/min, was increased in women who had early-onset pre-eclampsia more than those with late-onset pre-eclampsia. Brachial diastolic blood pressure was higher in early-onset pre-eclampsia which resulted in lower brachial pulse pressure than in the late-onset pre-eclampsia. Furthermore, the mean arterial pressure was higher in early-onset than late onset pre-eclampsia. This suggests that early onset pre-eclampsia is more severe condition than the late-onset pre-eclampsia. In part two, pulse wave velocity remained significantly higher in previously preeclamptic women than non-pregnant controls up to three months after delivery iii (p<0.05).Then it reduced to non significant values. Regional (aortic) arterial stiffness, though it persists for some time after delivery, it is transitory in previously pre-eclamptic women from the rural Africa setting. All blood pressure indices (central and brachial pressures), were increased in women who previously had pre-eclampsia as compared to non pregnant controls up to one year postpartum. Although pulse wave velocity and augmentation decrease to low values with time after delivery increased blood pressure is an indication of compromised arterial compliance in women with previously pre-eclampsia.
- Full Text:
ARTERIAL TONE IN BLACK WOMEN WITH PREECLAMPSIA FROM TRANSKEI REGION OF SOUTH AFRICA
- Authors: AMBROSE VINCENT NAMUGOWA
- Date: 2014
- Language: English
- Type: PhD Manuscript
- Identifier: http://hdl.handle.net/11260/2023 , vital:40803 , DOCTOR OF PHILOSOPHY (Ph.D) (In Health Sciences, Physiology)
- Description: Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The mechanisms which mediate this heightened risk are poorly understood; it was long believed that pre-eclampsia was cured by delivery of the foetus. But it is now apparent that the risks of complications persist for some time after delivery. The aim of the study was to establish the presence and pattern of endothelial dysfunction during gestation and postpartum among women who develop preeclampsia in the Transkei region of South Africa. This was a two parts study: part one was a cross-sectional experimental study, which involved 85 women with established pre-eclampsia (PE) and 112 pregnant controls (PC); part two was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC). Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperaemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperaemia index (RHI) as a measure of endothelial function. In part one, the measurements were adjusted for maternal age, heart rate, mean arterial pressure, and aortic time to wave reflection and expressed as multiples of the median (MoM) of the pregnant control group.PE group compared with pregnant controls, PE had higher median pulse wave velocity [1.2 inter-quartile range (IQR) 1.08-1.35 MoM vs. 0.97, IQR 8.6-1.09 MoM; p=0.0000].In contrast, there were no ii significant differences between the two groups median of central augmentation index (1.0, IQR -0.4 -1.7 MoM vs. 0.9, IQR 0.69-1.36 MoM; p=0.765). RHI was higher in PE than controls (1.16, IQR 1-1.33 MoM vs. 1, IQR 0.9- 1.18 MoM; p=0.0000). Early-onset pre-eclampsia had higher median brachial blood pressure (87.5, IQR 79-101 vs. 82, IQR 65-88 mmHg; p=0.02), higher mean arterial pressure (110, IQR97-120 vs.101 IQR 88-110 mmHg; p=0.04) and higher central diastolic blood pressure (90, IQR 80-103 vs.84, IQR 67-90 mmHg; p=0.017) than the lateonset pre-eclampsia. Pulse wave velocity (carotid-femoral) was increased in pregnant women with preeclampsia during the third trimester. Reactive hyperaemia index, a measure of endothelial function, was higher in pregnant women with pre-eclampsia than pregnant controls. This suggests that regional (aortic) arterial stiffness is increased, but endothelial function, as assessed by ENDOPAT 2000 device, was not compromised in rural African women with pre-eclampsia. Pulse wave reflection, as assessed by augmentation index adjusted to heart rate of 75 beats/min, was increased in women who had early-onset pre-eclampsia more than those with late-onset pre-eclampsia. Brachial diastolic blood pressure was higher in early-onset pre-eclampsia which resulted in lower brachial pulse pressure than in the late-onset pre-eclampsia. Furthermore, the mean arterial pressure was higher in early-onset than late onset pre-eclampsia. This suggests that early onset pre-eclampsia is more severe condition than the late-onset pre-eclampsia. In part two, pulse wave velocity remained significantly higher in previously preeclamptic women than non-pregnant controls up to three months after delivery iii (p<0.05).Then it reduced to non significant values. Regional (aortic) arterial stiffness, though it persists for some time after delivery, it is transitory in previously pre-eclamptic women from the rural Africa setting. All blood pressure indices (central and brachial pressures), were increased in women who previously had pre-eclampsia as compared to non pregnant controls up to one year postpartum. Although pulse wave velocity and augmentation decrease to low values with time after delivery increased blood pressure is an indication of compromised arterial compliance in women with previously pre-eclampsia.
