Incidence of porcine circovirus type 2 and porcine parvoviruses in swine herds of some communities in Eastern Cape, South Africa
- Authors: Afolabi, Kayode Olayinka
- Date: 2018
- Subjects: Swine -- Diseases Swine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9691 , vital:34820
- Description: Porcine circovirus type 2 (PCV2) is one of the swine pathogens of global economic importance. Since its first detection in early 1990s as the main etiologic agent of porcine multisystemic wasting syndrome (PMWS) and many other porcine circovirus-associated diseases (PCVAD), the virus has been extensively studied and has been found to be present in virtually all the pig producing countries of the world. As a viral pathogen that brings about clinical diseases aided by co-infecting pathogens, the involvement of many other viral agents including porcine parvoviruses (PPVs) have caught the attention of stakeholders worldwide. However, no surveillance study of the viral pathogens has been carried out in South Africa as there are little or no information on their prevalence in the swine herds of the country. This present study therefore aimed at detection and molecular characterization of PCV2 and PPVs in swine herds of some selected communities in Eastern Cape Province, South Africa. A total of 375 field samples were collected from seven commercial and communal farms from three District Municipalities of Eastern Cape, South Africa between 2015 and 2016. Structured questionnaires were also administered to each farm at the time of sample collection to obtain some important information relating to health status and farm management practices in the sampled farms. With the aid of conventional PCR method, 339 samples were initially screened for the presence of PCV2; positive amplicons were sequenced and obtained partial genomes of the virus were preliminarily analyzed. In order to obtain the complete genomes of the virus, four overlapping primer pairs were used to amplify the full-genome of PCV2 from the initial positive samples; amplified genomes were sequenced using the Sanger methods, sequenced PCV2 genomes were assembled and characterized. Furthermore, the prevalences of some designated PPVs in the sampled farms were obtained using 110 samples randomly selected from the previously archived samples and screened with 6 different primer pairs specific for the detection of 7 PPVs. All the amplified parvoviruses’ genomes were sequenced; their sequenced partial genomes were subsequently base-culled and analysed. The data obtained revealed that 54/339 (15.93 percent) samples from the swine herds were positive for PCV2; whereas the degree of occurrence of the viral pathogen as observed at farm level ranges from approximately 5.6 to 60 percent. The majority 15/17 (88 percent) of the analyzed partial sequences were found clustering with other PCV2b strains in the phylogenetic analysis. More interestingly, two other sequences obtained were also found clustering within PCV2d genotype in the initial screening and analysis. Furthermore, 15 complete PCV2 genomes were successfully amplified, sequenced and assembled. NJ and ML phylogenetic analysis of the complete ORF2 gene and full genomes unanimously showed 11 of the assembled genomes belonging to genotype PCV2b. Another 3 of the characterized sequences formed clade with other reference mutant PCV2b and PCV2b subtype 1C (PCV2d) strains from different parts of the world. The last sequence however, clustered with other reference strains belonging to PCV2 intermediate clade 2 (PCV2-IM2) recently identified in a global PCV2 strains phylogenetic analysis. Other genetic analyses including multiple sequence alignment and p-distance analysis also confirmed the outcomes of the phylogenetic analyses of the complete capsid gene and fullgenomes of the virus. On the other hand, the findings of the molecular profiling for PPVs showed that all the screened parvoviruses were present in the study area, having prevalence of 29.1 percent (PPV1), 21.8 percent (PPV2), 5.5 percent (PPV3), 43.6 percent (PPV4), 21.8 percent (PBo-likeV) and 44.6 percent for PBoV1 and PBoV2. Double infection of the screened PPVs was observed to be very rampant among the pigs as high as 20/110 (18.2 percent) for PPV2/PPV4 and PPV4/PBoV; followed by 19/110 (17.3 percent) of the samples for PPV1/PPV4 and PPV1/PBoV. Three of the viruses were found simultaneously in 19 of the screened samples representing 17.3 percent, whereas 8 (7.3 percent) samples were positive for four of the viruses. Phylogenetic analyses of PPV1, PPV2 and PBoVs 1 and 2 were conducted with two major clades homologous for each of them. This is the first report of PCV2 in swine herds of the Province and the first detection of PCV2b, PCV2d and PCV2-IM2 strains in South African swine herds. It follows the first reported case of PCV2a in an outbreak of porcine multisystemic wasting syndrome (PMWS) in Gauteng Province, South Africa over two decades ago. Also, this is the first major epidemiologic study on PPVs in the country following the initial case study of 1975. These findings confirmed the presence of the allimportant viral pathogens among pigs and also give preliminary insights into the possibility of co-infections of the pathogens in the studied area. This could however result in a serious large scale outbreak of devastating disease(s) associated with the viral pathogens, thereby ultimately resulting in huge economic losses if no appropriate measures are taken to effectively curb their spread across the country.
- Full Text:
- Date Issued: 2018
- Authors: Afolabi, Kayode Olayinka
- Date: 2018
- Subjects: Swine -- Diseases Swine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9691 , vital:34820
- Description: Porcine circovirus type 2 (PCV2) is one of the swine pathogens of global economic importance. Since its first detection in early 1990s as the main etiologic agent of porcine multisystemic wasting syndrome (PMWS) and many other porcine circovirus-associated diseases (PCVAD), the virus has been extensively studied and has been found to be present in virtually all the pig producing countries of the world. As a viral pathogen that brings about clinical diseases aided by co-infecting pathogens, the involvement of many other viral agents including porcine parvoviruses (PPVs) have caught the attention of stakeholders worldwide. However, no surveillance study of the viral pathogens has been carried out in South Africa as there are little or no information on their prevalence in the swine herds of the country. This present study therefore aimed at detection and molecular characterization of PCV2 and PPVs in swine herds of some selected communities in Eastern Cape Province, South Africa. A total of 375 field samples were collected from seven commercial and communal farms from three District Municipalities of Eastern Cape, South Africa between 2015 and 2016. Structured questionnaires were also administered to each farm at the time of sample collection to obtain some important information relating to health status and farm management practices in the sampled farms. With the aid of conventional PCR method, 339 samples were initially screened for the presence of PCV2; positive amplicons were sequenced and obtained partial genomes of the virus were preliminarily analyzed. In order to obtain the complete genomes of the virus, four overlapping primer pairs were used to amplify the full-genome of PCV2 from the initial positive samples; amplified genomes were sequenced using the Sanger methods, sequenced PCV2 genomes were assembled and characterized. Furthermore, the prevalences of some designated PPVs in the sampled farms were obtained using 110 samples randomly selected from the previously archived samples and screened with 6 different primer pairs specific for the detection of 7 PPVs. All the amplified parvoviruses’ genomes were sequenced; their sequenced partial genomes were subsequently base-culled and analysed. The data obtained revealed that 54/339 (15.93 percent) samples from the swine herds were positive for PCV2; whereas the degree of occurrence of the viral pathogen as observed at farm level ranges from approximately 5.6 to 60 percent. The majority 15/17 (88 percent) of the analyzed partial sequences were found clustering with other PCV2b strains in the phylogenetic analysis. More interestingly, two other sequences obtained were also found clustering within PCV2d genotype in the initial screening and analysis. Furthermore, 15 complete PCV2 genomes were successfully amplified, sequenced and assembled. NJ and ML phylogenetic analysis of the complete ORF2 gene and full genomes unanimously showed 11 of the assembled genomes belonging to genotype PCV2b. Another 3 of the characterized sequences formed clade with other reference mutant PCV2b and PCV2b subtype 1C (PCV2d) strains from different parts of the world. The last sequence however, clustered with other reference strains belonging to PCV2 intermediate clade 2 (PCV2-IM2) recently identified in a global PCV2 strains phylogenetic analysis. Other genetic analyses including multiple sequence alignment and p-distance analysis also confirmed the outcomes of the phylogenetic analyses of the complete capsid gene and fullgenomes of the virus. On the other hand, the findings of the molecular profiling for PPVs showed that all the screened parvoviruses were present in the study area, having prevalence of 29.1 percent (PPV1), 21.8 percent (PPV2), 5.5 percent (PPV3), 43.6 percent (PPV4), 21.8 percent (PBo-likeV) and 44.6 percent for PBoV1 and PBoV2. Double infection of the screened PPVs was observed to be very rampant among the pigs as high as 20/110 (18.2 percent) for PPV2/PPV4 and PPV4/PBoV; followed by 19/110 (17.3 percent) of the samples for PPV1/PPV4 and PPV1/PBoV. Three of the viruses were found simultaneously in 19 of the screened samples representing 17.3 percent, whereas 8 (7.3 percent) samples were positive for four of the viruses. Phylogenetic analyses of PPV1, PPV2 and PBoVs 1 and 2 were conducted with two major clades homologous for each of them. This is the first report of PCV2 in swine herds of the Province and the first detection of PCV2b, PCV2d and PCV2-IM2 strains in South African swine herds. It follows the first reported case of PCV2a in an outbreak of porcine multisystemic wasting syndrome (PMWS) in Gauteng Province, South Africa over two decades ago. Also, this is the first major epidemiologic study on PPVs in the country following the initial case study of 1975. These findings confirmed the presence of the allimportant viral pathogens among pigs and also give preliminary insights into the possibility of co-infections of the pathogens in the studied area. This could however result in a serious large scale outbreak of devastating disease(s) associated with the viral pathogens, thereby ultimately resulting in huge economic losses if no appropriate measures are taken to effectively curb their spread across the country.
- Full Text:
- Date Issued: 2018
Potential use of carbon nanotubes as a nanofiller for natural rubber latex condoms
- Authors: Agbakoba, Victor Chike
- Date: 2018
- Subjects: Nanotubes , Rubber chemistry Nanocomposites (Materials) Nanostructured materials
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/23393 , vital:30538
- Description: The recent advancement in the field of nano-technology has raised much interest in the area of natural rubber latex (NRL) processing. This interest stems from the exceptional properties of nano-material and the promising results obtained by several researchers. Studies have shown that very low loadings of inorganic nanomaterials such as carbon nanotube (CNT) in NRL matrix leads to enhanced tensile strength, tensile modulus, tear resistance and aberration resistance. Thus providing a great prospect for reinforcement of thin film NRL articles such as condom. In this research, prevulcanised natural rubber latex (PvNRL) composite blends containing single walled carbon nanotubes (SWCNTs) were prepared via direct mixing. A progressive discolouration of PvNRL was observed with increased loadings of CNTs. Thermal analysis revealed faster drying rates for the composite blends containing SWCNT. Results from equilibrium swelling experiments also suggested a slight increase in crosslink density in the presence of SWCNT. There was a significant influence on flow behaviour of PvNRL as a result of varying loadings of SWCNT suspension. This was reflected as a change in pseudoplasticity and apparent viscosity. For Instance, apparent viscosity at a shear rate of 1 s-1 at 25°C for PvNRL with ~0.08% SWCNT was 2.5 Pa.s, compared to 0.49 Pa.s for the blends with 0.02% SWCNT. Condoms were moulded via the straight dipping technique using custom made glass formers. A series of dilutions was performed to correct the viscosity differences. This also ensured good consistency and promoted uniform deposition of PvNRL on the glass former. The average dimensions of the condoms produced in terms of length and width were ~191.17 ± 5.17 mm and 52.67 ± 5.17 mm respectively. Thickness measurement varied slightly according to the method of determination. The water leakage test suggested the absence of holes in the condoms produced. However, results from electrical leakage test contradicted those from water leak test. The results from infrared spectroscopy (FTIR) did not confirm the presence of chemical interactions between the SWCNT and PvNRL matrix. Glass transition temperature (Tg) was also unaffected across the blends. The stiffness (or modulus) was unaffected in all the condoms, as revealed by results from indentation hardness analysis. The SWCNT showed no significant influence on thermal decomposition temperatures of the condoms. Nonetheless, images from optical microscopy revealed increased surface roughness corresponding to higher loadings of SWCNT. Results from stress relaxation studies revealed improved retention of modulus under constant strain for condom samples containing SWCNT.
