Anthropogenic effects on sustainability of fish biodiversity in Tyume River, Eastern Cape, South Africa
- Authors: Kinya, Jane Njeri
- Date: 2018
- Subjects: Fishes--Behavior Fishes--Physiology Biotic communities
- Language: English
- Type: Thesis , Doctoral , Zoology
- Identifier: http://hdl.handle.net/10353/11740 , vital:39102
- Description: To determine the anthropogenic effects on the sustainability of fish biodiversity in Tyhume River, a mixture of ecological, economic and institutional parameters were used. To measure ecological parameters, 10 study sites were selected to represent varying intensities of anthropogenic effects on habitat, to represent typical river zones, and to correspond with historical survey sites for trend analysis. In these study sites, habitat characteristics that represent geomorphology (habitat quantity), water quality and ‘alien’ (non–native) fishes were used to determine anthropogenic effects on habitat and fish assemblage. The measured geomorphology characteristics included current velocity, wetted width and depth. The water quality characteristics used were temperature, pH and conductivity. To determine the effects of native and non-native on indigenous fish species in situ, electro fishing was used in riffles, small pools and runs; as well, in situ seine-netting was done in pools. The riches of river fish species was measured, using numbers abundance and longitudinal distribution indices. It was established that only 11percent of the Tyhume River habitat was relatively near natural, while 89percent exhibited anthropogenic habitat modification. Three major sources ofanthropogenic modification on habitat were identified. The major contributor of anthropogenic effects was Binfield Park Dam which accounted for 43percent of modification. The second source of anthropogenic effects on habitat was Alice urban area where storm water runoff accounted for 28percent of modification. Agricultural and livestock grazing, the third anthropogenic effect, accounted for 18percent of modification. The Eastern Cape Rocky, Sandelia bainsii Castelnau, 1861 and Border Barb, Barbus trevelyani Günther, 1868, exhibited reduced distribution. B. trevelyani longitudinal distribution was less than 25 km along the river continuum, with sporadic presence in the sandy foothills. S. bainsii was not found in the Lowland Zone, while previously this species extended from the mountainous zone to the confluence of the Tyhume and Keiskamma Rivers in the Lowland Zone. These indices supported the homogenization theory, as reflected by increased dissimilarity for two indigenous fish species, S. bainsii and B. trevelyani, among study sites. S. bainsii was previously distributed from source to confluence, while B. trevelyani recorded a 50percent decline at the study site below the Binfield Park Dam. To assign economic value to ecosystem services and assess post Rio-institutional parameters two hypothetical scenarios were developed from the ecological survey; one depicting current conditions and another depicting improved ecosystem services. Using a structured interview questionnaire, five ecosystem services in need of restoration were described to respondents. Applying the contingent valuation method respondents were asked a dichotomous choice question on willingness to pay (WTP). Results of the economic study from 209 personal interviews revealed, individuals were willing to pay an additional R 32.00 on their monthly water bill or R 384.00 annually. Generalizing this to 2 829 households living in the Alice and Ntselamanzi urban areas, a total value of R 1 086 336 would be realized annually. This was equivalent to the Nkonkobe Municipality annual budget for storm water management in Alice urban area. Costs/benefits revealed a positive net present value (NPV) = 1, which, in line with economic theory, meant gainers were able to compensate losers The institutional part of the economic survey sought to determine the effects of post Rio Earth Summit institutional measures on sustainable management of Tyhume River fish assemblage. A desk review of Rio Declaration and three South African statutes were used namely; Constitution Act 108 of 1996 (South African Constitution 1996); the National Environmental Management Biodiversity Act No. 10 of 2004 (NEMBA 2004), the National Environmental Management Act (NEMA) No. 107 of 1998 (NEMA 1998), and the National Water Act No. 36 of 1998 (NWA 1998). The Institutional and Analytic Development (IAD) Framework, coupled with requirements for sustainability of Multiple Use Resource Domains were used for the analysis. De Jure, the statutes had internationalization of environmental costs through “polluter pays principle”, while sustainable use was the overarching goal. De facto, the community participation, a requisite of post Rio measures, was low; however 89percent of community respondents were willing to join an environmental conservation group. This, coupled with the fact that 77percent of those interviewed supported the establishment of a Tyhume River Restoration Fund, provided scope for a broad based community participation framework This study contributes to sustainable use of Tyhume River and other lotic systems by generating information on the link between anthropogenic effects on fish biodiversity, economic value of ecosystems services and institutional mechanisms.
