Assessment of drug resistant Tuberculosis and Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome: knowledge levels among community members in Nelson Mandela Metropolitan Municipality
- Authors: Fana, Thanduxolo
- Date: 2013
- Subjects: Multidrug-resistant tuberculosis -- South Africa -- Port Elizabeth , Tuberculosis -- South Africa -- Port Elizabeth -- Prevention
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8276 , http://hdl.handle.net/10948/d1016076
- Description: The aim of this study was to assess community members’ knowledge levels regarding Drug Resistant TB and HIV and AIDS. The study was conducted at ward 40 in Green bushes area in Nelson Mandela Metropolitan Municipality (NMMM). A quantitative research method was used in this study. Random sampling is the type of probability sampling method that was used in this study. The sample consisted of 100 respondents above 18 years who were randomly selected from the beneficiary list of for the RDP houses in Green bushes area in the Nelson Mandela Metropolitan Municipality. Data for this study were collected using close ended questions which were administered by the researcher to the selected participants. Data was analysed using bivariate and descriptive statistics according to the identified themes. The study revealed that community members had high knowledge levels regarding Drug Resistant TB and HIV and AIDS prevention, transmission modes and diagnosis and treatment methods. The findings revealed that community members were highly knowledgeable and aware of the fact that abstaining and practising safe sex were means of preventing the spread of HIV and AIDS as it was spread through unprotected sex, while opening of windows and minimisation of close contact with HIV positive people and children with people infected with Drug Resistant TB are infection control measures or methods of preventing the spread of the disease. Additionally, the study indicated that female respondents were more aware and knowledgeable about prevention, transmission modes and diagnosis and treatment of Drug Resistant TB and HIV and AIDS than male respondents. Furthermore, the findings revealed that the respondents were highly knowledgeable and aware about transmission of Drug Resistant TB and HIV and AIDS; knowledgeable about prevention and less knowledgeable about diagnosis and treatment. A high percentage of female respondents knew that there was no vaccine to neither prevent nor cure HIV and AIDS and that antiretroviral drug were used to manage it. The study also showed that female respondents knew that all people irrespective of race and economic class can be infected with Drug Resistant TB and HIV and AIDS. It is important to note that the respondents between 41-60 years possessed more knowledge regarding Drug Resistant TB and HIV and AIDS than the respondents who were between 18-40 years. Lastly, the study showed that there were significant differences in gender and knowledge and no significant differences in age and knowledge of the respondents regarding Drug Resistant TB and HIV and AIDS. It is recommended that in future, research regarding knowledge levels about Drug Resistant TB and HIV and AIDS be extended to other wards in the Nelson Mandela Metropolitan Municipality (NMMM). Accurate knowledge should be provided by ensuring that educational materials that are developed, are appropriate for the various levels of literacy, and that more appropriate and relevant information regarding these diseases is made more accessible to community members in their home languages. The researcher further recommends that during training interventions and educational campaigns more emphasis should be put on prevention, diagnosis and treatment of Drug Resistant TB and HIV and AIDS.
- Full Text:
- Date Issued: 2013
- Authors: Fana, Thanduxolo
- Date: 2013
- Subjects: Multidrug-resistant tuberculosis -- South Africa -- Port Elizabeth , Tuberculosis -- South Africa -- Port Elizabeth -- Prevention
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8276 , http://hdl.handle.net/10948/d1016076
- Description: The aim of this study was to assess community members’ knowledge levels regarding Drug Resistant TB and HIV and AIDS. The study was conducted at ward 40 in Green bushes area in Nelson Mandela Metropolitan Municipality (NMMM). A quantitative research method was used in this study. Random sampling is the type of probability sampling method that was used in this study. The sample consisted of 100 respondents above 18 years who were randomly selected from the beneficiary list of for the RDP houses in Green bushes area in the Nelson Mandela Metropolitan Municipality. Data for this study were collected using close ended questions which were administered by the researcher to the selected participants. Data was analysed using bivariate and descriptive statistics according to the identified themes. The study revealed that community members had high knowledge levels regarding Drug Resistant TB and HIV and AIDS prevention, transmission modes and diagnosis and treatment methods. The findings revealed that community members were highly knowledgeable and aware of the fact that abstaining and practising safe sex were means of preventing the spread of HIV and AIDS as it was spread through unprotected sex, while opening of windows and minimisation of close contact with HIV positive people and children with people infected with Drug Resistant TB are infection control measures or methods of preventing the spread of the disease. Additionally, the study indicated that female respondents were more aware and knowledgeable about prevention, transmission modes and diagnosis and treatment of Drug Resistant TB and HIV and AIDS than male respondents. Furthermore, the findings revealed that the respondents were highly knowledgeable and aware about transmission of Drug Resistant TB and HIV and AIDS; knowledgeable about prevention and less knowledgeable about diagnosis and treatment. A high percentage of female respondents knew that there was no vaccine to neither prevent nor cure HIV and AIDS and that antiretroviral drug were used to manage it. The study also showed that female respondents knew that all people irrespective of race and economic class can be infected with Drug Resistant TB and HIV and AIDS. It is important to note that the respondents between 41-60 years possessed more knowledge regarding Drug Resistant TB and HIV and AIDS than the respondents who were between 18-40 years. Lastly, the study showed that there were significant differences in gender and knowledge and no significant differences in age and knowledge of the respondents regarding Drug Resistant TB and HIV and AIDS. It is recommended that in future, research regarding knowledge levels about Drug Resistant TB and HIV and AIDS be extended to other wards in the Nelson Mandela Metropolitan Municipality (NMMM). Accurate knowledge should be provided by ensuring that educational materials that are developed, are appropriate for the various levels of literacy, and that more appropriate and relevant information regarding these diseases is made more accessible to community members in their home languages. The researcher further recommends that during training interventions and educational campaigns more emphasis should be put on prevention, diagnosis and treatment of Drug Resistant TB and HIV and AIDS.
- Full Text:
- Date Issued: 2013
Assessment of local economic development in the O.R. Tambo District Municipality: agriculture and food production
- Nongogo, Mbuyiselo Theophilus
- Authors: Nongogo, Mbuyiselo Theophilus
- Date: 2013
- Subjects: Economic development projects -- South Africa -- Eastern Cape , Community development -- South Africa -- O.R. Tambo District Municipality , Municipal government -- South Africa -- Eastern Cape , Agriculture and state -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8344 , http://hdl.handle.net/10948/d1020761
- Description: Local economic development (LED) is a government policy tool that seeks to build the economic capacity of a local area to improve its economic future and the quality of life for all. Partnerships between the public sector and the private sector are considered to be an important foundation for successful LED planning and implementation. The aim of the study was to assess whether the LED interventions, with specific emphasis on agriculture and food production programmes, are improving the livelihoods of the poor communities within the OR Tambo District Municipality. The researcher used the qualitative and quantitative research methods to collect the data through interviews and questionnaires respectively. Probability and non-probability sampling techniques were employed to identify the research sample from the target population. The researcher sampled the OR Tambo District Municipality as well as all the local municipalities therein. The target population consisted of LED directors, LED and IDP managers as well as LED councillors as respondents. Furthermore, the researcher also sampled other stakeholders that are crucial in LED, namely the Department of Economic Development and Environmental Affairs, the Department of Rural Development and Agrarian Reform and Transformation, the Eastern Cape Department of Local Government and Traditional Affairs, the Department of Social Development and Special Programmes as well as the Ntinga OR Tambo Development Agency. Budgetary constraints and agricultural infrastructure backlogs were identified as the main challenges facing the district. These challenges hinder the effectiveness of implementing sound LED programmes. Consequently, LED benefits are minimal. It is recommended that the municipality develop strategies for income generation to boost its financial viability in order to strengthen its financial capacity, embark on vigorous infrastructure rollout which will have a positive economic impact and open employment opportunities for the local communities. This can be achieved by the strengthening of partnerships and the attraction of private investors in order for the municipality to implement the LED programmes effectively and change the lives of the people in the local area.
- Full Text:
- Date Issued: 2013
- Authors: Nongogo, Mbuyiselo Theophilus
- Date: 2013
- Subjects: Economic development projects -- South Africa -- Eastern Cape , Community development -- South Africa -- O.R. Tambo District Municipality , Municipal government -- South Africa -- Eastern Cape , Agriculture and state -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8344 , http://hdl.handle.net/10948/d1020761
- Description: Local economic development (LED) is a government policy tool that seeks to build the economic capacity of a local area to improve its economic future and the quality of life for all. Partnerships between the public sector and the private sector are considered to be an important foundation for successful LED planning and implementation. The aim of the study was to assess whether the LED interventions, with specific emphasis on agriculture and food production programmes, are improving the livelihoods of the poor communities within the OR Tambo District Municipality. The researcher used the qualitative and quantitative research methods to collect the data through interviews and questionnaires respectively. Probability and non-probability sampling techniques were employed to identify the research sample from the target population. The researcher sampled the OR Tambo District Municipality as well as all the local municipalities therein. The target population consisted of LED directors, LED and IDP managers as well as LED councillors as respondents. Furthermore, the researcher also sampled other stakeholders that are crucial in LED, namely the Department of Economic Development and Environmental Affairs, the Department of Rural Development and Agrarian Reform and Transformation, the Eastern Cape Department of Local Government and Traditional Affairs, the Department of Social Development and Special Programmes as well as the Ntinga OR Tambo Development Agency. Budgetary constraints and agricultural infrastructure backlogs were identified as the main challenges facing the district. These challenges hinder the effectiveness of implementing sound LED programmes. Consequently, LED benefits are minimal. It is recommended that the municipality develop strategies for income generation to boost its financial viability in order to strengthen its financial capacity, embark on vigorous infrastructure rollout which will have a positive economic impact and open employment opportunities for the local communities. This can be achieved by the strengthening of partnerships and the attraction of private investors in order for the municipality to implement the LED programmes effectively and change the lives of the people in the local area.