- Full Text:
- Date Issued: 2018
- Authors: Agbakoba, Victor Chike
- Date: 2018
- Subjects: Nanotubes , Rubber chemistry Nanocomposites (Materials) Nanostructured materials
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/23393 , vital:30538
- Description: The recent advancement in the field of nano-technology has raised much interest in the area of natural rubber latex (NRL) processing. This interest stems from the exceptional properties of nano-material and the promising results obtained by several researchers. Studies have shown that very low loadings of inorganic nanomaterials such as carbon nanotube (CNT) in NRL matrix leads to enhanced tensile strength, tensile modulus, tear resistance and aberration resistance. Thus providing a great prospect for reinforcement of thin film NRL articles such as condom. In this research, prevulcanised natural rubber latex (PvNRL) composite blends containing single walled carbon nanotubes (SWCNTs) were prepared via direct mixing. A progressive discolouration of PvNRL was observed with increased loadings of CNTs. Thermal analysis revealed faster drying rates for the composite blends containing SWCNT. Results from equilibrium swelling experiments also suggested a slight increase in crosslink density in the presence of SWCNT. There was a significant influence on flow behaviour of PvNRL as a result of varying loadings of SWCNT suspension. This was reflected as a change in pseudoplasticity and apparent viscosity. For Instance, apparent viscosity at a shear rate of 1 s-1 at 25°C for PvNRL with ~0.08% SWCNT was 2.5 Pa.s, compared to 0.49 Pa.s for the blends with 0.02% SWCNT. Condoms were moulded via the straight dipping technique using custom made glass formers. A series of dilutions was performed to correct the viscosity differences. This also ensured good consistency and promoted uniform deposition of PvNRL on the glass former. The average dimensions of the condoms produced in terms of length and width were ~191.17 ± 5.17 mm and 52.67 ± 5.17 mm respectively. Thickness measurement varied slightly according to the method of determination. The water leakage test suggested the absence of holes in the condoms produced. However, results from electrical leakage test contradicted those from water leak test. The results from infrared spectroscopy (FTIR) did not confirm the presence of chemical interactions between the SWCNT and PvNRL matrix. Glass transition temperature (Tg) was also unaffected across the blends. The stiffness (or modulus) was unaffected in all the condoms, as revealed by results from indentation hardness analysis. The SWCNT showed no significant influence on thermal decomposition temperatures of the condoms. Nonetheless, images from optical microscopy revealed increased surface roughness corresponding to higher loadings of SWCNT. Results from stress relaxation studies revealed improved retention of modulus under constant strain for condom samples containing SWCNT.
- Full Text:
- Date Issued: 2018
The psycho-social functioning and experiences of children in child-headed households in Gauteng Province, South Africa
- Authors: Agere, Leonard Munyaradzi
- Date: 2018
- Subjects: Adult children -- South Africa -- Conduct of life Youth-headed households -- South Africa Child support -- South Africa
- Language: English
- Type: Thesis , Doctoral , Social Work
- Identifier: http://hdl.handle.net/10353/10646 , vital:35651
- Description: The study was aimed at investigating the psycho-social needs and lived experiences of child headed households in the Gauteng Province of South Africa. A mixed methods approach was used to collect and analyse the data. The qualitative approach was the dominant one, while a quantitative approach was used to corroborate the qualitative findings. The quantitative data was collected through a survey. Three hundred questionnaires were distributed among children in child headed households. The child headed households were selected through simple random sampling from the databases of the NGOs and community based organisations that had agreed to participate in the study. The quantitative component of the study produced results that supported the qualitative findings. The qualitative data was collected through in-depth interviews and focus group discussions, which were conducted with purposively selected social service practitioners and community structures who were involved in work with child headed households. The resilience approach, which posits that humans are born with inherent reserves to face adversity, and the ecological systems theory, which postulates the framework in which an individual can be understood in his constant interactions and relationships within community and wider society, inform this study. The findings of the study indicate that there were various psycho social needs and challenges that child headed households faced. As Maslow postulated in his hierarchy of needs theory, inferences were made to the diverse needs of the child headed households. Physiological needs like food, clothing and finance were found to be more presenting and eminent needs for the child headed households. The study findings highlighted safety needs in the form of need for formal housing as the majority lived in informal settlements where they were exposed to much vulnerability like violence, sexual exploitation and other social misdemeanours. Other needs were esteem and familial needs, which provided a platform to foster senses of identity and belonging. However, there were other child headed households who were fortunate to have extended family members and community based organisations that assisted by providing these needs and these gestures were appreciated by the households as they ameliorated dire situations and cushioned them from absolute poverty. The findings further revealed that the psycho social challenges and needs did not only present when the household became child headed household but when their parent/s was still with them and were only exacerbated in their absence. The effects of living with parental illness, sadness and anxiety due to dramatic changes in dynamics, pain and trauma witnessing a parent dying were among the psychosocial challenges faced when the parent was still present with the children. After their departure or absence the challenges shifted and the debilitating effects of grief and loss, emotional trauma, living without adult caregiver and stigma and discrimination, were among the cocktail of challenges that the child headed households faced. However, others had support from extended family members and community structures that supported them with palliative care for the terminally ill and this afforded them the much needed respite as they focused on their studies and enjoyed their rights to be children. The study reveals that children have several coping mechanisms that exude their resilience and this includes support from social workers in promoting sustainable development goals (SDG’s) including no poverty, good health and well-being and quality education (goals 1, 3 and 4). The study highlighted that others had to supplement education with paid work (informal) whilst some ended up disengaging from their education to pursue paid employment to eke a living and support their siblings. The community and NGO’s were seen as vital components of the ecosystem that promoted the resilience of the child headed households in coping with their day to day challenges and needs. On the basis of the findings, it is recommended that the South African government should, among other things, provide a properly resourced, co-ordinated and well managed child protection system to facilitate constituency work that responds to the real needs of child headed households and SMART planning by social workers, with systemic teaming around CHH with the DSD as lead agency. The study also recommends a psychosocial approach to CHH care in the form of a model that rallies for robust assessments that social service practitioners and every structure that has the “duty to care” for CHH, can embed in their practice for improved outcomes.
- Full Text:
- Date Issued: 2018
- Authors: Agere, Leonard Munyaradzi
- Date: 2018
- Subjects: Adult children -- South Africa -- Conduct of life Youth-headed households -- South Africa Child support -- South Africa
- Language: English
- Type: Thesis , Doctoral , Social Work
- Identifier: http://hdl.handle.net/10353/10646 , vital:35651
- Description: The study was aimed at investigating the psycho-social needs and lived experiences of child headed households in the Gauteng Province of South Africa. A mixed methods approach was used to collect and analyse the data. The qualitative approach was the dominant one, while a quantitative approach was used to corroborate the qualitative findings. The quantitative data was collected through a survey. Three hundred questionnaires were distributed among children in child headed households. The child headed households were selected through simple random sampling from the databases of the NGOs and community based organisations that had agreed to participate in the study. The quantitative component of the study produced results that supported the qualitative findings. The qualitative data was collected through in-depth interviews and focus group discussions, which were conducted with purposively selected social service practitioners and community structures who were involved in work with child headed households. The resilience approach, which posits that humans are born with inherent reserves to face adversity, and the ecological systems theory, which postulates the framework in which an individual can be understood in his constant interactions and relationships within community and wider society, inform this study. The findings of the study indicate that there were various psycho social needs and challenges that child headed households faced. As Maslow postulated in his hierarchy of needs theory, inferences were made to the diverse needs of the child headed households. Physiological needs like food, clothing and finance were found to be more presenting and eminent needs for the child headed households. The study findings highlighted safety needs in the form of need for formal housing as the majority lived in informal settlements where they were exposed to much vulnerability like violence, sexual exploitation and other social misdemeanours. Other needs were esteem and familial needs, which provided a platform to foster senses of identity and belonging. However, there were other child headed households who were fortunate to have extended family members and community based organisations that assisted by providing these needs and these gestures were appreciated by the households as they ameliorated dire situations and cushioned them from absolute poverty. The findings further revealed that the psycho social challenges and needs did not only present when the household became child headed household but when their parent/s was still with them and were only exacerbated in their absence. The effects of living with parental illness, sadness and anxiety due to dramatic changes in dynamics, pain and trauma witnessing a parent dying were among the psychosocial challenges faced when the parent was still present with the children. After their departure or absence the challenges shifted and the debilitating effects of grief and loss, emotional trauma, living without adult caregiver and stigma and discrimination, were among the cocktail of challenges that the child headed households faced. However, others had support from extended family members and community structures that supported them with palliative care for the terminally ill and this afforded them the much needed respite as they focused on their studies and enjoyed their rights to be children. The study reveals that children have several coping mechanisms that exude their resilience and this includes support from social workers in promoting sustainable development goals (SDG’s) including no poverty, good health and well-being and quality education (goals 1, 3 and 4). The study highlighted that others had to supplement education with paid work (informal) whilst some ended up disengaging from their education to pursue paid employment to eke a living and support their siblings. The community and NGO’s were seen as vital components of the ecosystem that promoted the resilience of the child headed households in coping with their day to day challenges and needs. On the basis of the findings, it is recommended that the South African government should, among other things, provide a properly resourced, co-ordinated and well managed child protection system to facilitate constituency work that responds to the real needs of child headed households and SMART planning by social workers, with systemic teaming around CHH with the DSD as lead agency. The study also recommends a psychosocial approach to CHH care in the form of a model that rallies for robust assessments that social service practitioners and every structure that has the “duty to care” for CHH, can embed in their practice for improved outcomes.
- Full Text:
- Date Issued: 2018
Development of InSb/GaSb quantum dots by MOVPE
- Authors: Ahia, Chinedu Christian
- Date: 2018
- Subjects: Semiconductors , Quantum electronics Organometallic compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23382 , vital:30537
- Description: There has been an increasing interest in the modification of semiconductor band structures through the reduction of their dimensions, which simultaneously increases the band gap energy of the material and gives rise to flexibility in device properties. Advances in III-V antimony (Sb) based semiconductor fabrication have triggered the quest for extension of the emission/absorption wavelength range of this family of compounds for optoelectronic devices operating in the mid-infrared region of the electromagnetic spectrum. An interesting material system for mid-infrared (MIR) applications is indium antimonide (InSb) quantum dots (QDs) within a gallium antimonide (GaSb) matrix. However, its band alignment and emission wavelength has been the subject of some interest and controversy over the years. This study focuses on the development of InSb/GaSb QDs by metal organic vapour phase epitaxy (MOVPE). The samples were grown on different substrates using various growth parameters in order to vary the size, density and aspect ratio of the dots. Interfacial growth interruptions while flowing various source precursors through the reactor were investigated in order to influence the chemical termination of the surface, and hence the resulting strain in the structures. The samples were characterized using photoluminescence spectroscopy, scanning probe microscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Likewise, the band alignment, energy levels, and carrier wave functions of the samples in this work were modelled theoretically using the nextnanomat software (version 3.1.0.0). A comparison of growth on two different GaSb substrates [(100) 2° off towards <111>B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.
- Full Text:
- Date Issued: 2018
- Authors: Ahia, Chinedu Christian
- Date: 2018
- Subjects: Semiconductors , Quantum electronics Organometallic compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23382 , vital:30537
- Description: There has been an increasing interest in the modification of semiconductor band structures through the reduction of their dimensions, which simultaneously increases the band gap energy of the material and gives rise to flexibility in device properties. Advances in III-V antimony (Sb) based semiconductor fabrication have triggered the quest for extension of the emission/absorption wavelength range of this family of compounds for optoelectronic devices operating in the mid-infrared region of the electromagnetic spectrum. An interesting material system for mid-infrared (MIR) applications is indium antimonide (InSb) quantum dots (QDs) within a gallium antimonide (GaSb) matrix. However, its band alignment and emission wavelength has been the subject of some interest and controversy over the years. This study focuses on the development of InSb/GaSb QDs by metal organic vapour phase epitaxy (MOVPE). The samples were grown on different substrates using various growth parameters in order to vary the size, density and aspect ratio of the dots. Interfacial growth interruptions while flowing various source precursors through the reactor were investigated in order to influence the chemical termination of the surface, and hence the resulting strain in the structures. The samples were characterized using photoluminescence spectroscopy, scanning probe microscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Likewise, the band alignment, energy levels, and carrier wave functions of the samples in this work were modelled theoretically using the nextnanomat software (version 3.1.0.0). A comparison of growth on two different GaSb substrates [(100) 2° off towards <111>B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.
- Full Text:
- Date Issued: 2018
Identity, culture, architecture & the design of a Chinese cultural school in Morningside, Kabega, Port Elizabeth, South Africa
- Authors: Akpokiniovo, Oghenetejiri
- Date: 2018
- Subjects: Architecture, Chinese -- South Africa -- Port Elizabeth , Interior architecture School buildings -- Design and construction
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/42727 , vital:36685
- Description: This treatise is born out of preoccupation with Identity, Culture and Architecture. Through the study of the fragility of the South-African Chinese community: their double heritage, their quest for a sense of place and permanence with the establishment of Chinese Schools that maintain the Chinese culture. It begins with identifying their almost unstable and fragmented nature of movement, their struggle to find a ‘place’ in Port Elizabeth, especially after the establishment of the Group Areas Act of 1960 and their fight against apartheid and discrimination. It becomes clear that migration, racial segregation, confusion, forced removals, and displacement have been their legacy in South Africa. The purpose of this document is to investigate the symbolic nature of architecture, and how it can be used as a tangible medium to bring about an affirmation of identity, and create a sense of place for the future; giving credence to the celebration of culture and social interaction. Through the use of literature reviews, informal interviews, desktop research, analysis, precedent studies and other qualitative studies; there will be an understanding of the community in terms of how they came about settling in South Africa; their migratory patterns due to forced removals and the current status of the community in terms of cultural revolution; understanding the cultural issues the community face; in the establishment of a centralised symbolic precinct that allows for the celebration and promotion of culture. Through the design of the Chinese Cultural School, it will be demonstrated that in order to create a sense of place for the Chinese community, aiding in integration and restoration; one will need to engage in the argument of the vitality of authentic architecture, the vernacular language of a particular culture, and the subjectivity of identity especially in a context outside of its homeland.