- Full Text:
- Authors: AMBROSE VINCENT NAMUGOWA
- Date: 2014
- Language: English
- Type: PhD Manuscript
- Identifier: http://hdl.handle.net/11260/2023 , vital:40803 , DOCTOR OF PHILOSOPHY (Ph.D) (In Health Sciences, Physiology)
- Description: Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The mechanisms which mediate this heightened risk are poorly understood; it was long believed that pre-eclampsia was cured by delivery of the foetus. But it is now apparent that the risks of complications persist for some time after delivery. The aim of the study was to establish the presence and pattern of endothelial dysfunction during gestation and postpartum among women who develop preeclampsia in the Transkei region of South Africa. This was a two parts study: part one was a cross-sectional experimental study, which involved 85 women with established pre-eclampsia (PE) and 112 pregnant controls (PC); part two was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC). Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperaemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperaemia index (RHI) as a measure of endothelial function. In part one, the measurements were adjusted for maternal age, heart rate, mean arterial pressure, and aortic time to wave reflection and expressed as multiples of the median (MoM) of the pregnant control group.PE group compared with pregnant controls, PE had higher median pulse wave velocity [1.2 inter-quartile range (IQR) 1.08-1.35 MoM vs. 0.97, IQR 8.6-1.09 MoM; p=0.0000].In contrast, there were no ii significant differences between the two groups median of central augmentation index (1.0, IQR -0.4 -1.7 MoM vs. 0.9, IQR 0.69-1.36 MoM; p=0.765). RHI was higher in PE than controls (1.16, IQR 1-1.33 MoM vs. 1, IQR 0.9- 1.18 MoM; p=0.0000). Early-onset pre-eclampsia had higher median brachial blood pressure (87.5, IQR 79-101 vs. 82, IQR 65-88 mmHg; p=0.02), higher mean arterial pressure (110, IQR97-120 vs.101 IQR 88-110 mmHg; p=0.04) and higher central diastolic blood pressure (90, IQR 80-103 vs.84, IQR 67-90 mmHg; p=0.017) than the lateonset pre-eclampsia. Pulse wave velocity (carotid-femoral) was increased in pregnant women with preeclampsia during the third trimester. Reactive hyperaemia index, a measure of endothelial function, was higher in pregnant women with pre-eclampsia than pregnant controls. This suggests that regional (aortic) arterial stiffness is increased, but endothelial function, as assessed by ENDOPAT 2000 device, was not compromised in rural African women with pre-eclampsia. Pulse wave reflection, as assessed by augmentation index adjusted to heart rate of 75 beats/min, was increased in women who had early-onset pre-eclampsia more than those with late-onset pre-eclampsia. Brachial diastolic blood pressure was higher in early-onset pre-eclampsia which resulted in lower brachial pulse pressure than in the late-onset pre-eclampsia. Furthermore, the mean arterial pressure was higher in early-onset than late onset pre-eclampsia. This suggests that early onset pre-eclampsia is more severe condition than the late-onset pre-eclampsia. In part two, pulse wave velocity remained significantly higher in previously preeclamptic women than non-pregnant controls up to three months after delivery iii (p<0.05).Then it reduced to non significant values. Regional (aortic) arterial stiffness, though it persists for some time after delivery, it is transitory in previously pre-eclamptic women from the rural Africa setting. All blood pressure indices (central and brachial pressures), were increased in women who previously had pre-eclampsia as compared to non pregnant controls up to one year postpartum. Although pulse wave velocity and augmentation decrease to low values with time after delivery increased blood pressure is an indication of compromised arterial compliance in women with previously pre-eclampsia.
- Full Text: