Modelling Ionospheric vertical drifts over the African low latitude region
- Dubazane, Makhosonke Berthwell
- Authors: Dubazane, Makhosonke Berthwell
- Date: 2018
- Subjects: Ionospheric drift , Magnetometers , Functions, Orthogonal , Neural networks (Computer science) , Ionospheric electron density -- Africa , Communication and Navigation Outage Forecasting Systems (C/NOFS)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63356 , vital:28396
- Description: Low/equatorial latitudes vertical plasma drifts and electric fields govern the formation and changes of ionospheric density structures which affect space-based systems such as communications, navigation and positioning. Dynamical and electrodynamical processes play important roles in plasma distribution at different altitudes. Because of the high variability of E × B drift in low latitude regions, coupled with various processes that sometimes originate from high latitudes especially during geomagnetic storm conditions, it is challenging to develop accurate vertical drift models. This is despite the fact that there are very few instruments dedicated to provide electric field and hence E × B drift data in low/equatorial latitude regions. To this effect, there exists no ground-based instrument for direct measurements of E×B drift data in the African sector. This study presents the first time investigation aimed at modelling the long-term variability of low latitude vertical E × B drift over the African sector using a combination of Communication and Navigation Outage Forecasting Systems (C/NOFS) and ground-based magnetometer observations/measurements during 2008-2013. Because the approach is based on the estimation of equatorial electrojet from ground-based magnetometer observations, the developed models are only valid for local daytime. Three modelling techniques have been considered. The application of Empirical Orthogonal Functions and partial least squares has been performed on vertical E × B drift modelling for the first time. The artificial neural networks that have the advantage of learning underlying changes between a set of inputs and known output were also used in vertical E × B drift modelling. Due to lack of E×B drift data over the African sector, the developed models were validated using satellite data and the climatological Scherliess-Fejer model incorporated within the International Reference Ionosphere model. Maximum correlation coefficient of ∼ 0.8 was achieved when validating the developed models with C/NOFS E × B drift observations that were not used in any model development. For most of the time, the climatological model overestimates the local daytime vertical E × B drift velocities. The methods and approach presented in this study provide a background for constructing vertical E ×B drift databases in longitude sectors that do not have radar instrumentation. This will in turn make it possible to study day-to-day variability of vertical E×B drift and hopefully lead to the development of regional and global models that will incorporate local time information in different longitude sectors.
- Full Text:
- Date Issued: 2018
- Authors: Dubazane, Makhosonke Berthwell
- Date: 2018
- Subjects: Ionospheric drift , Magnetometers , Functions, Orthogonal , Neural networks (Computer science) , Ionospheric electron density -- Africa , Communication and Navigation Outage Forecasting Systems (C/NOFS)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63356 , vital:28396
- Description: Low/equatorial latitudes vertical plasma drifts and electric fields govern the formation and changes of ionospheric density structures which affect space-based systems such as communications, navigation and positioning. Dynamical and electrodynamical processes play important roles in plasma distribution at different altitudes. Because of the high variability of E × B drift in low latitude regions, coupled with various processes that sometimes originate from high latitudes especially during geomagnetic storm conditions, it is challenging to develop accurate vertical drift models. This is despite the fact that there are very few instruments dedicated to provide electric field and hence E × B drift data in low/equatorial latitude regions. To this effect, there exists no ground-based instrument for direct measurements of E×B drift data in the African sector. This study presents the first time investigation aimed at modelling the long-term variability of low latitude vertical E × B drift over the African sector using a combination of Communication and Navigation Outage Forecasting Systems (C/NOFS) and ground-based magnetometer observations/measurements during 2008-2013. Because the approach is based on the estimation of equatorial electrojet from ground-based magnetometer observations, the developed models are only valid for local daytime. Three modelling techniques have been considered. The application of Empirical Orthogonal Functions and partial least squares has been performed on vertical E × B drift modelling for the first time. The artificial neural networks that have the advantage of learning underlying changes between a set of inputs and known output were also used in vertical E × B drift modelling. Due to lack of E×B drift data over the African sector, the developed models were validated using satellite data and the climatological Scherliess-Fejer model incorporated within the International Reference Ionosphere model. Maximum correlation coefficient of ∼ 0.8 was achieved when validating the developed models with C/NOFS E × B drift observations that were not used in any model development. For most of the time, the climatological model overestimates the local daytime vertical E × B drift velocities. The methods and approach presented in this study provide a background for constructing vertical E ×B drift databases in longitude sectors that do not have radar instrumentation. This will in turn make it possible to study day-to-day variability of vertical E×B drift and hopefully lead to the development of regional and global models that will incorporate local time information in different longitude sectors.
- Full Text:
- Date Issued: 2018
Modelling plant water use of the grassland and thicket biomes in the Eastern Cape, South Africa: towards an improved understanding of the impact of invasive alien plants on soil chemistry, biomass production and evapotranspiration
- Authors: Gwate, Onalenna
- Date: 2018
- Subjects: Grasslands -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Rangelands -- South Africa -- Eastern Cape , Range ecology-- South Africa -- Eastern Cape , Rangelands -- Water-supply , Rangelands -- Weed control , Evapotranspiration , Plant-water relationships
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54800 , vital:26617
- Description: It is imperative to understand the strong coupling between the carbon capture process and water use to sustainably manage rangelands. Woody encroachment is undermining rangelands grass production. Evapotranspiration (ET) highlights the links between ecosystem carbon capture process and water use. It forms the biggest flux of the hydrological cycle after precipitation yet it is not well understood. The Grassland and the Albany Thicket (AT) biomes in the Eastern Cape, South Africa, provide an interesting space to study the dynamics in rangelands biomass production and the associated water use. Therefore, the main purpose of this study was to contribute towards management of rangelands by understanding the dynamics in rangeland grass production and water use. To achieve this aim, the impact of Acacia mearnsii, an invasive alien plant, on soil chemical properties and rangelands grass production was investigated. This was achieved by analysing the biophysical attributes of A. mearnsii as they related to grass production. Secondly, selected soil variables that could be used as a prognosis for landscape recovery or deterioration were evaluated. In addition, aboveground grass biomass was measured in areas cleared of A. mearnsii and regression equations were prepared to help model aboveground grass biomass in areas cleared of A. mearnsi. The thesis also explored dynamics in water vapour and energy fluxes in these two biomes using an eddy covariance system. Consequently, water vapour and energy fluxes were evaluated in order to understand landscape water use and energy partitioning in the landscape. The study also tested the application of Penman-Monteith equation based algorithms for estimating ET with micrometeorological techniques used for validation. Pursuant to this, the Penman- Monteith-Leuning (PML) and Penman-Monteith-Palmer (PMP) equations were applied. In addition, some effort was devoted to improving the estimates of ET from the PMP by incorporating a direct soil evaporation component. Finally, the influence of local changes in catchment characteristics on ET was explored through the application of a variant of the Budyko framework and investigating dynamics in the evaporative index as well as applying tests for trends and shifts on ET and rainfall data to detect changes in mean quaternary catchment rainfall and ET. Results revealed that A. mearnsii affected soil chemical properties and impaired grass production in rangelands. Hence, thinning of canopies provided an optimal solution for enhanced landscape water use to sequestrate carbon, provide shade, grazing, and also wood fuel. It was also shown that across sites, ET was water limited since differences between reference ET and actual ET were large. ET was largely sensitive to vapour pressure deficit and surface conductance than to net radiation, indicating that the canopies were strongly coupled with the boundary layer. Rangeland ET was successfully simulated and evaporation from the soil was the dominant flux, hence there is scope for reducing the so-called ‘unproductive’ water use. Further, it was shown that the PML was better able to simulate ET compared to the PMP model as revealed by different model evaluation metrics such as the root mean square error, absolute mean square error and the root mean square observations standard deviation ratio. The incorporation of a soil evaporation component in the PMP model improved estimates of ET as revealed by the root mean square error. The results also indicated that both the catchment parameter (w) and the evaporative index were important in highlighting the impacts of land cover change on ET. It was also shown that, despite changes in the local environment such as catchment characteristics, global forces also affected ET at a local scale. Overall, the study demonstrated that combining remote sensing and ground based observations was important to better understand rangeland grass production and water use dynamics.
- Full Text:
- Date Issued: 2018
- Authors: Gwate, Onalenna
- Date: 2018
- Subjects: Grasslands -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Rangelands -- South Africa -- Eastern Cape , Range ecology-- South Africa -- Eastern Cape , Rangelands -- Water-supply , Rangelands -- Weed control , Evapotranspiration , Plant-water relationships
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54800 , vital:26617
- Description: It is imperative to understand the strong coupling between the carbon capture process and water use to sustainably manage rangelands. Woody encroachment is undermining rangelands grass production. Evapotranspiration (ET) highlights the links between ecosystem carbon capture process and water use. It forms the biggest flux of the hydrological cycle after precipitation yet it is not well understood. The Grassland and the Albany Thicket (AT) biomes in the Eastern Cape, South Africa, provide an interesting space to study the dynamics in rangelands biomass production and the associated water use. Therefore, the main purpose of this study was to contribute towards management of rangelands by understanding the dynamics in rangeland grass production and water use. To achieve this aim, the impact of Acacia mearnsii, an invasive alien plant, on soil chemical properties and rangelands grass production was investigated. This was achieved by analysing the biophysical attributes of A. mearnsii as they related to grass production. Secondly, selected soil variables that could be used as a prognosis for landscape recovery or deterioration were evaluated. In addition, aboveground grass biomass was measured in areas cleared of A. mearnsii and regression equations were prepared to help model aboveground grass biomass in areas cleared of A. mearnsi. The thesis also explored dynamics in water vapour and energy fluxes in these two biomes using an eddy covariance system. Consequently, water vapour and energy fluxes were evaluated in order to understand landscape water use and energy partitioning in the landscape. The study also tested the application of Penman-Monteith equation based algorithms for estimating ET with micrometeorological techniques used for validation. Pursuant to this, the Penman- Monteith-Leuning (PML) and Penman-Monteith-Palmer (PMP) equations were applied. In addition, some effort was devoted to improving the estimates of ET from the PMP by incorporating a direct soil evaporation component. Finally, the influence of local changes in catchment characteristics on ET was explored through the application of a variant of the Budyko framework and investigating dynamics in the evaporative index as well as applying tests for trends and shifts on ET and rainfall data to detect changes in mean quaternary catchment rainfall and ET. Results revealed that A. mearnsii affected soil chemical properties and impaired grass production in rangelands. Hence, thinning of canopies provided an optimal solution for enhanced landscape water use to sequestrate carbon, provide shade, grazing, and also wood fuel. It was also shown that across sites, ET was water limited since differences between reference ET and actual ET were large. ET was largely sensitive to vapour pressure deficit and surface conductance than to net radiation, indicating that the canopies were strongly coupled with the boundary layer. Rangeland ET was successfully simulated and evaporation from the soil was the dominant flux, hence there is scope for reducing the so-called ‘unproductive’ water use. Further, it was shown that the PML was better able to simulate ET compared to the PMP model as revealed by different model evaluation metrics such as the root mean square error, absolute mean square error and the root mean square observations standard deviation ratio. The incorporation of a soil evaporation component in the PMP model improved estimates of ET as revealed by the root mean square error. The results also indicated that both the catchment parameter (w) and the evaporative index were important in highlighting the impacts of land cover change on ET. It was also shown that, despite changes in the local environment such as catchment characteristics, global forces also affected ET at a local scale. Overall, the study demonstrated that combining remote sensing and ground based observations was important to better understand rangeland grass production and water use dynamics.
- Full Text:
- Date Issued: 2018
Modulation of human Hsp90α conformational dynamics by allosteric ligand interaction at the c-terminal domain:
- Penkler, David L, Tastan Bishop, Özlem
- Authors: Penkler, David L , Tastan Bishop, Özlem
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148402 , vital:38736 , DOI: 10.1101/386755
- Description: Recent years have seen heat shock protein 90 kDa (Hsp90) attract significant interest as a viable drug target, particularly for cancer. To date, designed inhibitors that target the ATPase domain demonstrate potent anti-proliferative effects, but have failed clinical trials due to high levels of associated toxicity. To circumvent this, the focus has shifted away from the ATPase domain. One option involves modulation of the protein through allosteric activation/inhibition. Here, we propose a novel approach: we use previously obtained information via residue perturbation scanning coupled with dynamic residue network analysis to identify allosteric drug targeting sites for inhibitor docking.
- Full Text:
- Date Issued: 2018
- Authors: Penkler, David L , Tastan Bishop, Özlem
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148402 , vital:38736 , DOI: 10.1101/386755
- Description: Recent years have seen heat shock protein 90 kDa (Hsp90) attract significant interest as a viable drug target, particularly for cancer. To date, designed inhibitors that target the ATPase domain demonstrate potent anti-proliferative effects, but have failed clinical trials due to high levels of associated toxicity. To circumvent this, the focus has shifted away from the ATPase domain. One option involves modulation of the protein through allosteric activation/inhibition. Here, we propose a novel approach: we use previously obtained information via residue perturbation scanning coupled with dynamic residue network analysis to identify allosteric drug targeting sites for inhibitor docking.