- Full Text:
- Date Issued: 2018
- Authors: Akpokiniovo, Oghenetejiri
- Date: 2018
- Subjects: Architecture, Chinese -- South Africa -- Port Elizabeth , Interior architecture School buildings -- Design and construction
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/42727 , vital:36685
- Description: This treatise is born out of preoccupation with Identity, Culture and Architecture. Through the study of the fragility of the South-African Chinese community: their double heritage, their quest for a sense of place and permanence with the establishment of Chinese Schools that maintain the Chinese culture. It begins with identifying their almost unstable and fragmented nature of movement, their struggle to find a ‘place’ in Port Elizabeth, especially after the establishment of the Group Areas Act of 1960 and their fight against apartheid and discrimination. It becomes clear that migration, racial segregation, confusion, forced removals, and displacement have been their legacy in South Africa. The purpose of this document is to investigate the symbolic nature of architecture, and how it can be used as a tangible medium to bring about an affirmation of identity, and create a sense of place for the future; giving credence to the celebration of culture and social interaction. Through the use of literature reviews, informal interviews, desktop research, analysis, precedent studies and other qualitative studies; there will be an understanding of the community in terms of how they came about settling in South Africa; their migratory patterns due to forced removals and the current status of the community in terms of cultural revolution; understanding the cultural issues the community face; in the establishment of a centralised symbolic precinct that allows for the celebration and promotion of culture. Through the design of the Chinese Cultural School, it will be demonstrated that in order to create a sense of place for the Chinese community, aiding in integration and restoration; one will need to engage in the argument of the vitality of authentic architecture, the vernacular language of a particular culture, and the subjectivity of identity especially in a context outside of its homeland.
- Full Text:
- Date Issued: 2018
Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) population ecology in citrus orchards: the influence of orchard age
- Authors: Albertyn, Sonnica
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Population biology , Insect populations , Orchards , Insect nematodes , Entomopathogenic fungi
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62615 , vital:28213
- Description: Anecdotal reports in the South African citrus industry claim higher populations of false codling moth (FCM), Thaumatotibia (Cryptophlebia) leucotreta (Meyr) (Lepidoptera: Tortricidae), in orchards during the first three to five harvesting years of citrus planted in virgin soil, after which, FCM numbers seem to decrease and remain consistent. Various laboratory studies and field surveys were conducted to determine if, and why juvenile orchards (four to eight years old) experience higher FCM infestation than mature orchards (nine years and older). In laboratory trials, Washington Navel oranges and Nova Mandarins from juvenile trees were shown to be significantly more susceptible to FCM damage and significantly more attractive for oviposition in both choice and no-choice trials, than fruit from mature trees. Although fruit from juvenile Cambria Navel trees were significantly more attractive than mature orchards for oviposition, they were not more susceptible to FCM damage. In contrast, fruit from juvenile and mature Midnight Valencia orchards were equally attractive for oviposition, but fruit from juvenile trees were significantly more susceptible to FCM damage than fruit from mature trees. Artificial diets were augmented with powder from fruit from juvenile or mature Washington Navel orchards at 5%, 10%, 15% or 30%. Higher larval survival of 76%, 63%, 50% and 34%, respectively, was recorded on diets containing fruit powder from the juvenile trees than on diets containing fruit powder from the mature trees, at 69%, 57%, 44% and 27% larval survival, respectively. Bioassays were conducted to determine if differences in plant chemistry between fruit from juvenile and mature trees will have an impact on the susceptibility FCM to entomopathogenic nematodes (EPN), entomopathogenic fungi (EPF) and Cryptophlebia leucotreta granulovirus (CrleGV). No significant differences in the susceptibility of larvae reared on diets containing 15% fruit powder from juvenile and mature trees to EPN and EPF were recorded. Mortality of neonate larvae was significantly lower when placed on diets containing 15% fruit powder from mature trees (45% mortality) than diets containing 15% fruit powder from juvenile trees (61% mortality), after larvae ingested the lowest virus concentration tested, being 2 x104 OBs/ml. Data collected from field surveys showed significantly lower egg parasitism, virus infection of larvae and EPF occurrence in juvenile orchards than mature orchards. Egg parasitism was between 11% and 54% higher in mature orchards than juvenile orchards, with the exception of Mandarins during 2015, where egg parasitism was slightly higher in juvenile orchards, but not significantly so. A significantly higher proportion of larvae retrieved from mature orchards (7% of larvae) were infected with CrleGV than larvae retrieved from juvenile orchards (4% of larvae). A significantly higher occurrence of EPF was recorded in non-bearing and mature orchards, with 40% and 37% occurrence respectively, than in juvenile orchards, with 25% occurrence recorded. EPF occurrence in juvenile orchards increased significantly by 16% to 32% from the first to the third year of sampling. In contrast to results recorded in laboratory trials, similar or higher pest pressure in juvenile orchards than mature orchards did not always result in significantly higher levels of FCM damage under field conditions. FCM damage in juvenile orchards may have been lower than expected, as greater extremes of temperature and lower humidity were recorded in juvenile orchards, which would increase larval mortality. Results of this study showed that juvenile and mature orchards are significantly different and should be managed differently.
- Full Text:
- Date Issued: 2018
- Authors: Albertyn, Sonnica
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Population biology , Insect populations , Orchards , Insect nematodes , Entomopathogenic fungi
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62615 , vital:28213
- Description: Anecdotal reports in the South African citrus industry claim higher populations of false codling moth (FCM), Thaumatotibia (Cryptophlebia) leucotreta (Meyr) (Lepidoptera: Tortricidae), in orchards during the first three to five harvesting years of citrus planted in virgin soil, after which, FCM numbers seem to decrease and remain consistent. Various laboratory studies and field surveys were conducted to determine if, and why juvenile orchards (four to eight years old) experience higher FCM infestation than mature orchards (nine years and older). In laboratory trials, Washington Navel oranges and Nova Mandarins from juvenile trees were shown to be significantly more susceptible to FCM damage and significantly more attractive for oviposition in both choice and no-choice trials, than fruit from mature trees. Although fruit from juvenile Cambria Navel trees were significantly more attractive than mature orchards for oviposition, they were not more susceptible to FCM damage. In contrast, fruit from juvenile and mature Midnight Valencia orchards were equally attractive for oviposition, but fruit from juvenile trees were significantly more susceptible to FCM damage than fruit from mature trees. Artificial diets were augmented with powder from fruit from juvenile or mature Washington Navel orchards at 5%, 10%, 15% or 30%. Higher larval survival of 76%, 63%, 50% and 34%, respectively, was recorded on diets containing fruit powder from the juvenile trees than on diets containing fruit powder from the mature trees, at 69%, 57%, 44% and 27% larval survival, respectively. Bioassays were conducted to determine if differences in plant chemistry between fruit from juvenile and mature trees will have an impact on the susceptibility FCM to entomopathogenic nematodes (EPN), entomopathogenic fungi (EPF) and Cryptophlebia leucotreta granulovirus (CrleGV). No significant differences in the susceptibility of larvae reared on diets containing 15% fruit powder from juvenile and mature trees to EPN and EPF were recorded. Mortality of neonate larvae was significantly lower when placed on diets containing 15% fruit powder from mature trees (45% mortality) than diets containing 15% fruit powder from juvenile trees (61% mortality), after larvae ingested the lowest virus concentration tested, being 2 x104 OBs/ml. Data collected from field surveys showed significantly lower egg parasitism, virus infection of larvae and EPF occurrence in juvenile orchards than mature orchards. Egg parasitism was between 11% and 54% higher in mature orchards than juvenile orchards, with the exception of Mandarins during 2015, where egg parasitism was slightly higher in juvenile orchards, but not significantly so. A significantly higher proportion of larvae retrieved from mature orchards (7% of larvae) were infected with CrleGV than larvae retrieved from juvenile orchards (4% of larvae). A significantly higher occurrence of EPF was recorded in non-bearing and mature orchards, with 40% and 37% occurrence respectively, than in juvenile orchards, with 25% occurrence recorded. EPF occurrence in juvenile orchards increased significantly by 16% to 32% from the first to the third year of sampling. In contrast to results recorded in laboratory trials, similar or higher pest pressure in juvenile orchards than mature orchards did not always result in significantly higher levels of FCM damage under field conditions. FCM damage in juvenile orchards may have been lower than expected, as greater extremes of temperature and lower humidity were recorded in juvenile orchards, which would increase larval mortality. Results of this study showed that juvenile and mature orchards are significantly different and should be managed differently.
- Full Text:
- Date Issued: 2018
Future role of community pharmacy in the national health insurance
- Authors: Aluko, Olubusola Aderonke
- Date: 2018
- Subjects: National health insurance -- South Africa , Health care reform -- South Africa Community health services -- South Africa Pharmacy -- Practice -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/21472 , vital:29525
- Description: Governments all over the world have shown interest in the healthcare system and various policies and measures have been adopted to ensure optimum health of the people. Inequity in health provision in South Africa is a great challenge. In South Africa, the healthcare system is currently characterised by distinctly different public and private sectors. The public sector serves approximately 84% of the population while the private sector services the smaller portion, 16% of the population. However, the expenditure in both the private and public sectors is almost the same, with approximately five times more being spent per capita in the private sector than in the public sector. The South African health care system is therefore unbalanced with respect to expenditure per capita resulting in inequitable access to, and quality of, health services. In particular, relative to the population it serves and the disease burden that it carries, the public sector is under-resourced. In order to address the inequities characteristic of the current two-tiered system, the South African Government is in the process of implementing a National Health Insurance (NHI). The NHI will provide a means of pooling all healthcare funding, thereby providing a means of cross subsidization within the public sector. Funding contributions will be linked to the ability of an individual to pay and benefits will be determined by an individual’s need for care. A core principle of NHI is to provide access to quality care. It has been suggested that within a NHI system private pharmacies may be contracted through service agreements to provide both chronic and acute medicines. However, there are currently no policies specifying the roles and functions of pharmacists in the NHI or in a re-engineered Primary Health Care system, although it has been suggested that for South Africa to have a successful healthcare system it requires the support and assistance of pharmacists. Research suggests that the majority of pharmacists do not believe that the NHI is a suitable means to address South Africa’s healthcare problems and many do not agree with the principles behind it. This study describes the perceptions and attitudes of community pharmacists and the lay public in Nelson Mandela Bay Metropole toward NHI and the potential role of community pharmacists within the NHI. A qualitative approach was used to provide an in-depth exploration of the attitudes and perceptions of community pharmacists and the lay public in Nelson Mandela Bay Metropole (NMBM). It is envisaged that this understanding will provide a basis for addressing pharmacists’ concerns and may contribute towards the further development of the role and the scope of practice of community pharmacists in the NHI. Semi-structured, in-depth interviews were conducted with both community pharmacists and with members of the public. The interviews were digitally recorded and then transcribed. The transcriptions were coded and analysed thematically. The analysis of the themes identified revealed that while community pharmacists and the public are aware of NHI they are uncertain as to how it is being implemented. However, both community pharmacists and patients see NHI as an advantage and display a positive attitude towards NHI.
- Full Text:
- Date Issued: 2018
- Authors: Aluko, Olubusola Aderonke
- Date: 2018
- Subjects: National health insurance -- South Africa , Health care reform -- South Africa Community health services -- South Africa Pharmacy -- Practice -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/21472 , vital:29525
- Description: Governments all over the world have shown interest in the healthcare system and various policies and measures have been adopted to ensure optimum health of the people. Inequity in health provision in South Africa is a great challenge. In South Africa, the healthcare system is currently characterised by distinctly different public and private sectors. The public sector serves approximately 84% of the population while the private sector services the smaller portion, 16% of the population. However, the expenditure in both the private and public sectors is almost the same, with approximately five times more being spent per capita in the private sector than in the public sector. The South African health care system is therefore unbalanced with respect to expenditure per capita resulting in inequitable access to, and quality of, health services. In particular, relative to the population it serves and the disease burden that it carries, the public sector is under-resourced. In order to address the inequities characteristic of the current two-tiered system, the South African Government is in the process of implementing a National Health Insurance (NHI). The NHI will provide a means of pooling all healthcare funding, thereby providing a means of cross subsidization within the public sector. Funding contributions will be linked to the ability of an individual to pay and benefits will be determined by an individual’s need for care. A core principle of NHI is to provide access to quality care. It has been suggested that within a NHI system private pharmacies may be contracted through service agreements to provide both chronic and acute medicines. However, there are currently no policies specifying the roles and functions of pharmacists in the NHI or in a re-engineered Primary Health Care system, although it has been suggested that for South Africa to have a successful healthcare system it requires the support and assistance of pharmacists. Research suggests that the majority of pharmacists do not believe that the NHI is a suitable means to address South Africa’s healthcare problems and many do not agree with the principles behind it. This study describes the perceptions and attitudes of community pharmacists and the lay public in Nelson Mandela Bay Metropole toward NHI and the potential role of community pharmacists within the NHI. A qualitative approach was used to provide an in-depth exploration of the attitudes and perceptions of community pharmacists and the lay public in Nelson Mandela Bay Metropole (NMBM). It is envisaged that this understanding will provide a basis for addressing pharmacists’ concerns and may contribute towards the further development of the role and the scope of practice of community pharmacists in the NHI. Semi-structured, in-depth interviews were conducted with both community pharmacists and with members of the public. The interviews were digitally recorded and then transcribed. The transcriptions were coded and analysed thematically. The analysis of the themes identified revealed that while community pharmacists and the public are aware of NHI they are uncertain as to how it is being implemented. However, both community pharmacists and patients see NHI as an advantage and display a positive attitude towards NHI.