- Full Text:
- Date Issued: 2013
Assessment of potential anti-cancer stem cell activity of marine algal compounds using an in vitro mammosphere assay:
- de la Mare, Jo-Anne, Sterrenberg, Jason N, Sukhthankar, Mugdha G, Chiwakata, Maynard T, Beukes, Denzil R, Blatch, Gregory L, Edkins, Adrienne L
- Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
- Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
- Full Text:
- Date Issued: 2013
- Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
- Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
- Full Text:
- Date Issued: 2013
Assessment of sources of livelihoods and opportunities to improve the contribution of farming within available food chains
- Authors: Mbusi, Nontembeko
- Date: 2013
- Subjects: Households -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Livelihood strategies , Outcomes , Poverty , Farming , Employment
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11204 , http://hdl.handle.net/10353/d1007575 , Households -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Livelihood strategies , Outcomes , Poverty , Farming , Employment
- Description: Official statistics suggest that as many as 40 percent to 60 percent of people in South Africa are living in poverty, and the 15 percent poorest are in a desperate struggle for survival. Since 1994, Government has been making an effort to help smallholder agriculture through numerous programmes, including those that address land ownership and provide credit and grants for farms and households, but very little change has taken place. Understanding the sources of livelihood and opportunities to improve the contribution of farming within available food chains is therefore an important practical need. The study investigated sources of livelihood and mapped the livelihoods profile of the farming households in parts of the Eastern Cape. The study was conducted in the Alice and Peddie communities in the Amathole district municipality. A set of structured questionnaires were used to interview the sample of 80 farming households selected through a random process within two irrigation schemes and communities that were selected purposively in line with the focus of the larger project on which this study is based. The resulting data were analyzed by means of descriptive statistics and multiple linear regression. The descriptive results indicated that members of most rural households were old, married, uneducated and unemployed. Farming was primary livelihood strategy employed in these areas. Rural households were also dependent on remittances, social grants and pension funds because the farming strategy could not meet all their household needs. The major crops that were grown for income and food security to sustain their livelihoods included maize, potatoes, onions and butternut. Factors that had significant influences on outcomes were extension services, grants, pension and remittances, land productivity, type of irrigation system, market accessibility, output price difference and value adding. The available opportunities were land productivity, irrigation facilities, government or NGO programmes and working as a group. For improved livelihood of rural communities in Alice and Peddie, government needs to strengthen agricultural activities and equip farmers with market information, improve their access to irrigation schemes, provide training on value adding and also improve access to extension services.
- Full Text:
- Date Issued: 2013
- Authors: Mbusi, Nontembeko
- Date: 2013
- Subjects: Households -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Livelihood strategies , Outcomes , Poverty , Farming , Employment
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11204 , http://hdl.handle.net/10353/d1007575 , Households -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Livelihood strategies , Outcomes , Poverty , Farming , Employment
- Description: Official statistics suggest that as many as 40 percent to 60 percent of people in South Africa are living in poverty, and the 15 percent poorest are in a desperate struggle for survival. Since 1994, Government has been making an effort to help smallholder agriculture through numerous programmes, including those that address land ownership and provide credit and grants for farms and households, but very little change has taken place. Understanding the sources of livelihood and opportunities to improve the contribution of farming within available food chains is therefore an important practical need. The study investigated sources of livelihood and mapped the livelihoods profile of the farming households in parts of the Eastern Cape. The study was conducted in the Alice and Peddie communities in the Amathole district municipality. A set of structured questionnaires were used to interview the sample of 80 farming households selected through a random process within two irrigation schemes and communities that were selected purposively in line with the focus of the larger project on which this study is based. The resulting data were analyzed by means of descriptive statistics and multiple linear regression. The descriptive results indicated that members of most rural households were old, married, uneducated and unemployed. Farming was primary livelihood strategy employed in these areas. Rural households were also dependent on remittances, social grants and pension funds because the farming strategy could not meet all their household needs. The major crops that were grown for income and food security to sustain their livelihoods included maize, potatoes, onions and butternut. Factors that had significant influences on outcomes were extension services, grants, pension and remittances, land productivity, type of irrigation system, market accessibility, output price difference and value adding. The available opportunities were land productivity, irrigation facilities, government or NGO programmes and working as a group. For improved livelihood of rural communities in Alice and Peddie, government needs to strengthen agricultural activities and equip farmers with market information, improve their access to irrigation schemes, provide training on value adding and also improve access to extension services.
- Full Text:
- Date Issued: 2013
Assessment of the impact of the Mdantsane Urban Renewal Programme on the lives and livelihoods of beneficiaries (2001-2011): the case of the Eastern Cape Buffalo City Metropolitan Municipality
- Authors: Mhlekude, Ntombizabantu
- Date: 2013
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11691 , http://hdl.handle.net/10353/d1014676
- Description: This study is centred on the Mdantsane Urban Renewal Programme (MURP) and how it has been implemented in the Buffalo City Metropolitan Municipality (BCMM) since inception. The inquiry covers the ten years (20012011) during which the Urban Renewal Programme (URP) was piloted in South Africa. This research evaluates the impact of the MURP on the lives and the livelihoods of beneficiaries (Mdantsane residents). Their perceptions and experiences are thus fundamental to determine the extent to which their lives have been affected through the implementation of the MURP. The areas explored through this research are social, economic, physical and community wellbeing of the Mdantsane residents. The study reviews the opinions and views of the various stakeholders and beneficiaries affected by the MURP and based on these, draws some conclusions and provides recommendations on what could possibly be done by the gBCMM in its implementation of the MURP.
- Full Text:
- Date Issued: 2013
- Authors: Mhlekude, Ntombizabantu
- Date: 2013
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11691 , http://hdl.handle.net/10353/d1014676
- Description: This study is centred on the Mdantsane Urban Renewal Programme (MURP) and how it has been implemented in the Buffalo City Metropolitan Municipality (BCMM) since inception. The inquiry covers the ten years (20012011) during which the Urban Renewal Programme (URP) was piloted in South Africa. This research evaluates the impact of the MURP on the lives and the livelihoods of beneficiaries (Mdantsane residents). Their perceptions and experiences are thus fundamental to determine the extent to which their lives have been affected through the implementation of the MURP. The areas explored through this research are social, economic, physical and community wellbeing of the Mdantsane residents. The study reviews the opinions and views of the various stakeholders and beneficiaries affected by the MURP and based on these, draws some conclusions and provides recommendations on what could possibly be done by the gBCMM in its implementation of the MURP.
- Full Text:
- Date Issued: 2013
Assessment of the incidence of E.coli in Tyume and Buffalo rivers in the Eastern Cape Province of South Africa
- Authors: Koba, Siziwe
- Date: 2013
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11272 , http://hdl.handle.net/10353/d1006889
- Description: Waterborne diseases are among the leading causes of morbidity and mortality in developing countries and every year around 2.2 million people die due to basic hygiene related diseases like coliform diarrhoea. Universal access to safe drinking water and sanitation has been promoted as an essential step in reducing these preventable diseases (Tambekar and Banginwar, 2005; Patil, 2004; Charan, 2004). Diarrheagenic Escherichia coli are one of the most important etiologic agents of acute diarrhea and represent a major public health problem in developing countries like South Africa The present study was conducted between August 2010 and July 2011 to investigate the prevalence and distribution of virulent E. coli strains from water samples collected from Tyume and Buffalo River, located in Eastern Cape Province of South Africa using conventional microbiological methods and PCR analysis. Twelve Water samples were collected from three different sites of the rivers, viz; upstream, middle stream and the downstream of the dam. E.coli was isolated by the membrane filtration method on mFC. A total of 374 isolates from both rivers were identified by convenctional microbiological techniques. For both Buffalo and Tyume River, A large proportion (87 and 114, respectively) of the isolates from the mid stream samples satisfied the identification characteristics for E. coli (blue colonies on MFC agar and violet/purple colonies on Chromocult agar) and thus revealing high levels contamination when compared to isolates from the downstream (55 and 47) and the upstream (30 and 31) All the isolates that satisfied the primary identification stage were subjected to PCR. DNA was extracted using the boiling method and then the DNA was used as a template for PCR. Specific PCR analysis was performed on all E. coli isolates to amplify the alr gene that codes for alanine racemase Out and of the 202 isolates amplified for Tyume river, 70 (35 percent) were positively identified as E. coli since they possessed the alr gene fragment. and out of the 172 isolates amplified from Buffalo River, 80(47 percent) were also positively identified as E. coli. For both Tyume and Buffalo River, the highest prevalence was observed midstream (39 percent and 56 pecent respectively). The identified E. coli were further characterized into different pathotypes. Amplification of the shig gene, LT gene, EaeA gene, Eagg gene and the ST gene were used to detect pathogenic E.coli. In Tyume River, Genes of ETEC (lt or st) were detected in 21/70 (30 percent); Gene of EPEC (eae) was detected in 14/70 specimens (35 percent); Genes of EAEC (Eagg) was detected in 14/70(35 percent) and genes of EIEC (shig) were detected in 11/70(16 percent). In Buffalo River, no DEC was recovered upstream and downstream of the river. EAEC (8 percent) was the only pathotypes recovered midstream of the river. Strains of all five E. coli categories showed high-level resistance to ampicillin, tetracycline, cotrimoxazole, and chloramphenicol but were highly susceptible to quinolones, aminoglycosides, and novobiocin. The highest resistance (100 percent) amongst the isolates was observed to ampicillin by EAEC, Heat Labile (ETEC) and EIEC, followed by 87.5 percent by EAEC to carbenicillin. The highest susceptibility was to quinolones (100 percent) by all the four categories of E.coli. The screening for antibiotic resistance genes revealed the absence of SHV, CTMX and TetC genes as they were not detected in any of the E.coli isolates. However, TEM genes were observed in 80 percent of the isolates. Integron conserved segment was detected in these same organisms in the same proportion as TEM
