Antibiotic-Resistant Pathogenic Escherichia Coli Isolated from Rooftop Rainwater-Harvesting Tanks in the Eastern Cape, South Africa
- Malema, Mokaba Shirley, Abia, Akebe Luther King, Tandlich, Roman, Zuma, Bonga, Kahinda, Jean-Marc Mwenge, Ubomba-Jaswa, Eunice
- Authors: Malema, Mokaba Shirley , Abia, Akebe Luther King , Tandlich, Roman , Zuma, Bonga , Kahinda, Jean-Marc Mwenge , Ubomba-Jaswa, Eunice
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71729 , vital:29931 , https://doi.org/10.3390/ijerph15050892
- Description: Although many developing countries use harvested rainwater (HRW) for drinking and other household purposes, its quality is seldom monitored. Continuous assessment of the microbial quality of HRW would ensure the safety of users of such water. The current study investigated the prevalence of pathogenic Escherichia coli strains and their antimicrobial resistance patterns in HRW tanks in the Eastern Cape, South Africa. Rainwater samples were collected weekly between June and September 2016 from 11 tanks in various areas of the province. Enumeration of E. coli was performed using the Colilert®18/Quanti-Tray® 2000 method. E. coli isolates were obtained and screened for their virulence potentials using polymerase chain reaction (PCR), and subsequently tested for antibiotic resistance using the disc-diffusion method against 11 antibiotics. The pathotype most detected was the neonatal meningitis E. coli (NMEC) (ibeA 28%) while pathotype enteroaggregative E. coli (EAEC) was not detected. The highest resistance of the E. coli isolates was observed against Cephalothin (76%). All tested pathotypes were susceptible to Gentamicin, and 52% demonstrated multiple-antibiotic resistance (MAR). The results of the current study are of public health concern since the use of untreated harvested rainwater for potable purposes may pose a risk of transmission of pathogenic and antimicrobial-resistant E. coli.
- Full Text:
- Date Issued: 2018
- Authors: Malema, Mokaba Shirley , Abia, Akebe Luther King , Tandlich, Roman , Zuma, Bonga , Kahinda, Jean-Marc Mwenge , Ubomba-Jaswa, Eunice
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71729 , vital:29931 , https://doi.org/10.3390/ijerph15050892
- Description: Although many developing countries use harvested rainwater (HRW) for drinking and other household purposes, its quality is seldom monitored. Continuous assessment of the microbial quality of HRW would ensure the safety of users of such water. The current study investigated the prevalence of pathogenic Escherichia coli strains and their antimicrobial resistance patterns in HRW tanks in the Eastern Cape, South Africa. Rainwater samples were collected weekly between June and September 2016 from 11 tanks in various areas of the province. Enumeration of E. coli was performed using the Colilert®18/Quanti-Tray® 2000 method. E. coli isolates were obtained and screened for their virulence potentials using polymerase chain reaction (PCR), and subsequently tested for antibiotic resistance using the disc-diffusion method against 11 antibiotics. The pathotype most detected was the neonatal meningitis E. coli (NMEC) (ibeA 28%) while pathotype enteroaggregative E. coli (EAEC) was not detected. The highest resistance of the E. coli isolates was observed against Cephalothin (76%). All tested pathotypes were susceptible to Gentamicin, and 52% demonstrated multiple-antibiotic resistance (MAR). The results of the current study are of public health concern since the use of untreated harvested rainwater for potable purposes may pose a risk of transmission of pathogenic and antimicrobial-resistant E. coli.
- Full Text:
- Date Issued: 2018
AP-MOVPE growth and characterisation of GaSb/GaAs quantum dots
- Authors: Tile, Ngcali
- Date: 2018
- Subjects: Quantum theory , Quantum electronics Quantum dots Semiconductors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36716 , vital:34047
- Description: GaSb/GaAs quantum dots (QD) were grown by atmospheric pressure (AP) metal-organic vapour phase epitaxy (MOVPE) using triethylgallium (TEGa), tertiarybutylarsine (tBAs) and trimethylantimony (TMSb) as gallium (Ga), arsenic (As) and (Sb) sources, respectively. The effect of AP-MOVPE growth parameters on the formation of GaSb QD structures on GaAs was studied. The formation of small, coherent GaSb dots on GaAs improved with decreasing V/III ratios, which were controlled through changing either the TMSb/TEGa ratio at a constant growth temperature or changing the growth temperature at a constant TMSb/TEGa ratio. The maximum effective V/III ratio for dot formation was 0.175. The dot density was more sensitive to growth time than to source mole fraction in the reactor, since time determines the amount of deposited material. The dot density increased with increasing growth time, while the shape and size of the dots were more sensitive to the source vapour mole fraction, which controls the growth rate. Lower mole fractions resulted in smaller sized dots with a more uniform distribution compared to higher mole fractions. Dome-shaped dots with densities as high as 4×1010 cm-2, average base length of 35 nm and average height of 5 nm were achieved. Capping of GaSb QDs at high temperatures caused flattening and the formation of a thin, inhomogeneous GaSb layer inside GaAs. No obvious QD photoluminescence (PL) peak was detected for these samples. A two stage process for capping the dots (involving growth of a low temperature GaAs cap, followed by a high temperature cap) led to the retention of the dot-like features in/on a wetting layer (WL) of GaSb and distinct PL peaks for both the QDs and WL. An increase in excitation power during PL measurements for this particular sample caused the QD and WL peaks to shift to higher energies. This is attributed to electrostatic band bending, leading to triangular potential wells, typical for type II band alignment between GaAs and strained GaSb. Variable temperature PL measurements showed the decrease in the intensity of the WL peak to be faster than that of the QD peak as the measurement temperature increased. A detailed high resolution transmission electron microscopy analysis was performed to study the morphology and chemical interaction between GaAs and GaSb regions for capped GaSb/GaAs QDs. The capped dots had dimensions similar to those of uncapped dots and had a higher concentration of Sb at their center, with the periphery being intermixed with GaAs. Measurement of lattice strain performed inside these dots revealed the strain to be distributed inhomogenously throughout the dot area. The effect of GaAs host matrix on excitonic behaviour in AP-MOVPE grown GaSb/GaAs quantum dots was investigated. Room temperature (RT) PL emission was achieved from a single layer of quantum dots by controlling the GaAs host matrix growth temperature. These samples were prepared using a GaSb dot growth temperature of 530 °C, followed by growth of a thin GaAs ‘cold’ cap, before depositing the final part of the GaAs capping layer at either 550 °C, 600 °C or 650 °C. PL measurements at 10 K revealed QD emission peaks for all the samples at around 1.1 eV. However, variable temperature PL revealed different thermal quenching rates of the emission, with the rates of quenching reduced with increasing GaAs growth temperature. This was ascribed to reduced defect densities in GaAs grown at higher temperature, which resulted in QD emission even at RT. This RT emission peaked at approximately 1 eV. The hole localisation energy determined for these samples at RT was approximately 470 meV.
- Full Text:
- Date Issued: 2018
- Authors: Tile, Ngcali
- Date: 2018
- Subjects: Quantum theory , Quantum electronics Quantum dots Semiconductors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36716 , vital:34047
- Description: GaSb/GaAs quantum dots (QD) were grown by atmospheric pressure (AP) metal-organic vapour phase epitaxy (MOVPE) using triethylgallium (TEGa), tertiarybutylarsine (tBAs) and trimethylantimony (TMSb) as gallium (Ga), arsenic (As) and (Sb) sources, respectively. The effect of AP-MOVPE growth parameters on the formation of GaSb QD structures on GaAs was studied. The formation of small, coherent GaSb dots on GaAs improved with decreasing V/III ratios, which were controlled through changing either the TMSb/TEGa ratio at a constant growth temperature or changing the growth temperature at a constant TMSb/TEGa ratio. The maximum effective V/III ratio for dot formation was 0.175. The dot density was more sensitive to growth time than to source mole fraction in the reactor, since time determines the amount of deposited material. The dot density increased with increasing growth time, while the shape and size of the dots were more sensitive to the source vapour mole fraction, which controls the growth rate. Lower mole fractions resulted in smaller sized dots with a more uniform distribution compared to higher mole fractions. Dome-shaped dots with densities as high as 4×1010 cm-2, average base length of 35 nm and average height of 5 nm were achieved. Capping of GaSb QDs at high temperatures caused flattening and the formation of a thin, inhomogeneous GaSb layer inside GaAs. No obvious QD photoluminescence (PL) peak was detected for these samples. A two stage process for capping the dots (involving growth of a low temperature GaAs cap, followed by a high temperature cap) led to the retention of the dot-like features in/on a wetting layer (WL) of GaSb and distinct PL peaks for both the QDs and WL. An increase in excitation power during PL measurements for this particular sample caused the QD and WL peaks to shift to higher energies. This is attributed to electrostatic band bending, leading to triangular potential wells, typical for type II band alignment between GaAs and strained GaSb. Variable temperature PL measurements showed the decrease in the intensity of the WL peak to be faster than that of the QD peak as the measurement temperature increased. A detailed high resolution transmission electron microscopy analysis was performed to study the morphology and chemical interaction between GaAs and GaSb regions for capped GaSb/GaAs QDs. The capped dots had dimensions similar to those of uncapped dots and had a higher concentration of Sb at their center, with the periphery being intermixed with GaAs. Measurement of lattice strain performed inside these dots revealed the strain to be distributed inhomogenously throughout the dot area. The effect of GaAs host matrix on excitonic behaviour in AP-MOVPE grown GaSb/GaAs quantum dots was investigated. Room temperature (RT) PL emission was achieved from a single layer of quantum dots by controlling the GaAs host matrix growth temperature. These samples were prepared using a GaSb dot growth temperature of 530 °C, followed by growth of a thin GaAs ‘cold’ cap, before depositing the final part of the GaAs capping layer at either 550 °C, 600 °C or 650 °C. PL measurements at 10 K revealed QD emission peaks for all the samples at around 1.1 eV. However, variable temperature PL revealed different thermal quenching rates of the emission, with the rates of quenching reduced with increasing GaAs growth temperature. This was ascribed to reduced defect densities in GaAs grown at higher temperature, which resulted in QD emission even at RT. This RT emission peaked at approximately 1 eV. The hole localisation energy determined for these samples at RT was approximately 470 meV.