- Full Text:
- Date Issued: 2018
Molecular characterization of streptococcus agalactiae isolated from pregnant women in the Eastern Cape, South Africa and Windhoek, Namibia and antibacterial activities of some medicinal plant extracts on the isolates
- Authors: Mukesi, Munyaradzi
- Date: 2018
- Subjects: Streptococcus Medicinal plants Pregnant women
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13034 , vital:39437
- Description: Streptococcus agalactiae (S. agalactiae) also known as group B Streptococcus (GBS) is one of the leading causes of bacterial morbidity and mortality among neonates worldwide. It is the cause of invasive Early Onset Disease (EOD), which occurs in the first 7 days of life and characterised by sepsis, pneumonia and meningitis and Late Onset Disease (LOD) occurring between 7 and 89 days of life. Late onset disease is characterised by meningitis and long term neurological sequelae such as cerebral palsy, hearing impairment and cognitive challenges. S. agalactiae does not only infect neonates, it also infects the elderly, immunocompromised individuals and pregnant and non-pregnant women, causing invasive disease. In the world, 10-40 percent of healthy women are rectally or vaginally colonised with GBS and they face the risk of passing it to their babies during the process of childbirth. During parturition, a GBS colonized pregnant woman transfers the bacterium to her new-born as the baby passes through the ruptured membrane, thus infecting the child. However, GBS has been reported to be transferred even without rupture of membranes. Once it infects the membranes, it is transferred into the amniotic fluid and subsequently infects the baby. It can be aspirated into the lungs causing pneumonia or it can infect the blood stream and disseminated round the body causing septicaemia, meningitis and other infections. Once in the neonate’s body, the bacteria is able to evade the immune system as the host immune system is not yet fully developed. Bacterial evasion of the immune system is enhanced by its various virulence factors which are deployed to help it escape the immune system. These include the polysaccharide capsule, haemolysin and the release of complement inactivating factors such C5a peptidase. The World Health Organisation (WHO) (2010) recommends universal screening of pregnant women to identify those colonised and who are at risk of passing the bacterium to their babies during birth. WHO also recommends identification of at risk women and providing Intrapartum Antibiotic Prophylaxis (IAP) using penicillin. However, problems arise in penicillin allergic women and while alternatives for IAP include erythromycin and clindamycin, there is increasing resistance to these drugs thereby limiting therapeutic options. Antimicrobial susceptibility testing is also not always possible in most resource constrained countries due to poor infrastructure, limited access to health care and the logistical problems in implementing the WHO guidelines. Alternative therapeutic options to GBS infection include developing new and potent antibiotics, development of a vaccine, use of medicinal plants and the use of bacteriophage therapy. While these look like better alternatives there is massive scientific work to be carried out to ensure proper characterisation and efficiency of such alternatives. This process should be followed by in vitro diagnostic testing, experiments with animal models and clinical trials. The problems encountered during vaccine development to curtail GBS infection are compounded by the multiplicity of S. agalactiae capsular types which vary in different geographic locations. Medicinal plants are a cheap and convenient option since they are widely used in communities but the phytochemical components of the plants have to be identified and subjected to in vitro testing to evaluate their therapeutic efficacy as antimicrobial agents. This study therefore sought to isolate GBS from pregnant women between 35 and 37 weeks gestation in Windhoek (Namibia) and the Eastern Cape (South Africa), to determine the prevalence of GBS colonisation in the vagina and rectum of the pregnant women, characterise the isolates by molecular techniques, determine the antimicrobial resistance profiles and genes of the isolates and explore the efficacies of medicinal plant extracts as possible candidates for therapeutic options.
- Full Text:
- Date Issued: 2018
- Authors: Mukesi, Munyaradzi
- Date: 2018
- Subjects: Streptococcus Medicinal plants Pregnant women
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13034 , vital:39437
- Description: Streptococcus agalactiae (S. agalactiae) also known as group B Streptococcus (GBS) is one of the leading causes of bacterial morbidity and mortality among neonates worldwide. It is the cause of invasive Early Onset Disease (EOD), which occurs in the first 7 days of life and characterised by sepsis, pneumonia and meningitis and Late Onset Disease (LOD) occurring between 7 and 89 days of life. Late onset disease is characterised by meningitis and long term neurological sequelae such as cerebral palsy, hearing impairment and cognitive challenges. S. agalactiae does not only infect neonates, it also infects the elderly, immunocompromised individuals and pregnant and non-pregnant women, causing invasive disease. In the world, 10-40 percent of healthy women are rectally or vaginally colonised with GBS and they face the risk of passing it to their babies during the process of childbirth. During parturition, a GBS colonized pregnant woman transfers the bacterium to her new-born as the baby passes through the ruptured membrane, thus infecting the child. However, GBS has been reported to be transferred even without rupture of membranes. Once it infects the membranes, it is transferred into the amniotic fluid and subsequently infects the baby. It can be aspirated into the lungs causing pneumonia or it can infect the blood stream and disseminated round the body causing septicaemia, meningitis and other infections. Once in the neonate’s body, the bacteria is able to evade the immune system as the host immune system is not yet fully developed. Bacterial evasion of the immune system is enhanced by its various virulence factors which are deployed to help it escape the immune system. These include the polysaccharide capsule, haemolysin and the release of complement inactivating factors such C5a peptidase. The World Health Organisation (WHO) (2010) recommends universal screening of pregnant women to identify those colonised and who are at risk of passing the bacterium to their babies during birth. WHO also recommends identification of at risk women and providing Intrapartum Antibiotic Prophylaxis (IAP) using penicillin. However, problems arise in penicillin allergic women and while alternatives for IAP include erythromycin and clindamycin, there is increasing resistance to these drugs thereby limiting therapeutic options. Antimicrobial susceptibility testing is also not always possible in most resource constrained countries due to poor infrastructure, limited access to health care and the logistical problems in implementing the WHO guidelines. Alternative therapeutic options to GBS infection include developing new and potent antibiotics, development of a vaccine, use of medicinal plants and the use of bacteriophage therapy. While these look like better alternatives there is massive scientific work to be carried out to ensure proper characterisation and efficiency of such alternatives. This process should be followed by in vitro diagnostic testing, experiments with animal models and clinical trials. The problems encountered during vaccine development to curtail GBS infection are compounded by the multiplicity of S. agalactiae capsular types which vary in different geographic locations. Medicinal plants are a cheap and convenient option since they are widely used in communities but the phytochemical components of the plants have to be identified and subjected to in vitro testing to evaluate their therapeutic efficacy as antimicrobial agents. This study therefore sought to isolate GBS from pregnant women between 35 and 37 weeks gestation in Windhoek (Namibia) and the Eastern Cape (South Africa), to determine the prevalence of GBS colonisation in the vagina and rectum of the pregnant women, characterise the isolates by molecular techniques, determine the antimicrobial resistance profiles and genes of the isolates and explore the efficacies of medicinal plant extracts as possible candidates for therapeutic options.
- Full Text:
- Date Issued: 2018
Molecular epidemiology of vibrio pathogens in selected surface waters and treated final effluents of wastewater treatment plants in Chris Hani District Municipality in the Eastern Cape Province, South Africa
- Authors: Ayodeji, Onsula Charles
- Date: 2018
- Subjects: Sewage disposal plants Sewage -- Purification Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/10464 , vital:35478
- Description: Access to clean and safe water is essential for the survival of human beings. Nevertheless pollution from wastewater treatment plants (WWTPs) effluents often impacts the microbiological qualities of surface waters. Availability of freshwater resources is indispensable for preventing waterborne diseases. The current study evaluated the physicochemical properties and abundance of Vibrio species in selected rivers and WWTPs in the Eastern Cape Province of South Africa, over a one year sampling regime (December, 2016 to November, 2017). Water samples were collected monthly at designated locations along the banks of two rivers, treated effluents from 500 m upstream and downstream discharge points of two WWTPs and examined for physicochemical qualities, prevalence of Vibrio pathogens and their antibiogram profiles using both cultural and molecular techniques. The findings reveal the qualities of Tsomo and Great Fish river qualities with respect to electrical conductivity (EC) (137.75 – 377.69 mg/l), total suspended solids (TSS) (52.00 – 725.19 mg/l) and temperature (12.7 – 23 oC) and the treated effluents of WW-AD and WW-CR WWTPs with respect to EC (525.73 – 1071.89 mg/l), free chlorine (0.00 mg/l – 0.68 mg/l), temperature (12.4 – 28.8 oC), TSS (14.67 – 276.44 mg/l) exceeds the permissible limits set for effluent discharged to freshwater by South Africa guidelines. Other physicochemical qualities such as turbidity (63.11 – 797.17 NTU), BOD (3.30 – 5.26 mg/l) and TDS (68.88 – 148.14 mg/l) for Tsomo and Great Fish river and turbidity (20.33 – 310 NTU), biological oxygen demand (BOD) (1.28 – 4.96 mg/l), and total dissolve solid (TDS) (262.89 – 534.89 mg/l) for WWTPs WW-AD and WW-CR did not comply with WHO and EU standards as no regulation is set for them in the South African guidelines for domestic water usage. Statistical analysis revealed that pH, electrical conductivities, dissolved oxygen and total dissolved solid were significantly different whereas temperature did not differ significantly with respect to the four seasons (P < 0.05). The Vibrio densities for Great Fish river ranged between 0 and 3.29 log10 CFU/ml with the highest obtained in the spring. The Tsomo River Vibrio densities varied between 0 to 3.56 log10 CFU/ml and the maximum densities recorded during summer. The presumptive Vibrio densities in WW-AD and WW-CR WWTPs ranged from 0 to 3.67 log10 CFU/ml and 0 to 4.42 log10 CFU/ml with autumn and spring having the highest loads respectively. Molecular identification of the presumptive Vibrio species revealed 424 positive for the Vibrio genus. Of these, 21.69 percent, 11.79 percent, 8.25 percent and 2.12 percent were confirmed as V. cholerae, V. mimicus, V. parahaemolyticus and V. fluvialis respectively. The presence of potentially Vibrio pathogens in the rivers and treated effluents suggests potential public health threat to the communities relying on receiving watersheds where the effluents are discharged. Results of antibiotic sensitivity testing revealed high sensitivities against Ofloxacin (85.54 percent), Cefuroxime (81.93 percent), and Ciprofloxacin (74.70 percent), whereas resistance against other antibiotics follow this order: Imipenem (42.17 percent), Amoxicillin-Clavulanic Acid (54.17 percent), Ampicillin (63.54 percent), Nitrofurantoin (71.79 percent) and Polymyxin B (97.44 percent). Surprisingly, the resistance of Vibrio species against the known effective Carbapenems was relatively high (Meropenem (38.54 percent) and Imipenem (58.88 percent). Multiple antibiotic resistance phenotypes (MARP) of the isolates were resistant to two or more antibiotics whereas the calculated multiple antibiotic resistance index (MARI) ranged from 0.2 to 0.7. The observed high multiple antibiotics index suggest the recovered Vibrio pathogens are of high antimicrobial usage origin. Increase in antimicrobial resistance profiles towards conventionally used antibiotics as indicated in this study calls for adequate sanitation facilities and proper surveillance programs towards monitoring of antimicrobial resistance determinants in wastewater treatment effluents and receiving watersheds. This will in turn enhance early detection of resistant strains of public health importance, and supports the prompt notification and investigation of outbreaks. It further advocates the need for constant monitoring programme by the relevant regulatory agencies to ensure total compliance of the wastewater treatment facilities to the stipulated standards.
- Full Text:
- Date Issued: 2018
- Authors: Ayodeji, Onsula Charles
- Date: 2018
- Subjects: Sewage disposal plants Sewage -- Purification Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/10464 , vital:35478
- Description: Access to clean and safe water is essential for the survival of human beings. Nevertheless pollution from wastewater treatment plants (WWTPs) effluents often impacts the microbiological qualities of surface waters. Availability of freshwater resources is indispensable for preventing waterborne diseases. The current study evaluated the physicochemical properties and abundance of Vibrio species in selected rivers and WWTPs in the Eastern Cape Province of South Africa, over a one year sampling regime (December, 2016 to November, 2017). Water samples were collected monthly at designated locations along the banks of two rivers, treated effluents from 500 m upstream and downstream discharge points of two WWTPs and examined for physicochemical qualities, prevalence of Vibrio pathogens and their antibiogram profiles using both cultural and molecular techniques. The findings reveal the qualities of Tsomo and Great Fish river qualities with respect to electrical conductivity (EC) (137.75 – 377.69 mg/l), total suspended solids (TSS) (52.00 – 725.19 mg/l) and temperature (12.7 – 23 oC) and the treated effluents of WW-AD and WW-CR WWTPs with respect to EC (525.73 – 1071.89 mg/l), free chlorine (0.00 mg/l – 0.68 mg/l), temperature (12.4 – 28.8 oC), TSS (14.67 – 276.44 mg/l) exceeds the permissible limits set for effluent discharged to freshwater by South Africa guidelines. Other physicochemical qualities such as turbidity (63.11 – 797.17 NTU), BOD (3.30 – 5.26 mg/l) and TDS (68.88 – 148.14 mg/l) for Tsomo and Great Fish river and turbidity (20.33 – 310 NTU), biological oxygen demand (BOD) (1.28 – 4.96 mg/l), and total dissolve solid (TDS) (262.89 – 534.89 mg/l) for WWTPs WW-AD and WW-CR did not comply with WHO and EU standards as no regulation is set for them in the South African guidelines for domestic water usage. Statistical analysis revealed that pH, electrical conductivities, dissolved oxygen and total dissolved solid were significantly different whereas temperature did not differ significantly with respect to the four seasons (P < 0.05). The Vibrio densities for Great Fish river ranged between 0 and 3.29 log10 CFU/ml with the highest obtained in the spring. The Tsomo River Vibrio densities varied between 0 to 3.56 log10 CFU/ml and the maximum densities recorded during summer. The presumptive Vibrio densities in WW-AD and WW-CR WWTPs ranged from 0 to 3.67 log10 CFU/ml and 0 to 4.42 log10 CFU/ml with autumn and spring having the highest loads respectively. Molecular identification of the presumptive Vibrio species revealed 424 positive for the Vibrio genus. Of these, 21.69 percent, 11.79 percent, 8.25 percent and 2.12 percent were confirmed as V. cholerae, V. mimicus, V. parahaemolyticus and V. fluvialis respectively. The presence of potentially Vibrio pathogens in the rivers and treated effluents suggests potential public health threat to the communities relying on receiving watersheds where the effluents are discharged. Results of antibiotic sensitivity testing revealed high sensitivities against Ofloxacin (85.54 percent), Cefuroxime (81.93 percent), and Ciprofloxacin (74.70 percent), whereas resistance against other antibiotics follow this order: Imipenem (42.17 percent), Amoxicillin-Clavulanic Acid (54.17 percent), Ampicillin (63.54 percent), Nitrofurantoin (71.79 percent) and Polymyxin B (97.44 percent). Surprisingly, the resistance of Vibrio species against the known effective Carbapenems was relatively high (Meropenem (38.54 percent) and Imipenem (58.88 percent). Multiple antibiotic resistance phenotypes (MARP) of the isolates were resistant to two or more antibiotics whereas the calculated multiple antibiotic resistance index (MARI) ranged from 0.2 to 0.7. The observed high multiple antibiotics index suggest the recovered Vibrio pathogens are of high antimicrobial usage origin. Increase in antimicrobial resistance profiles towards conventionally used antibiotics as indicated in this study calls for adequate sanitation facilities and proper surveillance programs towards monitoring of antimicrobial resistance determinants in wastewater treatment effluents and receiving watersheds. This will in turn enhance early detection of resistant strains of public health importance, and supports the prompt notification and investigation of outbreaks. It further advocates the need for constant monitoring programme by the relevant regulatory agencies to ensure total compliance of the wastewater treatment facilities to the stipulated standards.