- Full Text:
- Date Issued: 2013
- Authors: Koba, Siziwe
- Date: 2013
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11272 , http://hdl.handle.net/10353/d1006889
- Description: Waterborne diseases are among the leading causes of morbidity and mortality in developing countries and every year around 2.2 million people die due to basic hygiene related diseases like coliform diarrhoea. Universal access to safe drinking water and sanitation has been promoted as an essential step in reducing these preventable diseases (Tambekar and Banginwar, 2005; Patil, 2004; Charan, 2004). Diarrheagenic Escherichia coli are one of the most important etiologic agents of acute diarrhea and represent a major public health problem in developing countries like South Africa The present study was conducted between August 2010 and July 2011 to investigate the prevalence and distribution of virulent E. coli strains from water samples collected from Tyume and Buffalo River, located in Eastern Cape Province of South Africa using conventional microbiological methods and PCR analysis. Twelve Water samples were collected from three different sites of the rivers, viz; upstream, middle stream and the downstream of the dam. E.coli was isolated by the membrane filtration method on mFC. A total of 374 isolates from both rivers were identified by convenctional microbiological techniques. For both Buffalo and Tyume River, A large proportion (87 and 114, respectively) of the isolates from the mid stream samples satisfied the identification characteristics for E. coli (blue colonies on MFC agar and violet/purple colonies on Chromocult agar) and thus revealing high levels contamination when compared to isolates from the downstream (55 and 47) and the upstream (30 and 31) All the isolates that satisfied the primary identification stage were subjected to PCR. DNA was extracted using the boiling method and then the DNA was used as a template for PCR. Specific PCR analysis was performed on all E. coli isolates to amplify the alr gene that codes for alanine racemase Out and of the 202 isolates amplified for Tyume river, 70 (35 percent) were positively identified as E. coli since they possessed the alr gene fragment. and out of the 172 isolates amplified from Buffalo River, 80(47 percent) were also positively identified as E. coli. For both Tyume and Buffalo River, the highest prevalence was observed midstream (39 percent and 56 pecent respectively). The identified E. coli were further characterized into different pathotypes. Amplification of the shig gene, LT gene, EaeA gene, Eagg gene and the ST gene were used to detect pathogenic E.coli. In Tyume River, Genes of ETEC (lt or st) were detected in 21/70 (30 percent); Gene of EPEC (eae) was detected in 14/70 specimens (35 percent); Genes of EAEC (Eagg) was detected in 14/70(35 percent) and genes of EIEC (shig) were detected in 11/70(16 percent). In Buffalo River, no DEC was recovered upstream and downstream of the river. EAEC (8 percent) was the only pathotypes recovered midstream of the river. Strains of all five E. coli categories showed high-level resistance to ampicillin, tetracycline, cotrimoxazole, and chloramphenicol but were highly susceptible to quinolones, aminoglycosides, and novobiocin. The highest resistance (100 percent) amongst the isolates was observed to ampicillin by EAEC, Heat Labile (ETEC) and EIEC, followed by 87.5 percent by EAEC to carbenicillin. The highest susceptibility was to quinolones (100 percent) by all the four categories of E.coli. The screening for antibiotic resistance genes revealed the absence of SHV, CTMX and TetC genes as they were not detected in any of the E.coli isolates. However, TEM genes were observed in 80 percent of the isolates. Integron conserved segment was detected in these same organisms in the same proportion as TEM
- Full Text:
- Date Issued: 2013
Atmospheric pressure metal-organic vapour phase epitaxial growth of InAs/GaSb strained layer superlattices
- Authors: Miya, Senzo Simo
- Date: 2013
- Subjects: Gallium arsenide semiconductors , Organometallic compounds , Compound semiconductors , Metal organic chemical vapor deposition , Superlattices as materials , Epitaxy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10557 , http://hdl.handle.net/10948/d1020866
- Description: The importance of infrared (IR) technology (for detection in the 3-5 μm and 8-14 μm atmospheric windows) has spread from military applications to civilian applications since World War II. The commercial IR detector market in these wavelength ranges is dominated by mercury cadmium telluride (MCT) alloys. The use of these alloys has, however, been faced with technological difficulties. One of the materials that have been tipped to be suitable to replace MCT is InAs/InxGa1-xSb strained layer superlattices (SLS’s). Atmospheric pressure metal-organic vapour phase epitaxy (MOVPE) has been used to grow InAs/GaSb strained layer superlattices (SLS’s) at 510 °C in this study. This is a starting point towards the development of MOVPE InAs/InxGa1-xSb SLS’s using the same system. Before the SLS’s could be attempted, the growth parameters for GaSb were optimised. Growth parameters for InAs were taken from reports on previous studies conducted using the same reactor. Initially, trimethylgallium, a source that has been used extensively in the same growth system for the growth of GaSb and InxGa1-xSb was intended to be used for gallium species. The high growth rates yielded by this source were too large for the growth of SLS structures, however. Thus, triethylgallium (rarely used for atmospheric pressure MOVPE) was utilized. GaSb layers (between 1 and 2 μm thick) were grown at two different temperatures (550 °C and 510 °C) with a varying V/III ratio. A V/III ratio of 1.5 was found to be optimal at 550 °C. However, the low incorporation efficiency of indium into GaSb at this temperature was inadequate to obtain InxGa1-xSb with an indium mole fraction (x) of around 0.3, which had previously been reported to be optimal for the performance of InAs/InxGa1-xSb SLS’s, due to the maximum splitting of the valence mini bands for this composition. The growth temperature was thus lowered to 510 °C. This resulted in an increase in the optimum V/III ratio to 1.75 for GaSb and yielded much higher incorporation efficiencies of indium in InxGa1-xSb. However, this lower growth temperature also produced poorer surface morphologies for both the binary and ternary layers, due to the reduced surface diffusion of the adsorbed species. An interface control study during the growth of InAs/GaSb SLS’s was subsequently conducted, by investigating the influence of different gas switching sequences on the interface type and quality. It was noted that the growth of SLS’s without any growth interruptions at the interfaces leads to tensile strained SLS’s (GaAs-like interfaces) with a rather large lattice mismatch. A 5 second flow of TMSb over the InAs surface and a flow of H2 over GaSb surface yielded compressively strained SLS’s. Flowing TMIn for 1 second and following by a flow of TMSb for 4 seconds over the GaSb surface, while flowing H2 for 5 seconds over the InAs surface, resulted in SLS’s with GaAs-like interfacial layers and a reduced lattice mismatch. Temperature gradients across the surface of the susceptor led to SLS’s with different structural quality. High resolution x-ray diffraction (HRXRD) was used to determine the thicknesses as well as the type of interfacial layers. The physical parameters of the SLS’s obtained from simulating the HRXRD spectra were comparable to the parameters obtained from cross sectional transmission electron microscopy (XTEM) images. The thicknesses of the layers and the interface type played a major role in determining the cut-off wavelength of the SLS’s.
- Full Text:
- Date Issued: 2013
- Authors: Miya, Senzo Simo
- Date: 2013
- Subjects: Gallium arsenide semiconductors , Organometallic compounds , Compound semiconductors , Metal organic chemical vapor deposition , Superlattices as materials , Epitaxy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10557 , http://hdl.handle.net/10948/d1020866
- Description: The importance of infrared (IR) technology (for detection in the 3-5 μm and 8-14 μm atmospheric windows) has spread from military applications to civilian applications since World War II. The commercial IR detector market in these wavelength ranges is dominated by mercury cadmium telluride (MCT) alloys. The use of these alloys has, however, been faced with technological difficulties. One of the materials that have been tipped to be suitable to replace MCT is InAs/InxGa1-xSb strained layer superlattices (SLS’s). Atmospheric pressure metal-organic vapour phase epitaxy (MOVPE) has been used to grow InAs/GaSb strained layer superlattices (SLS’s) at 510 °C in this study. This is a starting point towards the development of MOVPE InAs/InxGa1-xSb SLS’s using the same system. Before the SLS’s could be attempted, the growth parameters for GaSb were optimised. Growth parameters for InAs were taken from reports on previous studies conducted using the same reactor. Initially, trimethylgallium, a source that has been used extensively in the same growth system for the growth of GaSb and InxGa1-xSb was intended to be used for gallium species. The high growth rates yielded by this source were too large for the growth of SLS structures, however. Thus, triethylgallium (rarely used for atmospheric pressure MOVPE) was utilized. GaSb layers (between 1 and 2 μm thick) were grown at two different temperatures (550 °C and 510 °C) with a varying V/III ratio. A V/III ratio of 1.5 was found to be optimal at 550 °C. However, the low incorporation efficiency of indium into GaSb at this temperature was inadequate to obtain InxGa1-xSb with an indium mole fraction (x) of around 0.3, which had previously been reported to be optimal for the performance of InAs/InxGa1-xSb SLS’s, due to the maximum splitting of the valence mini bands for this composition. The growth temperature was thus lowered to 510 °C. This resulted in an increase in the optimum V/III ratio to 1.75 for GaSb and yielded much higher incorporation efficiencies of indium in InxGa1-xSb. However, this lower growth temperature also produced poorer surface morphologies for both the binary and ternary layers, due to the reduced surface diffusion of the adsorbed species. An interface control study during the growth of InAs/GaSb SLS’s was subsequently conducted, by investigating the influence of different gas switching sequences on the interface type and quality. It was noted that the growth of SLS’s without any growth interruptions at the interfaces leads to tensile strained SLS’s (GaAs-like interfaces) with a rather large lattice mismatch. A 5 second flow of TMSb over the InAs surface and a flow of H2 over GaSb surface yielded compressively strained SLS’s. Flowing TMIn for 1 second and following by a flow of TMSb for 4 seconds over the GaSb surface, while flowing H2 for 5 seconds over the InAs surface, resulted in SLS’s with GaAs-like interfacial layers and a reduced lattice mismatch. Temperature gradients across the surface of the susceptor led to SLS’s with different structural quality. High resolution x-ray diffraction (HRXRD) was used to determine the thicknesses as well as the type of interfacial layers. The physical parameters of the SLS’s obtained from simulating the HRXRD spectra were comparable to the parameters obtained from cross sectional transmission electron microscopy (XTEM) images. The thicknesses of the layers and the interface type played a major role in determining the cut-off wavelength of the SLS’s.