- Full Text:
- Date Issued: 2018
Application of a quality by design approach to optimise an existing product
- Authors: Maxwell, Taryn Lee
- Date: 2018
- Subjects: Pharmaceutical chemistry , Drugs -- Design Pharmaceutical technology
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/32752 , vital:32341
- Description: Quality by design is a science and risk based approach whereby quality is built into the product or process during the pharmaceutical development. although quality by design is encouraged for pharmaceutical development. it is possible to apply quality by design to optimize an existing product as part of a continual improvement strategy. the purpose of this study is to determine which factors should be considered to justify the application of quality by design to optimize an existing product.
- Full Text: false
- Date Issued: 2018
- Authors: Maxwell, Taryn Lee
- Date: 2018
- Subjects: Pharmaceutical chemistry , Drugs -- Design Pharmaceutical technology
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/32752 , vital:32341
- Description: Quality by design is a science and risk based approach whereby quality is built into the product or process during the pharmaceutical development. although quality by design is encouraged for pharmaceutical development. it is possible to apply quality by design to optimize an existing product as part of a continual improvement strategy. the purpose of this study is to determine which factors should be considered to justify the application of quality by design to optimize an existing product.
- Full Text: false
- Date Issued: 2018
Application of health belief model in developing contextual guidelines for adherence to antiretroviral treatment among adolescents and youths in Buffalo City Metropolitan Municipality District, East London, South Africa
- Authors: Mayeye, Bulelwa
- Date: 2018
- Subjects: HIV-positive children--Treatment--Management AIDS (Disease) in adolescence HIV-positive youth
- Language: English
- Type: Thesis , Doctoral , Nursing
- Identifier: http://hdl.handle.net/10353/15572 , vital:40472
- Description: Background: Adhering to the treatment instructions for a long-term illness poses a great challenge to the client especially adolescents and youths. In public health centers it is observed that most adolescents and youths on Ante Retroviral Treatment (ART) do not continue taking ART and do not honor their Art related scheduled appointments at the clinic. An increase loss to follow up among these cohorts is noticeable in Buffalo City Metropolitan Municipality district. Inconsistent adherence to ART may result in the development of resistance mutations. Purpose: The purpose of the study was to develop and describe context – specific antiretroviral treatment guidelines based on the biomedical, cognitive and psychosocial needs of the adolescents and youths at the Buffalo City Metropolitan Municipality district. Methodology: The study was conducted in two phases, phase one consisted of quantitative and qualitative approaches. For phase one an explanatory sequential mixed method of quantitative and qualitative designs was employed. The study was guided by Health Belief Model. The target population were adolescents and youths receiving ART from the selected health facilities in Buffalo City Metropolitan Municipality District in the Province of the Eastern Cape. Participants were chosen based on purposive sampling. A convenience sample of 206 adolescents and youths between the ages of 14 to 24 attending ARV clinics were approached. Ethical considerations, that is, the rights of all the participants were honoured. Data was collected using self administered questionnaires followed by semi-structured interview where face to face interviews were conducted. Reliability validity and trustworthiness of the research was ensured. Quantitative data was analysed through descriptive statistics. For qualitative approach transcrips were coded thematically. In Phase 2, context – specific antiretroviral treatment guidelines were developed to promote adherence to ART by adolescents and youths of Buffalo City Metropolitan Municipality district. Results: About 35percent of the participants indicated low adherence, 31percent for moderate adherence and 34percent for high adherence. A strong correlation between interpersonal relationship and adherence (p = 0.008), a correlation between aspect of care related to clinic and adherence (p = 0.028), a significant correlation between social support and adherence to ART (p = 0.006) and a significant relationship between self- efficacy and adherence to ART (p = 0.000) were obtained. No correlation between demographic status and adherence except for race. Results from the interviews revealed that barriers to adherence were more evident than enabling factors. Recommendations: Health service providers should strengthen ART adherence programmes for adolescents and youths by applying principles as they appear in the context – based guidelines.
- Full Text:
- Date Issued: 2018
- Authors: Mayeye, Bulelwa
- Date: 2018
- Subjects: HIV-positive children--Treatment--Management AIDS (Disease) in adolescence HIV-positive youth
- Language: English
- Type: Thesis , Doctoral , Nursing
- Identifier: http://hdl.handle.net/10353/15572 , vital:40472
- Description: Background: Adhering to the treatment instructions for a long-term illness poses a great challenge to the client especially adolescents and youths. In public health centers it is observed that most adolescents and youths on Ante Retroviral Treatment (ART) do not continue taking ART and do not honor their Art related scheduled appointments at the clinic. An increase loss to follow up among these cohorts is noticeable in Buffalo City Metropolitan Municipality district. Inconsistent adherence to ART may result in the development of resistance mutations. Purpose: The purpose of the study was to develop and describe context – specific antiretroviral treatment guidelines based on the biomedical, cognitive and psychosocial needs of the adolescents and youths at the Buffalo City Metropolitan Municipality district. Methodology: The study was conducted in two phases, phase one consisted of quantitative and qualitative approaches. For phase one an explanatory sequential mixed method of quantitative and qualitative designs was employed. The study was guided by Health Belief Model. The target population were adolescents and youths receiving ART from the selected health facilities in Buffalo City Metropolitan Municipality District in the Province of the Eastern Cape. Participants were chosen based on purposive sampling. A convenience sample of 206 adolescents and youths between the ages of 14 to 24 attending ARV clinics were approached. Ethical considerations, that is, the rights of all the participants were honoured. Data was collected using self administered questionnaires followed by semi-structured interview where face to face interviews were conducted. Reliability validity and trustworthiness of the research was ensured. Quantitative data was analysed through descriptive statistics. For qualitative approach transcrips were coded thematically. In Phase 2, context – specific antiretroviral treatment guidelines were developed to promote adherence to ART by adolescents and youths of Buffalo City Metropolitan Municipality district. Results: About 35percent of the participants indicated low adherence, 31percent for moderate adherence and 34percent for high adherence. A strong correlation between interpersonal relationship and adherence (p = 0.008), a correlation between aspect of care related to clinic and adherence (p = 0.028), a significant correlation between social support and adherence to ART (p = 0.006) and a significant relationship between self- efficacy and adherence to ART (p = 0.000) were obtained. No correlation between demographic status and adherence except for race. Results from the interviews revealed that barriers to adherence were more evident than enabling factors. Recommendations: Health service providers should strengthen ART adherence programmes for adolescents and youths by applying principles as they appear in the context – based guidelines.