- Full Text:
- Date Issued: 2018
A formative intervention for developing Learner Representative Council (LRC) voice and leadership in a newly established school in Namibia
- Authors: Amadhila, Linda
- Date: 2018
- Subjects: School management and organization -- Namibia , Educational leadership -- Namibia , Education, Secondary -- Namibia , Student government -- Namibia , Student participation in administration -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/61744 , vital:28054
- Description: In Namibian schools, learner voice and leadership are being promoted through the policy document entitled the Education Act 16 of2001 which provides an opportunity to establish Learner Representative Councils (LRCs) in secondary schools. However, recent studies have found that this body of learner leaders do not function all that effectively and sometimes exist for the sake of adhering to the policy. This prompted me to conduct an activity theoretical interventionist case- study within the critical paradigm, to develop LRC voice and leadership in a newly established Namibian school. Framed by Cultural Historical Activity Theory, the study was divided into two phases to answer the over-arching question: How can LRC voice and leadership be developed in a school? Phase one was largely interpretive, the contextual profiling phase, where document analysis, individual interviews, questionnaires and observations were used to generate data to answer the following research sub-questions: How is learner leadership understood in the school? What leadership development opportunities for the LRC currently exist in the school? What underlying factors constrain the development of LRC voice and leadership in the newly established school? Phase two of the study was the expansive learning phase, which consisted of three intervention workshops. The Change Laboratory method and a focus group interview were used to generate data in response to the last research sub-question: In what ways can LRC participation in a Change Laboratory process contribute to their leadership development? Data generated were inductively and deductively analysed, using the activity theoretical principles of contradictions and double stimulation. Data revealed that learner leadership was largely understood as managerial roles carried out by the LRC in the school. Unlike many schools in Namibia, this case-study school offered numerous leadership development opportunities for the LRC. The community networking events such as: School Exchange Programmes, Town Council breakfast and Junior Regional Council, were opportunities offered to the LRC to solicit information, exchange ideas and discuss matters of common interest with the LRCs of the fully established schools. However, there were a number of challenges that constrained LRC voice and leadership development, the major one being the fact that this was a newly established school. Of significance was that LRC participation in the Change Laboratory process contributed positively to the development of voice and leadership in learners. During this Change Laboratory process, the LRC developed a new artefact - the vision and mission statement of the school - this signified that the learners expansively transformed the object of their activity. Recommendations emerging out of the study included that the School Management Team see the ‘newly established’ status of the school as an opportunity for development, rather than a limitation, and therefore invite the LRC to participate in the different leadership practices as the school becomes established. A significant recommendation for school leadership research is to use the third generation of CHAT to expand the unit of analysis, in order to understand the leadership relations and power dynamics between multiple activity systems in schools as complex organisations.
- Full Text:
- Date Issued: 2018
- Authors: Amadhila, Linda
- Date: 2018
- Subjects: School management and organization -- Namibia , Educational leadership -- Namibia , Education, Secondary -- Namibia , Student government -- Namibia , Student participation in administration -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/61744 , vital:28054
- Description: In Namibian schools, learner voice and leadership are being promoted through the policy document entitled the Education Act 16 of2001 which provides an opportunity to establish Learner Representative Councils (LRCs) in secondary schools. However, recent studies have found that this body of learner leaders do not function all that effectively and sometimes exist for the sake of adhering to the policy. This prompted me to conduct an activity theoretical interventionist case- study within the critical paradigm, to develop LRC voice and leadership in a newly established Namibian school. Framed by Cultural Historical Activity Theory, the study was divided into two phases to answer the over-arching question: How can LRC voice and leadership be developed in a school? Phase one was largely interpretive, the contextual profiling phase, where document analysis, individual interviews, questionnaires and observations were used to generate data to answer the following research sub-questions: How is learner leadership understood in the school? What leadership development opportunities for the LRC currently exist in the school? What underlying factors constrain the development of LRC voice and leadership in the newly established school? Phase two of the study was the expansive learning phase, which consisted of three intervention workshops. The Change Laboratory method and a focus group interview were used to generate data in response to the last research sub-question: In what ways can LRC participation in a Change Laboratory process contribute to their leadership development? Data generated were inductively and deductively analysed, using the activity theoretical principles of contradictions and double stimulation. Data revealed that learner leadership was largely understood as managerial roles carried out by the LRC in the school. Unlike many schools in Namibia, this case-study school offered numerous leadership development opportunities for the LRC. The community networking events such as: School Exchange Programmes, Town Council breakfast and Junior Regional Council, were opportunities offered to the LRC to solicit information, exchange ideas and discuss matters of common interest with the LRCs of the fully established schools. However, there were a number of challenges that constrained LRC voice and leadership development, the major one being the fact that this was a newly established school. Of significance was that LRC participation in the Change Laboratory process contributed positively to the development of voice and leadership in learners. During this Change Laboratory process, the LRC developed a new artefact - the vision and mission statement of the school - this signified that the learners expansively transformed the object of their activity. Recommendations emerging out of the study included that the School Management Team see the ‘newly established’ status of the school as an opportunity for development, rather than a limitation, and therefore invite the LRC to participate in the different leadership practices as the school becomes established. A significant recommendation for school leadership research is to use the third generation of CHAT to expand the unit of analysis, in order to understand the leadership relations and power dynamics between multiple activity systems in schools as complex organisations.
- Full Text:
- Date Issued: 2018
Inmate incarceration and rehabilitation : a cross sectional study of rehabilitation programmes and facilities in correctional centres in North Western Nigeria
- Authors: Amali, Sadiq Ewaoda
- Date: 2018
- Subjects: Criminal -- Rehabilitation Prisoners -- Counseling of Prisoners -- Mental health services
- Language: English
- Type: Thesis , Doctoral , Social Sciences
- Identifier: http://hdl.handle.net/10353/9984 , vital:35215
- Description: The study was conducted in Kano Central and Goron-Dutse prisons, North Western, Nigeria to determine the effectiveness of these correctional centres with regards to inmate rehabilitation. Both quantitative and qualitative collection was conducted concurrently and incorporated in the explanation of the results. This was achieved as the study empirically examined the experiences of convicted inmates and correctional officials in both correctional centres with a sample that compromised of both convicted male and female inmates as well as male and female correctional officials. A total of 250 questionnaires were administered to convicted inmates in Kano central and Goron-Dutse prisons. A sample size of 250 was determined using the sample size calculator at a confidence level of 95 percent, confidence interval of +/-5.97 percent, and with a population of 3488. Data for this study was generated from 250 respondents. Out of 250 respondents, questionnaires were administered to 140 inmates in Kano Central Prison and 110 questionnaires were administered to inmates in Goron Dutse Prison. The number of respondents in Kano Central Prisons is higher than that of Goron-Dutse Prison due to disparity in population of inmates. Also, 207 questionnaires were administered to correctional officials in Kano Central and Goron-Dutse prisons. A sample size of 207 was determined using the sample size calculator at a confidence interval of +/-5, confidence level of 95 percent and population of 449 correctional officials. Out of the 207 respondents, 107 questionnaires were administered to correctional officials in Kano Central Prison and 100 to correctional officials in Goron-Dutse Prison. The number of respondents in Kano Central Prison is higher than that of Goron-Dutse prison due to disparity in population of correctional officials. The selections were done using purposive sampling procedures. Rank, involvement in rehabilitation programmes were also used as criteria for selection of correctional officials as respondents. Furthermore, 28 correctional officials were selected purposively across the two correctional centres were interviewed. Thus, 14 correctional officials each were selected in Kano Central and Goron Dutse prisons using purposive sampling method. Thus, a total of 28 in-depth interviews were conducted in the study area. This study empirically probed into the factors mitigating against the effective rehabilitation of inmates. Therefore, against this background, this study involved an appraisal of rehabilitation programmes and facilities which was followed by an evaluation of inmates’ opinion of the correctional centre social setting and overall practices. Thus, inmate’s perceptions of correctional officials’ attitudes towards them and also its implication for re-integration principle was thoroughly appraised. The findings of this study were analyzed with the assistance of computer applications such as SPSS and atlas.ti.6. Some findings from this study revealed that only 15.7 percent of inmates in Kano Central prisons were satisfied with rehabilitation programmes, 37.3 percent were satisfied in Goron-Dutse prison while the majority of the inmates (88 percent) in Goron-Dutse prison stated that the relationship with correctional officials was cordial compared to 53.5 percent of the inmates in Kano Central prison. Also, data revealed that 64.2 percent of the inmates in Goron-Dutse Prison stated that medical attention was good and very good. The results also reveals that (58.9 percent) correctional officials stated that their relationship with inmates was very cordial compared to those of Goron-Dutse Prison (41.1 percent).Pearson Chi-square statistics showed that there was no statistical difference in correctional officials’ perceptions of the relationship with inmates between the two correctional centres (p.value>0.05). This study recommends that it is imperative for the Nigerian government to make more efforts with the provision of adequate rehabilitation programmes and facilities in the two correctional centres and correctional centres across the country as an exploration of existing literature reveals that most correctional centres in Nigeria lacked basic facilities for inmate rehabilitation as inmates were idle during incarceration.
- Full Text:
- Date Issued: 2018
- Authors: Amali, Sadiq Ewaoda
- Date: 2018
- Subjects: Criminal -- Rehabilitation Prisoners -- Counseling of Prisoners -- Mental health services
- Language: English
- Type: Thesis , Doctoral , Social Sciences
- Identifier: http://hdl.handle.net/10353/9984 , vital:35215
- Description: The study was conducted in Kano Central and Goron-Dutse prisons, North Western, Nigeria to determine the effectiveness of these correctional centres with regards to inmate rehabilitation. Both quantitative and qualitative collection was conducted concurrently and incorporated in the explanation of the results. This was achieved as the study empirically examined the experiences of convicted inmates and correctional officials in both correctional centres with a sample that compromised of both convicted male and female inmates as well as male and female correctional officials. A total of 250 questionnaires were administered to convicted inmates in Kano central and Goron-Dutse prisons. A sample size of 250 was determined using the sample size calculator at a confidence level of 95 percent, confidence interval of +/-5.97 percent, and with a population of 3488. Data for this study was generated from 250 respondents. Out of 250 respondents, questionnaires were administered to 140 inmates in Kano Central Prison and 110 questionnaires were administered to inmates in Goron Dutse Prison. The number of respondents in Kano Central Prisons is higher than that of Goron-Dutse Prison due to disparity in population of inmates. Also, 207 questionnaires were administered to correctional officials in Kano Central and Goron-Dutse prisons. A sample size of 207 was determined using the sample size calculator at a confidence interval of +/-5, confidence level of 95 percent and population of 449 correctional officials. Out of the 207 respondents, 107 questionnaires were administered to correctional officials in Kano Central Prison and 100 to correctional officials in Goron-Dutse Prison. The number of respondents in Kano Central Prison is higher than that of Goron-Dutse prison due to disparity in population of correctional officials. The selections were done using purposive sampling procedures. Rank, involvement in rehabilitation programmes were also used as criteria for selection of correctional officials as respondents. Furthermore, 28 correctional officials were selected purposively across the two correctional centres were interviewed. Thus, 14 correctional officials each were selected in Kano Central and Goron Dutse prisons using purposive sampling method. Thus, a total of 28 in-depth interviews were conducted in the study area. This study empirically probed into the factors mitigating against the effective rehabilitation of inmates. Therefore, against this background, this study involved an appraisal of rehabilitation programmes and facilities which was followed by an evaluation of inmates’ opinion of the correctional centre social setting and overall practices. Thus, inmate’s perceptions of correctional officials’ attitudes towards them and also its implication for re-integration principle was thoroughly appraised. The findings of this study were analyzed with the assistance of computer applications such as SPSS and atlas.ti.6. Some findings from this study revealed that only 15.7 percent of inmates in Kano Central prisons were satisfied with rehabilitation programmes, 37.3 percent were satisfied in Goron-Dutse prison while the majority of the inmates (88 percent) in Goron-Dutse prison stated that the relationship with correctional officials was cordial compared to 53.5 percent of the inmates in Kano Central prison. Also, data revealed that 64.2 percent of the inmates in Goron-Dutse Prison stated that medical attention was good and very good. The results also reveals that (58.9 percent) correctional officials stated that their relationship with inmates was very cordial compared to those of Goron-Dutse Prison (41.1 percent).Pearson Chi-square statistics showed that there was no statistical difference in correctional officials’ perceptions of the relationship with inmates between the two correctional centres (p.value>0.05). This study recommends that it is imperative for the Nigerian government to make more efforts with the provision of adequate rehabilitation programmes and facilities in the two correctional centres and correctional centres across the country as an exploration of existing literature reveals that most correctional centres in Nigeria lacked basic facilities for inmate rehabilitation as inmates were idle during incarceration.