- Full Text:
- Date Issued: 2013
Attracting and retaining talent: identifying employee value proposition (EVP) drivers of attraction and retention in the South African labour market
- Authors: Knox, Heather Joy
- Date: 2013
- Subjects: Employee retention -- South Africa , Personnel management -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9410 , http://hdl.handle.net/10948/d1020065
- Description: Rapid changes in the business environment as a result of globalisation, mergers and acquisitions, skills shortages and demographic changes in the workplace have led to a greater realisation of the importance of talent management and its role in ensuring a sustainable and successful organisation. Attracting and retaining talent has become one of the most important activities for organisations in order to ensure their competitive advantage. Companies must now differentiate themselves from competitors by offering current and potential employees an employment offering that they value. The employee value proposition (EVP) communicates to the internal and external workforce why they should work for and remain with a particular organisation. Identifying the attributes that employees' value is important in attracting and retaining the best talent. The aim of the study was therefore to identify the EVP drivers that a) attract and b) retain employees as well as those attributes that drive both attraction and retention. The influence of demographic variables, such as age and gender, on attracting and retaining employees was also explored. A structured questionnaire, based on the Corporate Leadership Council‟s EVP model, was developed and respondents were asked to indicate the importance they attach to each EVP attribute. A total of 204 respondents from 13 medium-sized to large-sized organisations in South Africa, participated in the study. The results showed that the quality of senior leadership, quality of managers and the organisation's reputation for managing people were the most important EVP drivers of both attraction and retention. The size of the organisation's workforce was the least important attribute for both attraction and retention. In addition, the results revealed there were no significant differences between EVP attributes that attract and retain males and those that attract and retain females. Furthermore, age plays a significant role in attracting and retaining talent. These results have significant implications for companies as they should design their EVP‟s based on what employees' value and deem to be the most important to them. Organisations need to start focusing on the generational differences that are present in today's business and adapt their EVP‟s accordingly.
- Full Text:
- Date Issued: 2013
- Authors: Knox, Heather Joy
- Date: 2013
- Subjects: Employee retention -- South Africa , Personnel management -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9410 , http://hdl.handle.net/10948/d1020065
- Description: Rapid changes in the business environment as a result of globalisation, mergers and acquisitions, skills shortages and demographic changes in the workplace have led to a greater realisation of the importance of talent management and its role in ensuring a sustainable and successful organisation. Attracting and retaining talent has become one of the most important activities for organisations in order to ensure their competitive advantage. Companies must now differentiate themselves from competitors by offering current and potential employees an employment offering that they value. The employee value proposition (EVP) communicates to the internal and external workforce why they should work for and remain with a particular organisation. Identifying the attributes that employees' value is important in attracting and retaining the best talent. The aim of the study was therefore to identify the EVP drivers that a) attract and b) retain employees as well as those attributes that drive both attraction and retention. The influence of demographic variables, such as age and gender, on attracting and retaining employees was also explored. A structured questionnaire, based on the Corporate Leadership Council‟s EVP model, was developed and respondents were asked to indicate the importance they attach to each EVP attribute. A total of 204 respondents from 13 medium-sized to large-sized organisations in South Africa, participated in the study. The results showed that the quality of senior leadership, quality of managers and the organisation's reputation for managing people were the most important EVP drivers of both attraction and retention. The size of the organisation's workforce was the least important attribute for both attraction and retention. In addition, the results revealed there were no significant differences between EVP attributes that attract and retain males and those that attract and retain females. Furthermore, age plays a significant role in attracting and retaining talent. These results have significant implications for companies as they should design their EVP‟s based on what employees' value and deem to be the most important to them. Organisations need to start focusing on the generational differences that are present in today's business and adapt their EVP‟s accordingly.
- Full Text:
- Date Issued: 2013
Audio Device Representation, Control, and Monitoring Using SNMP
- Eales, Andrew, Foss, Richard
- Authors: Eales, Andrew , Foss, Richard
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426855 , vital:72396 , https://www.aes.org/e-lib/browse.cfm?elib=17012
- Description: The Simple Network Management Protocol (SNMP) is widely used to configure and monitor networked devices. The architecture of complex audio devices can be elegantly represented using SNMP tables. Carefully considered table indexing schemes support a logical device model that can be accessed using standard SNMP commands. This paper examines the use of SNMP tables to represent the architecture of audio devices. A representational scheme that uses table indexes to provide direct-access to context-sensitive SNMP data objects is presented. The monitoring of parameter values and the implementation of connection management using SNMP are also discussed.
- Full Text:
- Date Issued: 2013
- Authors: Eales, Andrew , Foss, Richard
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426855 , vital:72396 , https://www.aes.org/e-lib/browse.cfm?elib=17012
- Description: The Simple Network Management Protocol (SNMP) is widely used to configure and monitor networked devices. The architecture of complex audio devices can be elegantly represented using SNMP tables. Carefully considered table indexing schemes support a logical device model that can be accessed using standard SNMP commands. This paper examines the use of SNMP tables to represent the architecture of audio devices. A representational scheme that uses table indexes to provide direct-access to context-sensitive SNMP data objects is presented. The monitoring of parameter values and the implementation of connection management using SNMP are also discussed.
- Full Text:
- Date Issued: 2013
Automated classification of computer network attacks
- van Heerden, Renier, Leenen, Louise, Irwin, Barry V W
- Authors: van Heerden, Renier , Leenen, Louise , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429622 , vital:72627 , 10.1109/ICASTech.2013.6707510
- Description: In this paper we demonstrate how an automated reasoner, HermiT, is used to classify instances of computer network based attacks in conjunction with a network attack ontology. The ontology describes different types of network attacks through classes and inter-class relationships and has previously been implemented in the Protege ontology editor. Two significant recent instances of network based attacks are presented as individuals in the ontology and correctly classified by the automated reasoner according to the relevant types of attack scenarios depicted in the ontology. The two network attack instances are the Distributed Denial of Service attack on SpamHaus in 2013 and the theft of 42 million Rand ($6.7 million) from South African Postbank in 2012.
- Full Text:
- Date Issued: 2013
- Authors: van Heerden, Renier , Leenen, Louise , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429622 , vital:72627 , 10.1109/ICASTech.2013.6707510
- Description: In this paper we demonstrate how an automated reasoner, HermiT, is used to classify instances of computer network based attacks in conjunction with a network attack ontology. The ontology describes different types of network attacks through classes and inter-class relationships and has previously been implemented in the Protege ontology editor. Two significant recent instances of network based attacks are presented as individuals in the ontology and correctly classified by the automated reasoner according to the relevant types of attack scenarios depicted in the ontology. The two network attack instances are the Distributed Denial of Service attack on SpamHaus in 2013 and the theft of 42 million Rand ($6.7 million) from South African Postbank in 2012.
- Full Text:
- Date Issued: 2013
Axial coordination of zinc and silicon phthalocyanines to silver and gold nanoparticles: an investigation of their photophysicochemical and antimicrobial behavior
- Masilela, Nkosiphile, Antunes, Edith M, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241818 , vital:50972 , xlink:href="https://doi.org/10.1142/S1088424613500016"
- Description: This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
- Full Text:
- Date Issued: 2013
- Authors: Masilela, Nkosiphile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241818 , vital:50972 , xlink:href="https://doi.org/10.1142/S1088424613500016"
- Description: This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
- Full Text:
- Date Issued: 2013
Barriers to implementation of evidence-based practices in a critical care unit
- Authors: Bowers, Candice Andrea
- Date: 2013
- Subjects: Evidence-based medicine , Critical care medicine , Nursing ethics
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: vital:10048 , http://hdl.handle.net/10948/d1013612
- Description: Over the last three decades there has been a greater need for health care practitioners to base their decision on the best available in order to optimise quality and cost-effective patient care. Evidence-based practice necessitates guideline development, education and review in order to achieve improved patient outcomes. However, initiatives that endeavour to disseminate and implement evidence-based practice have faced barriers and opposition. Barriers that might hamper the implementation of evidence-based practice include characteristics of the evidence itself, personal, institutional or organizational factors. The research study explored and described the barriers to implementation of evidence-based practices in a critical care unit. Based on the data analysis, recommendations were made to enhance the implementation of evidence-based practices in the critical care unit. A quantitative, explorative, descriptive and contextual research design was used to operationalize the research objectives. The target population comprised professional nurses in the critical care unit. Non-probability sampling was used to obtain data by means of a structured self-administered questionnaire. Descriptive data analysis was applied, using a statistical programme and the aid of a statistician. The results are graphically displayed using bar graphs and tables. Recommendations for nursing practice, education and research were made. Ethical principles have been maintained throughout the study.
- Full Text:
- Date Issued: 2013
- Authors: Bowers, Candice Andrea
- Date: 2013
- Subjects: Evidence-based medicine , Critical care medicine , Nursing ethics
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: vital:10048 , http://hdl.handle.net/10948/d1013612
- Description: Over the last three decades there has been a greater need for health care practitioners to base their decision on the best available in order to optimise quality and cost-effective patient care. Evidence-based practice necessitates guideline development, education and review in order to achieve improved patient outcomes. However, initiatives that endeavour to disseminate and implement evidence-based practice have faced barriers and opposition. Barriers that might hamper the implementation of evidence-based practice include characteristics of the evidence itself, personal, institutional or organizational factors. The research study explored and described the barriers to implementation of evidence-based practices in a critical care unit. Based on the data analysis, recommendations were made to enhance the implementation of evidence-based practices in the critical care unit. A quantitative, explorative, descriptive and contextual research design was used to operationalize the research objectives. The target population comprised professional nurses in the critical care unit. Non-probability sampling was used to obtain data by means of a structured self-administered questionnaire. Descriptive data analysis was applied, using a statistical programme and the aid of a statistician. The results are graphically displayed using bar graphs and tables. Recommendations for nursing practice, education and research were made. Ethical principles have been maintained throughout the study.