- Full Text:
- Date Issued: 2018
Application of hidden Markov models and their extensions to animal movement data
- Authors: Van Niekerk, Bracken
- Date: 2018
- Subjects: Markov processes Animal locomotion Time-series analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/23835 , vital:30624
- Description: Hidden Markov Models (HMMs) have become increasingly popular in animal movement studies as they provide a flexible modelling approach and take the correlation between successive observations into account. They can segment the movement paths into latent states, which can be considered as rough proxies for the behaviours of the animals. This study comprises of two sections, both involving the application of HMMs to large terrestrial mammal movement data. Usually step lengths representing the displacement distances between successive observations, turning angles measuring the tortuosity, or a bivariate input of both variables are used as inputs in the models. It has been found in the literature that the turning angle is either included in the modelling process or it is excluded without much justification for doing so. The first part of this study investigates the nfluence of the turning angle on the model output and resultant interpretations of the HMMs when modelling the trajectories of large terrestrial mammals in southern Africa. Results revealed at different time scales, and for both predator and herbivore species in this study, that the turning angle does not influence the state allocation of the HMMs, which is the main output in terms of interpreting the behaviours of the animals. It is thought in most cases that the inclusion of the turning angle overcomplicates the models unnecessarily without contributing any additional information in terms of the behavioural interpretations or improving the overall fit of the models. This was found for the variety of movements of the species under observation in this study. The second part of this study attempts to validate the state allocation of the HMMs fitted to eland trajectories in the Greater Addo Elephant National Park in the Eastern Cape, with the use of camera trap data. This presented a unique opportunity as this type of data is mainly used for abundance or capture-recapture studies, and the HMMs are rarely validated as the true behaviours of the animals are seldom known. Results revealed that the same diel patterns were detected by the HMMs that were shown by the classified camera trap data. Direct comparisons of the observations where the dates and times matched for the telemetry and camera trap data could be done in several rare instances, which revealed many similarities. Although it was not an ideal comparison, the camera trap data provided a rough validation of the state allocation of the HMMs used in the study.
- Full Text:
- Date Issued: 2018
- Authors: Van Niekerk, Bracken
- Date: 2018
- Subjects: Markov processes Animal locomotion Time-series analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/23835 , vital:30624
- Description: Hidden Markov Models (HMMs) have become increasingly popular in animal movement studies as they provide a flexible modelling approach and take the correlation between successive observations into account. They can segment the movement paths into latent states, which can be considered as rough proxies for the behaviours of the animals. This study comprises of two sections, both involving the application of HMMs to large terrestrial mammal movement data. Usually step lengths representing the displacement distances between successive observations, turning angles measuring the tortuosity, or a bivariate input of both variables are used as inputs in the models. It has been found in the literature that the turning angle is either included in the modelling process or it is excluded without much justification for doing so. The first part of this study investigates the nfluence of the turning angle on the model output and resultant interpretations of the HMMs when modelling the trajectories of large terrestrial mammals in southern Africa. Results revealed at different time scales, and for both predator and herbivore species in this study, that the turning angle does not influence the state allocation of the HMMs, which is the main output in terms of interpreting the behaviours of the animals. It is thought in most cases that the inclusion of the turning angle overcomplicates the models unnecessarily without contributing any additional information in terms of the behavioural interpretations or improving the overall fit of the models. This was found for the variety of movements of the species under observation in this study. The second part of this study attempts to validate the state allocation of the HMMs fitted to eland trajectories in the Greater Addo Elephant National Park in the Eastern Cape, with the use of camera trap data. This presented a unique opportunity as this type of data is mainly used for abundance or capture-recapture studies, and the HMMs are rarely validated as the true behaviours of the animals are seldom known. Results revealed that the same diel patterns were detected by the HMMs that were shown by the classified camera trap data. Direct comparisons of the observations where the dates and times matched for the telemetry and camera trap data could be done in several rare instances, which revealed many similarities. Although it was not an ideal comparison, the camera trap data provided a rough validation of the state allocation of the HMMs used in the study.
- Full Text:
- Date Issued: 2018
Appraisal of wastewater final effluents and river water as reservoirs of cholera and non-cholera causing vibrio species : case study of the Amatole and OR Tambo District Municipalities
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
- Full Text:
- Date Issued: 2018
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
- Full Text:
- Date Issued: 2018
Approaches to detecting and assessing patterns, processes and responses to change in South African estuaries
- Authors: Van Niekerk, Lara
- Date: 2018
- Subjects: Estuaries -- South Africa , Climatic changes -- South Africa
- Language: English
- Type: Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10948/45491 , vital:38621
- Description: The research presented indicates deep knowledge of estuary pattern-process-function across a broad range of estuary types. This study successfully developed and applied approaches to detect change at varying temporal and spatial scales in South African estuaries. This assessment was based on the physical characteristics of estuaries and predicted or measured change in the drivers of estuary health. This is the first study in the country to review and synthesise the vulnerability of South African estuaries to Climate Change on a regional scale. Through sound scientific approaches this research has advanced our knowledge on complex estuarine systems and made a significant contribution globally to approaches for the conservation and management of estuaries.
- Full Text:
- Date Issued: 2018
- Authors: Van Niekerk, Lara
- Date: 2018
- Subjects: Estuaries -- South Africa , Climatic changes -- South Africa
- Language: English
- Type: Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10948/45491 , vital:38621
- Description: The research presented indicates deep knowledge of estuary pattern-process-function across a broad range of estuary types. This study successfully developed and applied approaches to detect change at varying temporal and spatial scales in South African estuaries. This assessment was based on the physical characteristics of estuaries and predicted or measured change in the drivers of estuary health. This is the first study in the country to review and synthesise the vulnerability of South African estuaries to Climate Change on a regional scale. Through sound scientific approaches this research has advanced our knowledge on complex estuarine systems and made a significant contribution globally to approaches for the conservation and management of estuaries.
- Full Text:
- Date Issued: 2018
Aquatic habitat shift assessment in a groundwater-fed semi-arid stream: an investigation into the response of Karoo hydroecology to system variability
- Authors: Ellis, Natalie
- Date: 2018
- Subjects: Aquatic habitats -- South Africa -- Karoo , Arid regions -- South Africa -- Karoo , Biotic communities -- South Africa -- Karoo , Stream ecology -- South Africa -- Karoo
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61882 , vital:28072
- Description: From introduction: The subject of biological response to changes in aquatic habitat is one which has been well explored in many regions of the world. Examples include work in south east Spain by Mellado Diaz et al. (2008) and Oliva-Paterna et al. (2003), in western United States of America by Hauer and Lorang (2004), and in West Germany by Meyer et al. (2003). Similarly, a number of studies have been conducted in semi-arid regions, exploring elements such as erosion, climate, lithology and landscape formations (e.g. Boardman et al., 2013; Le Maitre et al., 2007; Meyer et al., 2003). However, apart from the study by Uys (1997), and Uys and O’Keeffe (1997), there is a noticeable lack of literature on aquatic habitat shifts in semi-arid stream systems, despite these systems being recognised for their high natural variability. This study provides a base-level approach to conducting habitat shift assessments in a semi-arid stream system and monitoring the hydroecological responses to system variability.
- Full Text:
- Date Issued: 2018
- Authors: Ellis, Natalie
- Date: 2018
- Subjects: Aquatic habitats -- South Africa -- Karoo , Arid regions -- South Africa -- Karoo , Biotic communities -- South Africa -- Karoo , Stream ecology -- South Africa -- Karoo
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61882 , vital:28072
- Description: From introduction: The subject of biological response to changes in aquatic habitat is one which has been well explored in many regions of the world. Examples include work in south east Spain by Mellado Diaz et al. (2008) and Oliva-Paterna et al. (2003), in western United States of America by Hauer and Lorang (2004), and in West Germany by Meyer et al. (2003). Similarly, a number of studies have been conducted in semi-arid regions, exploring elements such as erosion, climate, lithology and landscape formations (e.g. Boardman et al., 2013; Le Maitre et al., 2007; Meyer et al., 2003). However, apart from the study by Uys (1997), and Uys and O’Keeffe (1997), there is a noticeable lack of literature on aquatic habitat shifts in semi-arid stream systems, despite these systems being recognised for their high natural variability. This study provides a base-level approach to conducting habitat shift assessments in a semi-arid stream system and monitoring the hydroecological responses to system variability.