- Full Text:
- Date Issued: 2018
Molecular studies on cholera and non-cholera causing vibrio pathogens isolated from some water resources and aquatic animals in Eastern Cape Province, South Africa
- Authors: Abioye, Oluwatayo Emmanuel
- Date: 2018
- Subjects: Vibrio cholerae -- Pathogens Vibrio cholerae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9154 , vital:34283
- Description: The global socioeconomic and disease burdens of cholera; a disease caused by Vibrio cholerae have been ongoing since it was first reported in India in 1563. Unfortunately, emerging non-cholera causing Vibrio pathogens have been contributing to the malady of Vibrio genus globally in the recent years. The history of cholera outbreaks in South Africa have been well documented but information regarding other non-cholera Vibrio pathogens, is deficient in the literature. This study evaluated the statuses of aquatic animals including crustaceans, molluscs, and fish as important reservoirs of six key pathogenic Vibrio spp. in some important water resources and fish markets in the Eastern Cape, South Africa, between December 2016 and November 2017. Physiochemical parameters that are vital for water quality assessment were determined for all the water sampling points using standard methods. The parameters include pH, electrical conductivity (EC), total dissolved solids (TDS), salinity, temperature, total dissolved solids, turbidity and biological oxygen demand (BOD5). Vibrio spp. densities in water and aquatic animal samples were determined using membrane filtration and Most Probable NumberPolymerase chain reaction (MPN-PCR) methods respectively. Presumptive Vibrio spp. were recovered from the samples by direct plating of water samples and aliquots of aquatic animal homogenates on thiosulfate-citrate-bile salts-sucrose (TCBS) agar. Where necessary, samples were enriched using alkaline peptone water (APW) for optimum isolation of the targeted Vibrio spp. Presumptive isolates were identified and delineated into the six targeted pathogenic Vibrio spp. using PCR method. The antibiogram fingerprint of selected Vibrio spp. against a panel 18 panels of antibacterial agents were also carried out. Multiple antibiotic resistance phenotypes (MARPs) per set of isolates from water sampling sites and aquatic animal types were determined. Finally, multiple antibiotic resistance indices (MARI) for isolates recovered from the samples were determined. All experiments were done in replicate and data compared using one-way analysis of variance and one-tail t-test as appropriate. Correlation and regression analysis were also carried out as appropriate. Uncontrolled agricultural, industrial and domestic wastewater influxes, as well as run-off intrusions into the water resources investigated, were observed throughout the sampling season. The physicochemical qualities of the water resources varied with seasons. While pH observed for all the water sampling sites complied with South Africa and international standards, most sampling sites did not comply with set standards for one or more of the remaining physicochemical parameters. The parameters that frequently exhibited significant correlation and regression with Vibrio spp. densities were TDS, TSS, turbidity and temperature. The densities of Vibrio spp. in the samples studied varied with season and the highest density per sample types were observed in the summer. The prevalence of Vibrio spp. in freshwater, brackish water and aquatic animal samples were 79 percent, 78 percent and 86 percent respectively. The respective prevalence of V. cholerae, V. mimicus, V. fluvialis, V.alginolyticus, V. vulnificus and V. parahaemolyticus in freshwater samples (18 percent, 3 percent, ~1 percent, ~1 percent, <1 percent, < percent), brackish water(12 percent, 3 percent, 28 percent,~1 percent, ~1 percent, 9 percent) and aquatic animals (9 percent, 1 percent, 17 percent, 1 percent, 1 percent, 17 percent) were observed. All isolates from all the sample types showed very high antibiotic resistance against ampicillin and polymyxin B. Furthermore, MARPs were observed among isolates from the three sample types. Multiple antibiotic resistance indices (MARI) above 0.2 was observed at one site on Kowie River, three on Kubusi River and one on Buffalo River. The findings of this study suggest that most South Africa water-bodies especially freshwater resources are not well protected. This need to be addressed in a country like South Africa where availability of the freshwater resource for human activities is a critical issue. Base on the prevalence of pathogenic Vibrio spp. especially MARPs and sites that exhibited above 0.2 threshold for MARI, environmental base Vibrio species monitoring programs are recommended.
- Full Text:
- Date Issued: 2018
- Authors: Abioye, Oluwatayo Emmanuel
- Date: 2018
- Subjects: Vibrio cholerae -- Pathogens Vibrio cholerae
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9154 , vital:34283
- Description: The global socioeconomic and disease burdens of cholera; a disease caused by Vibrio cholerae have been ongoing since it was first reported in India in 1563. Unfortunately, emerging non-cholera causing Vibrio pathogens have been contributing to the malady of Vibrio genus globally in the recent years. The history of cholera outbreaks in South Africa have been well documented but information regarding other non-cholera Vibrio pathogens, is deficient in the literature. This study evaluated the statuses of aquatic animals including crustaceans, molluscs, and fish as important reservoirs of six key pathogenic Vibrio spp. in some important water resources and fish markets in the Eastern Cape, South Africa, between December 2016 and November 2017. Physiochemical parameters that are vital for water quality assessment were determined for all the water sampling points using standard methods. The parameters include pH, electrical conductivity (EC), total dissolved solids (TDS), salinity, temperature, total dissolved solids, turbidity and biological oxygen demand (BOD5). Vibrio spp. densities in water and aquatic animal samples were determined using membrane filtration and Most Probable NumberPolymerase chain reaction (MPN-PCR) methods respectively. Presumptive Vibrio spp. were recovered from the samples by direct plating of water samples and aliquots of aquatic animal homogenates on thiosulfate-citrate-bile salts-sucrose (TCBS) agar. Where necessary, samples were enriched using alkaline peptone water (APW) for optimum isolation of the targeted Vibrio spp. Presumptive isolates were identified and delineated into the six targeted pathogenic Vibrio spp. using PCR method. The antibiogram fingerprint of selected Vibrio spp. against a panel 18 panels of antibacterial agents were also carried out. Multiple antibiotic resistance phenotypes (MARPs) per set of isolates from water sampling sites and aquatic animal types were determined. Finally, multiple antibiotic resistance indices (MARI) for isolates recovered from the samples were determined. All experiments were done in replicate and data compared using one-way analysis of variance and one-tail t-test as appropriate. Correlation and regression analysis were also carried out as appropriate. Uncontrolled agricultural, industrial and domestic wastewater influxes, as well as run-off intrusions into the water resources investigated, were observed throughout the sampling season. The physicochemical qualities of the water resources varied with seasons. While pH observed for all the water sampling sites complied with South Africa and international standards, most sampling sites did not comply with set standards for one or more of the remaining physicochemical parameters. The parameters that frequently exhibited significant correlation and regression with Vibrio spp. densities were TDS, TSS, turbidity and temperature. The densities of Vibrio spp. in the samples studied varied with season and the highest density per sample types were observed in the summer. The prevalence of Vibrio spp. in freshwater, brackish water and aquatic animal samples were 79 percent, 78 percent and 86 percent respectively. The respective prevalence of V. cholerae, V. mimicus, V. fluvialis, V.alginolyticus, V. vulnificus and V. parahaemolyticus in freshwater samples (18 percent, 3 percent, ~1 percent, ~1 percent, <1 percent, < percent), brackish water(12 percent, 3 percent, 28 percent,~1 percent, ~1 percent, 9 percent) and aquatic animals (9 percent, 1 percent, 17 percent, 1 percent, 1 percent, 17 percent) were observed. All isolates from all the sample types showed very high antibiotic resistance against ampicillin and polymyxin B. Furthermore, MARPs were observed among isolates from the three sample types. Multiple antibiotic resistance indices (MARI) above 0.2 was observed at one site on Kowie River, three on Kubusi River and one on Buffalo River. The findings of this study suggest that most South Africa water-bodies especially freshwater resources are not well protected. This need to be addressed in a country like South Africa where availability of the freshwater resource for human activities is a critical issue. Base on the prevalence of pathogenic Vibrio spp. especially MARPs and sites that exhibited above 0.2 threshold for MARI, environmental base Vibrio species monitoring programs are recommended.
- Full Text:
- Date Issued: 2018
Molecularly imprinted polymeric materials for adsorptive removal of nitrogen compounds from fuel oils
- Abdul-Quadir, Muhammad Sabiu
- Authors: Abdul-Quadir, Muhammad Sabiu
- Date: 2018
- Subjects: Polymerization , Organonitrogen compounds Nitrogen compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23426 , vital:30542
- Description: The deleterious effects of refractory polyaromatic hydrocarbons found in fuels such as organonitrogen compounds (quinoline, carbazole and its alkylated derivatives) are such that they emit NOx to the environment when combusted, thereby reducing air quality. These compounds also deactivate the catalyst used during fuel refinement and in catalytic converters of cars. Hydro-denitrogenation (HDN), a process currently being employed in petroleum refineries to eliminate organonitrogen compounds in fuels, is limited in treating these refractory compounds. Hence, this thesis describes the use of two separate complimentary approaches for the removal of organonitrogen compounds in fuel such as oxidative denitrogenation and adsorptive denitrogenation. The catalyzed oxidation of fuel oil model nitrogen containing compound, quinoline to quinoline N-oxide, was conducted under batch and continuous flow microreactor at 70°C by using tert-butylhydroperoxide (t-BuOOH) as oxidant and silica supported V2O5 as catalyst, followed by the selective adsorption of the quinoline N-oxide. An overall conversion of 62% quinoline N-oxide was observed. Quinoline-N-oxide in model fuel was absorbed by employing synthesized molecularly imprinted 2,6-pyridine-polybenzimidazole (2,6-PyPBI) nanofibers, 86% of quinoline-N-oxide was removed to give an adsorption capacity (qe) of 4.8 mg/g. DFT calculations to study the interactions of quinoline-N-oxide vs 2,6-PyPBI indicated that: (i) hydrogen bonding (through amino group of 2,6-PyPBI and oxygen atoms of the quinoline-N-oxide), (ii) pi-pi stacking and (iii) extensive number of van der Waals interactions took place. Several oxygenates from N-compounds were produced, thus, complicating the fuel matrix. Therefore, there is a need to move towards adsorptive denitrogenation. Poly-2-(1H-imidazol-2-yl)-4-phenol (PIMH) imprinted microspheres was prepared by suspension polymerization using 2-(2’-hydroxy-4-ethenylphenyl) imidazole as a functional monomer and ethylene glycol dimethacrylate as a crosslinker in the presence of various organonitrogen compounds (templates) to produce 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH). Imprinted microspheres show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 6.8 ± 0.2 mg/g, 6.3 ± 0.3 mg/g and 5.8 ± 0.3 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of quinoline (αi-r = 136.9) ˃ pyrimidine (αi-r = 126.2) ˃carbazole (αi-r = 86.3), when naphthalene was selected as a reference compound. Though, imprinted microspheres displayed excellent nitrogen compound removal both in model and real fuel, there was a need to improve the adsorbent adsorption capacity for N-compounds in fuel through the fabrication of imprinted nanofibers. Molecularly imprinted poly-2-(1H-imidazol-2-yl)-4-phenol nanofibers was prepared by electrospinning of 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH) in the presence of various organonitrogen compounds. These imprinted nanofibers show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 11.7 ± 0.9 mg/g, 11.9 ± 0.8 mg/g and 11.3 ± 1.1 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 258.8) ˃ quinoline (αi-r = 235.5) ˃ carbazole (αi-r = 168.2). It further displayed excellent nitrogen removal in real fuel. The use of polybenzimidazole (PBI) nanofibers showed selective adsorption of organonitrogen compounds as imprinted sorbent also displayed high selectivity for their target model nitrogen-containing compounds with adsorption capacities of 11.4 ± 0.4 mg/g, 11.9 ± 0.2 mg/g and 10.9 ± 0.7 mg/g for quinoline, pyrimidine and carbazole respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 241.5) ˃ quinoline (αi-r = 237.6) ˃ carbazole (αi-r = 170). Thermodynamic parameters obtained from isothermal titration calorimetry (ITC) revealed that quinoline-PIMH/PBI and pyrimidine-PIMH/PBI interactions are exothermic in nature, while carbazole-PIMH/PBI is endothermic in nature. DFT calculations indicated that π-π interactions/stacking and hydrogen bond interactions took place between N-compounds (carbazole, quinoline and pyrimidine) and adsorbent (PIMH and PBI). A significant reduction in the quantity of nitrogen containing compounds in hydrotreated fuel was observed (peak area reduction) when adsorbents (PIMH and PBI) was employed, however, the complex nature of organonitrogen compounds in fuel complicate the structure/function approach on MIPs for targeting these unwanted compounds.