- Full Text:
- Date Issued: 2013
Barriers to public participation in developmental projects : a Nigerian community perspective (case study of the Gbaran-Ubie oil and gas project)
- Authors: Akoh, Emmanuel Inalegwu
- Date: 2013
- Subjects: Gbaran-Ubie oil and gas project -- Public opinion Community development -- Nigeria Economic development -- Nigeria -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:715 , http://hdl.handle.net/10962/d1001869
- Description: This research paper is broken up into three sections, namely an evaluation report, a literature review and research methodology. The evaluation report section is the assessment of the current state of change readiness within the Eskom Contact Centre’s based upon what the literature on change readiness prescribes. The timing of the change readiness assessment is just prior to significant organisational change. The organisational change that was about to be initiated by the organisation was initiated from the boardroom of the most senior echelons of the organisation, and was directed in a top down approach, being a strategic organisational change. The change is deemed to be critical to the organisation being able to meet its long term strategic and sustainability objectives. A critical examination of the literature explored the meaning of change readiness, the importance of it and explained the consequences for organisations that commit to transformational agendas without being ready. Key concepts such as such resistance to change and organisational inertia are described and differentiated from change readiness. The ADKAR change model and its change readiness assessment instrument were used due to the organisations preference for the model. The ADKAR model formed the framework for the analyses of the data, the discussion of the results and the recommendations to the organisation. The research conducted was quantitative in nature; a questionnaire was distributed to the employees of the seven Eskom Contact centre sites around the country through an email. A slightly modified version of the ADKAR change readiness questionnaire was sent via email with an on-line questionnaire link on it; and questions on individual readiness for change were used to assess the level of readiness of the employees. Most of the descriptive and inferential statistics were analysed with the use of Excel (version, 2010), with Factor Analysis being done in Statistica. The results of the research showed that: [iii] - The factors as proposed by the ADKAR change readiness assessment questionnaire (i.e. Awareness, Desire, Knowledge, Ability and Reinforcement) are not different enough to be considered as independent factors for this data set. Based on factor analysis, the factors were subsequently amended from five to three, namely Readiness, Opportunity Realisation and Uncertainty. - The Contact Centre employees were somewhat ready for change. - The Contact Centres needed to focus on all amended ADKAR factors in order to improve the readiness of the department. - The readiness levels in response to the roll out were more or less uniform. The study shows that given Eskom’s preference for the ADKAR model, future research within Eskom should therefore be conducted more circumspectly with respect to ascertaining the validity of the ADKAR factors. The study also makes mention that future work and/or research will need to be conducted, specifically on the readiness of the organisation itself, in order to improve the probability of transformational success. The ADKAR assessment is a people focused assessment and therefore focuses only on the readiness of the individual. Factors such as the adequacy of the current state of resources within the organisation, which incorporate aspects such as infrastructure, technology and staffing, will also need to be assessed to make a more holistic statement of change readiness. A concise review of the literature is incorporated into the Evaluation Report of Section 1 to underpin the study. In Section 2 a more extensive review of the literature is presented. Similarly, the design of the research is discussed in more detail in Section 3 to both describe and justify the appropriateness of the research methodology, and to give a detailed account of the way in which the research was carried out.
- Full Text:
- Date Issued: 2013
- Authors: Akoh, Emmanuel Inalegwu
- Date: 2013
- Subjects: Gbaran-Ubie oil and gas project -- Public opinion Community development -- Nigeria Economic development -- Nigeria -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:715 , http://hdl.handle.net/10962/d1001869
- Description: This research paper is broken up into three sections, namely an evaluation report, a literature review and research methodology. The evaluation report section is the assessment of the current state of change readiness within the Eskom Contact Centre’s based upon what the literature on change readiness prescribes. The timing of the change readiness assessment is just prior to significant organisational change. The organisational change that was about to be initiated by the organisation was initiated from the boardroom of the most senior echelons of the organisation, and was directed in a top down approach, being a strategic organisational change. The change is deemed to be critical to the organisation being able to meet its long term strategic and sustainability objectives. A critical examination of the literature explored the meaning of change readiness, the importance of it and explained the consequences for organisations that commit to transformational agendas without being ready. Key concepts such as such resistance to change and organisational inertia are described and differentiated from change readiness. The ADKAR change model and its change readiness assessment instrument were used due to the organisations preference for the model. The ADKAR model formed the framework for the analyses of the data, the discussion of the results and the recommendations to the organisation. The research conducted was quantitative in nature; a questionnaire was distributed to the employees of the seven Eskom Contact centre sites around the country through an email. A slightly modified version of the ADKAR change readiness questionnaire was sent via email with an on-line questionnaire link on it; and questions on individual readiness for change were used to assess the level of readiness of the employees. Most of the descriptive and inferential statistics were analysed with the use of Excel (version, 2010), with Factor Analysis being done in Statistica. The results of the research showed that: [iii] - The factors as proposed by the ADKAR change readiness assessment questionnaire (i.e. Awareness, Desire, Knowledge, Ability and Reinforcement) are not different enough to be considered as independent factors for this data set. Based on factor analysis, the factors were subsequently amended from five to three, namely Readiness, Opportunity Realisation and Uncertainty. - The Contact Centre employees were somewhat ready for change. - The Contact Centres needed to focus on all amended ADKAR factors in order to improve the readiness of the department. - The readiness levels in response to the roll out were more or less uniform. The study shows that given Eskom’s preference for the ADKAR model, future research within Eskom should therefore be conducted more circumspectly with respect to ascertaining the validity of the ADKAR factors. The study also makes mention that future work and/or research will need to be conducted, specifically on the readiness of the organisation itself, in order to improve the probability of transformational success. The ADKAR assessment is a people focused assessment and therefore focuses only on the readiness of the individual. Factors such as the adequacy of the current state of resources within the organisation, which incorporate aspects such as infrastructure, technology and staffing, will also need to be assessed to make a more holistic statement of change readiness. A concise review of the literature is incorporated into the Evaluation Report of Section 1 to underpin the study. In Section 2 a more extensive review of the literature is presented. Similarly, the design of the research is discussed in more detail in Section 3 to both describe and justify the appropriateness of the research methodology, and to give a detailed account of the way in which the research was carried out.
- Full Text:
- Date Issued: 2013
Behavioural observations of the common octopus Octopus vulgaris in Baía dos Tigres, southern Angola
- de Beer, Chénelle L, Potts, Warren M
- Authors: de Beer, Chénelle L , Potts, Warren M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123233 , vital:35419 , https://doi.org/10.2989/1814232X.2013.847496
- Description: The common octopus Octopus vulgaris (Cuvier 1797) is a shallow-water cephalopod species that inhabits coastal rocky areas or reefs. It is the most studied and widely distributed species in its genus. This species has a short lifespan and a rapid growth rate of over 5% of body weight per day (García and Valverde 2006, Ibáñez and Keyl 2010). It is semelparous, with females laying large strings of eggs that they attach to the substrata in their dens (Hernández- García et al. 2002). There is a paucity of information on the preferred habitat and behaviour of O. vulgaris in its natural environment (Anderson 1997, Meisel et al. 2006). The species has been classified as highly mobile, yet resident individuals may exhibit high levels of territoriality. Its mobility allows it to move efficiently between a wide range of suitable habitats (Katsanevakis and Verriopoulos 2004). Octopus make use of both tactile and visual senses to forage, feed and seek suitable shelter (Forsythe and Hanlon 1997, Carvalho and Sousa Reis 2003, Rodríguez-Rúa et al. 2005). They are active feeders that seek out prey such as crustaceans, sessile molluscs and small fish (Forsythe and Hanlon 1997, Boyle and Rodhouse 2005), as well as their smaller conspecifics (Ibáñez and Keyl 2010). The majority of behavioural ecology studies on octopus have been on captive individuals. However, the activity patterns (Mather 1988), foraging strategies and aspects of the movement behaviour (Mather and O’Dor 1991) of juvenile O. vulgaris in the wild were described for an exploited population in Bermuda. Because intertidal octopus stocks are exploited by recreational, subsistence and artisanal fisheries (e.g. Oosthuizen and Smale 2003, Sauer et al. 2011), there are few opportunities to study the behavioural ecology of unexploited populations. An opportunity arose to study various behavioural patterns in an unexploited population in Baía dos Tigres, a large (~200 km2) coastal embayment situated on an isolated stretch of the southern Angolan coast (Figure 1). This study provides information on the population size structure, aspects of the movement behaviour, activity patterns and foraging strategies of O. vulgaris in this largely unstudied coastal embayment.