- Full Text:
- Date Issued: 2018
Arbuscular mycorrhizal fungi persist in dying Euphorbia ingens trees
- Vivas, M, Crous, C J, Dames, Joanna F, Van der Linde, J A, Coetzee, M P A, Roux, J
- Authors: Vivas, M , Crous, C J , Dames, Joanna F , Van der Linde, J A , Coetzee, M P A , Roux, J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
- Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Vivas, M , Crous, C J , Dames, Joanna F , Van der Linde, J A , Coetzee, M P A , Roux, J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
- Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
- Full Text:
- Date Issued: 2018
Archie Mafeje and the question of philosophy as a liberatory discourse
- Authors: Dladla, Thabang
- Date: 2018
- Subjects: Philosophy, African Eurocentrism Liberty
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10353/12160 , vital:39192
- Description: This dissertation seeks to articulate a liberatory conception of philosophy which interprets reality on its own terms. It is an attempt to intervene in the practice of philosophy in South Africa, which has continued along colonial lines expressed through the marginality of African philosophy up to the present, to the general neglect of the unjust and divisive social reality that defines South Africa. It is our argument that such a continuity is indicative of outstanding liberation on the part of the indigenous people conquered in the unjust wars of colonisation. Our main task then is to struggle for this liberation at the epistemic level with Archie Mafeje, through an examination of his intellectual works and life as a revolutionary intellectual, as an inspiration and an instance of a liberatory practice of philosophy. We draw on the work of Archie Mafeje to elaborate and defend his account of African Philosophy, as a historically specific expression of the liberatory struggle of Africans against unjust Euro-centric colonial domination. This shall be achieved in three instances. In the first instance, Chapter 1, we trace the history of institutionalised philosophy in South Africa outlining Eurocentrism and mimesis as its defining features. In the second instance, Chapter 2, a history of contemporary African philosophy is outlined as emanative from the question concerning the existence of African philosophy, of which mainstream South African philosophy has largely been ignorant. In the final instance, Chapter 3 and 4, a liberatory practice of philosophy is presented, as a necessary response to this context, with Mafeje’s account of African philosophy defended as such an instance. The birth of the Azanian Philosophical Society is also presented as such an instance and as a challenge to the unchallenged hegemony of white philosophy in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Dladla, Thabang
- Date: 2018
- Subjects: Philosophy, African Eurocentrism Liberty
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10353/12160 , vital:39192
- Description: This dissertation seeks to articulate a liberatory conception of philosophy which interprets reality on its own terms. It is an attempt to intervene in the practice of philosophy in South Africa, which has continued along colonial lines expressed through the marginality of African philosophy up to the present, to the general neglect of the unjust and divisive social reality that defines South Africa. It is our argument that such a continuity is indicative of outstanding liberation on the part of the indigenous people conquered in the unjust wars of colonisation. Our main task then is to struggle for this liberation at the epistemic level with Archie Mafeje, through an examination of his intellectual works and life as a revolutionary intellectual, as an inspiration and an instance of a liberatory practice of philosophy. We draw on the work of Archie Mafeje to elaborate and defend his account of African Philosophy, as a historically specific expression of the liberatory struggle of Africans against unjust Euro-centric colonial domination. This shall be achieved in three instances. In the first instance, Chapter 1, we trace the history of institutionalised philosophy in South Africa outlining Eurocentrism and mimesis as its defining features. In the second instance, Chapter 2, a history of contemporary African philosophy is outlined as emanative from the question concerning the existence of African philosophy, of which mainstream South African philosophy has largely been ignorant. In the final instance, Chapter 3 and 4, a liberatory practice of philosophy is presented, as a necessary response to this context, with Mafeje’s account of African philosophy defended as such an instance. The birth of the Azanian Philosophical Society is also presented as such an instance and as a challenge to the unchallenged hegemony of white philosophy in South Africa.
- Full Text:
- Date Issued: 2018
Art topples monuments: artistic practice and colonial/postcolonial relations in the public space of Luanda
- Authors: Siegert, Nadine
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147014 , vital:38585
- Description: Even though there have been very few modern and contemporary artworks in the urban space of Luanda in the years after independence in 1975—and especially after the end of the civil war in 2002—there are two works by Angolan artists that are of particular interest: the sculpture Mitologias II (1984) by António Ole (b. 1951) and the photographic series Redefining the Power (2011) by Kiluanji Kia Henda (b. 1978). Both works address the possibility of using contemporary art as a symbolic form of the replacement of power, since both are built on pedestals that had previously supported monuments of Portuguese colonial power. They might, therefore, be read as a form of substitution for monuments that would commemorate and celebrate independence or the end of colonialism. This article also discusses whether these two artworks can also be regarded as counter-monuments and this contributes to the discourse on the visual and material culture of Lusophone Africa.
- Full Text:
- Date Issued: 2018
- Authors: Siegert, Nadine
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147014 , vital:38585
- Description: Even though there have been very few modern and contemporary artworks in the urban space of Luanda in the years after independence in 1975—and especially after the end of the civil war in 2002—there are two works by Angolan artists that are of particular interest: the sculpture Mitologias II (1984) by António Ole (b. 1951) and the photographic series Redefining the Power (2011) by Kiluanji Kia Henda (b. 1978). Both works address the possibility of using contemporary art as a symbolic form of the replacement of power, since both are built on pedestals that had previously supported monuments of Portuguese colonial power. They might, therefore, be read as a form of substitution for monuments that would commemorate and celebrate independence or the end of colonialism. This article also discusses whether these two artworks can also be regarded as counter-monuments and this contributes to the discourse on the visual and material culture of Lusophone Africa.
- Full Text:
- Date Issued: 2018
Artisanal mining and its contribution to sustainable rural livelihoods : a case of Esigodini area, Umzingwane rural district, Matabeleland South Province of Zimbabwe
- Authors: Nkala, Khayelihle
- Date: 2018
- Subjects: Mineral industries Rural poor Sustainable development
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10353/15551 , vital:40458
- Description: This study examined the contribution of artisanal mining to the livelihoods of rural communities. Artisanal mining has over the past decade been taken up by rural communities as an alternative of sustaining their livelihoods due to the collapse of agriculture due to the successive droughts, economic meltdown and the general failure of the fast track land reform program. Hence this study sought to fill this knowledge gap using Esigodini as a case. The study made use of focus group discussions, interviews and documents review to gather information on how artisanal mining activities have contributed to the livelihoods of rural communities. Although artisanal mining has its negative impacts to the environment it does contribute to the livelihoods of communities, as the findings of the study reveal that the Esigodini community has benefited from improved socio-economic activities as a result of the practice.
- Full Text:
- Date Issued: 2018
- Authors: Nkala, Khayelihle
- Date: 2018
- Subjects: Mineral industries Rural poor Sustainable development
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10353/15551 , vital:40458
- Description: This study examined the contribution of artisanal mining to the livelihoods of rural communities. Artisanal mining has over the past decade been taken up by rural communities as an alternative of sustaining their livelihoods due to the collapse of agriculture due to the successive droughts, economic meltdown and the general failure of the fast track land reform program. Hence this study sought to fill this knowledge gap using Esigodini as a case. The study made use of focus group discussions, interviews and documents review to gather information on how artisanal mining activities have contributed to the livelihoods of rural communities. Although artisanal mining has its negative impacts to the environment it does contribute to the livelihoods of communities, as the findings of the study reveal that the Esigodini community has benefited from improved socio-economic activities as a result of the practice.
- Full Text:
- Date Issued: 2018
Aspects Allocentristes de l’Humanisme dans l’Univers Romanesque de Williams Sassine
- Authors: Dami, Emmanuel Naancin
- Date: 2018
- Subjects: Sassine, Williams, 1944-1997 -- Criticism and interpretation , Guinean fiction (French) -- 20th century -- History and criticism , Humanism in literature , Human beings in literature , Postcolonialism in literature , Existentialism in literature
- Language: French , English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61957 , vital:28089
- Description: The human being, his behaviour and more importantly, his very essence have, for time immemorial, proven to be enigmatic to many a man and to researchers in particular. Consequently, the need for a thorough and more profound understanding of man has made him the epicentre of epistemic investigations across many academic disciplines. This, unfortunately, does not seem to have shaded bright lights on the grey areas bordering on his nature to his behavior. This, in turn, opens up other windows requiring further probes. For instance, proponents of the Neo-classical economic school contend that the human being is homo oeconomicus. This implies that man is intrinsically egocentric and a rational being whose decisions are based on informed choices driven by his urge for maximal utility geared towards his personal satisfaction (O’Boyle 2009; Caruso 2012). This stance invalidates man’s ability to do ‘disinterested good’ in any form. African francophone literature is replete with different and diverse images of man, his behaviour and existential conditions: sufferings and struggles. It, therefore, constitutes, inter alia, a laboratory in which researchers undertake investigative endeavours. This thesis beams its floodlights on the allocentric aspects of humanism in the novels of Williams Sassine. Thus, using the phenomenological and ‘clavieniste’ lenses as overarching operational theories, the thesis investigates Sassine’s novels with the view to shading a ray of light on the ‘humanistic man’ especially the allocentric dimensions of his nature and comportment. Emphasis is laid on the motives and motivations underlying the individual and the in-group struggle of the sassinien heroes in the emancipation of their society from the shackles of colonial and postcolonial domination, exploitation and subjugation resulting in self-determination and the subsequent disenchantment. Furthermore, the thesis examines the nature and character of human charity, generosity and sacrifices among the characters in the novels. In conclusion, the thesis establishes, through an x-ray of the nature of actions and decisions of certain characters in the novels, the examination of the conscious and subconscious intentions underlying these same actions and decisions which, on a face value, are apparently altruistic, that the sassinien heroes’ efforts and sacrifices are geared towards the common and greater good. This invariably means that man is, indeed, capable of posing disinterested acts of charity and bringing succour, devoid of any ulterior motives for personal gain, to his fellow humans. The position of the Neo-classical economists is consequently over-assuming, sweeping and tad generalizing. The sassinien characters have demonstrated beyond reasonable doubt that they are humanists. Their nature, the remote and immediate causes of their fights, the goals and objectives of their struggles and their spirit of abnegation have indeed proven that “human beings have the right and the responsibility to give meaning and shape to their own lives. [They have stood] for the building of a more humane society through an ethics based on the human and other natural values in a spirit of reason and free inquiry through human capabilities” (AHA 2017 : 3).