- Full Text:
- Date Issued: 2018
- Authors: Kinya, Jane Njeri
- Date: 2018
- Subjects: Fishes--Behavior Fishes--Physiology Biotic communities
- Language: English
- Type: Thesis , Doctoral , Zoology
- Identifier: http://hdl.handle.net/10353/11740 , vital:39102
- Description: To determine the anthropogenic effects on the sustainability of fish biodiversity in Tyhume River, a mixture of ecological, economic and institutional parameters were used. To measure ecological parameters, 10 study sites were selected to represent varying intensities of anthropogenic effects on habitat, to represent typical river zones, and to correspond with historical survey sites for trend analysis. In these study sites, habitat characteristics that represent geomorphology (habitat quantity), water quality and ‘alien’ (non–native) fishes were used to determine anthropogenic effects on habitat and fish assemblage. The measured geomorphology characteristics included current velocity, wetted width and depth. The water quality characteristics used were temperature, pH and conductivity. To determine the effects of native and non-native on indigenous fish species in situ, electro fishing was used in riffles, small pools and runs; as well, in situ seine-netting was done in pools. The riches of river fish species was measured, using numbers abundance and longitudinal distribution indices. It was established that only 11percent of the Tyhume River habitat was relatively near natural, while 89percent exhibited anthropogenic habitat modification. Three major sources ofanthropogenic modification on habitat were identified. The major contributor of anthropogenic effects was Binfield Park Dam which accounted for 43percent of modification. The second source of anthropogenic effects on habitat was Alice urban area where storm water runoff accounted for 28percent of modification. Agricultural and livestock grazing, the third anthropogenic effect, accounted for 18percent of modification. The Eastern Cape Rocky, Sandelia bainsii Castelnau, 1861 and Border Barb, Barbus trevelyani Günther, 1868, exhibited reduced distribution. B. trevelyani longitudinal distribution was less than 25 km along the river continuum, with sporadic presence in the sandy foothills. S. bainsii was not found in the Lowland Zone, while previously this species extended from the mountainous zone to the confluence of the Tyhume and Keiskamma Rivers in the Lowland Zone. These indices supported the homogenization theory, as reflected by increased dissimilarity for two indigenous fish species, S. bainsii and B. trevelyani, among study sites. S. bainsii was previously distributed from source to confluence, while B. trevelyani recorded a 50percent decline at the study site below the Binfield Park Dam. To assign economic value to ecosystem services and assess post Rio-institutional parameters two hypothetical scenarios were developed from the ecological survey; one depicting current conditions and another depicting improved ecosystem services. Using a structured interview questionnaire, five ecosystem services in need of restoration were described to respondents. Applying the contingent valuation method respondents were asked a dichotomous choice question on willingness to pay (WTP). Results of the economic study from 209 personal interviews revealed, individuals were willing to pay an additional R 32.00 on their monthly water bill or R 384.00 annually. Generalizing this to 2 829 households living in the Alice and Ntselamanzi urban areas, a total value of R 1 086 336 would be realized annually. This was equivalent to the Nkonkobe Municipality annual budget for storm water management in Alice urban area. Costs/benefits revealed a positive net present value (NPV) = 1, which, in line with economic theory, meant gainers were able to compensate losers The institutional part of the economic survey sought to determine the effects of post Rio Earth Summit institutional measures on sustainable management of Tyhume River fish assemblage. A desk review of Rio Declaration and three South African statutes were used namely; Constitution Act 108 of 1996 (South African Constitution 1996); the National Environmental Management Biodiversity Act No. 10 of 2004 (NEMBA 2004), the National Environmental Management Act (NEMA) No. 107 of 1998 (NEMA 1998), and the National Water Act No. 36 of 1998 (NWA 1998). The Institutional and Analytic Development (IAD) Framework, coupled with requirements for sustainability of Multiple Use Resource Domains were used for the analysis. De Jure, the statutes had internationalization of environmental costs through “polluter pays principle”, while sustainable use was the overarching goal. De facto, the community participation, a requisite of post Rio measures, was low; however 89percent of community respondents were willing to join an environmental conservation group. This, coupled with the fact that 77percent of those interviewed supported the establishment of a Tyhume River Restoration Fund, provided scope for a broad based community participation framework This study contributes to sustainable use of Tyhume River and other lotic systems by generating information on the link between anthropogenic effects on fish biodiversity, economic value of ecosystems services and institutional mechanisms.