- Full Text:
- Date Issued: 2018
- Authors: Abdul-Quadir, Muhammad Sabiu
- Date: 2018
- Subjects: Polymerization , Organonitrogen compounds Nitrogen compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23426 , vital:30542
- Description: The deleterious effects of refractory polyaromatic hydrocarbons found in fuels such as organonitrogen compounds (quinoline, carbazole and its alkylated derivatives) are such that they emit NOx to the environment when combusted, thereby reducing air quality. These compounds also deactivate the catalyst used during fuel refinement and in catalytic converters of cars. Hydro-denitrogenation (HDN), a process currently being employed in petroleum refineries to eliminate organonitrogen compounds in fuels, is limited in treating these refractory compounds. Hence, this thesis describes the use of two separate complimentary approaches for the removal of organonitrogen compounds in fuel such as oxidative denitrogenation and adsorptive denitrogenation. The catalyzed oxidation of fuel oil model nitrogen containing compound, quinoline to quinoline N-oxide, was conducted under batch and continuous flow microreactor at 70°C by using tert-butylhydroperoxide (t-BuOOH) as oxidant and silica supported V2O5 as catalyst, followed by the selective adsorption of the quinoline N-oxide. An overall conversion of 62% quinoline N-oxide was observed. Quinoline-N-oxide in model fuel was absorbed by employing synthesized molecularly imprinted 2,6-pyridine-polybenzimidazole (2,6-PyPBI) nanofibers, 86% of quinoline-N-oxide was removed to give an adsorption capacity (qe) of 4.8 mg/g. DFT calculations to study the interactions of quinoline-N-oxide vs 2,6-PyPBI indicated that: (i) hydrogen bonding (through amino group of 2,6-PyPBI and oxygen atoms of the quinoline-N-oxide), (ii) pi-pi stacking and (iii) extensive number of van der Waals interactions took place. Several oxygenates from N-compounds were produced, thus, complicating the fuel matrix. Therefore, there is a need to move towards adsorptive denitrogenation. Poly-2-(1H-imidazol-2-yl)-4-phenol (PIMH) imprinted microspheres was prepared by suspension polymerization using 2-(2’-hydroxy-4-ethenylphenyl) imidazole as a functional monomer and ethylene glycol dimethacrylate as a crosslinker in the presence of various organonitrogen compounds (templates) to produce 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH). Imprinted microspheres show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 6.8 ± 0.2 mg/g, 6.3 ± 0.3 mg/g and 5.8 ± 0.3 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of quinoline (αi-r = 136.9) ˃ pyrimidine (αi-r = 126.2) ˃carbazole (αi-r = 86.3), when naphthalene was selected as a reference compound. Though, imprinted microspheres displayed excellent nitrogen compound removal both in model and real fuel, there was a need to improve the adsorbent adsorption capacity for N-compounds in fuel through the fabrication of imprinted nanofibers. Molecularly imprinted poly-2-(1H-imidazol-2-yl)-4-phenol nanofibers was prepared by electrospinning of 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH) in the presence of various organonitrogen compounds. These imprinted nanofibers show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 11.7 ± 0.9 mg/g, 11.9 ± 0.8 mg/g and 11.3 ± 1.1 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 258.8) ˃ quinoline (αi-r = 235.5) ˃ carbazole (αi-r = 168.2). It further displayed excellent nitrogen removal in real fuel. The use of polybenzimidazole (PBI) nanofibers showed selective adsorption of organonitrogen compounds as imprinted sorbent also displayed high selectivity for their target model nitrogen-containing compounds with adsorption capacities of 11.4 ± 0.4 mg/g, 11.9 ± 0.2 mg/g and 10.9 ± 0.7 mg/g for quinoline, pyrimidine and carbazole respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 241.5) ˃ quinoline (αi-r = 237.6) ˃ carbazole (αi-r = 170). Thermodynamic parameters obtained from isothermal titration calorimetry (ITC) revealed that quinoline-PIMH/PBI and pyrimidine-PIMH/PBI interactions are exothermic in nature, while carbazole-PIMH/PBI is endothermic in nature. DFT calculations indicated that π-π interactions/stacking and hydrogen bond interactions took place between N-compounds (carbazole, quinoline and pyrimidine) and adsorbent (PIMH and PBI). A significant reduction in the quantity of nitrogen containing compounds in hydrotreated fuel was observed (peak area reduction) when adsorbents (PIMH and PBI) was employed, however, the complex nature of organonitrogen compounds in fuel complicate the structure/function approach on MIPs for targeting these unwanted compounds.
- Full Text:
- Date Issued: 2018
Monetary policy and microfinance in Sub-Sahara Africa: Ghana’s perspective
- Authors: Wiredu, Nana Kwame
- Date: 2018
- Subjects: Monetary policy -- Ghana , Microfinance -- Ghana Ghana -- Economic policy
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/36037 , vital:33884
- Description: Ghana, like many other developing countries in Sub-Sahara Africa, recognises the important role that the micro, small and medium-sized enterprises (MSMEs) play in economic development. These enterprises need an environment conducive to thriving and growth, to contribute to employment and overall output. A key pillar to this is access to affordable credit. Credit in itself is thought to be affected by monetary policy formulated and put forth by the central bank, on behalf of government. The pass-through effect of monetary policy on commercial banking rates, as charged by bank and non-bank financial institutions (NBFIs), is a concern for MSMEs. Therefore, this study sought to highlight cause and effects relationship between monetary policy, the lending rate and private sector credit, and also sought to find a possible cushion for MSMEs through the microfinance targeting approach. Annual aggregate monetary time series data from the Bank of Ghana (BoG) was analysed. Multiple linear regression and analysis of variance test results reveal evidence of a significant and proportional effect of both the monetary policy rate and commercial banking rate on credit to the private sector. The key implication of the findings is that the pass-through effect of monetary policy negatively affects MSMEs. The study recommends that governments in Sub-Sahara Africa (SSA), and particularly the government of Ghana, should take into consideration the effects of monetary policy on MSMEs, when formulating monetary policies. It is also recommended that governments in SSA should formulate policies that enhance MSMEs access to adequate and affordable credit to enable it contribute more to economic growth. Perhaps, this can be done through microfinance.
- Full Text:
- Date Issued: 2018
- Authors: Wiredu, Nana Kwame
- Date: 2018
- Subjects: Monetary policy -- Ghana , Microfinance -- Ghana Ghana -- Economic policy
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/36037 , vital:33884
- Description: Ghana, like many other developing countries in Sub-Sahara Africa, recognises the important role that the micro, small and medium-sized enterprises (MSMEs) play in economic development. These enterprises need an environment conducive to thriving and growth, to contribute to employment and overall output. A key pillar to this is access to affordable credit. Credit in itself is thought to be affected by monetary policy formulated and put forth by the central bank, on behalf of government. The pass-through effect of monetary policy on commercial banking rates, as charged by bank and non-bank financial institutions (NBFIs), is a concern for MSMEs. Therefore, this study sought to highlight cause and effects relationship between monetary policy, the lending rate and private sector credit, and also sought to find a possible cushion for MSMEs through the microfinance targeting approach. Annual aggregate monetary time series data from the Bank of Ghana (BoG) was analysed. Multiple linear regression and analysis of variance test results reveal evidence of a significant and proportional effect of both the monetary policy rate and commercial banking rate on credit to the private sector. The key implication of the findings is that the pass-through effect of monetary policy negatively affects MSMEs. The study recommends that governments in Sub-Sahara Africa (SSA), and particularly the government of Ghana, should take into consideration the effects of monetary policy on MSMEs, when formulating monetary policies. It is also recommended that governments in SSA should formulate policies that enhance MSMEs access to adequate and affordable credit to enable it contribute more to economic growth. Perhaps, this can be done through microfinance.
- Full Text:
- Date Issued: 2018
Monetary policy credibility, exchange rate pass through and inflation in South Africa
- Authors: Bom, Sandisiwe Abongile
- Date: 2018
- Subjects: Foreign exchange rates -- South Africa Monetary policy -- South Africa
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/13303 , vital:39632
- Description: The South African Reserve Bank (SARB) implemented inflation targeting as a monetary policy framework in 2000 with the aim of achieving low and stable price associated with economic growth. However, the period in which the framework was implemented is characterised by periods of price instability and low economic growth. This contradicts the view of different views in the literature that indicates that inflation targeting ensures low inflation rates. The purpose of the current study was to investigate the nexus between monetary policy credibility, exchange rate pass-through and inflation in South Africa. The study employed the Johansen co-integration test, Vector error correction modelling (VECM) techniques, impulse response and variance decomposition for the period from 2000 to 2017 using quarterly data. The Johansen cointegration indicated that there was a long-term relationship between the variables of interest. The VECM was estimated together with the impulse response and variance decomposition. The empirical results indicated that the variables utilised in the study are positively related. Impulse response functions also proved that in the long run, changes in consumer prices are a result of fluctuations in oil prices and the repo rate. It is evident that consumer prices (inflation) are positively related to changes in exchange rates and monetary policy credibility. Thus, the study recommends that changes in the exchange rate must be considered when implementing the monetary policy as the prices move in the same direction as changes in the NEER. Further, the lack of monetary policy credibility seems to be an issue for monetary authorities as there is supposed to be an inverse relationship among the CPI and MPCRED, which is opposed by the study. Additionally, the results also indicate that the repo rate is positively related to the consumer price and this opposes previous literature. Thus, recommending that the SARB needs to evaluate the monetary policy or the inflation targeting framework to ensure they achieve credibility
- Full Text:
- Date Issued: 2018
- Authors: Bom, Sandisiwe Abongile
- Date: 2018
- Subjects: Foreign exchange rates -- South Africa Monetary policy -- South Africa
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/13303 , vital:39632
- Description: The South African Reserve Bank (SARB) implemented inflation targeting as a monetary policy framework in 2000 with the aim of achieving low and stable price associated with economic growth. However, the period in which the framework was implemented is characterised by periods of price instability and low economic growth. This contradicts the view of different views in the literature that indicates that inflation targeting ensures low inflation rates. The purpose of the current study was to investigate the nexus between monetary policy credibility, exchange rate pass-through and inflation in South Africa. The study employed the Johansen co-integration test, Vector error correction modelling (VECM) techniques, impulse response and variance decomposition for the period from 2000 to 2017 using quarterly data. The Johansen cointegration indicated that there was a long-term relationship between the variables of interest. The VECM was estimated together with the impulse response and variance decomposition. The empirical results indicated that the variables utilised in the study are positively related. Impulse response functions also proved that in the long run, changes in consumer prices are a result of fluctuations in oil prices and the repo rate. It is evident that consumer prices (inflation) are positively related to changes in exchange rates and monetary policy credibility. Thus, the study recommends that changes in the exchange rate must be considered when implementing the monetary policy as the prices move in the same direction as changes in the NEER. Further, the lack of monetary policy credibility seems to be an issue for monetary authorities as there is supposed to be an inverse relationship among the CPI and MPCRED, which is opposed by the study. Additionally, the results also indicate that the repo rate is positively related to the consumer price and this opposes previous literature. Thus, recommending that the SARB needs to evaluate the monetary policy or the inflation targeting framework to ensure they achieve credibility
- Full Text:
- Date Issued: 2018
Moral individualism in South African emerging adults
- Authors: Geddie, Alison Sarah
- Date: 2018
- Subjects: Moral development -- South Africa , Corporate culture -- South Africa -- Psychological aspects Business ethics -- South Africa Young adults -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/22145 , vital:29854
- Description: The intention of this study was to explore moral individualism in South African emerging adults. This was done by examining emerging adults’ ability to identify moral issue, the propensity for moral individualism among emerging adults, identifying moral individualism’s impact on emerging adult’s moral judgments of others and exploring future implications of moral individualism for organisations. This was a qualitative study and data was obtained by conducting focus group discussions. Four focus groups of five to seven people were conducted. Twenty participants participated in total and these groups were conducted until data saturation was reached. These focus groups consisted of prospective professionals studying towards a qualification. There individuals were between the ages of eighteen and twenty-three. Data collected from these focus groups was analysed using thematic analysis. The findings of this study suggest that, although participants exhibit elements of moral individualism, many of their views, specifically views on moral judgements of others, do not align with the framework presented by moral individualism. This suggests that although individual moral frameworks play a role in how individuals interact with organisations, this is not done from a moral individualist frame work.
- Full Text:
- Date Issued: 2018
- Authors: Geddie, Alison Sarah
- Date: 2018
- Subjects: Moral development -- South Africa , Corporate culture -- South Africa -- Psychological aspects Business ethics -- South Africa Young adults -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/22145 , vital:29854
- Description: The intention of this study was to explore moral individualism in South African emerging adults. This was done by examining emerging adults’ ability to identify moral issue, the propensity for moral individualism among emerging adults, identifying moral individualism’s impact on emerging adult’s moral judgments of others and exploring future implications of moral individualism for organisations. This was a qualitative study and data was obtained by conducting focus group discussions. Four focus groups of five to seven people were conducted. Twenty participants participated in total and these groups were conducted until data saturation was reached. These focus groups consisted of prospective professionals studying towards a qualification. There individuals were between the ages of eighteen and twenty-three. Data collected from these focus groups was analysed using thematic analysis. The findings of this study suggest that, although participants exhibit elements of moral individualism, many of their views, specifically views on moral judgements of others, do not align with the framework presented by moral individualism. This suggests that although individual moral frameworks play a role in how individuals interact with organisations, this is not done from a moral individualist frame work.