- Full Text:
- Date Issued: 2018
- Authors: Dami, Emmanuel Naancin
- Date: 2018
- Subjects: Sassine, Williams, 1944-1997 -- Criticism and interpretation , Guinean fiction (French) -- 20th century -- History and criticism , Humanism in literature , Human beings in literature , Postcolonialism in literature , Existentialism in literature
- Language: French , English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61957 , vital:28089
- Description: The human being, his behaviour and more importantly, his very essence have, for time immemorial, proven to be enigmatic to many a man and to researchers in particular. Consequently, the need for a thorough and more profound understanding of man has made him the epicentre of epistemic investigations across many academic disciplines. This, unfortunately, does not seem to have shaded bright lights on the grey areas bordering on his nature to his behavior. This, in turn, opens up other windows requiring further probes. For instance, proponents of the Neo-classical economic school contend that the human being is homo oeconomicus. This implies that man is intrinsically egocentric and a rational being whose decisions are based on informed choices driven by his urge for maximal utility geared towards his personal satisfaction (O’Boyle 2009; Caruso 2012). This stance invalidates man’s ability to do ‘disinterested good’ in any form. African francophone literature is replete with different and diverse images of man, his behaviour and existential conditions: sufferings and struggles. It, therefore, constitutes, inter alia, a laboratory in which researchers undertake investigative endeavours. This thesis beams its floodlights on the allocentric aspects of humanism in the novels of Williams Sassine. Thus, using the phenomenological and ‘clavieniste’ lenses as overarching operational theories, the thesis investigates Sassine’s novels with the view to shading a ray of light on the ‘humanistic man’ especially the allocentric dimensions of his nature and comportment. Emphasis is laid on the motives and motivations underlying the individual and the in-group struggle of the sassinien heroes in the emancipation of their society from the shackles of colonial and postcolonial domination, exploitation and subjugation resulting in self-determination and the subsequent disenchantment. Furthermore, the thesis examines the nature and character of human charity, generosity and sacrifices among the characters in the novels. In conclusion, the thesis establishes, through an x-ray of the nature of actions and decisions of certain characters in the novels, the examination of the conscious and subconscious intentions underlying these same actions and decisions which, on a face value, are apparently altruistic, that the sassinien heroes’ efforts and sacrifices are geared towards the common and greater good. This invariably means that man is, indeed, capable of posing disinterested acts of charity and bringing succour, devoid of any ulterior motives for personal gain, to his fellow humans. The position of the Neo-classical economists is consequently over-assuming, sweeping and tad generalizing. The sassinien characters have demonstrated beyond reasonable doubt that they are humanists. Their nature, the remote and immediate causes of their fights, the goals and objectives of their struggles and their spirit of abnegation have indeed proven that “human beings have the right and the responsibility to give meaning and shape to their own lives. [They have stood] for the building of a more humane society through an ethics based on the human and other natural values in a spirit of reason and free inquiry through human capabilities” (AHA 2017 : 3).
- Full Text:
- Date Issued: 2018
Aspects of the nutritional physiology of the perlemoen Haliotis midae (L.) and red abalone H. rufescens (Swainson)
- Authors: Kemp, Justin Oliver Gordon
- Date: 2018
- Subjects: Haliotis midae , Haliotis midae fisheries , Red abalone , Haliotis midae -- Feeding and feeds , Red abalone -- Feeding and feeds , Haliotis midae -- Nutrition -- Requirements , Red abalone -- Nutrition -- Requirements , Haliotis midae -- Metabolism , Red abalone -- Metabolism , Haliotis midae -- Physiology , Red abalone -- Physiology , Stable isotopes , Algae as feed
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62314 , vital:28154
- Description: The source of abalone for human consumption has shown a dramatic shift away from wild-capture fisheries in the last 30 years, with over 90% of global production now coming from aquaculture. Farmers initially relied on the natural food of abalone (macroalgae) as a culture feed, though in regions where macroalgae availability was limiting, the need to develop formulated feeds was evident. Extensive research effort has led to the development of a number of formulated feed products currently employed in the industry. These feeds, however, differ markedly from the mixed macroalgal diets that abalone have evolved to utilise, particularly in terms of protein content and carbohydrate structure. The degree to which the nutritional physiology of abalone responds to these novel formulated diets, with and without macroalgal supplementation, was investigated in the current study. A multifaceted approach, combining growth trials, stable isotope nutrient tracers and metabolic experiments, was employed to gain insight into the post-absorption dynamics and utilisation of dietary nutrients under varying dietary regimes of fresh macroalgae and formulated feed. Growth trials conducted with both Haliotis rufescens and H. midae showed significantly higher growth and protein utilisation efficiency for abalone fed macroalgal diets compared to formulated feeds. Furthermore, when formulated feeds were supplemented with macroalgae to form combination diets, growth and the utilization of protein was improved compared to the formulated-feed-only diet. The poor utilisation of protein by H. midae fed the formulated feed could be traced, using a method combining stable isotope bio-markers with a Bayesian mixing model (SIAR), to the low incorporation of the fishmeal component of protein in the diet. The marked postprandial drop in the O:N ratio on abalone fed formulated feeds indicate that the protein was being diverted into catabolic metabolic pathways. The metabolic cost of digestion, termed specific dynamic action (SDA), was negated as a factor in the improved growth of abalone fed macroalgal diets, with the SDA coefficient 2.1 times that observed for formulated feed. Furthermore, the postprandial haemolymph glucose concentration (HGC) in H. midae was elevated when fed formulated feed compared to macroalgae. The high levels of circulating glucose are likely a result of the structure the carbohydrate source in formulated feeds and stimulate the deposition of glycogen through the allosteric control of glycogen synthase. Formulated feeds produced higher cooked meat yields in canning simulation trials, suggesting that muscle glycogen content may indirectly play a role in increasing canning yields through the displacement of collagen. The results of these empirical studies are synthesised under key themes, discussed within the context of their potential commercial relevance and future research directions are highlighted.
- Full Text:
- Date Issued: 2018
- Authors: Kemp, Justin Oliver Gordon
- Date: 2018
- Subjects: Haliotis midae , Haliotis midae fisheries , Red abalone , Haliotis midae -- Feeding and feeds , Red abalone -- Feeding and feeds , Haliotis midae -- Nutrition -- Requirements , Red abalone -- Nutrition -- Requirements , Haliotis midae -- Metabolism , Red abalone -- Metabolism , Haliotis midae -- Physiology , Red abalone -- Physiology , Stable isotopes , Algae as feed
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62314 , vital:28154
- Description: The source of abalone for human consumption has shown a dramatic shift away from wild-capture fisheries in the last 30 years, with over 90% of global production now coming from aquaculture. Farmers initially relied on the natural food of abalone (macroalgae) as a culture feed, though in regions where macroalgae availability was limiting, the need to develop formulated feeds was evident. Extensive research effort has led to the development of a number of formulated feed products currently employed in the industry. These feeds, however, differ markedly from the mixed macroalgal diets that abalone have evolved to utilise, particularly in terms of protein content and carbohydrate structure. The degree to which the nutritional physiology of abalone responds to these novel formulated diets, with and without macroalgal supplementation, was investigated in the current study. A multifaceted approach, combining growth trials, stable isotope nutrient tracers and metabolic experiments, was employed to gain insight into the post-absorption dynamics and utilisation of dietary nutrients under varying dietary regimes of fresh macroalgae and formulated feed. Growth trials conducted with both Haliotis rufescens and H. midae showed significantly higher growth and protein utilisation efficiency for abalone fed macroalgal diets compared to formulated feeds. Furthermore, when formulated feeds were supplemented with macroalgae to form combination diets, growth and the utilization of protein was improved compared to the formulated-feed-only diet. The poor utilisation of protein by H. midae fed the formulated feed could be traced, using a method combining stable isotope bio-markers with a Bayesian mixing model (SIAR), to the low incorporation of the fishmeal component of protein in the diet. The marked postprandial drop in the O:N ratio on abalone fed formulated feeds indicate that the protein was being diverted into catabolic metabolic pathways. The metabolic cost of digestion, termed specific dynamic action (SDA), was negated as a factor in the improved growth of abalone fed macroalgal diets, with the SDA coefficient 2.1 times that observed for formulated feed. Furthermore, the postprandial haemolymph glucose concentration (HGC) in H. midae was elevated when fed formulated feed compared to macroalgae. The high levels of circulating glucose are likely a result of the structure the carbohydrate source in formulated feeds and stimulate the deposition of glycogen through the allosteric control of glycogen synthase. Formulated feeds produced higher cooked meat yields in canning simulation trials, suggesting that muscle glycogen content may indirectly play a role in increasing canning yields through the displacement of collagen. The results of these empirical studies are synthesised under key themes, discussed within the context of their potential commercial relevance and future research directions are highlighted.