- Full Text:
- Date Issued: 2018
Citizen science, treatment and microbial compliance monitoring in rainwater harvesting in Namibia
- Angala, Hallo Angaleni Nameya
- Authors: Angala, Hallo Angaleni Nameya
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62082 , vital:28105
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: Angala, Hallo Angaleni Nameya
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62082 , vital:28105
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
Evaluation of Raymond Mhlaba Local Municipality communication strategies in reducing the risk of water-borne diseases outbreak
- Animawun, Oluwatosin Tolulope
- Authors: Animawun, Oluwatosin Tolulope
- Date: 2018
- Subjects: Communication in public health Communicable diseases -- Prevention Waterborne infection -- Prevention
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/10531 , vital:35595
- Description: Health Communication plays an important role in health sustenance. It is cardinal to disease prevention, health promotion and quality of life. Water-borne diseases are known to pose a significant threat to global health and has claimed many lives. This study seeks to evaluate Raymond Mhlaba Local Municipality’s communication strategies employed in reducing the risk of water-borne diseases outbreak in the community. The research method used for this study is mixed method. In-depth interview and questionnaire was used to collect data. The two sampling procedures that were used in this study are purposive sampling for the qualitative aspect of this study and simple random sampling for the quantitative aspect of this study. The conclusion that was drawn from this study is that Raymond Mhlaba (formerly Nkonkobe) Local Municipality makes use of a communication strategy, which is awareness campaign, in educating its people about water-borne diseases and its prevention but the information is limited in its reach. This study recommends that the awareness campaign done by Raymond Mhlaba (formerly Nkonkobe) Local Municipality should be embarked on more frequently because the more the messages are reinforced for a long time, the more the people in the community are able to remember and the greater the likelihood that they will act upon the message. In addition, Raymond Mhlaba (formerly Nkonkobe) Local Municipality should carry out evaluations like this research at least quarterly in order to assess the impact of the awareness campaigns on the Community, which can also be used as a tool to educate the people of Raymond Mhlaba Local Municipality about Water-borne diseases. Finally, social media is a new trend that most people are now into, most especially the youths; Raymond Mhlaba (formerly Nkonkobe) Local Municipality should key into this and educate the public on platforms on social media as it can be seen as a form of reinforcing health information.
- Full Text:
- Date Issued: 2018
- Authors: Animawun, Oluwatosin Tolulope
- Date: 2018
- Subjects: Communication in public health Communicable diseases -- Prevention Waterborne infection -- Prevention
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/10531 , vital:35595
- Description: Health Communication plays an important role in health sustenance. It is cardinal to disease prevention, health promotion and quality of life. Water-borne diseases are known to pose a significant threat to global health and has claimed many lives. This study seeks to evaluate Raymond Mhlaba Local Municipality’s communication strategies employed in reducing the risk of water-borne diseases outbreak in the community. The research method used for this study is mixed method. In-depth interview and questionnaire was used to collect data. The two sampling procedures that were used in this study are purposive sampling for the qualitative aspect of this study and simple random sampling for the quantitative aspect of this study. The conclusion that was drawn from this study is that Raymond Mhlaba (formerly Nkonkobe) Local Municipality makes use of a communication strategy, which is awareness campaign, in educating its people about water-borne diseases and its prevention but the information is limited in its reach. This study recommends that the awareness campaign done by Raymond Mhlaba (formerly Nkonkobe) Local Municipality should be embarked on more frequently because the more the messages are reinforced for a long time, the more the people in the community are able to remember and the greater the likelihood that they will act upon the message. In addition, Raymond Mhlaba (formerly Nkonkobe) Local Municipality should carry out evaluations like this research at least quarterly in order to assess the impact of the awareness campaigns on the Community, which can also be used as a tool to educate the people of Raymond Mhlaba Local Municipality about Water-borne diseases. Finally, social media is a new trend that most people are now into, most especially the youths; Raymond Mhlaba (formerly Nkonkobe) Local Municipality should key into this and educate the public on platforms on social media as it can be seen as a form of reinforcing health information.
- Full Text:
- Date Issued: 2018
Incidence of bacterial infections and colonisation in patients admitted to a tuberculosis hospital
- Authors: Annear, Dale John
- Date: 2018
- Subjects: Medical microbiology , Microbiology Bacteriology Tuberculosis -- Hospitals -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/21482 , vital:29526
- Description: Patients with drug resistant tuberculosis (TB) are treated with multiple antibiotics including moxifloxacin, linezolid, and meropenem, which puts them at greater risk for colonisation by multi-drug resistant (MDR) bacteria. The objectives of this study were to: (i) assess the antimicrobial prescribing patterns practiced within the hospital by retrospective patient file review; (ii) determine the spectrum of bacterial colonisation in TB patients upon admission and during hospitalisation; (iii) identify bacterial isolates and evaluate antimicrobial susceptibility profiles; (iv) detect antimicrobial resistance genes in the bacterial isolates by PCR and DNA sequencing; and (v) investigate genetic relatedness of Klebsiella pneumoniae isolates using Multi Locus Sequence Typing. Nasal, groin and rectal swabs [for the detection of extended spectrum beta lactamases (EBSLs), carbapenem-resistant Enterobacteriaceae (CRE), vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA)] were analysed from a cohort of patients (n=37) admitted either from the community (n = 28) or from other healthcare facilities (n=9) to a TB hospital. Swab samples were collected at admission and at four week intervals thereafter during hospitalization. Identification and antimicrobial susceptibility testing of bacterial isolates (n=62) were determined at the National Health Laboratory Services (NHLS) by the VITEK-MS and Vitek 2 systems respectively. Additional antimicrobial susceptibility testing was conducted by Sensititre Gram Negative Xtra (GNFX2) MIC plates. PCR and DNA sequencing were used for detection of resistance genes. Patients (n=13/37; 35%) were colonized by MDR bacteria (ESBLs [n=11], MRSA [n=2]) on admission. Colonization rates were lower in patients admitted from the community (9/28; 32%) compared to those transferred from other healthcare facilities (4/9; 44%). All admitted patients who did not exhibit colonization at baseline and who were resident within the hospital for longer than 4 weeks (17/37; 46% of total patients) became colonised by an ESBL-producing Enterobacteriaceae species. No patients acquired MRSA during hospitalisation. Among ESBL Enterobacteriaceae, Escherichia coli (41/62; 66%) and K. pneumoniae [14/62; 23%]) predominated. Nineteen percent (7/37) of patients demised during their hospitalization. Both the Vitek system and Sensititre Gram Negative Xtra (GNFX2) MIC plates susceptibilities were similar for most antimicrobials, however there were discrepancies for tigecycline susceptibility profiles. A high number of isolates exhibited resistance to aminoglycosides and fluoroquinolones. Genes encoding for ESBLs (CTX-M-14, CTX-M-15, SHV-28, OXA-1, and OXY-2-9) were detected among ESBL Enterobacteriaceae. Two Enterobacteriaceae isolates with reduced carbapenem susceptibility did not contain carbapenemase-encoding genes. MLST revealed unique sequence types and genetic diversity among the K. pneumoniae isolates from hospitalised patients. However, the source and colonization routes of these isolates could not be determined, which requires further investigation. This study provides insight into the spectrum of bacterial pathogen colonisation in hospitalised TB patients and suggests a review of infection control programs and practices at the TB hospital.
- Full Text:
- Date Issued: 2018
- Authors: Annear, Dale John
- Date: 2018
- Subjects: Medical microbiology , Microbiology Bacteriology Tuberculosis -- Hospitals -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/21482 , vital:29526
- Description: Patients with drug resistant tuberculosis (TB) are treated with multiple antibiotics including moxifloxacin, linezolid, and meropenem, which puts them at greater risk for colonisation by multi-drug resistant (MDR) bacteria. The objectives of this study were to: (i) assess the antimicrobial prescribing patterns practiced within the hospital by retrospective patient file review; (ii) determine the spectrum of bacterial colonisation in TB patients upon admission and during hospitalisation; (iii) identify bacterial isolates and evaluate antimicrobial susceptibility profiles; (iv) detect antimicrobial resistance genes in the bacterial isolates by PCR and DNA sequencing; and (v) investigate genetic relatedness of Klebsiella pneumoniae isolates using Multi Locus Sequence Typing. Nasal, groin and rectal swabs [for the detection of extended spectrum beta lactamases (EBSLs), carbapenem-resistant Enterobacteriaceae (CRE), vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA)] were analysed from a cohort of patients (n=37) admitted either from the community (n = 28) or from other healthcare facilities (n=9) to a TB hospital. Swab samples were collected at admission and at four week intervals thereafter during hospitalization. Identification and antimicrobial susceptibility testing of bacterial isolates (n=62) were determined at the National Health Laboratory Services (NHLS) by the VITEK-MS and Vitek 2 systems respectively. Additional antimicrobial susceptibility testing was conducted by Sensititre Gram Negative Xtra (GNFX2) MIC plates. PCR and DNA sequencing were used for detection of resistance genes. Patients (n=13/37; 35%) were colonized by MDR bacteria (ESBLs [n=11], MRSA [n=2]) on admission. Colonization rates were lower in patients admitted from the community (9/28; 32%) compared to those transferred from other healthcare facilities (4/9; 44%). All admitted patients who did not exhibit colonization at baseline and who were resident within the hospital for longer than 4 weeks (17/37; 46% of total patients) became colonised by an ESBL-producing Enterobacteriaceae species. No patients acquired MRSA during hospitalisation. Among ESBL Enterobacteriaceae, Escherichia coli (41/62; 66%) and K. pneumoniae [14/62; 23%]) predominated. Nineteen percent (7/37) of patients demised during their hospitalization. Both the Vitek system and Sensititre Gram Negative Xtra (GNFX2) MIC plates susceptibilities were similar for most antimicrobials, however there were discrepancies for tigecycline susceptibility profiles. A high number of isolates exhibited resistance to aminoglycosides and fluoroquinolones. Genes encoding for ESBLs (CTX-M-14, CTX-M-15, SHV-28, OXA-1, and OXY-2-9) were detected among ESBL Enterobacteriaceae. Two Enterobacteriaceae isolates with reduced carbapenem susceptibility did not contain carbapenemase-encoding genes. MLST revealed unique sequence types and genetic diversity among the K. pneumoniae isolates from hospitalised patients. However, the source and colonization routes of these isolates could not be determined, which requires further investigation. This study provides insight into the spectrum of bacterial pathogen colonisation in hospitalised TB patients and suggests a review of infection control programs and practices at the TB hospital.
- Full Text:
- Date Issued: 2018
The impact of foreign direct investment (FDI) on economic growth in South Africa
- Authors: Ansong, Ama Yiadomaa
- Date: 2018
- Subjects: Investments, Foreign -- South Africa , Infrastructure (Economics) -- South Africa Gross domestic product -- South Africa Economic development -- South Africa South Africa -- Economic conditions
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/21494 , vital:29527
- Description: Numerous studies have investigated FDI and the possible benefits for African countries in terms of job creation opportunities, technology transfers, growth and development. Despite these potential benefits, FDI also has its negative effects on the host country in terms of market dominance, profit repatriation and loss of tax revenue if tax incentives are offered. In an effort to attract more FDI, host countries have undertaken various policy incentives to attract foreign investors. This study examines the trends and determinants of FDI flows to South Africa and other African countries. The period chosen for this study is from 1990- 2016. The study commences with a background study of FDI and GDP. Various literature offerings and different schools of thought with regard to FDI are also deliberated. To offer a better understanding of the relationship between FDI and GDP, econometric estimation was employed. The econometric estimation methods employed were, Unit Root, Johansen Cointegration, Vector Error Correction (VECM), Impulse Response Test, Variance Decomposition and the Granger Causality Test. Based on Granger causality test it can be concluded that South Africa’s economic growth attracts FDI and not vice versa. South Africa must therefore focus on growing its economy to attract more FDI.