- Full Text:
- Date Issued: 2013
- Authors: de Beer, Chénelle L , Potts, Warren M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123233 , vital:35419 , https://doi.org/10.2989/1814232X.2013.847496
- Description: The common octopus Octopus vulgaris (Cuvier 1797) is a shallow-water cephalopod species that inhabits coastal rocky areas or reefs. It is the most studied and widely distributed species in its genus. This species has a short lifespan and a rapid growth rate of over 5% of body weight per day (García and Valverde 2006, Ibáñez and Keyl 2010). It is semelparous, with females laying large strings of eggs that they attach to the substrata in their dens (Hernández- García et al. 2002). There is a paucity of information on the preferred habitat and behaviour of O. vulgaris in its natural environment (Anderson 1997, Meisel et al. 2006). The species has been classified as highly mobile, yet resident individuals may exhibit high levels of territoriality. Its mobility allows it to move efficiently between a wide range of suitable habitats (Katsanevakis and Verriopoulos 2004). Octopus make use of both tactile and visual senses to forage, feed and seek suitable shelter (Forsythe and Hanlon 1997, Carvalho and Sousa Reis 2003, Rodríguez-Rúa et al. 2005). They are active feeders that seek out prey such as crustaceans, sessile molluscs and small fish (Forsythe and Hanlon 1997, Boyle and Rodhouse 2005), as well as their smaller conspecifics (Ibáñez and Keyl 2010). The majority of behavioural ecology studies on octopus have been on captive individuals. However, the activity patterns (Mather 1988), foraging strategies and aspects of the movement behaviour (Mather and O’Dor 1991) of juvenile O. vulgaris in the wild were described for an exploited population in Bermuda. Because intertidal octopus stocks are exploited by recreational, subsistence and artisanal fisheries (e.g. Oosthuizen and Smale 2003, Sauer et al. 2011), there are few opportunities to study the behavioural ecology of unexploited populations. An opportunity arose to study various behavioural patterns in an unexploited population in Baía dos Tigres, a large (~200 km2) coastal embayment situated on an isolated stretch of the southern Angolan coast (Figure 1). This study provides information on the population size structure, aspects of the movement behaviour, activity patterns and foraging strategies of O. vulgaris in this largely unstudied coastal embayment.
- Full Text:
- Date Issued: 2013
Being South African and belonging: the status and practice of mediated citizenship in a new democracy
- Wasserman, Herman, Garman, Anthea
- Authors: Wasserman, Herman , Garman, Anthea
- Date: 2013
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/159769 , vital:40342 , ISBN 978-1-84888-186-0
- Description: Democratic South Africa, with its highly inclusive constitution and embrace of all races, creeds and colours, could be understood as having an ideal form of citizenship to be emulated by other nations. At the heart of the 1996 constitution is the eradication of apartheid separation and the provision that all South Africans have shared humanity (‘ubuntu’). The Truth and Reconciliation Commission entrenched three founding critical ideas in public life: the right to talk, the recognition of shared humanity and the impulse to speak out about the horrors of the past. As a result the public sphere is filled with a great outpouring of personal stories and experiences in both the mainstream and popular forms of media. But South Africans continue to be preoccupied with the status of their citizenship; who a South African is and who belongs is uppermost in many public conversations.
- Full Text:
- Date Issued: 2013
- Authors: Wasserman, Herman , Garman, Anthea
- Date: 2013
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/159769 , vital:40342 , ISBN 978-1-84888-186-0
- Description: Democratic South Africa, with its highly inclusive constitution and embrace of all races, creeds and colours, could be understood as having an ideal form of citizenship to be emulated by other nations. At the heart of the 1996 constitution is the eradication of apartheid separation and the provision that all South Africans have shared humanity (‘ubuntu’). The Truth and Reconciliation Commission entrenched three founding critical ideas in public life: the right to talk, the recognition of shared humanity and the impulse to speak out about the horrors of the past. As a result the public sphere is filled with a great outpouring of personal stories and experiences in both the mainstream and popular forms of media. But South Africans continue to be preoccupied with the status of their citizenship; who a South African is and who belongs is uppermost in many public conversations.
- Full Text:
- Date Issued: 2013
Beyond the threshold: explorations of liminality in literature. A book review
- Authors: Dass, Minesh
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142520 , vital:38087 , DOI: 10.1080/10131752.2013.783395
- Description: Beyond the Threshold: Explorations of Liminality in Literature, an edited collection of essays, is the culmination of research project on liminality done under the title “Poetics of boundaries and Hybridity”. This venture was undertaken in what is now known as the Research Unit Languages and Literature in the South African Context at North-West University. Some of the articles were initially presented at a conference on “Hybridity, Liminality and Boundaries” which was held in Potchefstroom from 30 June to 2 July 2005. Furthermore, shorter versions of some chapters have already been published in a special edition of Literator (Vol. 27. 1).
- Full Text:
- Date Issued: 2013
- Authors: Dass, Minesh
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142520 , vital:38087 , DOI: 10.1080/10131752.2013.783395
- Description: Beyond the Threshold: Explorations of Liminality in Literature, an edited collection of essays, is the culmination of research project on liminality done under the title “Poetics of boundaries and Hybridity”. This venture was undertaken in what is now known as the Research Unit Languages and Literature in the South African Context at North-West University. Some of the articles were initially presented at a conference on “Hybridity, Liminality and Boundaries” which was held in Potchefstroom from 30 June to 2 July 2005. Furthermore, shorter versions of some chapters have already been published in a special edition of Literator (Vol. 27. 1).
- Full Text:
- Date Issued: 2013
Biochemical characterisation of Pfj2, a Plasmodium falciparum heat shock protein 40 chaperone potentially involved in protein quality control in the endoplasmic reticulum
- Authors: Afolayan, Omolola Folasade
- Date: 2013
- Subjects: Plasmodium falciparum Endoplasmic reticulum Heat shock proteins Malaria , Mosquito-borne infectious disease
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3883 , http://hdl.handle.net/10962/d1001617
- Description: Plasmodium falciparum is a protozoan parasite that causes a severe form of malaria, a mosquito-borne infectious disease in humans. P. falciparum encodes a number of proteins to facilitate its life-cycle, including a type II heat shock protein 40 (Hsp40), Pfj2. Pfj2 shows a degree of homology to human ERdj5, a resident protein of the endoplasmic reticulum (ER) that promotes protein quality control by facilitating the degradation of misfolded proteins. The overall aim of this study was to further understand the function of Pfj2 in the P. falciparum cell by characterising it biochemically. A bioinformatic analysis of Pfj2 was carried out to enable the identification of a potential ER signal sequence and cleavage site. Furthermore, an analysis of Pfj2 protein sequence was performed to compare domain similarities and identities with typical type II Hsp40s namely, human ERdj5, S. cerevisiae Sis1, human Hsj1a and human DnaJB4. The method used included the insertion of the codon-optimised coding sequence for the processed ER form of Pfj2 into the prokaryotic expression vector, pQE30, to enable overproduction of a histidine-tagged protein. A 62 kDa His₆-Pfj2 was successfully expressed in Escherichia coli and purified using denaturing nickel affinity chromatography. ATPase assays were performed to determine the ability of His₆- Pfj2 to stimulate the chaperone activity of the ER Hsp70, also called immunoglobulin binding protein (BiP). Initial studies were conducted on readily available mammalian His₆-BiP as a control, which was shown to have an intrinsic activity of 12.07±3.92 nmolPi/min/mg. His₆- Pfj2 did not stimulate the ATPase activity of mammalian His₆-BiP, suggesting that it either could not act as a co-chaperone of mammalian His₆-BiP (specificity), or it required a misfolded substrate in the system. Therefore, ongoing studies are addressing the interaction of Pfj2 and misfolded substrates with P. falciparum BiP. The results of these studies will further our understanding of a poorly-studied parasite chaperone that represents a potential drug target for development of novel strategies for the control of a serious human disease
- Full Text:
- Date Issued: 2013
- Authors: Afolayan, Omolola Folasade
- Date: 2013
- Subjects: Plasmodium falciparum Endoplasmic reticulum Heat shock proteins Malaria , Mosquito-borne infectious disease
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3883 , http://hdl.handle.net/10962/d1001617
- Description: Plasmodium falciparum is a protozoan parasite that causes a severe form of malaria, a mosquito-borne infectious disease in humans. P. falciparum encodes a number of proteins to facilitate its life-cycle, including a type II heat shock protein 40 (Hsp40), Pfj2. Pfj2 shows a degree of homology to human ERdj5, a resident protein of the endoplasmic reticulum (ER) that promotes protein quality control by facilitating the degradation of misfolded proteins. The overall aim of this study was to further understand the function of Pfj2 in the P. falciparum cell by characterising it biochemically. A bioinformatic analysis of Pfj2 was carried out to enable the identification of a potential ER signal sequence and cleavage site. Furthermore, an analysis of Pfj2 protein sequence was performed to compare domain similarities and identities with typical type II Hsp40s namely, human ERdj5, S. cerevisiae Sis1, human Hsj1a and human DnaJB4. The method used included the insertion of the codon-optimised coding sequence for the processed ER form of Pfj2 into the prokaryotic expression vector, pQE30, to enable overproduction of a histidine-tagged protein. A 62 kDa His₆-Pfj2 was successfully expressed in Escherichia coli and purified using denaturing nickel affinity chromatography. ATPase assays were performed to determine the ability of His₆- Pfj2 to stimulate the chaperone activity of the ER Hsp70, also called immunoglobulin binding protein (BiP). Initial studies were conducted on readily available mammalian His₆-BiP as a control, which was shown to have an intrinsic activity of 12.07±3.92 nmolPi/min/mg. His₆- Pfj2 did not stimulate the ATPase activity of mammalian His₆-BiP, suggesting that it either could not act as a co-chaperone of mammalian His₆-BiP (specificity), or it required a misfolded substrate in the system. Therefore, ongoing studies are addressing the interaction of Pfj2 and misfolded substrates with P. falciparum BiP. The results of these studies will further our understanding of a poorly-studied parasite chaperone that represents a potential drug target for development of novel strategies for the control of a serious human disease
- Full Text:
- Date Issued: 2013
Biogeographical boundaries, functional group structure and diversity of rocky shore communities along the Argentinean coast
- Wieters, Evie A, McQuaid, Christopher D, Palomo, Gabriela, Pappalardo, Paula
- Authors: Wieters, Evie A , McQuaid, Christopher D , Palomo, Gabriela , Pappalardo, Paula
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6835 , http://hdl.handle.net/10962/d1010956
- Description: We investigate the extent to which functional structure and spatial variability of intertidal communities coincide with major biogeographical boundaries, areas where extensive compositional changes in the biota are observed over a limited geographic extension. We then investigate whether spatial variation in the biomass of functional groups, over geographic (10′s km) and local (10′s m) scales, could be associated to species diversity within and among these groups. Functional community structure expressed as abundance (density, cover and biomass) and composition of major functional groups was quantified through field surveys at 20 rocky intertidal shores spanning six degrees of latitude along the southwest Atlantic coast of Argentina and extending across the boundaries between the Argentinean and Magellanic Provinces. Patterns of abundance of individual functional groups were not uniformly matched with biogeographical regions. Only ephemeral algae showed an abrupt geographical discontinuity coincident with changes in biogeographic boundaries, and this was limited to the mid intertidal zone. We identified 3–4 main ‘groups’ of sites in terms of the total and relative abundance of the major functional groups, but these did not coincide with biogeographical boundaries, nor did they follow latitudinal arrangement. Thus, processes that determine the functional structure of these intertidal communities are insensitive to biogeographical boundaries. Over both geographical and local spatial scales, and for most functional groups and tidal levels, increases in species richness within the functional group was significantly associated to increased total biomass and reduced spatial variability of the group. These results suggest that species belonging to the same functional group are sufficiently uncorrelated over space (i.e. metres and site-to-site ) to stabilize patterns of biomass variability and, in this manner, provide a buffer, or “insurance”, against spatial variability in environmental conditions.