- Full Text:
- Date Issued: 2018
Aspects of the population ecology, habitat use and behaviour of the endangered Knysna seahorse (Hippocampus capensis Boulenger, 1900) in a residential marina estate, Knysna, South Africa: implications for conservation
- Authors: Claassens, Louw
- Date: 2018
- Subjects: Endangered species -- South Africa -- Knysna , Sea horses -- Behavior -- South Africa -- Knysna , Sea horses -- Habitat -- South Africa -- Knysna , Sea horses -- Ecology -- South Africa -- Knysna
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54789 , vital:26616
- Description: The Knysna seahorse Hippocampus capensis is South Africa’s only endemic seahorse species, and is found in only three adjacent estuaries along the southern coast. The conservation of this endangered species is important on a national and international level. This study presents the first research on this species within the Knysna estuary since 2001 and specifically focuses on aspects of its ecology within a residential marina estate (Thesen Islands Marina). The physico-chemical and habitat features of the marina were described and the population ecology, habitat use, and behaviour of the Knysna seahorse were investigated. Physico-chemical conditions within the western section of the marina, characterised by high water current velocities, were similar to that of the adjacent estuary. The eastern section of the marina was characterised by lower water current velocities and higher turbidity. Four major habitat types were identified within the marina canals: (I) artificial Reno mattress (wire baskets filled with rocks); (II) Codium tenue beds; (III) mixed vegetation on sediment; and (IV) barren canal floor. Seahorse densities within the marina were significantly higher compared to densities found historically within the estuary. Highest seahorse densities were specifically found within the artificial Reno mattress structures and within the western section of the marina. Seahorse density varied spatially and temporally and the type of habitat was an important predictor for seahorse occurrence. An experimental investigation found that H. capensis chooses artificial Reno mattress habitat over Zostera capensis when given a choice. GoPro cameras were used successfully to investigate daytime seahorse behaviour within the Reno mattress habitat. Seahorses were more active during the morning, spent most of their time (> 80 %) feeding, and morning courting behaviour for this species were confirmed. However, during the summer holiday period (mid-December to mid-January) few seahorses were observed on camera, which suggests that the increase in motor boat activity and the related increase in noise had a negative effect on H. capensis feeding and courting behaviour. The marina development, and in particular the Reno mattresses, created a new habitat for this endangered species within the Knysna estuary. In addition to the protection and restoration of natural habitats in which H. capensis is found, the conservation potential of artificial structures such as Reno mattresses should be realised.
- Full Text:
- Date Issued: 2018
- Authors: Claassens, Louw
- Date: 2018
- Subjects: Endangered species -- South Africa -- Knysna , Sea horses -- Behavior -- South Africa -- Knysna , Sea horses -- Habitat -- South Africa -- Knysna , Sea horses -- Ecology -- South Africa -- Knysna
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54789 , vital:26616
- Description: The Knysna seahorse Hippocampus capensis is South Africa’s only endemic seahorse species, and is found in only three adjacent estuaries along the southern coast. The conservation of this endangered species is important on a national and international level. This study presents the first research on this species within the Knysna estuary since 2001 and specifically focuses on aspects of its ecology within a residential marina estate (Thesen Islands Marina). The physico-chemical and habitat features of the marina were described and the population ecology, habitat use, and behaviour of the Knysna seahorse were investigated. Physico-chemical conditions within the western section of the marina, characterised by high water current velocities, were similar to that of the adjacent estuary. The eastern section of the marina was characterised by lower water current velocities and higher turbidity. Four major habitat types were identified within the marina canals: (I) artificial Reno mattress (wire baskets filled with rocks); (II) Codium tenue beds; (III) mixed vegetation on sediment; and (IV) barren canal floor. Seahorse densities within the marina were significantly higher compared to densities found historically within the estuary. Highest seahorse densities were specifically found within the artificial Reno mattress structures and within the western section of the marina. Seahorse density varied spatially and temporally and the type of habitat was an important predictor for seahorse occurrence. An experimental investigation found that H. capensis chooses artificial Reno mattress habitat over Zostera capensis when given a choice. GoPro cameras were used successfully to investigate daytime seahorse behaviour within the Reno mattress habitat. Seahorses were more active during the morning, spent most of their time (> 80 %) feeding, and morning courting behaviour for this species were confirmed. However, during the summer holiday period (mid-December to mid-January) few seahorses were observed on camera, which suggests that the increase in motor boat activity and the related increase in noise had a negative effect on H. capensis feeding and courting behaviour. The marina development, and in particular the Reno mattresses, created a new habitat for this endangered species within the Knysna estuary. In addition to the protection and restoration of natural habitats in which H. capensis is found, the conservation potential of artificial structures such as Reno mattresses should be realised.
- Full Text:
- Date Issued: 2018
Assessing factors influencing professional nurses' attrition in South Africa : a case study of private hospitals in Johannesburg
- Authors: Mbobo, Angelina Pretty
- Date: 2018
- Subjects: Intensive care nursing
- Language: English
- Type: Thesis , Masters , Public Health Leadership
- Identifier: http://hdl.handle.net/10353/11181 , vital:37200
- Description: South Africa faces an immense shortage of healthcare professionals, especially trained and experienced critical care nurses. This thesis assesses factors influencing professional nurses ‘attrition in two selected private hospitals. This results in an HR risk; loss of skills, task shifting and the use of less skilled nurses, and not limited to the high workloads in intensive care units together with the job dissatisfaction consequently. To confirm this, a case study making use of a qualitative approach, follows the definition of a social constructivism framework. The study assessed 40 trained and experienced critical care nurses in focus groups of 5, with which a stratified purposive sampling technique was used and the focus group interviews were 90 minutes Seven structured interviews were undertaken, (using a narrative summary) with hospital operational managers working directly with the critical care nurses. Audio-recorded data were analysed by thematic content analysis using Creswell’s steps content analysis method. Multiple reasons, as given by nurses, to discontinue their services in private hospitals emerged. These were: Heavy workloads, shortage of trained staff, medico-legal risks; lack of supervision, support and teamwork, physical and emotional exhaustion, fatigue, stress and burnout, differential salary scales, non-competitive retirement packages role ambiguity, inadequate equipment, unresolved conflict with colleagues or management, personal financial crisis, lack of recognition and Lack of career development or promotion. These factors make use of themes, which include issues related to line management, administration, subjective and uncertainty of roles. Operational managers confirmed such reasons for the discontinuation of services offered by critical care nurses in private hospitals. Management views to the attrition of critical care nurses were that: (a) The staffing crisis was a serious matter of concern, (b) the use of less skilled staff resulted in negative effects on patient care and (c) the low number of critical care nursing staff negatively affected organisational goals.
- Full Text:
- Date Issued: 2018
- Authors: Mbobo, Angelina Pretty
- Date: 2018
- Subjects: Intensive care nursing
- Language: English
- Type: Thesis , Masters , Public Health Leadership
- Identifier: http://hdl.handle.net/10353/11181 , vital:37200
- Description: South Africa faces an immense shortage of healthcare professionals, especially trained and experienced critical care nurses. This thesis assesses factors influencing professional nurses ‘attrition in two selected private hospitals. This results in an HR risk; loss of skills, task shifting and the use of less skilled nurses, and not limited to the high workloads in intensive care units together with the job dissatisfaction consequently. To confirm this, a case study making use of a qualitative approach, follows the definition of a social constructivism framework. The study assessed 40 trained and experienced critical care nurses in focus groups of 5, with which a stratified purposive sampling technique was used and the focus group interviews were 90 minutes Seven structured interviews were undertaken, (using a narrative summary) with hospital operational managers working directly with the critical care nurses. Audio-recorded data were analysed by thematic content analysis using Creswell’s steps content analysis method. Multiple reasons, as given by nurses, to discontinue their services in private hospitals emerged. These were: Heavy workloads, shortage of trained staff, medico-legal risks; lack of supervision, support and teamwork, physical and emotional exhaustion, fatigue, stress and burnout, differential salary scales, non-competitive retirement packages role ambiguity, inadequate equipment, unresolved conflict with colleagues or management, personal financial crisis, lack of recognition and Lack of career development or promotion. These factors make use of themes, which include issues related to line management, administration, subjective and uncertainty of roles. Operational managers confirmed such reasons for the discontinuation of services offered by critical care nurses in private hospitals. Management views to the attrition of critical care nurses were that: (a) The staffing crisis was a serious matter of concern, (b) the use of less skilled staff resulted in negative effects on patient care and (c) the low number of critical care nursing staff negatively affected organisational goals.