- Full Text:
- Date Issued: 2018
More than just fields: Reframing deagrarianisation in landscapes and livelihoods
- Hebinck, Paul, Mtati, Nosiseko, Shackleton, Charlie M
- Authors: Hebinck, Paul , Mtati, Nosiseko , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180322 , vital:43353 , xlink:href="https://doi.org/10.1016/j.jrurstud.2018.01.004"
- Description: This paper discusses the emergent properties of deagrarianisation processes in two villages in the central Eastern Cape, South Africa. The claim of is that much of the deagrarianisation literature and debate does not acknowledge the importance of landscapes and the interaction between their constituent elements, notably people, forests, grasslands, fields, grazing lands, open spaces, built environments and homesteads, all of which contribute to shaping and, in turn, are shaped by livelihoods. Conceptualising a landscape as a spatial entity and associated assemblage of practices, discourses and history, this paper dissects the landscape in terms of land uses for residential and cultural purposes, growing, grazing and gathering. These land use categories together represent the rural domain to which the villagers are attached as a place and a home. Their use of the land is not necessarily oriented to fully exploring its productive potential. The article explores the transformation from a productive landscape to one which largely hinges on consumption. The blurring of boundaries between the formally designated land use categories signifies the transformations occurring in many of the rural areas in the former homelands of South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Hebinck, Paul , Mtati, Nosiseko , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180322 , vital:43353 , xlink:href="https://doi.org/10.1016/j.jrurstud.2018.01.004"
- Description: This paper discusses the emergent properties of deagrarianisation processes in two villages in the central Eastern Cape, South Africa. The claim of is that much of the deagrarianisation literature and debate does not acknowledge the importance of landscapes and the interaction between their constituent elements, notably people, forests, grasslands, fields, grazing lands, open spaces, built environments and homesteads, all of which contribute to shaping and, in turn, are shaped by livelihoods. Conceptualising a landscape as a spatial entity and associated assemblage of practices, discourses and history, this paper dissects the landscape in terms of land uses for residential and cultural purposes, growing, grazing and gathering. These land use categories together represent the rural domain to which the villagers are attached as a place and a home. Their use of the land is not necessarily oriented to fully exploring its productive potential. The article explores the transformation from a productive landscape to one which largely hinges on consumption. The blurring of boundaries between the formally designated land use categories signifies the transformations occurring in many of the rural areas in the former homelands of South Africa.
- Full Text:
- Date Issued: 2018
Morphological and genetic variation of Gymnothorax undulatus (Anguilliformes: Muraenidae) in the Western Indian Ocean
- Authors: Sithole, Yonela
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63722 , vital:28476
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Sithole, Yonela
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63722 , vital:28476
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
Morphological and symbiotic root modifications for mineral acquisition from nutrient-poor soils
- Kleinert, Aleysia, Benedito, V A, Morcillo, R J L, Dames, Joanna F, Cornejo-Rivas, P, Zuniga-Feest, A, Delgado, Mabel, Muñoz, Gaston
- Authors: Kleinert, Aleysia , Benedito, V A , Morcillo, R J L , Dames, Joanna F , Cornejo-Rivas, P , Zuniga-Feest, A , Delgado, Mabel , Muñoz, Gaston
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448640 , vital:74748 , https://doi.org/10.1007/978-3-319-75910-4_4
- Description: Plants have the ability to form vast root systems with lengths measuring up to several kilometers and branch roots numbering in millions. These expansive root systems provide plants with a large surface area for water and nutrient uptake from the surrounding soil. Roots also have further equally important functions to fulfil such as vegetative reproduction, hormone biosynthesis, photoassimilate storage, and the establishment of symbiotic relationships with microorganisms. Root systems have evolved several adaptations to aid them in maximizing nutrient uptake. These adaptations can be morphological such as changes in the root architecture or formation of cluster roots or may be symbiotic associations with mycorrhizae or nitrogen-fixing bacteria. Improvement of nutrient acquisition and use by plants is imperative for economic, humanitarian, and environmental reasons, and a better understanding of the processes governing root adaptations would enable us to adapt fertilizer and pesticide programs. In this chapter, we will focus on both morphological (cluster roots) and symbiotic root adaptations (associations with ectomycorrhizae, arbuscular mycorrhizae, and nitrogen-fixing bacteria) to soil nutrient deficiencies.
- Full Text:
- Date Issued: 2018
- Authors: Kleinert, Aleysia , Benedito, V A , Morcillo, R J L , Dames, Joanna F , Cornejo-Rivas, P , Zuniga-Feest, A , Delgado, Mabel , Muñoz, Gaston
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448640 , vital:74748 , https://doi.org/10.1007/978-3-319-75910-4_4
- Description: Plants have the ability to form vast root systems with lengths measuring up to several kilometers and branch roots numbering in millions. These expansive root systems provide plants with a large surface area for water and nutrient uptake from the surrounding soil. Roots also have further equally important functions to fulfil such as vegetative reproduction, hormone biosynthesis, photoassimilate storage, and the establishment of symbiotic relationships with microorganisms. Root systems have evolved several adaptations to aid them in maximizing nutrient uptake. These adaptations can be morphological such as changes in the root architecture or formation of cluster roots or may be symbiotic associations with mycorrhizae or nitrogen-fixing bacteria. Improvement of nutrient acquisition and use by plants is imperative for economic, humanitarian, and environmental reasons, and a better understanding of the processes governing root adaptations would enable us to adapt fertilizer and pesticide programs. In this chapter, we will focus on both morphological (cluster roots) and symbiotic root adaptations (associations with ectomycorrhizae, arbuscular mycorrhizae, and nitrogen-fixing bacteria) to soil nutrient deficiencies.
- Full Text:
- Date Issued: 2018
Morphological, genetic and biological characterisation of a novel alphabaculovirus isolated from Cryptophlebia peltastica (Lepidoptera: Tortricidae)
- Marsberg, Tamryn, Jukes, Michael, Krejmer-Rabalska, Martyna, Rabalski, Lukasz, Knox, Caroline M, Moore, Sean D, Hill, Martin P, Szewczyk, Boguslaw
- Authors: Marsberg, Tamryn , Jukes, Michael , Krejmer-Rabalska, Martyna , Rabalski, Lukasz , Knox, Caroline M , Moore, Sean D , Hill, Martin P , Szewczyk, Boguslaw
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419330 , vital:71635 , xlink:href="https://doi.org/10.1016/j.jip.2018.08.006"
- Description: Cryptophlebia peltastica is an agricultural pest of litchis and macadamias in South Africa with phytosanitary status for certain markets. Current control methods rely on chemical, cultural and classical biological control. However, a microbial control option has not been developed. An Alphabaculovirus from C. peltastica was recovered from a laboratory reared colony and morphologically characterised by transmission electron microscopy (TEM). Analysis of occlusion bodies indicated a single NPV (SNPV) varying in size from 421 to 1263 nm. PCR amplification and sequencing of the polh gene region using universal primers followed by BLAST analysis revealed a 93% similarity to a partial polh gene sequence from Epinotia granitalis NPV. Further genetic characterisation involving single restriction endonuclease (REN) digestion of genomic DNA was carried out to generate profiles for comparison against other baculovirus species and potential new isolates of the same virus. The complete genome of the virus was sequenced, assembled and analysed for a more comprehensive genetic analysis. The genome was 115 728 base pairs (bp) in length with a GC content of 37.2%. A total of 126 open reading frames (ORFs) were identified with minimal overlap and no preference in orientation. Bioassays were used to determine the virulence of the NPV against C. peltastica. The NPV was virulent against C. peltastica with an LC50 value of 6.46 × 103 OBs/ml and an LC90 value of 2.46 × 105 OBs/ml, and time mortality ranging between 76.32 h and 93.49 h. This is the first study to describe the isolation and genetic characterisation of a novel SNPV from C. peltastica, which has potential for development into a biopesticide for the control of this pest in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Marsberg, Tamryn , Jukes, Michael , Krejmer-Rabalska, Martyna , Rabalski, Lukasz , Knox, Caroline M , Moore, Sean D , Hill, Martin P , Szewczyk, Boguslaw
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419330 , vital:71635 , xlink:href="https://doi.org/10.1016/j.jip.2018.08.006"
- Description: Cryptophlebia peltastica is an agricultural pest of litchis and macadamias in South Africa with phytosanitary status for certain markets. Current control methods rely on chemical, cultural and classical biological control. However, a microbial control option has not been developed. An Alphabaculovirus from C. peltastica was recovered from a laboratory reared colony and morphologically characterised by transmission electron microscopy (TEM). Analysis of occlusion bodies indicated a single NPV (SNPV) varying in size from 421 to 1263 nm. PCR amplification and sequencing of the polh gene region using universal primers followed by BLAST analysis revealed a 93% similarity to a partial polh gene sequence from Epinotia granitalis NPV. Further genetic characterisation involving single restriction endonuclease (REN) digestion of genomic DNA was carried out to generate profiles for comparison against other baculovirus species and potential new isolates of the same virus. The complete genome of the virus was sequenced, assembled and analysed for a more comprehensive genetic analysis. The genome was 115 728 base pairs (bp) in length with a GC content of 37.2%. A total of 126 open reading frames (ORFs) were identified with minimal overlap and no preference in orientation. Bioassays were used to determine the virulence of the NPV against C. peltastica. The NPV was virulent against C. peltastica with an LC50 value of 6.46 × 103 OBs/ml and an LC90 value of 2.46 × 105 OBs/ml, and time mortality ranging between 76.32 h and 93.49 h. This is the first study to describe the isolation and genetic characterisation of a novel SNPV from C. peltastica, which has potential for development into a biopesticide for the control of this pest in South Africa.
- Full Text:
- Date Issued: 2018
Motherhood narratives by women who access support services from an Non-Governmental Organisation in East London
- Authors: Du Preez, Jaydene
- Date: 2018
- Subjects: Motherhood--South Africa Motherhood--Psychological aspects
- Language: English
- Type: Thesis , Masters , Counselling Psychology
- Identifier: http://hdl.handle.net/10353/16842 , vital:40778
- Description: Motherhood comes with little guidance or direction and the experience itself is often one that is saturated with mixed feelings and realities. Yet the ideologies and narratives that exist about the experience of motherhood often point to the idea that motherhood is a natural, easy and all-fulfilling position for a woman to have. Such contradictions between the thoughts and ideas about motherhood versus actual experiences of motherhood have resulted in a great deal of discomfort and difficulty for women. This is possibly as a result of the way in which motherhood has been studied in the past. But feminist, sociological and social psychological perspectives have sought to research the experiences of motherhood differently and in recent years through a growing interest in women-centred psychological research, there has been a shift in focus to the actual experiences of women as mothers. This research aims to be a continuing and contributing study of the experiences of mothers. Six mothers were interviewed through a semi-structured interviewing process. A narrative form of inquiry was used to facilitate the telling of the mothers’ stories. The aim of the research was to discover the experiences of motherhood by the mothers who made use of the services at a chosen NGO in East London. The findings suggest that the mothers experienced a number of contradictions between the dominant narratives of motherhood and their actual experiences. What also became evident was that many, if not all the mothers, were not as affected or concerned about these contradictions as mothers in other studies have been. It was thought that this was either a result of the personal characteristics of the mothers – their race, class and socioeconomic status (as suggested in other studies) or that the NGO itself was acting as a protective factor, allowing the mothers to fulfil their ideas about good mothering, thus contributing to their ideas and views of themselves, as mothers.
- Full Text:
- Date Issued: 2018
- Authors: Du Preez, Jaydene
- Date: 2018
- Subjects: Motherhood--South Africa Motherhood--Psychological aspects
- Language: English
- Type: Thesis , Masters , Counselling Psychology
- Identifier: http://hdl.handle.net/10353/16842 , vital:40778
- Description: Motherhood comes with little guidance or direction and the experience itself is often one that is saturated with mixed feelings and realities. Yet the ideologies and narratives that exist about the experience of motherhood often point to the idea that motherhood is a natural, easy and all-fulfilling position for a woman to have. Such contradictions between the thoughts and ideas about motherhood versus actual experiences of motherhood have resulted in a great deal of discomfort and difficulty for women. This is possibly as a result of the way in which motherhood has been studied in the past. But feminist, sociological and social psychological perspectives have sought to research the experiences of motherhood differently and in recent years through a growing interest in women-centred psychological research, there has been a shift in focus to the actual experiences of women as mothers. This research aims to be a continuing and contributing study of the experiences of mothers. Six mothers were interviewed through a semi-structured interviewing process. A narrative form of inquiry was used to facilitate the telling of the mothers’ stories. The aim of the research was to discover the experiences of motherhood by the mothers who made use of the services at a chosen NGO in East London. The findings suggest that the mothers experienced a number of contradictions between the dominant narratives of motherhood and their actual experiences. What also became evident was that many, if not all the mothers, were not as affected or concerned about these contradictions as mothers in other studies have been. It was thought that this was either a result of the personal characteristics of the mothers – their race, class and socioeconomic status (as suggested in other studies) or that the NGO itself was acting as a protective factor, allowing the mothers to fulfil their ideas about good mothering, thus contributing to their ideas and views of themselves, as mothers.