- Full Text:
- Date Issued: 2013
- Authors: Wieters, Evie A , McQuaid, Christopher D , Palomo, Gabriela , Pappalardo, Paula
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6835 , http://hdl.handle.net/10962/d1010956
- Description: We investigate the extent to which functional structure and spatial variability of intertidal communities coincide with major biogeographical boundaries, areas where extensive compositional changes in the biota are observed over a limited geographic extension. We then investigate whether spatial variation in the biomass of functional groups, over geographic (10′s km) and local (10′s m) scales, could be associated to species diversity within and among these groups. Functional community structure expressed as abundance (density, cover and biomass) and composition of major functional groups was quantified through field surveys at 20 rocky intertidal shores spanning six degrees of latitude along the southwest Atlantic coast of Argentina and extending across the boundaries between the Argentinean and Magellanic Provinces. Patterns of abundance of individual functional groups were not uniformly matched with biogeographical regions. Only ephemeral algae showed an abrupt geographical discontinuity coincident with changes in biogeographic boundaries, and this was limited to the mid intertidal zone. We identified 3–4 main ‘groups’ of sites in terms of the total and relative abundance of the major functional groups, but these did not coincide with biogeographical boundaries, nor did they follow latitudinal arrangement. Thus, processes that determine the functional structure of these intertidal communities are insensitive to biogeographical boundaries. Over both geographical and local spatial scales, and for most functional groups and tidal levels, increases in species richness within the functional group was significantly associated to increased total biomass and reduced spatial variability of the group. These results suggest that species belonging to the same functional group are sufficiently uncorrelated over space (i.e. metres and site-to-site ) to stabilize patterns of biomass variability and, in this manner, provide a buffer, or “insurance”, against spatial variability in environmental conditions.
- Full Text:
- Date Issued: 2013
Biological activities of medical plants traditionally used in the Eastern Cape to treat pneumonia
- Kamanga, Melvin Chalochapasi
- Authors: Kamanga, Melvin Chalochapasi
- Date: 2013
- Subjects: Communicable diseases -- Eastern Cape , Medicinal plants -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10124 , http://hdl.handle.net/10948/d1020051
- Description: Infectious diseases such as pneumonia still pose a major global health concern. Currently, the world is facing widespread emergence of acquired bacterial resistance to antibiotics which constitute one of the chief causes of infectious diseases. The accumulation of different antibiotic resistance mechanisms within the same strains has induced the appearance of the so called “superbugs”, or “multiple-drug resistant bacteria”. Due to antibiotic resistance, attention is currently being drawn towards biologically active components isolated from plant species commonly used as herbal medicine, as they may offer a new source of antibacterial, antifungal and antiviral activities. This is the basis of this study. In this study four medicinal plants namely, Cassia abbreviata, Geranium incanum, Pelargonium hortorum and Tecoma capensis were investigated for their antimicrobial potential. In vitro antimicrobial activity using agar disc diffusion method, agar dilution method and broth microdilution plate determination of minimum inhibitory concentration (MIC), were carried out against ATCC (American Type Culture Collection) strains and clinical isolates known to cause pneumonia. Aqueous, methanol and acetone extracts from the selected plants were thus tested against strains of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Candida albicans. The plants exhibited pronounced antimicrobial activity and were more active against Gram-positive bacteria than Gram-negative bacteria. During agar disc diffusion method, the highest inhibition zone was demonstrated by the acetone extract of P. hortorum (IZ=22mm and AI=0.73) against the reference strain of S. pneumoniae (ATCC 49619). The range of zones of inhibition in diameter across strains of S. pneumoniae and H. influenzae was 7mm to 22mm with activity index range of 0.23 to 0.74. The lowest MIC produced by medicinal plants in the study during agar disc diffusion method against S. pneumoniae and H. influenzae strains, was 2.5mg/ml. In broth microdilution plate assay, the lowest MIC demonstrated by C. abbreviata, T. capensis and P. hortorum extracts on tested bacteria was 0.031mg/ml and that of G. incanum was 0.063mg/ml. Candida albicans strains were only inhibited at 20mg/ml by the study plants. The highest activity among the individual extracts was shown by P. hortorum methanol extract which inhibited 71% of the studied bacteria. T. capensis methanol extract was the least and inhibited only 17% of the tested bacteria. The strains of Klebsiella pneumoniae showed the highest resistance to medicinal plants employed in this study. Traditional preparation of selected medicinal plants did not show any significant antimicrobial activity. Bioactive analysis of compounds on study plants was carried out using standard methods which revealed the presence of anthraquinones, flavonoids, phytosterol, saponins, tannins and triterpenoids. Comparison of the inhibitory effect of the plant extracts against some broad spectrum antibiotics revealed that the tested medicinal plants showed greater antimicrobial activity than standard antibiotics. However, there was no correlation between the antibiotic susceptibility patterns of the bacteria and the effects of the plants, signifying that plants probably function through different mechanisms. Bioautographic findings on thin-layer chromatography plate, exhibited clear zones of inhibition of bacterial growth with the Rf value range of 0.09 to 0.94. Anti-mutagenic activity was assayed by the Ames mutagenicity test in the plate-incorporation method using histidine mutants of S. typhimurium strains TA 100. The selected plant extracts at 2.5mg/ml and 5mg/ml did not induce mutagenesis in the absence of liver-metabolizing enzymes. The study results indicated that the selected plants are capable of inhibiting the growth of the studied pathogenic microorganisms to a varied degree. The leaves of G. incanum, P. hortorum, T. capensis as well as the stem bark of C. abbreviata could be novel sources of antimicrobial agents that might have broad spectrum activity. The anti-mutagenic properties of the studied medicinal plants may also provide additional health supplemental value to the other claimed therapeutic properties of the plants.
- Full Text:
- Date Issued: 2013
- Authors: Kamanga, Melvin Chalochapasi
- Date: 2013
- Subjects: Communicable diseases -- Eastern Cape , Medicinal plants -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10124 , http://hdl.handle.net/10948/d1020051
- Description: Infectious diseases such as pneumonia still pose a major global health concern. Currently, the world is facing widespread emergence of acquired bacterial resistance to antibiotics which constitute one of the chief causes of infectious diseases. The accumulation of different antibiotic resistance mechanisms within the same strains has induced the appearance of the so called “superbugs”, or “multiple-drug resistant bacteria”. Due to antibiotic resistance, attention is currently being drawn towards biologically active components isolated from plant species commonly used as herbal medicine, as they may offer a new source of antibacterial, antifungal and antiviral activities. This is the basis of this study. In this study four medicinal plants namely, Cassia abbreviata, Geranium incanum, Pelargonium hortorum and Tecoma capensis were investigated for their antimicrobial potential. In vitro antimicrobial activity using agar disc diffusion method, agar dilution method and broth microdilution plate determination of minimum inhibitory concentration (MIC), were carried out against ATCC (American Type Culture Collection) strains and clinical isolates known to cause pneumonia. Aqueous, methanol and acetone extracts from the selected plants were thus tested against strains of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Candida albicans. The plants exhibited pronounced antimicrobial activity and were more active against Gram-positive bacteria than Gram-negative bacteria. During agar disc diffusion method, the highest inhibition zone was demonstrated by the acetone extract of P. hortorum (IZ=22mm and AI=0.73) against the reference strain of S. pneumoniae (ATCC 49619). The range of zones of inhibition in diameter across strains of S. pneumoniae and H. influenzae was 7mm to 22mm with activity index range of 0.23 to 0.74. The lowest MIC produced by medicinal plants in the study during agar disc diffusion method against S. pneumoniae and H. influenzae strains, was 2.5mg/ml. In broth microdilution plate assay, the lowest MIC demonstrated by C. abbreviata, T. capensis and P. hortorum extracts on tested bacteria was 0.031mg/ml and that of G. incanum was 0.063mg/ml. Candida albicans strains were only inhibited at 20mg/ml by the study plants. The highest activity among the individual extracts was shown by P. hortorum methanol extract which inhibited 71% of the studied bacteria. T. capensis methanol extract was the least and inhibited only 17% of the tested bacteria. The strains of Klebsiella pneumoniae showed the highest resistance to medicinal plants employed in this study. Traditional preparation of selected medicinal plants did not show any significant antimicrobial activity. Bioactive analysis of compounds on study plants was carried out using standard methods which revealed the presence of anthraquinones, flavonoids, phytosterol, saponins, tannins and triterpenoids. Comparison of the inhibitory effect of the plant extracts against some broad spectrum antibiotics revealed that the tested medicinal plants showed greater antimicrobial activity than standard antibiotics. However, there was no correlation between the antibiotic susceptibility patterns of the bacteria and the effects of the plants, signifying that plants probably function through different mechanisms. Bioautographic findings on thin-layer chromatography plate, exhibited clear zones of inhibition of bacterial growth with the Rf value range of 0.09 to 0.94. Anti-mutagenic activity was assayed by the Ames mutagenicity test in the plate-incorporation method using histidine mutants of S. typhimurium strains TA 100. The selected plant extracts at 2.5mg/ml and 5mg/ml did not induce mutagenesis in the absence of liver-metabolizing enzymes. The study results indicated that the selected plants are capable of inhibiting the growth of the studied pathogenic microorganisms to a varied degree. The leaves of G. incanum, P. hortorum, T. capensis as well as the stem bark of C. abbreviata could be novel sources of antimicrobial agents that might have broad spectrum activity. The anti-mutagenic properties of the studied medicinal plants may also provide additional health supplemental value to the other claimed therapeutic properties of the plants.