- Full Text:
- Date Issued: 2018
Assessing grade 9 learners' attitude towards their academic performance in mathematics in Pinetown education district, KwaZulu-Natal
- Authors: Olorunfemi, Sunday Olayinka
- Date: 2018
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/8518 , vital:32859
- Description: The world education system is faced with many challenges. Learners’ performance in mathematics in particular is one of the main areas of concern. Over decades, Mathematics has become an indispensable tool in the march towards technological breakthrough. The use of Mathematics reveals how people deal with their various private, social, and civil lives. The indispensable implications of Mathematics in the society made it to become a compulsory subject in the primary and secondary education in most countries of the world. Nevertheless, despite its wide application of Mathematics in the society, there are still many learners particularly in secondary schools who struggle to achieve the best knowledge of Mathematics. As applicable to most countries of the world, the performance of learner in South Africa is not encouraging. For example, the performance of Grade 9 learners, Pinetown Education District in particular, is not improving. Attitude is one major factor identified among learners that gravely affects learner’s performance in Mathematics. The study adopted qualitative approach which is rooted in interpretive paradigm to frame and focus the study. Interpretive paradigm is consistent with the assumption that experience of the world is subjective and best understood in terms of individuals’ subjective meanings rather than the researcher’s objective definitions. The sample included 15 participants (which include three Mathematics educators and twelve Grade nine learners) selected purposefully across three secondary schools, with attitudes and performance as inclusion criteria. Data were obtained through classroom observations and semi-structured interviews conducted with the selected Mathematics educators and learners of the selected schools to obtain their views on the impact of the attitudes of Grade nine learners on their performances in the subject. The study found that the learners perceived difficulty in Mathematics because of the information that was passed to them through their parents or guardians, seniors and peers who have negative attitudes towards Mathematics; their previous performances at early grades; the nature of Mathematics itself; and that learners were not well prepared from primary schools. It was also indicated that many learners have negative attitude towards Mathematics whose behaviours in the classroom affected others who would have loved to enjoy Mathematics. The study also revealed that all stakeholders (the educators, school managements, policy makers and parents) have part to play in motivating the learners to engage more in Mathematics. Also the study found that qualified educators who will develop good and friendly classroom environment, employing a highly interactive teaching method and as well giving adequate homework and assignments to the learners are needed to teach Mathematics in secondary schools. The study revealed that learning resources are not made available to the learners. There study therefore potentially provides that, educators can help mould the learners with negative preset mind about Mathematics through their classroom behaviours. The study further provides that learning materials such as textbooks and other geometry tools be made available for the learners use at home. The study also, provides that consideration be given to Mathematics class in the morning hours. The study concluded by giving general recommendations for improving learners’ participation and attitudes towards learning Mathematics.
- Full Text:
- Date Issued: 2018
- Authors: Olorunfemi, Sunday Olayinka
- Date: 2018
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/8518 , vital:32859
- Description: The world education system is faced with many challenges. Learners’ performance in mathematics in particular is one of the main areas of concern. Over decades, Mathematics has become an indispensable tool in the march towards technological breakthrough. The use of Mathematics reveals how people deal with their various private, social, and civil lives. The indispensable implications of Mathematics in the society made it to become a compulsory subject in the primary and secondary education in most countries of the world. Nevertheless, despite its wide application of Mathematics in the society, there are still many learners particularly in secondary schools who struggle to achieve the best knowledge of Mathematics. As applicable to most countries of the world, the performance of learner in South Africa is not encouraging. For example, the performance of Grade 9 learners, Pinetown Education District in particular, is not improving. Attitude is one major factor identified among learners that gravely affects learner’s performance in Mathematics. The study adopted qualitative approach which is rooted in interpretive paradigm to frame and focus the study. Interpretive paradigm is consistent with the assumption that experience of the world is subjective and best understood in terms of individuals’ subjective meanings rather than the researcher’s objective definitions. The sample included 15 participants (which include three Mathematics educators and twelve Grade nine learners) selected purposefully across three secondary schools, with attitudes and performance as inclusion criteria. Data were obtained through classroom observations and semi-structured interviews conducted with the selected Mathematics educators and learners of the selected schools to obtain their views on the impact of the attitudes of Grade nine learners on their performances in the subject. The study found that the learners perceived difficulty in Mathematics because of the information that was passed to them through their parents or guardians, seniors and peers who have negative attitudes towards Mathematics; their previous performances at early grades; the nature of Mathematics itself; and that learners were not well prepared from primary schools. It was also indicated that many learners have negative attitude towards Mathematics whose behaviours in the classroom affected others who would have loved to enjoy Mathematics. The study also revealed that all stakeholders (the educators, school managements, policy makers and parents) have part to play in motivating the learners to engage more in Mathematics. Also the study found that qualified educators who will develop good and friendly classroom environment, employing a highly interactive teaching method and as well giving adequate homework and assignments to the learners are needed to teach Mathematics in secondary schools. The study revealed that learning resources are not made available to the learners. There study therefore potentially provides that, educators can help mould the learners with negative preset mind about Mathematics through their classroom behaviours. The study further provides that learning materials such as textbooks and other geometry tools be made available for the learners use at home. The study also, provides that consideration be given to Mathematics class in the morning hours. The study concluded by giving general recommendations for improving learners’ participation and attitudes towards learning Mathematics.
- Full Text:
- Date Issued: 2018
Assessing growth response patterns of microalgae to varying environmental conditions using sediments from ephemeral wetlands
- Authors: Mazwane, Sixolile
- Date: 2018
- Subjects: Microalgae -- South Africa , Wetland conservation -- South Africa Landscape ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/22398 , vital:29966
- Description: Ephemeral wetlands serve as habitats for different fauna and flora. Microalgae make up a bulk of primary production in newly inundated wetlands and have a big influence on the aquatic community structure. As ephemeral wetlands have cyclical drying and wetting phases, algal species found in these habitats have evolved adaptations (i.e. dormancy and cysts) to survive during dry periods and become productive upon inundation. Algae have been used as ecological indicators in many aquatic ecosystems including wetlands, particularly associated with water quality and with varying inundation states. Whilst temperature and water level have been shown to affect microalgal biomass independently, this study aims to assess the effects of these two factors simultaneously on microalgal biomass, species diversity and community changes. The aim of the study was to investigate microalgal dynamics using two ephemeral wetlands in the Nelson Mandela Bay Municipality. The growth response patterns of microalgal communities to varying temperatures and inundation levels through experiments using dry temporary wetland sediments was also assessed. Dry sediments were collected from two depression wetlands with different sediment characteristics (1592 and Elephant Wallow (EW)). The study consisted of replicated treatments with three different surface area: volume ratios (SA:V) (Low surface area: volume (LSAV), Medium (MSAV) and High (HSAV)), inundated with distilled water. The microcosms were placed inside a Conviron environmental growth chamber and illuminated at between 106 to 138 μmol.m-2s-1, with a 12:12 light-dark cycle at constant temperatures of 12 °C (mean winter) and 22 °C (mean summer). Physicochemical data were recorded, and biological samples were collected every 4 days over a 28-day inundation period. In the field, Electrical conductivity (EC) and pH showed a gradual increase over the inundation period. The systems were well oxygenated (6-10 mg L-1). Overall, phytoplankton biomass in the field was ~10 μg L-1 whereas benthic biomass (MPB) was significantly higher 10 – 300 mg L-1. Within the experiments, the phytoplankton biomass showed a pattern while MPB biomass increased gradually for both experiments. There were no significant (p>0.05) differences between the 1592 and EW phytoplankton biomass. However, the MPB biomass showed significant (p<0.05) differences between the two sediments (EW high, 1592 low) and the experiments, respectively. In the winter experiment, the 1592 sediment had high phytoplankton biomass compared to EW, the reverse was observed for the MPB biomass. In summer experiment, similar results were observed in terms of phytoplankton biomass. For the MPBs, 1592 had greater biomass for all treatments compared to EW. The phytoplankton community for both field samples and experiments was dominated by chlorophytes (>50 %), followed by cyanophytes and euglenophytes (with cryptophytes in summer experiment) for both field and experiments. The MPB community was dominated by bacillariophytes (55 %) and chlorophytes (25 %) in the 1592 sediments and this was also the case with EW sediments bacillariophytes (70 %), although cyanophytes (15 %) made up the remainder of the MPB community. The 1592 sediments supported higher diatom abundances under the HSAV compared to the same treatment from the EW wetland suggesting that possibly grain size or texture might be responsible. In contrast, sediments from EW under LSAV conditions showed higher diatom cell numbers possibly indicating that increased water depth has the propensity to support greater diatom assemblages compared with the same water level for sediments from 1592. The results indicate that microalgae community is influenced by sediment type more than it is by water level. From this study it was also established that microalgae were able to reemerge from their dormancy state upon inundation and that tank experiments were successful in simulating natural ephemeral wetland conditions. The findings from this study will add to the available baseline data on microalgal dynamics in the ephemeral wetlands in South Africa, especially in semi-arid areas. This information can be valuable in enhancing our understanding regarding the role of microalgae in ephemeral wetlands in order to conserve them.