- Full Text:
- Date Issued: 2018
Motivation for landscape stewardship as a driver of change-Garden Route, South Africa
- Authors: Heider, Lisa
- Date: 2018
- Subjects: Social ecology , Environmental psychology Conservation (Psychology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30116 , vital:30826
- Description: Stewardship, as portrayed in much of contemporary literature is considered as a key to the sustainability challenges of the biosphere. In disciplines which regard sustainability in the context of Social Ecological Systems (SES), stewardship is associated with the goal of building resilience through the informal governance structures that dictate how the landscape is utilized. These disciplines lack a better integration of individual roles and responsibilities as they relate to their daily interactions with the environment. Formally initiated stewardship can evoke maladaptation, in other words the attempts to conserve a specific natural assets in one particular locality can shift the problem of degradation or exploitation to another place or point in time. This is because the individual, as an inevitable driver of unsustainability, has not been addressed. What is needed is the knowledge of strategies which resolve human disconnection from nature and the biosphere, through a greater focus on the individual motivational scale. In Chapter 2, which consists of a literature review of recent stewardship discourses, I extract alternative theories which consider individual motivation and subjectivity as the underlying drivers of resilience. These include knowledge about Sense of Place, and theories from Conservation Psychology. Basic Human Value theory is also presented as a possible entry point for societal transformation through individual motivation. These ought to inform conservation interventions with mechanisms which truly grasp unsustainability at its roots. This is a place-based, qualitative study where the results assist in interrogating the question: How does individual motivation for stewardship mediate socialecological trajectories of change? The context of the study and the methods used to generate my research findings are presented in Chapter 3 and 4. The Garden Route provides the place-based context for this research and is situated in the Western Cape Province of South Africa. The region is home to diverse cultures representative of Western and indigenous regions who meet and negotiate what it means to care for the environment. The area is biologically rich and ecologically highly sensitive to current trajectories of development, fragmentation and global change. Mixed methods and a qualitative approach was used to answer three sub-questions: (1) Which theories facilitate greater understanding of transformative stewardship pathways? (2) How can a transformative pathway be recognized? and (3) How can transformative pathways be pursued? One method used in this study is a photo-voice technique, which is coupled with self-directed journaling and in-depth interviews. Other sources of data include communication and engagement, observations iii and focus groups. I apply a content analysis to the transcribed qualitative data to resolve the research questions. Research results are presented in Chapter 5. In this empirical chapter I present three competing meanings of stewardship and visions for change held by individuals in the Garden Route. The three meanings are described as: protect nature from human influence (Nature despite People); work together and communicate (Nature for People/Nature and People); and be the change you want to see in this world (People in Nature). The variable which best describes the differences in visions is Critical Connectivity. Resilience in a SES is critically dependent on three levels of connectivity in stewardship. Firstly, individuals’ consciousness of being interrelated and interdependent within a community of life; Secondly, expressions in the physical landscape which promote the connectivity of ecological systems as well as the connectivity between people and nature. Thirdly, Connectedness with the Biosphere, which means that the boundaries of the planet and the functioning of the life-supporting earth system are considered in behaviours. I use Basic Human Value theory to test whether it can explain how the differences between and commonalities within the three groups arise. The results support the theory, suggesting that Basic Human Values underlie individual motivation for stewardship. However, inconsistencies and shortcomings of Basic Human Value theory became evident. I identified new values and value combinations which were not made explicit in the framework. These emerged due to my in-depth qualitative approach, as opposed to the common quantitative uses of the framework. The qualitative approach allows for values to emerge inductively and it elicits nuances of individual value interpretations that the definitions of Basic Human Values do not depict. In the second part of the empirical chapter, I present evidence of maladaptive and transformative stewardship pathways in the Garden Route. A maladaptive pathway is one in which individuals’ expression of care for the environment undermines Critical Connectivity and transfers vulnerabilities in the SES. A transformative pathway is one in which individuals pro-actively invest into Critical Connectivity and enhance resilience. The differences in these pathways are directly related to the differences in motivation. iv The findings of this research reveal that stewardship is the act of ‘place creation’ which is motivated by unique and nuanced differences in basic values and individual consciousness. Recognizable features of transformative and maladaptive stewardship pathways are discussed in Chapter 6. I present a conceptual model that critically evaluates stewardship. This model firstly assists researchers and practitioners to become alert to early warning signs of maladaptive pathways. Secondly, it informs them of potential leverage points for interventions which can induce sustainability transformations. I then apply this model to discuss transformative and maladaptive pathways against the backdrop of my findings and the literature. The elements which emerged as critical in this assessment are risk perceptions, stewardship meaning, connectivity with nature, connectedness with the biosphere, relationship with place, sustenance and identity. Different configurations of each indicator help explain the different pathways. Lastly, I discuss the role of Basic Human Values in each of the pathways. I compare how the motivational orientation towards self-enhancement and self-transcendence, or towards openness to change and conservation, play roles in SES resilience. This discussion brings to the surface the fact that transformative stewardship rests on a combination of these four value categories. In contrast, the absence of self-transcendent values and the presence of power, security and conformity underlie the motivation for maladaptation. I leave the reader with suggestions for interventions which have become relevant as a result of my study. Policy, media, conservation agencies and science shape meanings of stewardship, portray social norms and hence must motivate Critical Connectivity. Transformations can be achieved by targeting changes in values which must include autonomy, universalism, benevolence and spirituality. I discuss how policy and planning, communication, marketing and education can lever transformation through mechanisms identified in my research. Chapter 7 concludes this research with a reflective summary of the academic and practical contributions my study has made for stewardship discourses and for the management of SES resilience in local landscapes. I provide recommendations for further research, as they apply to socio-political change in Post-Apartheid South Africa. I end the concluding chapter by encapsulating my research finding in future scenarios for the Garden Route in the face of change, which namely relate to abrupt and uncertain environmental change, immigration, population growth and implications for spatial planning, and the Garden Route Biosphere Reserve. v In Chapter 8, I provide a reflection of this research. This entails foremost a reflection of how I have accounted for four quality criteria in social research, which are namely dependability, credibility, conformability and transferability. I end the chapter with the limitations and outline of scope of my study..
- Full Text:
- Date Issued: 2018
- Authors: Heider, Lisa
- Date: 2018
- Subjects: Social ecology , Environmental psychology Conservation (Psychology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30116 , vital:30826
- Description: Stewardship, as portrayed in much of contemporary literature is considered as a key to the sustainability challenges of the biosphere. In disciplines which regard sustainability in the context of Social Ecological Systems (SES), stewardship is associated with the goal of building resilience through the informal governance structures that dictate how the landscape is utilized. These disciplines lack a better integration of individual roles and responsibilities as they relate to their daily interactions with the environment. Formally initiated stewardship can evoke maladaptation, in other words the attempts to conserve a specific natural assets in one particular locality can shift the problem of degradation or exploitation to another place or point in time. This is because the individual, as an inevitable driver of unsustainability, has not been addressed. What is needed is the knowledge of strategies which resolve human disconnection from nature and the biosphere, through a greater focus on the individual motivational scale. In Chapter 2, which consists of a literature review of recent stewardship discourses, I extract alternative theories which consider individual motivation and subjectivity as the underlying drivers of resilience. These include knowledge about Sense of Place, and theories from Conservation Psychology. Basic Human Value theory is also presented as a possible entry point for societal transformation through individual motivation. These ought to inform conservation interventions with mechanisms which truly grasp unsustainability at its roots. This is a place-based, qualitative study where the results assist in interrogating the question: How does individual motivation for stewardship mediate socialecological trajectories of change? The context of the study and the methods used to generate my research findings are presented in Chapter 3 and 4. The Garden Route provides the place-based context for this research and is situated in the Western Cape Province of South Africa. The region is home to diverse cultures representative of Western and indigenous regions who meet and negotiate what it means to care for the environment. The area is biologically rich and ecologically highly sensitive to current trajectories of development, fragmentation and global change. Mixed methods and a qualitative approach was used to answer three sub-questions: (1) Which theories facilitate greater understanding of transformative stewardship pathways? (2) How can a transformative pathway be recognized? and (3) How can transformative pathways be pursued? One method used in this study is a photo-voice technique, which is coupled with self-directed journaling and in-depth interviews. Other sources of data include communication and engagement, observations iii and focus groups. I apply a content analysis to the transcribed qualitative data to resolve the research questions. Research results are presented in Chapter 5. In this empirical chapter I present three competing meanings of stewardship and visions for change held by individuals in the Garden Route. The three meanings are described as: protect nature from human influence (Nature despite People); work together and communicate (Nature for People/Nature and People); and be the change you want to see in this world (People in Nature). The variable which best describes the differences in visions is Critical Connectivity. Resilience in a SES is critically dependent on three levels of connectivity in stewardship. Firstly, individuals’ consciousness of being interrelated and interdependent within a community of life; Secondly, expressions in the physical landscape which promote the connectivity of ecological systems as well as the connectivity between people and nature. Thirdly, Connectedness with the Biosphere, which means that the boundaries of the planet and the functioning of the life-supporting earth system are considered in behaviours. I use Basic Human Value theory to test whether it can explain how the differences between and commonalities within the three groups arise. The results support the theory, suggesting that Basic Human Values underlie individual motivation for stewardship. However, inconsistencies and shortcomings of Basic Human Value theory became evident. I identified new values and value combinations which were not made explicit in the framework. These emerged due to my in-depth qualitative approach, as opposed to the common quantitative uses of the framework. The qualitative approach allows for values to emerge inductively and it elicits nuances of individual value interpretations that the definitions of Basic Human Values do not depict. In the second part of the empirical chapter, I present evidence of maladaptive and transformative stewardship pathways in the Garden Route. A maladaptive pathway is one in which individuals’ expression of care for the environment undermines Critical Connectivity and transfers vulnerabilities in the SES. A transformative pathway is one in which individuals pro-actively invest into Critical Connectivity and enhance resilience. The differences in these pathways are directly related to the differences in motivation. iv The findings of this research reveal that stewardship is the act of ‘place creation’ which is motivated by unique and nuanced differences in basic values and individual consciousness. Recognizable features of transformative and maladaptive stewardship pathways are discussed in Chapter 6. I present a conceptual model that critically evaluates stewardship. This model firstly assists researchers and practitioners to become alert to early warning signs of maladaptive pathways. Secondly, it informs them of potential leverage points for interventions which can induce sustainability transformations. I then apply this model to discuss transformative and maladaptive pathways against the backdrop of my findings and the literature. The elements which emerged as critical in this assessment are risk perceptions, stewardship meaning, connectivity with nature, connectedness with the biosphere, relationship with place, sustenance and identity. Different configurations of each indicator help explain the different pathways. Lastly, I discuss the role of Basic Human Values in each of the pathways. I compare how the motivational orientation towards self-enhancement and self-transcendence, or towards openness to change and conservation, play roles in SES resilience. This discussion brings to the surface the fact that transformative stewardship rests on a combination of these four value categories. In contrast, the absence of self-transcendent values and the presence of power, security and conformity underlie the motivation for maladaptation. I leave the reader with suggestions for interventions which have become relevant as a result of my study. Policy, media, conservation agencies and science shape meanings of stewardship, portray social norms and hence must motivate Critical Connectivity. Transformations can be achieved by targeting changes in values which must include autonomy, universalism, benevolence and spirituality. I discuss how policy and planning, communication, marketing and education can lever transformation through mechanisms identified in my research. Chapter 7 concludes this research with a reflective summary of the academic and practical contributions my study has made for stewardship discourses and for the management of SES resilience in local landscapes. I provide recommendations for further research, as they apply to socio-political change in Post-Apartheid South Africa. I end the concluding chapter by encapsulating my research finding in future scenarios for the Garden Route in the face of change, which namely relate to abrupt and uncertain environmental change, immigration, population growth and implications for spatial planning, and the Garden Route Biosphere Reserve. v In Chapter 8, I provide a reflection of this research. This entails foremost a reflection of how I have accounted for four quality criteria in social research, which are namely dependability, credibility, conformability and transferability. I end the chapter with the limitations and outline of scope of my study..
- Full Text:
- Date Issued: 2018
Motivation of construction workers in the nelson Mandela Bay Metropole, South Africa
- Jesumoroti, Christtestimony Oluwafemi
- Authors: Jesumoroti, Christtestimony Oluwafemi
- Date: 2018
- Subjects: Employee motivation -- South Africa -- Nelson Mandela Bay Municipality , Performance standards -- South Africa -- Nelson Mandela Bay Municipality Construction workers -- South Africa -- Nelson Mandela Bay Municipality Construction industry -- Employees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/30573 , vital:30962
- Description: The issue of construction workers’ motivation has become a subject of debate among construction project management professionals. Construction workers mostly work long hours in relatively disagreeable environments and, far from their families. Most of the activities are done under difficult conditions including harsh weather conditions, however, employees are required to be motivated towards ensuring the attractiveness of the industry to them. Moreover, there are diverse perceptions that the motivation of construction workers positively impacts construction workers performance or rather adversely affects the general performance of construction workers. Although, workers motivation has been proven to improve construction productivity globally, motivation of construction workers seems not to be effectively implemented in South African Construction Industry. As a result, it is difficult for management to identify motivational factors that affect workers productivity in a work environment. A quantitative research approach was employed to analyse the result obtained from a structured questionnaire survey. The research respondents included: bricklayers, plumbers, concrete workers, electricians, carpenters, and professionals. This study used data from primary source which focus on tradesman, labourer and professional context. A survey was conducted with tradesmen, labourers and professionals regarding motivation on construction workers which was conducted in the Nelson Mandela Bay Metropole, Eastern Cape. It was found that motivation is important to construction workers’ performance. Awarding bonuses to workers is important to improving workers’ efficiency and there is a need for construction workers recognition by management. Construction industry stakeholder should shift their attention and prioritise the motivation of its workers since the industry has a way of cubing poverty and uplifting the county’s economy. The findings revealed that motivational communication, rather than functional communication, would enhance worker productivity. It was found that both intrinsic and extrinsic rewards are needed to improve worker productivity. It was also found that positive reinforcement techniques, should be used to enhance worker productivity. The findings from this research study revealed that the motivational theories apply to construction workers, and management needs to apply these theories wisely to achieve improved productivity. The study therefore concludes that motivational techniques are necessary to improve construction workers productivity on a vii construction site. It is recommended that supervisors use motivational communication, extrinsic rewards, intrinsic rewards and positive reinforcement to motivate their workers to achieve higher levels of productivity.
- Full Text:
- Date Issued: 2018
- Authors: Jesumoroti, Christtestimony Oluwafemi
- Date: 2018
- Subjects: Employee motivation -- South Africa -- Nelson Mandela Bay Municipality , Performance standards -- South Africa -- Nelson Mandela Bay Municipality Construction workers -- South Africa -- Nelson Mandela Bay Municipality Construction industry -- Employees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/30573 , vital:30962
- Description: The issue of construction workers’ motivation has become a subject of debate among construction project management professionals. Construction workers mostly work long hours in relatively disagreeable environments and, far from their families. Most of the activities are done under difficult conditions including harsh weather conditions, however, employees are required to be motivated towards ensuring the attractiveness of the industry to them. Moreover, there are diverse perceptions that the motivation of construction workers positively impacts construction workers performance or rather adversely affects the general performance of construction workers. Although, workers motivation has been proven to improve construction productivity globally, motivation of construction workers seems not to be effectively implemented in South African Construction Industry. As a result, it is difficult for management to identify motivational factors that affect workers productivity in a work environment. A quantitative research approach was employed to analyse the result obtained from a structured questionnaire survey. The research respondents included: bricklayers, plumbers, concrete workers, electricians, carpenters, and professionals. This study used data from primary source which focus on tradesman, labourer and professional context. A survey was conducted with tradesmen, labourers and professionals regarding motivation on construction workers which was conducted in the Nelson Mandela Bay Metropole, Eastern Cape. It was found that motivation is important to construction workers’ performance. Awarding bonuses to workers is important to improving workers’ efficiency and there is a need for construction workers recognition by management. Construction industry stakeholder should shift their attention and prioritise the motivation of its workers since the industry has a way of cubing poverty and uplifting the county’s economy. The findings revealed that motivational communication, rather than functional communication, would enhance worker productivity. It was found that both intrinsic and extrinsic rewards are needed to improve worker productivity. It was also found that positive reinforcement techniques, should be used to enhance worker productivity. The findings from this research study revealed that the motivational theories apply to construction workers, and management needs to apply these theories wisely to achieve improved productivity. The study therefore concludes that motivational techniques are necessary to improve construction workers productivity on a vii construction site. It is recommended that supervisors use motivational communication, extrinsic rewards, intrinsic rewards and positive reinforcement to motivate their workers to achieve higher levels of productivity.