- Full Text:
- Date Issued: 2018
- Authors: Ansong, Ama Yiadomaa
- Date: 2018
- Subjects: Investments, Foreign -- South Africa , Infrastructure (Economics) -- South Africa Gross domestic product -- South Africa Economic development -- South Africa South Africa -- Economic conditions
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/21494 , vital:29527
- Description: Numerous studies have investigated FDI and the possible benefits for African countries in terms of job creation opportunities, technology transfers, growth and development. Despite these potential benefits, FDI also has its negative effects on the host country in terms of market dominance, profit repatriation and loss of tax revenue if tax incentives are offered. In an effort to attract more FDI, host countries have undertaken various policy incentives to attract foreign investors. This study examines the trends and determinants of FDI flows to South Africa and other African countries. The period chosen for this study is from 1990- 2016. The study commences with a background study of FDI and GDP. Various literature offerings and different schools of thought with regard to FDI are also deliberated. To offer a better understanding of the relationship between FDI and GDP, econometric estimation was employed. The econometric estimation methods employed were, Unit Root, Johansen Cointegration, Vector Error Correction (VECM), Impulse Response Test, Variance Decomposition and the Granger Causality Test. Based on Granger causality test it can be concluded that South Africa’s economic growth attracts FDI and not vice versa. South Africa must therefore focus on growing its economy to attract more FDI.
- Full Text:
- Date Issued: 2018
The role of family structure and financial socialisation in influencing students' financial capabilities
- Authors: Antoni, Xolile Lucas
- Date: 2018
- Subjects: Finance, Personal , Families -- Economic aspects Finance -- Social aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21505 , vital:29531
- Description: This research used three theories to develop a theoretical framework that investigated the role of family structures and financial socialisation in influencing students’ levels of financial knowledge, attitudes, self-efficacy and behaviour (financial capabilities). It also examined the mediating role of family financial situation in the relationship between the family structure and the mechanisms of financial socialisation. The theories of consumer socialisation, family financial socialisation and family structure model, guided the development of a proposed theoretical framework and development of five major hypotheses. To answer the research questions of the study and test the hypotheses, this study followed a quantitative survey research design. Undergraduate students in the Faculty of Business and Economic Sciences completed 350 questionnaires. Using exploratory factor analyses results, the theoretical framework was updated, and statistical relationships tested. Simple regression analysis results showed that students who were born or raised in an intact family structure reported more financial socialisation in terms of the mechanisms of financial socialisation than students who were born or raised in non-intact family structures. Simple regression results showed that intact family structures had positive significant relationships with four of the six components of the mechanisms of financial socialisation. Furthermore, intact family structures had negative significant relationships with two components of the mechanisms of financial socialisation. Multiple regression results showed four components of the mechanisms of financial socialisation (teaching and monitoring, reinforcement of financial behaviour, modelling of financial behaviour and financial conflict) had positive significant relationships with financial capabilities. The components of financial socialisation agents (peers and media) had positive significant relationships with three components of financial capabilities (financial behaviour, money is respect and freedom, and money is good). In addition, family financial situation partially mediated the relationship between intact family structure and three components of the mechanisms of financial socialisation, namely, parental teaching and monitoring, modelling of financial behaviour and parental relationship. Furthermore, family financial situation perfectly mediated the relationship between intact family structures and one component of the mechanisms of financial socialisation (reinforcement of financial behaviour). Three components of the mechanisms of financial socialisation (parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour) also perfectly mediated the relationship between intact family structure and one component of financial capabilities, namely, financial behaviour. Similarly, one component of the mechanisms of financial socialisation (parental teaching and monitoring) also perfectly mediated the relationship between intact family structure and one component of financial capabilities (financial self-efficacy). These results assisted in the development of a new empirically tested model to investigate the role of family structure and financial socialisation in influencing students’ financial capabilities. This study showed that family structures was an important variable that should not be excluded in financial planning as it influenced all the components of the mechanisms of financial socialisation. Financial socialisation agents also had an influence on financial capabilities and, thus, the parental financial socialisation should not be investigated in isolation. It was also important to identify the mechanisms of financial socialisation as seen in this study, as the components of the mechanisms had different influences on students’ financial capabilities. For this study, parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour proved to be the most important components of the mechanisms of financial socialisation, which ultimately influenced students’ financial capabilities. This study has proved that family structures and financial socialisation influence the financial capabilities of students. To improve financial capabilities of students, parents should increase their level of modelling of financial behaviour and decrease the level of secrecy about money in the household. Parents should also instill positive financial attitudes in students, monitor their financial behaviour, and reinforce positive financial behaviour. This study contributes to the much-needed body of knowledge in financial planning by showing through empirical results that family structure has an influence on the components of the factor mechanisms of financial socialisation, and the factor financial capabilities. As little information exists to explain these relationships, this study makes a valuable contribution to new knowledge in this area.
- Full Text:
- Date Issued: 2018
- Authors: Antoni, Xolile Lucas
- Date: 2018
- Subjects: Finance, Personal , Families -- Economic aspects Finance -- Social aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21505 , vital:29531
- Description: This research used three theories to develop a theoretical framework that investigated the role of family structures and financial socialisation in influencing students’ levels of financial knowledge, attitudes, self-efficacy and behaviour (financial capabilities). It also examined the mediating role of family financial situation in the relationship between the family structure and the mechanisms of financial socialisation. The theories of consumer socialisation, family financial socialisation and family structure model, guided the development of a proposed theoretical framework and development of five major hypotheses. To answer the research questions of the study and test the hypotheses, this study followed a quantitative survey research design. Undergraduate students in the Faculty of Business and Economic Sciences completed 350 questionnaires. Using exploratory factor analyses results, the theoretical framework was updated, and statistical relationships tested. Simple regression analysis results showed that students who were born or raised in an intact family structure reported more financial socialisation in terms of the mechanisms of financial socialisation than students who were born or raised in non-intact family structures. Simple regression results showed that intact family structures had positive significant relationships with four of the six components of the mechanisms of financial socialisation. Furthermore, intact family structures had negative significant relationships with two components of the mechanisms of financial socialisation. Multiple regression results showed four components of the mechanisms of financial socialisation (teaching and monitoring, reinforcement of financial behaviour, modelling of financial behaviour and financial conflict) had positive significant relationships with financial capabilities. The components of financial socialisation agents (peers and media) had positive significant relationships with three components of financial capabilities (financial behaviour, money is respect and freedom, and money is good). In addition, family financial situation partially mediated the relationship between intact family structure and three components of the mechanisms of financial socialisation, namely, parental teaching and monitoring, modelling of financial behaviour and parental relationship. Furthermore, family financial situation perfectly mediated the relationship between intact family structures and one component of the mechanisms of financial socialisation (reinforcement of financial behaviour). Three components of the mechanisms of financial socialisation (parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour) also perfectly mediated the relationship between intact family structure and one component of financial capabilities, namely, financial behaviour. Similarly, one component of the mechanisms of financial socialisation (parental teaching and monitoring) also perfectly mediated the relationship between intact family structure and one component of financial capabilities (financial self-efficacy). These results assisted in the development of a new empirically tested model to investigate the role of family structure and financial socialisation in influencing students’ financial capabilities. This study showed that family structures was an important variable that should not be excluded in financial planning as it influenced all the components of the mechanisms of financial socialisation. Financial socialisation agents also had an influence on financial capabilities and, thus, the parental financial socialisation should not be investigated in isolation. It was also important to identify the mechanisms of financial socialisation as seen in this study, as the components of the mechanisms had different influences on students’ financial capabilities. For this study, parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour proved to be the most important components of the mechanisms of financial socialisation, which ultimately influenced students’ financial capabilities. This study has proved that family structures and financial socialisation influence the financial capabilities of students. To improve financial capabilities of students, parents should increase their level of modelling of financial behaviour and decrease the level of secrecy about money in the household. Parents should also instill positive financial attitudes in students, monitor their financial behaviour, and reinforce positive financial behaviour. This study contributes to the much-needed body of knowledge in financial planning by showing through empirical results that family structure has an influence on the components of the factor mechanisms of financial socialisation, and the factor financial capabilities. As little information exists to explain these relationships, this study makes a valuable contribution to new knowledge in this area.
- Full Text:
- Date Issued: 2018
The experiences of secondary traumatic stress among social workers who deal with traumatised populations : a case study of Buffalo City Municipality, Eastern Cape, South Africa
- Authors: Anyi, Marynet Ema Tangwe
- Date: 2018
- Subjects: Secondary traumatic stress Social workers -- Mental health Social service -- Psychological aspects
- Language: English
- Type: Thesis , Masters , Social Work
- Identifier: http://hdl.handle.net/10353/9951 , vital:35207
- Description: The aim of the research study was to investigate the experiences of secondary traumatic stress among social workers who deal with traumatised populations in the Buffalo City Municipality in the province of the Eastern Cape in South Africa. Qualitative research methods were employed to collect data from thirty participants; twenty were interviewed and 10 participated in a focus group discussion. The most significant finding of this study was that there is a high rate of secondary traumatic stress among social workers, particularly among those who practice in nongovernmental organisations (NGOs), especially those social workers who work with children. The intensity of secondary traumatic stress among social workers appears to be growing steadily, owing to either inadequate or a complete lack of supervision and support on the part of the agencies concerned. The study concludes that social workers are highly at risk of experiencing secondary traumatic stress. The study therefore recommends that policies that are there to protect social workers should be implemented and institutions of higher learning which educate and train social workers need to implement courses in their syllabuses which prepare students for the stresses which they will inevitably encounter while working in the field of social work, particularly secondary traumatic stress.
- Full Text:
- Date Issued: 2018
- Authors: Anyi, Marynet Ema Tangwe
- Date: 2018
- Subjects: Secondary traumatic stress Social workers -- Mental health Social service -- Psychological aspects
- Language: English
- Type: Thesis , Masters , Social Work
- Identifier: http://hdl.handle.net/10353/9951 , vital:35207
- Description: The aim of the research study was to investigate the experiences of secondary traumatic stress among social workers who deal with traumatised populations in the Buffalo City Municipality in the province of the Eastern Cape in South Africa. Qualitative research methods were employed to collect data from thirty participants; twenty were interviewed and 10 participated in a focus group discussion. The most significant finding of this study was that there is a high rate of secondary traumatic stress among social workers, particularly among those who practice in nongovernmental organisations (NGOs), especially those social workers who work with children. The intensity of secondary traumatic stress among social workers appears to be growing steadily, owing to either inadequate or a complete lack of supervision and support on the part of the agencies concerned. The study concludes that social workers are highly at risk of experiencing secondary traumatic stress. The study therefore recommends that policies that are there to protect social workers should be implemented and institutions of higher learning which educate and train social workers need to implement courses in their syllabuses which prepare students for the stresses which they will inevitably encounter while working in the field of social work, particularly secondary traumatic stress.
- Full Text:
- Date Issued: 2018
The intersection between social development and the internationalisation of higher education in Colombia
- Authors: Anzola-Pardo, Giovanni
- Date: 2018
- Subjects: Education, Higher -- Colombia , Education and globalization International education -- Colombia Education, Higher -- International cooperation -- Colombia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/23371 , vital:30536
- Description: The study addresses the nature of Colombian sustainable social development and the internationalisation of higher education (iHE). This intersection is analysed within various theoretical paradigms surrounding social sustainable development and the internationalisation of higher education. This study aims at reviewing the activities of Higher Education Institutions (HEIs) which focus on internationalisation. The analysis focuses on the manner in which HEIs in Colombia approach internationalisation vis-à-vis social sustainable development, and emphasis is made on knowledge transfer, research and community engagement. Using the theories of sustainable development, the iHE, in terms of practises and policies, are assessed. Within a mixed-methods approach, data gathered from Colombian university heads (16 presidents and vice-presidents) and 133 individuals responsible for internationalisation affairs is analysed. Concurrent triangulation is used to help introduce a series of themes and sub-themes derived from the qualitative and quantitative information. Within a social constructionist framework, this study has a twofold purpose. On the one hand, it is sought to identify and understand the challenges for Colombia’s academic internationalisation; on the other, an in-depth approach is presented in relation to the way different stakeholders perceive the society-HE internationalisation nexus. The major findings of the study indicate that there is a need to clarify and revise Colombia’s Higher Education policy to address both the education needs of the society and its social development requirements. It was also found that higher education internationalisation could act as an important agent of social change.