- Full Text:
- Date Issued: 2018
Appraisal of wastewater final effluents and river water as reservoirs of cholera and non-cholera causing vibrio species : case study of the Amatole and OR Tambo District Municipalities
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
- Full Text:
- Date Issued: 2018
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
- Full Text:
- Date Issued: 2018
Assessment of the human health implications of climate variability in East London, Eastern Cape, South Africa
- Authors: Orimoloye, Israel Ropo
- Date: 2018
- Subjects: Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Geography
- Identifier: http://hdl.handle.net/10353/10113 , vital:35346
- Description: Impacts associated with climate variability and extreme heat are already obvious in varying degrees and expected to be disruptive in the near future across the globe especially in the urban regions. Urban areas have distinctive features that leave their residents and properties vulnerable to extreme climate events. Global temperatures continue to change, reaching new levels almost every year for the past two decades. However, even though the causes are debated it is evident that climate variability is real. Climate variability and disaster risk are threats to human health that adversely reinforce each other. Better knowledge on the association between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce vulnerabilities. The impacts of climate variability on the health of residents in East London (EL) area in the Eastern Cape Province, South Africa were explored through four interdependent research segments. The first section examined the climate variability and urban surface thermal characteristics implication on human health using Remote Sensing (RS) and Geographic Information System (GIS) techniques. Remote sensing was used to assess the Land Surface Temperature (LST) and estimated Radiation (R) of East London area from Landsat Thematic Mapper (TM) images for 1986, 1996, 2006 as well as from Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for 2016 spanning a period of 30 years. Rapid urbanization and land cover changes in this area have contributed significantly to this drastic change in the natural land surface characteristics (increased land surface temperature and surface solar radiation). For instance, vegetation cover declined by about 358.812km2 while built-up areas increased by 175.473km2 during this period which correlates with the area thermal characteristics changes. Radiation levels also increased over the years with values exceeding the global solar radiation index. Exposure to increased surface radiation poses risks of heat stroke, skin cancer and heart disease to the local population. Consequently, this study provides pertinent information on human health sustainability and epidemiological case management. The second part explored past temperature and humidity trends (1986-2016) and projects future trends (2017-2030). The historical data of meteorological variables were obtained from the archives of the South African Weather Service and analyzed using the ordinary least square regression model in GRETL (GNU Regression Econometric and Time-series Library) statistical software. This study discovered a local consistency between models and the observations add to existing knowledge and this is crucial in knowing the shifts in climatic change as well as recognizing variability and its conflicting effects on human health, environment, agriculture, ecological sustainability and socioeconomic status in the region. The third segment assessed the potential impacts of climate variability on health using existing heat indices during the study period. The results demonstrated that in East London from 1986 to 2016 during summer and autumn (December to May) of various years exceeded high heat index values. It is obvious that summer and autumn months are more vulnerable to heat extreme and humidex. The humidex and Heat Index (HI) increased annually by 0.03percent and 0.9percent respectively throughout the study period. The increment in the various indices showed highly significant ill-health and environmental impacts on humans especially with prolonged exposure. The last segment appraised the association between climatic elements and epidemiological incidences of the study area between 2012 and 2016. The epidemiology incidences data were obtained from the archives of the Cecilia Makiwane Hospital in East London area and National Tertiary Service Grant (NTSG) database for the period. The results have showed that there exists significant effects of climate variability on the health of East London residents and these have been identified to have negative impacts on health of the people in the area. This study also revealed noticeable impacts of extreme heat on human health and a positive correlation between meteorological components (HI and temperature) and epidemiological cases (cardiovascular, skin cancer and diarrhea) during the study period.
- Full Text:
- Date Issued: 2018
- Authors: Orimoloye, Israel Ropo
- Date: 2018
- Subjects: Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Geography
- Identifier: http://hdl.handle.net/10353/10113 , vital:35346
- Description: Impacts associated with climate variability and extreme heat are already obvious in varying degrees and expected to be disruptive in the near future across the globe especially in the urban regions. Urban areas have distinctive features that leave their residents and properties vulnerable to extreme climate events. Global temperatures continue to change, reaching new levels almost every year for the past two decades. However, even though the causes are debated it is evident that climate variability is real. Climate variability and disaster risk are threats to human health that adversely reinforce each other. Better knowledge on the association between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce vulnerabilities. The impacts of climate variability on the health of residents in East London (EL) area in the Eastern Cape Province, South Africa were explored through four interdependent research segments. The first section examined the climate variability and urban surface thermal characteristics implication on human health using Remote Sensing (RS) and Geographic Information System (GIS) techniques. Remote sensing was used to assess the Land Surface Temperature (LST) and estimated Radiation (R) of East London area from Landsat Thematic Mapper (TM) images for 1986, 1996, 2006 as well as from Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for 2016 spanning a period of 30 years. Rapid urbanization and land cover changes in this area have contributed significantly