- Full Text:
- Date Issued: 2018
Movement of coastal fishery species in Southern Africa: research trends, characterisation of behaviours and a case study on fishery implications
- Authors: Maggs, Jade Quinton
- Date: 2018
- Subjects: Fishery management -- Africa, Southern , Fisheries -- Africa, Southern , Fisheries -- Catch effort , Fisheries -- Environmental aspects , Fisheries --Monitoring , Biotelemetry , Sustainable fisheries -- Africa, Southern , Overfishing -- Africa, Southern
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60574 , vital:27798
- Description: Movement of fishes is an integral part of their daily life, but has significant implications for fishery management. As with nearly all coastal countries, South Africa relies on coastal fisheries as a renewable resource, but many stocks have been overexploited for decades. Although it has long been recognised that an understanding of fish movement is necessary for effective management, it is with some difficulty that the subject has been studied in the past. In recent years, however, improvements in technology have provided the means for more in-depth investigations into fish movement. This research has revealed a range of complex movement behaviours. Movement in fishes occurs on a variety of temporal and spatial scales leading to the characteristic patterns of distribution and abundance observed in marine ecosystems. Fishes move nearly constantly in search of food, shelter or reproductive opportunities. Observations of behaviours such as long-term site fidelity, longdistance migration and natal homing are enabling ecologists to understand patterns of distribution and abundance within a species' range. Fish movement around the South African coast has been studied on numerous occasions but this has largely been confined to studies on single species. Movement behaviour of multiple species has been studied, but this has been limited to spatially localised marine protected area research. There has been little attempt in southern Africa to synthesize interspecific movement behaviour over wide spatial scales.Unprecedented concern over the biological effects of overexploitation, together with rapid technological advances in biotelemetry, have provided the impetus for much research, on a global scale, into the movement of marine animals. I reviewed 101 marine and estuarine fish movement studies from southern Africa, published from 1928 to 2014, with the aim of synthesising research trends and findings. Trends showed an increasing emphasis on fish movement research in publications in the sub-tropical and warm-temperate biogeographic regions along the south and east coasts of southern Africa. Although 63% of publications featured only marine studies, research into fine-scale habitat use in estuaries has been on the increase, concomitant with increasing accessibility of biotelemetry. Overall, 26 fish families were identified in the surveyed literature with regionally endemic sparids featuring in 32% of the publications. Ten movement themes were identified in the surveyed literature, including broad-scale movement patterns, which featured in 68% of studies, followed by fine- scale habitat usage (33%) and protected areas (26%). The most prominent phenomenon, emerging from this research, is that of partial migration, which describes the occurrence of resident and migratory behaviour within a coexisting animal population. Substantial progress has also been made in unravelling the complexities of fine-scale movements in marine reserves and habitat usage in estuaries. While this knowledge has enabled more effective management of South Africa's multi-user, multi-species fisheries, focus should now be directed at improving our understanding of the commonalities in movement behaviour, the associated driving forces behind this behaviour and the extent of movement across reserve boundaries. Mark-recapture data, collected over the past 30 years by the Oceanographic Research Institute’s Cooperative Fish Tagging Project (ORICFTP), were used to investigate broad- scale movement patterns of 30 prominent coastal fishery species (Chapter 4). Fishes were tagged with plastic dart tags along the coastline of southern Africa from Angola to Mozambique. This exercise yielded more than 10000 recaptures. The 30 chosen species represented 14 families, although 12 species belonged to a single family (Sparidae). Overall, 67% of recaptures were reported from the original tagging locality and 73% were recorded within 5 km of the tagging locality. The remaining observations extended from 6-3000 km. Movements were assigned to four distance bins (0-5 km, 6-50km, 51-500km and >500 km) and modelled with an ordinal logistic regression. Species, life-stage (juvenile/adult) and time- at-liberty were included as predictor variables. Model coefficients were then included in a cluster analysis, which produced two primary groupings of species (Category I and II), with two sub-groupings (Category IIa and IIb). Category I species were characterised by wide-ranging movements, greatest median recapture length and highest trophic levels. Category II species were characterised by residency, lower median recapture length and lower trophic levels. These findings have implications for fisheries management. Exploitation of resident species may lead to localised depletion, but their diffuse spatial distribution may offer some resilience. In contrast, even localised targeting of migratory species may pose a population level risk if individuals are known to aggregate. Life-cycle diversity or intra-population variability describes the existence of alternative strategies or tactics among coexisting individuals within an animal population (Chapter 5). Partial migration is a specific case of life-cycle diversity where coexisting groups exhibit either resident or migratory (wide-ranging) behaviour within a single population. Mark- recapture data collected under the auspices of the ORICFTP were used to investigate the occurrence and nature of life-cycle diversity in the movement behaviour of five non- diadromous fish species around the coastline of southern Africa. Among the five species were three teleosts (Category I and IIa) and two elasmobranchs (Category I). A fish was considered to have remained resident if recaptured within 0-5 km after 365 days at liberty. A fish was considered to have undertaken a wide-ranging movement if recaptured more than 50 km away from the release site in 365 days or less. A total of 1848 individuals from the five study species were recaptured during the study, of which 73% of the observations were classified as being resident. Binomial logistic regression confirmed that species, life-stage (juvenile/adult) and ecoregion were significant (p < 0.001) predictors of the probability of wide-ranging behaviour. A Gaussian model confirmed that species and ecoregion were also significant (p < 0.001) predictors of direction and distance of wide-ranging movement. However, the direction and distance of wide-ranging movements in juveniles did not differ significantly (p > 0.05) to that of adults. The median growth rate was mostly greater in wide- ranging individuals; however, this was only statistically significant (p < 0.05) in two cases. These findings provide unequivocal evidence of life-cycle diversity in five fish species, with vastly different life-histories. This ecological phenomenon may provide species resilience at the population level and needs to be considered in fisheries management initiatives. The movement of fishes is a fundamental aspect to consider when designing fishery management regimes. Unfortunately, traditional management strategies have often disregarded movement behaviour to the detriment of fish populations (Chapter 6). As a case study, the management of Lichia amia (Category I: wide-ranging) was evaluated in the context of its movement behaviour. Long-term catch-per-unit-effort (CPUE) datasets were examined for three South African recreational fishery sectors. The CPUE was standardised using generalized linear models (delta-Gamma/hurdle approach) to reduce the effect of factors other than abundance. Factors that were available for this purpose were year, month and locality/zone. Year was included in every model as the primary objective was to detect trends in abundance over time. Although standardised CPUE for all sectors showed an overall long-term decline, there was considerable variability in trends between the different recreational sectors and between datasets. Contrasting trends between competitive shore angling and general shore angling datasets were ascribed to hyperstability in competitive CPUE data. Hyperstability in this case was mostly influenced by rapidly improving technology, techniques and communication networks amongst competitive anglers. Month and locality were significant factors explaining the probability of catching L. amia. This suggests that the predictable aggregatory behaviour of this species could further compound the observed CPUE hyperstability. Although the CPUE responded positively for six years after implementation of the first minimum size and bag limits, and for one year after the decommercialisation of the species, these regulations and their amendments failed to arrest a long-term decline in the CPUE despite the ample evidence for hyperstability. It is clear from this case study that the predictable nature of wide-ranging behaviour in L. amia has made the population vulnerable to exploitation. This has led to the demise in the population, which could have been worse if not for the occurrence of intra-population variability in its movement behaviour, which may provide some measure of resilience.
- Full Text:
- Date Issued: 2018
- Authors: Maggs, Jade Quinton
- Date: 2018
- Subjects: Fishery management -- Africa, Southern , Fisheries -- Africa, Southern , Fisheries -- Catch effort , Fisheries -- Environmental aspects , Fisheries --Monitoring , Biotelemetry , Sustainable fisheries -- Africa, Southern , Overfishing -- Africa, Southern
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60574 , vital:27798
- Description: Movement of fishes is an integral part of their daily life, but has significant implications for fishery management. As with nearly all coastal countries, South Africa relies on coastal fisheries as a renewable resource, but many stocks have been overexploited for decades. Although it has long been recognised that an understanding of fish movement is necessary for effective management, it is with some difficulty that the subject has been studied in the past. In recent years, however, improvements in technology have provided the means for more in-depth investigations into fish movement. This research has revealed a range of complex movement behaviours. Movement in fishes occurs on a variety of temporal and spatial scales leading to the characteristic patterns of distribution and abundance observed in marine ecosystems. Fishes move nearly constantly in search of food, shelter or reproductive opportunities. Observations of behaviours such as long-term site fidelity, longdistance migration and natal homing are enabling ecologists to understand patterns of distribution and abundance within a species' range. Fish movement around the South African coast has been studied on numerous occasions but this has largely been confined to studies on single species. Movement behaviour of multiple species has been studied, but this has been limited to spatially localised marine protected area research. There has been little attempt in southern Africa to synthesize interspecific movement behaviour over wide spatial scales.Unprecedented concern over the biological effects of overexploitation, together with rapid technological advances in biotelemetry, have provided the impetus for much research, on a global scale, into the movement of marine animals. I reviewed 101 marine and estuarine fish movement studies from southern Africa, published from 1928 to 2014, with the aim of synthesising research trends and findings. Trends showed an increasing emphasis on fish movement research in publications in the sub-tropical and warm-temperate biogeographic regions along the south and east coasts of southern Africa. Although 63% of publications featured only marine studies, research into fine-scale habitat use in estuaries has been on the increase, concomitant with increasing accessibility of biotelemetry. Overall, 26 fish families were identified in the surveyed literature with regionally endemic sparids featuring in 32% of the publications. Ten movement themes were identified in the surveyed literature, including broad-scale movement patterns, which featured in 68% of studies, followed by fine- scale habitat usage (33%) and protected areas (26%). The most prominent phenomenon, emerging from this research, is that of partial migration, which describes the occurrence of resident and migratory behaviour within a coexisting animal population. Substantial progress has also been made in unravelling the complexities of fine-scale movements in marine reserves and habitat usage in estuaries. While this knowledge has enabled more effective management of South Africa's multi-user, multi-species fisheries, focus should now be directed at improving our understanding of the commonalities in movement behaviour, the associated driving forces behind this behaviour and the extent of movement across reserve boundaries. Mark-recapture data, collected over the past 30 years by the Oceanographic Research Institute’s Cooperative Fish Tagging Project (ORICFTP), were used to investigate broad- scale movement patterns of 30 prominent coastal fishery species (Chapter 4). Fishes were tagged with plastic dart tags along the coastline of southern Africa from Angola to Mozambique. This exercise yielded more than 10000 recaptures. The 30 chosen species represented 14 families, although 12 species belonged to a single family (Sparidae). Overall, 67% of recaptures were reported from the original tagging locality and 73% were recorded within 5 km of the tagging locality. The remaining observations extended from 6-3000 km. Movements were assigned to four distance bins (0-5 km, 6-50km, 51-500km and >500 km) and modelled with an ordinal logistic regression. Species, life-stage (juvenile/adult) and time- at-liberty were included as predictor variables. Model coefficients were then included in a cluster analysis, which produced two primary groupings of species (Category I and II), with two sub-groupings (Category IIa and IIb). Category I species were characterised by wide-ranging movements, greatest median recapture length and highest trophic levels. Category II species were characterised by residency, lower median recapture length and lower trophic levels. These findings have implications for fisheries management. Exploitation of resident species may lead to localised depletion, but their diffuse spatial distribution may offer some resilience. In contrast, even localised targeting of migratory species may pose a population level risk if individuals are known to aggregate. Life-cycle diversity or intra-population variability describes the existence of alternative strategies or tactics among coexisting individuals within an animal population (Chapter 5). Partial migration is a specific case of life-cycle diversity where coexisting groups exhibit either resident or migratory (wide-ranging) behaviour within a single population. Mark- recapture data collected under the auspices of the ORICFTP were used to investigate the occurrence and nature of life-cycle diversity in the movement behaviour of five non- diadromous fish species around the coastline of southern Africa. Among the five species were three teleosts (Category I and IIa) and two elasmobranchs (Category I). A fish was considered to have remained resident if recaptured within 0-5 km after 365 days at liberty. A fish was considered to have undertaken a wide-ranging movement if recaptured more than 50 km away from the release site in 365 days or less. A total of 1848 individuals from the five study species were recaptured during the study, of which 73% of the observations were classified as being resident. Binomial logistic regression confirmed that species, life-stage (juvenile/adult) and ecoregion were significant (p < 0.001) predictors of the probability of wide-ranging behaviour. A Gaussian model confirmed that species and ecoregion were also significant (p < 0.001) predictors of direction and distance of wide-ranging movement. However, the direction and distance of wide-ranging movements in juveniles did not differ significantly (p > 0.05) to that of adults. The median growth rate was mostly greater in wide- ranging individuals; however, this was only statistically significant (p < 0.05) in two cases. These findings provide unequivocal evidence of life-cycle diversity in five fish species, with vastly different life-histories. This ecological phenomenon may provide species resilience at the population level and needs to be considered in fisheries management initiatives. The movement of fishes is a fundamental aspect to consider when designing fishery management regimes. Unfortunately, traditional management strategies have often disregarded movement behaviour to the detriment of fish populations (Chapter 6). As a case study, the management of Lichia amia (Category I: wide-ranging) was evaluated in the context of its movement behaviour. Long-term catch-per-unit-effort (CPUE) datasets were examined for three South African recreational fishery sectors. The CPUE was standardised using generalized linear models (delta-Gamma/hurdle approach) to reduce the effect of factors other than abundance. Factors that were available for this purpose were year, month and locality/zone. Year was included in every model as the primary objective was to detect trends in abundance over time. Although standardised CPUE for all sectors showed an overall long-term decline, there was considerable variability in trends between the different recreational sectors and between datasets. Contrasting trends between competitive shore angling and general shore angling datasets were ascribed to hyperstability in competitive CPUE data. Hyperstability in this case was mostly influenced by rapidly improving technology, techniques and communication networks amongst competitive anglers. Month and locality were significant factors explaining the probability of catching L. amia. This suggests that the predictable aggregatory behaviour of this species could further compound the observed CPUE hyperstability. Although the CPUE responded positively for six years after implementation of the first minimum size and bag limits, and for one year after the decommercialisation of the species, these regulations and their amendments failed to arrest a long-term decline in the CPUE despite the ample evidence for hyperstability. It is clear from this case study that the predictable nature of wide-ranging behaviour in L. amia has made the population vulnerable to exploitation. This has led to the demise in the population, which could have been worse if not for the occurrence of intra-population variability in its movement behaviour, which may provide some measure of resilience.