- Full Text:
- Date Issued: 2018
- Authors: Anzola-Pardo, Giovanni
- Date: 2018
- Subjects: Education, Higher -- Colombia , Education and globalization International education -- Colombia Education, Higher -- International cooperation -- Colombia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/23371 , vital:30536
- Description: The study addresses the nature of Colombian sustainable social development and the internationalisation of higher education (iHE). This intersection is analysed within various theoretical paradigms surrounding social sustainable development and the internationalisation of higher education. This study aims at reviewing the activities of Higher Education Institutions (HEIs) which focus on internationalisation. The analysis focuses on the manner in which HEIs in Colombia approach internationalisation vis-à-vis social sustainable development, and emphasis is made on knowledge transfer, research and community engagement. Using the theories of sustainable development, the iHE, in terms of practises and policies, are assessed. Within a mixed-methods approach, data gathered from Colombian university heads (16 presidents and vice-presidents) and 133 individuals responsible for internationalisation affairs is analysed. Concurrent triangulation is used to help introduce a series of themes and sub-themes derived from the qualitative and quantitative information. Within a social constructionist framework, this study has a twofold purpose. On the one hand, it is sought to identify and understand the challenges for Colombia’s academic internationalisation; on the other, an in-depth approach is presented in relation to the way different stakeholders perceive the society-HE internationalisation nexus. The major findings of the study indicate that there is a need to clarify and revise Colombia’s Higher Education policy to address both the education needs of the society and its social development requirements. It was also found that higher education internationalisation could act as an important agent of social change.
- Full Text:
- Date Issued: 2018
An investigation into the introduction of a new wealth tax in South Africa
- Authors: Arendse, Jacqueline A
- Date: 2018
- Subjects: Wealth tax -- Law and legislation -- South Africa , Taxation -- Law and legislation -- South Africa , Income tax -- South Africa , Fiscal policy -- South Africa , South Africa -- Economic conditions , Income distribution -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61379 , vital:28020
- Description: In a world of economic uncertainty and manifold social problems, South Africa has its own unique challenges of low economic growth, persistent budget deficits that produce increasing government debt and the highest level of economic inequality in the world. The history of injustice and economic marginalisation and the failure of the economy to provide inclusive growth drives an urgent need to address economic inequality through tax policy, placing ever more focus on wealth taxes as a possible solution. There is a hope is that taxing the wealthy may provide the opportunity to redistribute desperately-needed resources to those denied the opportunity to build wealth and who are trapped in the cycle of poverty. Yet, as appealing as a new wealth tax may seem, the introduction of such a tax carries with it a range of risks, not all of which are known. Of great concern is the possible effect on the economy, which, in its vulnerable state, cannot afford any loss of capital and investment. Very little research has been done on wealth tax in the South African context and there is a dearth of literature focusing on the views and perceptions of the wealthy individuals themselves. This qualitative study investigates the merits and disadvantages of a new wealth tax and seeks to identify any unintended consequences that could result from the implementation of a new wealth tax in South Africa, drawing from historical and international experience and primary data obtained from interviews with individuals likely to be affected by such a tax. Having explored the literature and international experiences with wealth tax and having probed the thinking of wealthy individuals who would be the payers of a wealth tax, the study finds that a new wealth tax may contribute towards the progressivity of the tax system, but it is doubtful whether such a tax would provide a sustainable revenue stream that would be sufficient to address economic inequality and there is a risk of causing harm to the economy. Recognising that the motivation for wealth taxes is often driven more by political argument and public perception than by rational quantitative analysis, the study also anticipates the introduction of a new wealth tax and suggests guidelines for the design of such a tax within the framework for evaluating a good tax system. This study informs the debate on wealth taxes in South Africa and contributes to the design of such a tax, should it be implemented.
- Full Text:
- Date Issued: 2018
- Authors: Arendse, Jacqueline A
- Date: 2018
- Subjects: Wealth tax -- Law and legislation -- South Africa , Taxation -- Law and legislation -- South Africa , Income tax -- South Africa , Fiscal policy -- South Africa , South Africa -- Economic conditions , Income distribution -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61379 , vital:28020
- Description: In a world of economic uncertainty and manifold social problems, South Africa has its own unique challenges of low economic growth, persistent budget deficits that produce increasing government debt and the highest level of economic inequality in the world. The history of injustice and economic marginalisation and the failure of the economy to provide inclusive growth drives an urgent need to address economic inequality through tax policy, placing ever more focus on wealth taxes as a possible solution. There is a hope is that taxing the wealthy may provide the opportunity to redistribute desperately-needed resources to those denied the opportunity to build wealth and who are trapped in the cycle of poverty. Yet, as appealing as a new wealth tax may seem, the introduction of such a tax carries with it a range of risks, not all of which are known. Of great concern is the possible effect on the economy, which, in its vulnerable state, cannot afford any loss of capital and investment. Very little research has been done on wealth tax in the South African context and there is a dearth of literature focusing on the views and perceptions of the wealthy individuals themselves. This qualitative study investigates the merits and disadvantages of a new wealth tax and seeks to identify any unintended consequences that could result from the implementation of a new wealth tax in South Africa, drawing from historical and international experience and primary data obtained from interviews with individuals likely to be affected by such a tax. Having explored the literature and international experiences with wealth tax and having probed the thinking of wealthy individuals who would be the payers of a wealth tax, the study finds that a new wealth tax may contribute towards the progressivity of the tax system, but it is doubtful whether such a tax would provide a sustainable revenue stream that would be sufficient to address economic inequality and there is a risk of causing harm to the economy. Recognising that the motivation for wealth taxes is often driven more by political argument and public perception than by rational quantitative analysis, the study also anticipates the introduction of a new wealth tax and suggests guidelines for the design of such a tax within the framework for evaluating a good tax system. This study informs the debate on wealth taxes in South Africa and contributes to the design of such a tax, should it be implemented.
- Full Text:
- Date Issued: 2018
The scalability of small and medium enterprises in South Africa
- Authors: Augustyn, Wesley
- Date: 2018
- Subjects: Small business -- South Africa -- Management , Business planning -- South Africa Corporations -- South Africa -- Growth Success in business -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/21516 , vital:29532
- Description: It has long been recognised that small and medium enterprises (SMEs) account for an overwhelming part of businesses worldwide and that they contribute considerably to private sector Gross Domestic Product (GDP), growth and are the source for most new employment opportunities. It may therefore be postulated that scaling and growing SMEs are of notable importance to the economic wealth of the country and to this extent it eliminates economic stagnation. This treatise argues the significant impact that entrepreneurship exerts on the South African economy. This would allow the role players to identify the strategic interventions necessary to grow and scale SMEs. A literature review was conducted to develop insights on the factors that affect the scalability of SMEs. The aforementioned section expounds on the concept of SMEs. Secondly, the emergence of SMEs across developed and emerging economies is discussed by exploring the United States of America, Europe and the BRICS economies respectively. Thirdly, SMEs in the South African context are explored. Fourthly, the requirements and challenges of SMEs in the South African economy are highlighted. The primary data for this study were collected from the sample by means of an online questionnaire and through fieldworkers who were deployed to collect responses from the sample group. A representative sample of n = 295 responses were received. Descriptive statistics were used to summarize the data in a way to simplify the interpretation of the data. Inferential statistics were used to authenticate conclusions made from the data. The model was developed and identified the following factors as exerting influence on the scalability of SMEs: Access to Finance, Access to Markets and Access to Human Capital, Entrepreneurial Intention, Regulatory Framework, Business Support and Networks. The average mean values of the factors were then used to establish their position or ranking as determined from the responses received. All factors ranked above a mean value of 3 which indicates that SMEs have a neutral to positive opinion of the factors identified in the model. According to a one-tailed t-test from the sample of SMEs it was shown that two of the nine factors had a large effect size in the factors of Human Capital and Entrepreneurial Intention. The Scalability of SMEs’ model developed in this study specified the factors that influence the growth of SMEs.
- Full Text:
- Date Issued: 2018
- Authors: Augustyn, Wesley
- Date: 2018
- Subjects: Small business -- South Africa -- Management , Business planning -- South Africa Corporations -- South Africa -- Growth Success in business -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/21516 , vital:29532
- Description: It has long been recognised that small and medium enterprises (SMEs) account for an overwhelming part of businesses worldwide and that they contribute considerably to private sector Gross Domestic Product (GDP), growth and are the source for most new employment opportunities. It may therefore be postulated that scaling and growing SMEs are of notable importance to the economic wealth of the country and to this extent it eliminates economic stagnation. This treatise argues the significant impact that entrepreneurship exerts on the South African economy. This would allow the role players to identify the strategic interventions necessary to grow and scale SMEs. A literature review was conducted to develop insights on the factors that affect the scalability of SMEs. The aforementioned section expounds on the concept of SMEs. Secondly, the emergence of SMEs across developed and emerging economies is discussed by exploring the United States of America, Europe and the BRICS economies respectively. Thirdly, SMEs in the South African context are explored. Fourthly, the requirements and challenges of SMEs in the South African economy are highlighted. The primary data for this study were collected from the sample by means of an online questionnaire and through fieldworkers who were deployed to collect responses from the sample group. A representative sample of n = 295 responses were received. Descriptive statistics were used to summarize the data in a way to simplify the interpretation of the data. Inferential statistics were used to authenticate conclusions made from the data. The model was developed and identified the following factors as exerting influence on the scalability of SMEs: Access to Finance, Access to Markets and Access to Human Capital, Entrepreneurial Intention, Regulatory Framework, Business Support and Networks. The average mean values of the factors were then used to establish their position or ranking as determined from the responses received. All factors ranked above a mean value of 3 which indicates that SMEs have a neutral to positive opinion of the factors identified in the model. According to a one-tailed t-test from the sample of SMEs it was shown that two of the nine factors had a large effect size in the factors of Human Capital and Entrepreneurial Intention. The Scalability of SMEs’ model developed in this study specified the factors that influence the growth of SMEs.
- Full Text:
- Date Issued: 2018
Mannich base metal complexes and their thiocyanate analogues as catalysts in the oxidation of Catechol
- Authors: Ayeni, Ayowole Olaolu
- Date: 2018
- Subjects: Mannich bases , Catechol , Catechol -- Oxidation , Thiocyanates , Catalysts
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62339 , vital:28156
- Description: The study focused on the design of new Cu(II) and Fe(III) complexes, with or without thiocyanate (NCS-), as possible candidates of catechol oxidation using 3,5-di-tert-butyl catechol (3,5-DTBC) as substrate. Two classes of Mannich bases were studied depending on the active methylene group from which they were formed, being either p-cresol or acetaminophen. The ligands were characterised by 1H and 13C NMR spectroscopy. Crystal structures of three of the ligands are newly reported, along with detailed discussion of polymorphism observed in one of the ligands, and the nature of the hydrogen within the ligands in the solid state as well as in solution. The Mannich bases behaved as bidentate (NO), tridentate (NNO) and tetradentate (NNOO) ligands on coordination to Cu(II) and Fe(III) ions in which the hydroxyl group may be protonated or deprotonated. Coordination was determined by IR spectroscopy, investigating shifts in vOH, vC-O and in vCNC of the Mannich bases. The vCNC stretching frequencies v1 and v2 of asymmetrical piperazine Mannich bases were observed to shift upward in few cases upon complexation and this is attributed to (chair-boat) conformational change. The mode of coordination of the thiocyanate was determined by IR spectroscopy. Of the forty metal complexes investigated, six groups of metal complexes were identified as follows: (i) Ma(Ln)aClb-cH2O; (ii) Ma(HLn)a(NCS)aClb; (iii) Ma(Ln)a(NCS)aClb; (iv) Ma(HLn)aClb-cH2O; (v) Ma(Ln)a(NCS)a-cH2O; (vi) Ma(HLn)a(NCS)a-cH2O where a = 1 - 2 ; b = 1 - 4, c = 1 - 8. Molar conductivity values of 4.38 - 161.77 Q-1.cm2.mol-1 for the Cu(II) and Fe(III) complexes in DMSO showed that they range from non-electrolytes to 1:1 and 1:2 electrolytes. Electronic spectra for the ligands and the complexes were conducted in DMF and DMSO. The ligands are characterised by and n→n* and n→n* transitions. Intraligand charge transfer transitions peculiar to the nitro group were observed at about 430 nm for the nitro containing ligands. On coordination, these bands overshadowed the d-d transitions particularly for the nitro-Mannich bases. On complexation, ligand to metal charge transfer transitions associated with the hydroxyl were observed between 320 - 420 nm. Charge transfer transitions associated with the thiocyanates were also observed and discussed. The d-d transitions for high spin Fe(III) complexes are spin forbidden and generally uninformative. Those of Cu(II) are spin allowed and allow tentative structural proposals. Square planar and octahedral geometry are generally prevalent in the Cu(II) complexes with trigonal bipyramidal observed in few instances. The Fe(III) complexes are generally octahedral. Thirty-nine of the forty synthesised Cu(II) and Fe(III) complexes were catalytically active on the substrate (3,5-DTBC) in DMF with turnover rates (kcat) reported in the range of 1.86 ± 0.09 to 112.32 ± 3.72 h-1. From this pool of complexes, sixteen isostructural pairs were identified in terms of geometry, molecular formula and the source of the Mannich base and the following conclusions were made: The presence of thiocyanate in the metal complexes reduce catecholase activity; the Cu(II) complexes generally have better activity but the Fe(III) complexes become more relatively active with highly electron donating groups while the Cu(II) complexes become less; dinuclear complexes have greater activity than the mononuclear.