- Full Text:
- Date Issued: 2013
Biology and ecology of largemouth bass Micropterus salmoides in two temperate South African impoundments
- Authors: Taylor, Geraldine Claire
- Date: 2013 , 2013-03-19
- Subjects: Largemouth bass -- Ecology -- South Africa -- Eastern Cape , Largemouth bass -- Behavior -- South Africa -- Eastern Cape , Largemouth bass -- Growth -- South Africa -- Eastern Cape , Largemouth bass -- Reproduction -- South Africa -- Eastern Cape , Largemouth bass -- Food -- South Africa -- Eastern Cape , Largemouth bass -- Age determination -- South Africa -- Eastern Cape , Introduced fishes -- South Africa -- Eastern Cape , Fish populations -- South Africa -- Eastern Cape , Otoliths , Largemouth bass -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5181 , http://hdl.handle.net/10962/d1001668 , Largemouth bass -- Ecology -- South Africa -- Eastern Cape , Largemouth bass -- Behavior -- South Africa -- Eastern Cape , Largemouth bass -- Growth -- South Africa -- Eastern Cape , Largemouth bass -- Reproduction -- South Africa -- Eastern Cape , Largemouth bass -- Food -- South Africa -- Eastern Cape , Largemouth bass -- Age determination -- South Africa -- Eastern Cape , Introduced fishes -- South Africa -- Eastern Cape , Fish populations -- South Africa -- Eastern Cape , Otoliths
- Description: Globally largemouth bass Micropterus salmoides is one of the most widely introduced game fish species which has now become invasive in many countries. Well researched in its native North America, there are few studies on this species in its introduced range. This study aims to improve the understanding of the biology and ecology of M. salmoides in temperate southern Africa, where it threatens native biota and supports a popular recreational fishery. This aim was addressed by assessing the age, growth, maturity, reproductive seasonality, feeding, mortality and movement, of two M. salmoides populations from Wriggleswade (1000 ha, 723 m amsl, 32º35'S; 27º33'E) and Mankazana (35 ha, 66 m amsl, 33º09'S; 26º57'E) Dams in the Eastern Cape of South Africa. The most suitable structure for ageing M. salmoides was determined by comparing the accuracy and precision of otoliths and scales. Scales tended to underestimate the age of fish older than five years. Sectioned sagittal otoliths were the more precise structures for ageing (otoliths CV = 15.8 vs. scales CV = 21.9). The periodicity of growth zone formation was validated as annual for otoliths using both edge analysis (EA), and mark recapture of chemically tagged fish (MRCT). EA indicated one annual peak in the frequency of opaque margins between September and January using a periodic logistic regression and a binomial model linked with a von Mises distribution for circular data. MRCT showed the linear relationship between time at liberty and number of growth zones distal to the fluorescent band was not significantly different from one (slope = 0.89). Reproduction was similar to that in native and non-native populations with fish reaching age at 50% maturity at ca. two years, and length at 50% maturity at 259-290 mm FL depending on growth rate. Spawning season occurred in the spring months of August to October. The Wriggleswade Dam population reached similar ages (14 yrs) to populations in temperate North America. Growth was described using the von Bertalanffy growth equations of (Lt = 420(1-ᵉ⁻°·³³⁽ᵗ⁺°·²¹⁾) mm FL in Wriggleswade and (Lt = 641(1-ᵉ⁻°·²²⁽ᵗ⁺°·⁷⁶⁾) mm FL in Mankazana. Growth performance of both populations, described using the phi prime index, seemed to be correlated with temperature and the Wriggleswade Dam population (Φ’ = 2.8) grew similarly to those native temperate North American populations and the non-native populations of Japan and Italy. The Mankazana population had a higher growth performance (Φ’ = 2.9) compared to Wriggleswade and growth was comparable to other nonnative African populations. Both populations utilised all available food resources, with the Mankazana population being in better condition than the Wriggleswade population as a result of a more diverse diet, highly abundant food sources throughout the year, and potentially the adoption of a more conservative ambush feeding strategy. The Wriggleswade population, which was utilised by competitive anglers, showed low mortality rates (Z = 0.43 yr⁻¹), and translocated fish dispersed from the common release site, travelling an average distance of 4km over the study time of 494 days. These results indicated that M. salmoides are successful in these environments, growing at expected temperature dependant rates, maturing at two years, using all available food groups, and suffering from low mortality. It is therefore likely that they will persist in South Africa and establish where introduced.
- Full Text:
- Date Issued: 2013
- Authors: Taylor, Geraldine Claire
- Date: 2013 , 2013-03-19
- Subjects: Largemouth bass -- Ecology -- South Africa -- Eastern Cape , Largemouth bass -- Behavior -- South Africa -- Eastern Cape , Largemouth bass -- Growth -- South Africa -- Eastern Cape , Largemouth bass -- Reproduction -- South Africa -- Eastern Cape , Largemouth bass -- Food -- South Africa -- Eastern Cape , Largemouth bass -- Age determination -- South Africa -- Eastern Cape , Introduced fishes -- South Africa -- Eastern Cape , Fish populations -- South Africa -- Eastern Cape , Otoliths , Largemouth bass -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5181 , http://hdl.handle.net/10962/d1001668 , Largemouth bass -- Ecology -- South Africa -- Eastern Cape , Largemouth bass -- Behavior -- South Africa -- Eastern Cape , Largemouth bass -- Growth -- South Africa -- Eastern Cape , Largemouth bass -- Reproduction -- South Africa -- Eastern Cape , Largemouth bass -- Food -- South Africa -- Eastern Cape , Largemouth bass -- Age determination -- South Africa -- Eastern Cape , Introduced fishes -- South Africa -- Eastern Cape , Fish populations -- South Africa -- Eastern Cape , Otoliths
- Description: Globally largemouth bass Micropterus salmoides is one of the most widely introduced game fish species which has now become invasive in many countries. Well researched in its native North America, there are few studies on this species in its introduced range. This study aims to improve the understanding of the biology and ecology of M. salmoides in temperate southern Africa, where it threatens native biota and supports a popular recreational fishery. This aim was addressed by assessing the age, growth, maturity, reproductive seasonality, feeding, mortality and movement, of two M. salmoides populations from Wriggleswade (1000 ha, 723 m amsl, 32º35'S; 27º33'E) and Mankazana (35 ha, 66 m amsl, 33º09'S; 26º57'E) Dams in the Eastern Cape of South Africa. The most suitable structure for ageing M. salmoides was determined by comparing the accuracy and precision of otoliths and scales. Scales tended to underestimate the age of fish older than five years. Sectioned sagittal otoliths were the more precise structures for ageing (otoliths CV = 15.8 vs. scales CV = 21.9). The periodicity of growth zone formation was validated as annual for otoliths using both edge analysis (EA), and mark recapture of chemically tagged fish (MRCT). EA indicated one annual peak in the frequency of opaque margins between September and January using a periodic logistic regression and a binomial model linked with a von Mises distribution for circular data. MRCT showed the linear relationship between time at liberty and number of growth zones distal to the fluorescent band was not significantly different from one (slope = 0.89). Reproduction was similar to that in native and non-native populations with fish reaching age at 50% maturity at ca. two years, and length at 50% maturity at 259-290 mm FL depending on growth rate. Spawning season occurred in the spring months of August to October. The Wriggleswade Dam population reached similar ages (14 yrs) to populations in temperate North America. Growth was described using the von Bertalanffy growth equations of (Lt = 420(1-ᵉ⁻°·³³⁽ᵗ⁺°·²¹⁾) mm FL in Wriggleswade and (Lt = 641(1-ᵉ⁻°·²²⁽ᵗ⁺°·⁷⁶⁾) mm FL in Mankazana. Growth performance of both populations, described using the phi prime index, seemed to be correlated with temperature and the Wriggleswade Dam population (Φ’ = 2.8) grew similarly to those native temperate North American populations and the non-native populations of Japan and Italy. The Mankazana population had a higher growth performance (Φ’ = 2.9) compared to Wriggleswade and growth was comparable to other nonnative African populations. Both populations utilised all available food resources, with the Mankazana population being in better condition than the Wriggleswade population as a result of a more diverse diet, highly abundant food sources throughout the year, and potentially the adoption of a more conservative ambush feeding strategy. The Wriggleswade population, which was utilised by competitive anglers, showed low mortality rates (Z = 0.43 yr⁻¹), and translocated fish dispersed from the common release site, travelling an average distance of 4km over the study time of 494 days. These results indicated that M. salmoides are successful in these environments, growing at expected temperature dependant rates, maturing at two years, using all available food groups, and suffering from low mortality. It is therefore likely that they will persist in South Africa and establish where introduced.
- Full Text:
- Date Issued: 2013