- Full Text:
- Date Issued: 2018
Multi-temporal analysis of changes in vegetation distribution in the Great Fish River Game Reserve, Eastern Cape Province, South Africa :1982-2012
- Authors: Dikweni, Sipho
- Date: 2018
- Subjects: Climatic changes -- South Africa|zEastern Cape Biodiversity conservation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10511 , vital:35550
- Description: Great Fish River Game Reserve plays an important role in curtailing the ever-increasing biodiversity declines in Eastern Cape Province and South Africa at large. Though this area plays an important role in the conservation of natural biodiversity, it has been observed that it is undergoing considerable changes with regards to conditions and composition of vegetation cover. These changes signal a decline in the capacity of the Great Fish River Game Reserve to support wildlife population. In this study, remote sensing was used to investigate multi-temporal changes in vegetation distribution in this particular reserve over a period of 30 years (1982-2012). A supervised classification was carried out to classify four Landsat images including; Landsat TM, Landsat ETM and Landsat 8 imagery of 1984, 1992, 2002 and 2013 respectively to map historical and present vegetation conditions and distribution in the Great Fish River Game Reserve. A comparative examination of the classified images showed that there were significant changes in the composition and structure of vegetation with much of the palatable plant species being driven to extinction. The results showed that herbivory pressure inconjuction with climate variability has subsequently resulted in a decrease of the supporting potential of the reserve to sustain wildlife due to mortality of the most preferred plant species and abundant increase of non-palatable plant species. As grazing and browsing intensity increased, there was a decline in regenerative potential of the selected plant species by wild herbivores and successful increase in abundance of the non-palatable plant species. The results of this investigation suggest that the current increase in wildlife population will facilitate the deterioration of habitat condition to support wildlife up to the point of no recovery.
- Full Text:
- Date Issued: 2018
- Authors: Dikweni, Sipho
- Date: 2018
- Subjects: Climatic changes -- South Africa|zEastern Cape Biodiversity conservation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10511 , vital:35550
- Description: Great Fish River Game Reserve plays an important role in curtailing the ever-increasing biodiversity declines in Eastern Cape Province and South Africa at large. Though this area plays an important role in the conservation of natural biodiversity, it has been observed that it is undergoing considerable changes with regards to conditions and composition of vegetation cover. These changes signal a decline in the capacity of the Great Fish River Game Reserve to support wildlife population. In this study, remote sensing was used to investigate multi-temporal changes in vegetation distribution in this particular reserve over a period of 30 years (1982-2012). A supervised classification was carried out to classify four Landsat images including; Landsat TM, Landsat ETM and Landsat 8 imagery of 1984, 1992, 2002 and 2013 respectively to map historical and present vegetation conditions and distribution in the Great Fish River Game Reserve. A comparative examination of the classified images showed that there were significant changes in the composition and structure of vegetation with much of the palatable plant species being driven to extinction. The results showed that herbivory pressure inconjuction with climate variability has subsequently resulted in a decrease of the supporting potential of the reserve to sustain wildlife due to mortality of the most preferred plant species and abundant increase of non-palatable plant species. As grazing and browsing intensity increased, there was a decline in regenerative potential of the selected plant species by wild herbivores and successful increase in abundance of the non-palatable plant species. The results of this investigation suggest that the current increase in wildlife population will facilitate the deterioration of habitat condition to support wildlife up to the point of no recovery.
- Full Text:
- Date Issued: 2018
Naming in Germany in the 20th century: a sociological study of naming in times of social change, with a focus on statistical problems in empirical onomastic research
- Authors: Huschka, Denis
- Date: 2018
- Subjects: Onomastics , Names, Personal -- Germany , Names, German -- Etymology , Names, German -- Social aspects , German language -- Etymology -- Names , German Socio Economic Panel Study (SOEP)
- Language: German , English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63054 , vital:28359
- Description: In this thesis names are used as social indicators to observe social change in Germany in the 20th century. The German Socio Economic Panel Study (SOEP) offers the rare opportunity to analyse representative survey data of first names. The empirical results of the analyses in this thesis offer a comprehensive picture on how the naming reality in Germany looks like and how naming changed in a period of about 100 years. Names can serve as social indicators. It is demonstrated how chosen names mirror social change in the German society: Name choices have become less traditional and more individual. Over time names from other world regions and cultures have found their way into the German culture. There are more different names in use today than 100 years ago and the names have become more evenly distributed over the population. Today children are less likely to share their names with many of their peers. These are signs of an increasingly individualised, transnationalised modern behaviour of the people in contemporary Germany. Almost all of these developments started earlier and tend to be more pronounced for girl’s names. The secularisation of the German society - however - did not cause substantial changes in naming over time. Christian names still are used to the greatest extent, but – possibly – not because they are regarded as being of Christian origin. The analyses of the social-structural influences on naming touch on some effects of education and status. The analyses of differences in naming between the two German states during the time of division adds some evidence to the real-life experience that naming in the communist East Germany was much more oriented towards the free western hemisphere – a kind of silent protest. Obviously naming was a possibility to distance oneself from an un-loved regime. On a methodological level referring to onomastics, the so-called „Large Number of are Events-Zone (LNRE)“, a feature of the distribution of names that has mostly been handled inappropriately up to now, is discussed with respect to its effects on name statistics when using samples. An alternative approach is proposed for the appropriate handling of this feature. , In der vorliegenden Arbeit werden Vornamen als soziale Indikatoren benutzt, um gesellschaftlichen Wandel im 20. Jahrhundert zu beschreiben. Das Soziooekonomische Panel (SOEP) bietet die seltene Möglichkeit, Umfragedaten über die Vornamen der Deutschen repräsentativ auszuwerten. Die empirischen Ergebnisse der vorliegenden Arbeit bieten einen umfassenden Einblick in die deutsche Vornamensrealität und über die Entwicklungen der Namensvergabe in 100 Jahren. Namen sind soziale Indikatoren. Es wird aufgezeigt, wie die Namensgebung den sozialen Wandel in der deutschen Gesellschaft spiegelt: Namenwahlen weisen über die Zeit weniger traditionelle Bezüge auf, sie wurden individueller. Namen aus anderen Kulturen und Ländern fanden Eingang in die deutsche Kultur. Es werden mehr verschiedene Namen benutzt als vor 100 Jahren und die typischerweise hoch konzentrierten Verteilungen der Vornamen stellen sich über die Zeit etwas weniger konzentriert dar. Heute geborene Kinder teilen ihre Namen mit anteilig weniger anderen Kindern ihrer Kohorte. Dies sind Anzeichen für eine individualisierte, transnational orientierte moderne Gesellschaft. Fast alle dieser Entwicklungen sind für Mädchennamen früher und in deutlicherem Maße zu beobachten. Die Säkularisierung der deutschen Gesellschaft hat hingegen wenig Einfluss auf die Vornamenswahlen genommen. Nach wie vor werden vor allem christliche Namen vergeben, auch wenn der christliche Bezug unter Umständen nicht mehr der maßgebliche Grund für die Auswahl ist. Die Analyse der sozialstrukturellen Einflüsse auf Namenswahlen bestätigt einige Effekte von Bildung und Status der Mütter. Die Analyse der Unterschiede in der Namensgebung der beiden deutschen Staaten während der 40 jährigen Teilung zeigt, dass der lebensweltliche Eindruck einer zunehmenden West-Orientierung der Namenswahlen ostdeutscher Eltern nicht trügt. Offenbar waren westliche Namen eine Möglichkeit, sich vom ungeliebten Regime zu distanzieren. Auf einer statistisch-methodischen Ebene wird eine bislang in der empirischen Onomastik unrichtig gehandhabte Besonderheit von Vornamensverteilungen – die Large Number of Rare Events-Zone (LNRE) – diskutiert und Lösungsvorschläge für den statistisch korrekten Umgang mit dieser Besonderheit in Gruppenvergleichen auf der Basis von Stichproben vorgelegt.
- Full Text:
- Date Issued: 2018
- Authors: Huschka, Denis
- Date: 2018
- Subjects: Onomastics , Names, Personal -- Germany , Names, German -- Etymology , Names, German -- Social aspects , German language -- Etymology -- Names , German Socio Economic Panel Study (SOEP)
- Language: German , English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63054 , vital:28359
- Description: In this thesis names are used as social indicators to observe social change in Germany in the 20th century. The German Socio Economic Panel Study (SOEP) offers the rare opportunity to analyse representative survey data of first names. The empirical results of the analyses in this thesis offer a comprehensive picture on how the naming reality in Germany looks like and how naming changed in a period of about 100 years. Names can serve as social indicators. It is demonstrated how chosen names mirror social change in the German society: Name choices have become less traditional and more individual. Over time names from other world regions and cultures have found their way into the German culture. There are more different names in use today than 100 years ago and the names have become more evenly distributed over the population. Today children are less likely to share their names with many of their peers. These are signs of an increasingly individualised, transnationalised modern behaviour of the people in contemporary Germany. Almost all of these developments started earlier and tend to be more pronounced for girl’s names. The secularisation of the German society - however - did not cause substantial changes in naming over time. Christian names still are used to the greatest extent, but – possibly – not because they are regarded as being of Christian origin. The analyses of the social-structural influences on naming touch on some effects of education and status. The analyses of differences in naming between the two German states during the time of division adds some evidence to the real-life experience that naming in the communist East Germany was much more oriented towards the free western hemisphere – a kind of silent protest. Obviously naming was a possibility to distance oneself from an un-loved regime. On a methodological level referring to onomastics, the so-called „Large Number of are Events-Zone (LNRE)“, a feature of the distribution of names that has mostly been handled inappropriately up to now, is discussed with respect to its effects on name statistics when using samples. An alternative approach is proposed for the appropriate handling of this feature. , In der vorliegenden Arbeit werden Vornamen als soziale Indikatoren benutzt, um gesellschaftlichen Wandel im 20. Jahrhundert zu beschreiben. Das Soziooekonomische Panel (SOEP) bietet die seltene Möglichkeit, Umfragedaten über die Vornamen der Deutschen repräsentativ auszuwerten. Die empirischen Ergebnisse der vorliegenden Arbeit bieten einen umfassenden Einblick in die deutsche Vornamensrealität und über die Entwicklungen der Namensvergabe in 100 Jahren. Namen sind soziale Indikatoren. Es wird aufgezeigt, wie die Namensgebung den sozialen Wandel in der deutschen Gesellschaft spiegelt: Namenwahlen weisen über die Zeit weniger traditionelle Bezüge auf, sie wurden individueller. Namen aus anderen Kulturen und Ländern fanden Eingang in die deutsche Kultur. Es werden mehr verschiedene Namen benutzt als vor 100 Jahren und die typischerweise hoch konzentrierten Verteilungen der Vornamen stellen sich über die Zeit etwas weniger konzentriert dar. Heute geborene Kinder teilen ihre Namen mit anteilig weniger anderen Kindern ihrer Kohorte. Dies sind Anzeichen für eine individualisierte, transnational orientierte moderne Gesellschaft. Fast alle dieser Entwicklungen sind für Mädchennamen früher und in deutlicherem Maße zu beobachten. Die Säkularisierung der deutschen Gesellschaft hat hingegen wenig Einfluss auf die Vornamenswahlen genommen. Nach wie vor werden vor allem christliche Namen vergeben, auch wenn der christliche Bezug unter Umständen nicht mehr der maßgebliche Grund für die Auswahl ist. Die Analyse der sozialstrukturellen Einflüsse auf Namenswahlen bestätigt einige Effekte von Bildung und Status der Mütter. Die Analyse der Unterschiede in der Namensgebung der beiden deutschen Staaten während der 40 jährigen Teilung zeigt, dass der lebensweltliche Eindruck einer zunehmenden West-Orientierung der Namenswahlen ostdeutscher Eltern nicht trügt. Offenbar waren westliche Namen eine Möglichkeit, sich vom ungeliebten Regime zu distanzieren. Auf einer statistisch-methodischen Ebene wird eine bislang in der empirischen Onomastik unrichtig gehandhabte Besonderheit von Vornamensverteilungen – die Large Number of Rare Events-Zone (LNRE) – diskutiert und Lösungsvorschläge für den statistisch korrekten Umgang mit dieser Besonderheit in Gruppenvergleichen auf der Basis von Stichproben vorgelegt.
- Full Text:
- Date Issued: 2018