- Full Text:
- Date Issued: 2018
- Authors: Mazwane, Sixolile
- Date: 2018
- Subjects: Microalgae -- South Africa , Wetland conservation -- South Africa Landscape ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/22398 , vital:29966
- Description: Ephemeral wetlands serve as habitats for different fauna and flora. Microalgae make up a bulk of primary production in newly inundated wetlands and have a big influence on the aquatic community structure. As ephemeral wetlands have cyclical drying and wetting phases, algal species found in these habitats have evolved adaptations (i.e. dormancy and cysts) to survive during dry periods and become productive upon inundation. Algae have been used as ecological indicators in many aquatic ecosystems including wetlands, particularly associated with water quality and with varying inundation states. Whilst temperature and water level have been shown to affect microalgal biomass independently, this study aims to assess the effects of these two factors simultaneously on microalgal biomass, species diversity and community changes. The aim of the study was to investigate microalgal dynamics using two ephemeral wetlands in the Nelson Mandela Bay Municipality. The growth response patterns of microalgal communities to varying temperatures and inundation levels through experiments using dry temporary wetland sediments was also assessed. Dry sediments were collected from two depression wetlands with different sediment characteristics (1592 and Elephant Wallow (EW)). The study consisted of replicated treatments with three different surface area: volume ratios (SA:V) (Low surface area: volume (LSAV), Medium (MSAV) and High (HSAV)), inundated with distilled water. The microcosms were placed inside a Conviron environmental growth chamber and illuminated at between 106 to 138 μmol.m-2s-1, with a 12:12 light-dark cycle at constant temperatures of 12 °C (mean winter) and 22 °C (mean summer). Physicochemical data were recorded, and biological samples were collected every 4 days over a 28-day inundation period. In the field, Electrical conductivity (EC) and pH showed a gradual increase over the inundation period. The systems were well oxygenated (6-10 mg L-1). Overall, phytoplankton biomass in the field was ~10 μg L-1 whereas benthic biomass (MPB) was significantly higher 10 – 300 mg L-1. Within the experiments, the phytoplankton biomass showed a pattern while MPB biomass increased gradually for both experiments. There were no significant (p>0.05) differences between the 1592 and EW phytoplankton biomass. However, the MPB biomass showed significant (p<0.05) differences between the two sediments (EW high, 1592 low) and the experiments, respectively. In the winter experiment, the 1592 sediment had high phytoplankton biomass compared to EW, the reverse was observed for the MPB biomass. In summer experiment, similar results were observed in terms of phytoplankton biomass. For the MPBs, 1592 had greater biomass for all treatments compared to EW. The phytoplankton community for both field samples and experiments was dominated by chlorophytes (>50 %), followed by cyanophytes and euglenophytes (with cryptophytes in summer experiment) for both field and experiments. The MPB community was dominated by bacillariophytes (55 %) and chlorophytes (25 %) in the 1592 sediments and this was also the case with EW sediments bacillariophytes (70 %), although cyanophytes (15 %) made up the remainder of the MPB community. The 1592 sediments supported higher diatom abundances under the HSAV compared to the same treatment from the EW wetland suggesting that possibly grain size or texture might be responsible. In contrast, sediments from EW under LSAV conditions showed higher diatom cell numbers possibly indicating that increased water depth has the propensity to support greater diatom assemblages compared with the same water level for sediments from 1592. The results indicate that microalgae community is influenced by sediment type more than it is by water level. From this study it was also established that microalgae were able to reemerge from their dormancy state upon inundation and that tank experiments were successful in simulating natural ephemeral wetland conditions. The findings from this study will add to the available baseline data on microalgal dynamics in the ephemeral wetlands in South Africa, especially in semi-arid areas. This information can be valuable in enhancing our understanding regarding the role of microalgae in ephemeral wetlands in order to conserve them.
- Full Text:
- Date Issued: 2018
Assessing process safety action in selected South African oil companies
- Mashiloane, Mosebetsi Stanley
- Authors: Mashiloane, Mosebetsi Stanley
- Date: 2018
- Subjects: Industrial safety -- South Africa -- Management , Manufacturing processes -- South Africa -- Safety measures Petroleum industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/22596 , vital:30017
- Description: The study was triggered by the number of process safety incidents that are taking place in South African oil companies. The impact of these process safety incidents has resulted in multiple fatalities, revenue loss, fires and explosions in the past. The problem is so immense that the process safety actions, coming from the process safety studies to prevent and mitigate these incidents have been ignored, not attended to, not implemented or not understood by the oil industries for the past 15-20 years. Hence the process safety incidents are still happening and the oil industry has not learnt from previous incidents.
- Full Text:
- Date Issued: 2018
- Authors: Mashiloane, Mosebetsi Stanley
- Date: 2018
- Subjects: Industrial safety -- South Africa -- Management , Manufacturing processes -- South Africa -- Safety measures Petroleum industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/22596 , vital:30017
- Description: The study was triggered by the number of process safety incidents that are taking place in South African oil companies. The impact of these process safety incidents has resulted in multiple fatalities, revenue loss, fires and explosions in the past. The problem is so immense that the process safety actions, coming from the process safety studies to prevent and mitigate these incidents have been ignored, not attended to, not implemented or not understood by the oil industries for the past 15-20 years. Hence the process safety incidents are still happening and the oil industry has not learnt from previous incidents.
- Full Text:
- Date Issued: 2018
Assessing teaching strategies of grade four English second language teachers in Amathole District, Eastern Cape Province, South Africa
- Authors: Adegoriolu, Emmanuel Tobi
- Date: 2018
- Subjects: Education--South Africa English language--Study and teaching--Foreign speakers Second language acquisition
- Language: English
- Type: Thesis , Masters , Applied Linguistics
- Identifier: http://hdl.handle.net/10353/15474 , vital:40411
- Description: The intention of this study was to assess the teaching strategies of Grade 4 English second language teachers in the Amathole district of the Eastern Cape. The objectives of the study were firstly, to identify the teaching strategies currently employed by Grade 4 teachers in the teaching of English as a second language in selected schools in Amathole district of the Eastern Cape in South Africa. Secondly, the study sought to establish how the existing teaching strategies impacted on the performance of the learners of English as a second language in the selected schools in Amathloe district of the Eastern Cape, and to establish the teachers‟ perceptions on the most effective teaching strategies in the selected schools. The study used translanguaging and communicative language teaching as the theoretical lens and guide in data collection and analysis. The study employed the use of mixed methods of both quantitative and qualitative research design. Data was collected through the use of eight comprehensive classroom observations and eight teacher questionnaires in four different primary schools. The conclusion of the study as established in the outcome of data showed that there was no recommended teaching strategy by the Department of Education for English second language teachers teaching Grade 4. The study observed that the language teachers made use of various teaching strategies in the instruction of Grade 4 learners. In addition, it was concluded that the placement of the English language subject on the timetable affected the performance of young learners during the summer period. Moreover, the absence of teacher-learner cordial relationship compromised learning outcomes and performance of Grade 4 learners in the skills of English second language. The study recommends that teachers of English as a second language be trained on communicative language teaching in order to achieve positive outcomes in the classroom.
- Full Text:
- Date Issued: 2018
- Authors: Adegoriolu, Emmanuel Tobi
- Date: 2018
- Subjects: Education--South Africa English language--Study and teaching--Foreign speakers Second language acquisition
- Language: English
- Type: Thesis , Masters , Applied Linguistics
- Identifier: http://hdl.handle.net/10353/15474 , vital:40411
- Description: The intention of this study was to assess the teaching strategies of Grade 4 English second language teachers in the Amathole district of the Eastern Cape. The objectives of the study were firstly, to identify the teaching strategies currently employed by Grade 4 teachers in the teaching of English as a second language in selected schools in Amathole district of the Eastern Cape in South Africa. Secondly, the study sought to establish how the existing teaching strategies impacted on the performance of the learners of English as a second language in the selected schools in Amathloe district of the Eastern Cape, and to establish the teachers‟ perceptions on the most effective teaching strategies in the selected schools. The study used translanguaging and communicative language teaching as the theoretical lens and guide in data collection and analysis. The study employed the use of mixed methods of both quantitative and qualitative research design. Data was collected through the use of eight comprehensive classroom observations and eight teacher questionnaires in four different primary schools. The conclusion of the study as established in the outcome of data showed that there was no recommended teaching strategy by the Department of Education for English second language teachers teaching Grade 4. The study observed that the language teachers made use of various teaching strategies in the instruction of Grade 4 learners. In addition, it was concluded that the placement of the English language subject on the timetable affected the performance of young learners during the summer period. Moreover, the absence of teacher-learner cordial relationship compromised learning outcomes and performance of Grade 4 learners in the skills of English second language. The study recommends that teachers of English as a second language be trained on communicative language teaching in order to achieve positive outcomes in the classroom.
- Full Text:
- Date Issued: 2018