- Full Text:
- Date Issued: 2018
- Authors: Ayeni, Ayowole Olaolu
- Date: 2018
- Subjects: Mannich bases , Catechol , Catechol -- Oxidation , Thiocyanates , Catalysts
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62339 , vital:28156
- Description: The study focused on the design of new Cu(II) and Fe(III) complexes, with or without thiocyanate (NCS-), as possible candidates of catechol oxidation using 3,5-di-tert-butyl catechol (3,5-DTBC) as substrate. Two classes of Mannich bases were studied depending on the active methylene group from which they were formed, being either p-cresol or acetaminophen. The ligands were characterised by 1H and 13C NMR spectroscopy. Crystal structures of three of the ligands are newly reported, along with detailed discussion of polymorphism observed in one of the ligands, and the nature of the hydrogen within the ligands in the solid state as well as in solution. The Mannich bases behaved as bidentate (NO), tridentate (NNO) and tetradentate (NNOO) ligands on coordination to Cu(II) and Fe(III) ions in which the hydroxyl group may be protonated or deprotonated. Coordination was determined by IR spectroscopy, investigating shifts in vOH, vC-O and in vCNC of the Mannich bases. The vCNC stretching frequencies v1 and v2 of asymmetrical piperazine Mannich bases were observed to shift upward in few cases upon complexation and this is attributed to (chair-boat) conformational change. The mode of coordination of the thiocyanate was determined by IR spectroscopy. Of the forty metal complexes investigated, six groups of metal complexes were identified as follows: (i) Ma(Ln)aClb-cH2O; (ii) Ma(HLn)a(NCS)aClb; (iii) Ma(Ln)a(NCS)aClb; (iv) Ma(HLn)aClb-cH2O; (v) Ma(Ln)a(NCS)a-cH2O; (vi) Ma(HLn)a(NCS)a-cH2O where a = 1 - 2 ; b = 1 - 4, c = 1 - 8. Molar conductivity values of 4.38 - 161.77 Q-1.cm2.mol-1 for the Cu(II) and Fe(III) complexes in DMSO showed that they range from non-electrolytes to 1:1 and 1:2 electrolytes. Electronic spectra for the ligands and the complexes were conducted in DMF and DMSO. The ligands are characterised by and n→n* and n→n* transitions. Intraligand charge transfer transitions peculiar to the nitro group were observed at about 430 nm for the nitro containing ligands. On coordination, these bands overshadowed the d-d transitions particularly for the nitro-Mannich bases. On complexation, ligand to metal charge transfer transitions associated with the hydroxyl were observed between 320 - 420 nm. Charge transfer transitions associated with the thiocyanates were also observed and discussed. The d-d transitions for high spin Fe(III) complexes are spin forbidden and generally uninformative. Those of Cu(II) are spin allowed and allow tentative structural proposals. Square planar and octahedral geometry are generally prevalent in the Cu(II) complexes with trigonal bipyramidal observed in few instances. The Fe(III) complexes are generally octahedral. Thirty-nine of the forty synthesised Cu(II) and Fe(III) complexes were catalytically active on the substrate (3,5-DTBC) in DMF with turnover rates (kcat) reported in the range of 1.86 ± 0.09 to 112.32 ± 3.72 h-1. From this pool of complexes, sixteen isostructural pairs were identified in terms of geometry, molecular formula and the source of the Mannich base and the following conclusions were made: The presence of thiocyanate in the metal complexes reduce catecholase activity; the Cu(II) complexes generally have better activity but the Fe(III) complexes become more relatively active with highly electron donating groups while the Cu(II) complexes become less; dinuclear complexes have greater activity than the mononuclear.
- Full Text:
- Date Issued: 2018
Molecular epidemiology of vibrio pathogens in selected surface waters and treated final effluents of wastewater treatment plants in Chris Hani District Municipality in the Eastern Cape Province, South Africa
- Authors: Ayodeji, Onsula Charles
- Date: 2018
- Subjects: Sewage disposal plants Sewage -- Purification Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/10464 , vital:35478
- Description: Access to clean and safe water is essential for the survival of human beings. Nevertheless pollution from wastewater treatment plants (WWTPs) effluents often impacts the microbiological qualities of surface waters. Availability of freshwater resources is indispensable for preventing waterborne diseases. The current study evaluated the physicochemical properties and abundance of Vibrio species in selected rivers and WWTPs in the Eastern Cape Province of South Africa, over a one year sampling regime (December, 2016 to November, 2017). Water samples were collected monthly at designated locations along the banks of two rivers, treated effluents from 500 m upstream and downstream discharge points of two WWTPs and examined for physicochemical qualities, prevalence of Vibrio pathogens and their antibiogram profiles using both cultural and molecular techniques. The findings reveal the qualities of Tsomo and Great Fish river qualities with respect to electrical conductivity (EC) (137.75 – 377.69 mg/l), total suspended solids (TSS) (52.00 – 725.19 mg/l) and temperature (12.7 – 23 oC) and the treated effluents of WW-AD and WW-CR WWTPs with respect to EC (525.73 – 1071.89 mg/l), free chlorine (0.00 mg/l – 0.68 mg/l), temperature (12.4 – 28.8 oC), TSS (14.67 – 276.44 mg/l) exceeds the permissible limits set for effluent discharged to freshwater by South Africa guidelines. Other physicochemical qualities such as turbidity (63.11 – 797.17 NTU), BOD (3.30 – 5.26 mg/l) and TDS (68.88 – 148.14 mg/l) for Tsomo and Great Fish river and turbidity (20.33 – 310 NTU), biological oxygen demand (BOD) (1.28 – 4.96 mg/l), and total dissolve solid (TDS) (262.89 – 534.89 mg/l) for WWTPs WW-AD and WW-CR did not comply with WHO and EU standards as no regulation is set for them in the South African guidelines for domestic water usage. Statistical analysis revealed that pH, electrical conductivities, dissolved oxygen and total dissolved solid were significantly different whereas temperature did not differ significantly with respect to the four seasons (P < 0.05). The Vibrio densities for Great Fish river ranged between 0 and 3.29 log10 CFU/ml with the highest obtained in the spring. The Tsomo River Vibrio densities varied between 0 to 3.56 log10 CFU/ml and the maximum densities recorded during summer. The presumptive Vibrio densities in WW-AD and WW-CR WWTPs ranged from 0 to 3.67 log10 CFU/ml and 0 to 4.42 log10 CFU/ml with autumn and spring having the highest loads respectively. Molecular identification of the presumptive Vibrio species revealed 424 positive for the Vibrio genus. Of these, 21.69 percent, 11.79 percent, 8.25 percent and 2.12 percent were confirmed as V. cholerae, V. mimicus, V. parahaemolyticus and V. fluvialis respectively. The presence of potentially Vibrio pathogens in the rivers and treated effluents suggests potential public health threat to the communities relying on receiving watersheds where the effluents are discharged. Results of antibiotic sensitivity testing revealed high sensitivities against Ofloxacin (85.54 percent), Cefuroxime (81.93 percent), and Ciprofloxacin (74.70 percent), whereas resistance against other antibiotics follow this order: Imipenem (42.17 percent), Amoxicillin-Clavulanic Acid (54.17 percent), Ampicillin (63.54 percent), Nitrofurantoin (71.79 percent) and Polymyxin B (97.44 percent). Surprisingly, the resistance of Vibrio species against the known effective Carbapenems was relatively high (Meropenem (38.54 percent) and Imipenem (58.88 percent). Multiple antibiotic resistance phenotypes (MARP) of the isolates were resistant to two or more antibiotics whereas the calculated multiple antibiotic resistance index (MARI) ranged from 0.2 to 0.7. The observed high multiple antibiotics index suggest the recovered Vibrio pathogens are of high antimicrobial usage origin. Increase in antimicrobial resistance profiles towards conventionally used antibiotics as indicated in this study calls for adequate sanitation facilities and proper surveillance programs towards monitoring of antimicrobial resistance determinants in wastewater treatment effluents and receiving watersheds. This will in turn enhance early detection of resistant strains of public health importance, and supports the prompt notification and investigation of outbreaks. It further advocates the need for constant monitoring programme by the relevant regulatory agencies to ensure total compliance of the wastewater treatment facilities to the stipulated standards.
- Full Text:
- Date Issued: 2018
- Authors: Ayodeji, Onsula Charles
- Date: 2018
- Subjects: Sewage disposal plants Sewage -- Purification Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/10464 , vital:35478
- Description: Access to clean and safe water is essential for the survival of human beings. Nevertheless pollution from wastewater treatment plants (WWTPs) effluents often impacts the microbiological qualities of surface waters. Availability of freshwater resources is indispensable for preventing waterborne diseases. The current study evaluated the physicochemical properties and abundance of Vibrio species in selected rivers and WWTPs in the Eastern Cape Province of South Africa, over a one year sampling regime (December, 2016 to November, 2017). Water samples were collected monthly at designated locations along the banks of two rivers, treated effluents from 500 m upstream and downstream discharge points of two WWTPs and examined for physicochemical qualities, prevalence of Vibrio pathogens and their antibiogram profiles using both cultural and molecular techniques. The findings reveal the qualities of Tsomo and Great Fish river qualities with respect to electrical conductivity (EC) (137.75 – 377.69 mg/l), total suspended solids (TSS) (52.00 – 725.19 mg/l) and temperature (12.7 – 23 oC) and the treated effluents of WW-AD and WW-CR WWTPs with respect to EC (525.73 – 1071.89 mg/l), free chlorine (0.00 mg/l – 0.68 mg/l), temperature (12.4 – 28.8 oC), TSS (14.67 – 276.44 mg/l) exceeds the permissible limits set for effluent discharged to freshwater by South Africa guidelines. Other physicochemical qualities such as turbidity (63.11 – 797.17 NTU), BOD (3.30 – 5.26 mg/l) and TDS (68.88 – 148.14 mg/l) for Tsomo and Great Fish river and turbidity (20.33 – 310 NTU), biological oxygen demand (BOD) (1.28 – 4.96 mg/l), and total dissolve solid (TDS) (262.89 – 534.89 mg/l) for WWTPs WW-AD and WW-CR did not comply with WHO and EU standards as no regulation is set for them in the South African guidelines for domestic water usage. Statistical analysis revealed that pH, electrical conductivities, dissolved oxygen and total dissolved solid were significantly different whereas temperature did not differ significantly with respect to the four seasons (P < 0.05). The Vibrio densities for Great Fish river ranged between 0 and 3.29 log10 CFU/ml with the highest obtained in the spring. The Tsomo River Vibrio densities varied between 0 to 3.56 log10 CFU/ml and the maximum densities recorded during summer. The presumptive Vibrio densities in WW-AD and WW-CR WWTPs ranged from 0 to 3.67 log10 CFU/ml and 0 to 4.42 log10 CFU/ml with autumn and spring having the highest loads respectively. Molecular identification of the presumptive Vibrio species revealed 424 positive for the Vibrio genus. Of these, 21.69 percent, 11.79 percent, 8.25 percent and 2.12 percent were confirmed as V. cholerae, V. mimicus, V. parahaemolyticus and V. fluvialis respectively. The presence of potentially Vibrio pathogens in the rivers and treated effluents suggests potential public health threat to the communities relying on receiving watersheds where the effluents are discharged. Results of antibiotic sensitivity testing revealed high sensitivities against Ofloxacin (85.54 percent), Cefuroxime (81.93 percent), and Ciprofloxacin (74.70 percent), whereas resistance against other antibiotics follow this order: Imipenem (42.17 percent), Amoxicillin-Clavulanic Acid (54.17 percent), Ampicillin (63.54 percent), Nitrofurantoin (71.79 percent) and Polymyxin B (97.44 percent). Surprisingly, the resistance of Vibrio species against the known effective Carbapenems was relatively high (Meropenem (38.54 percent) and Imipenem (58.88 percent). Multiple antibiotic resistance phenotypes (MARP) of the isolates were resistant to two or more antibiotics whereas the calculated multiple antibiotic resistance index (MARI) ranged from 0.2 to 0.7. The observed high multiple antibiotics index suggest the recovered Vibrio pathogens are of high antimicrobial usage origin. Increase in antimicrobial resistance profiles towards conventionally used antibiotics as indicated in this study calls for adequate sanitation facilities and proper surveillance programs towards monitoring of antimicrobial resistance determinants in wastewater treatment effluents and receiving watersheds. This will in turn enhance early detection of resistant strains of public health importance, and supports the prompt notification and investigation of outbreaks. It further advocates the need for constant monitoring programme by the relevant regulatory agencies to ensure total compliance of the wastewater treatment facilities to the stipulated standards.
- Full Text:
- Date Issued: 2018