to this drastic change in the natural land surface characteristics (increased land surface temperature and surface solar radiation). For instance, vegetation cover declined by about 358.812km2 while built-up areas increased by 175.473km2 during this period which correlates with the area thermal characteristics changes. Radiation levels also increased over the years with values exceeding the global solar radiation index. Exposure to increased surface radiation poses risks of heat stroke, skin cancer and heart disease to the local population. Consequently, this study provides pertinent information on human health sustainability and epidemiological case management. The second part explored past temperature and humidity trends (1986-2016) and projects future trends (2017-2030). The historical data of meteorological variables were obtained from the archives of the South African Weather Service and analyzed using the ordinary least square regression model in GRETL (GNU Regression Econometric and Time-series Library) statistical software. This study discovered a local consistency between models and the observations add to existing knowledge and this is crucial in knowing the shifts in climatic change as well as recognizing variability and its conflicting effects on human health, environment, agriculture, ecological sustainability and socioeconomic status in the region. The third segment assessed the potential impacts of climate variability on health using existing heat indices during the study period. The results demonstrated that in East London from 1986 to 2016 during summer and autumn (December to May) of various years exceeded high heat index values. It is obvious that summer and autumn months are more vulnerable to heat extreme and humidex. The humidex and Heat Index (HI) increased annually by 0.03percent and 0.9percent respectively throughout the study period. The increment in the various indices showed highly significant ill-health and environmental impacts on humans especially with prolonged exposure. The last segment appraised the association between climatic elements and epidemiological incidences of the study area between 2012 and 2016. The epidemiology incidences data were obtained from the archives of the Cecilia Makiwane Hospital in East London area and National Tertiary Service Grant (NTSG) database for the period. The results have showed that there exists significant effects of climate variability on the health of East London residents and these have been identified to have negative impacts on health of the people in the area. This study also revealed noticeable impacts of extreme heat on human health and a positive correlation between meteorological components (HI and temperature) and epidemiological cases (cardiovascular, skin cancer and diarrhea) during the study period.
- Full Text:
- Date Issued: 2018
Assessment of the impact of land use practices on vegetation , soil and carbon-nitrogen sequestration potential in Mopane rangelands of Central Northern Namibia
- Authors: Kahumba, Absalom
- Date: 2018
- Subjects: Rural development Land use Land tenure
- Language: English
- Type: Thesis , Doctoral , Pasture Science
- Identifier: http://hdl.handle.net/10353/11718 , vital:39100
- Description: This study was conducted in Ogongo district, situated in Omusati Region of the central northern Namibia. The objectives of this study were to assess the impact of land use practices on 1) vegetation distribution and status; 2) soil properties; 3) carbon-nitrogen sequestration potential, and 4) investigate the indigenous pastoralists’ knowledge and perceptions on livestock production, rangeland degradation and its indicators in three villages (Omaandi, Epukunoyana and Oshitutuma) in Mopane savannah rangelands of central northern Namibia. For vegetation and soil assessment, three grazing land management systems (communal, game reserve and cattle ranch) were identified adjacent to each other. In each grazing system, three sites (for game reserve and cattle ranch, these were camps) were selected. In each site, three belt transects of 50 m x 5 m2 were marked to record vegetation and soil data as well as to collect vegetation samples for analysis. Grass species composition was recorded using step point methods from 250 points per belt transect. A total of five 0.25 m2 quadrats were randomly laid within each 250 m2 belt transect to record the herbaceous plant density, tuft diameter, tuft distance and biomass. All woody plants in the belt transect (250 m2) were measured and recorded for species plant height and canopy diameters. Three soil samples per belt transect were collected at the time of forage sampling down to a depth of 20 cm using a soil auger. Soil and plant samples were analysed for macro and micro minerals, total organic carbon, total nitrogen, carbon-nitrogen ratios, and carbon and nitrogen isotopes. For bulk density, soil samples were collected using soil core samplers. In the social study, a total of 90 households were randomly selected from three villages and a total of 48 elders were purposefully selected based on the age, time spent in the village and livestock ownership. A combination of structured and semi-structured questionnaires were used to gather household information, while a structured questionnaire and open ended discussion were used to interview elders on the constraints of livestock production, rangeland degradation related issues and their consequences on livelihood. Field vegetation and soil data were analyzed using a General Linear Model (GLM) in SAS (2007), whereas the social data were analyzed using SPSS version 21 (2014). A total of 23 grass species were identified in all three land management systems, of which 48% were perennials and the remaining 52% were annuals. Aristida meridionalis dominated the game reserve and the ranch, whereas Eragrostis trichophora was dominant in all land management systems. Forbs occurred commonly in the game reserve and the ranch, but were dominant in the communal areas. The abundance of A. meridionalis responded significantly (P < 0.001) to land management systems with the game reserve showing remarkably greater abundance than the ranch. In summer, the abundance of E. trichophora was high (P < 0.001) in the game reserve followed by the communal and ranch sites, whereas in winter, the species had still greater abundance in the game reserve followed by the ranch. In summer, the mean grass density was greatest (P < 0.001) in the game reserve and least in the communal lands, but vice versa for the tuft distance. In summer, the average distance between tufts showed great variations (P < 0.001) with the communal areas having greater values than the ranch and game reserve. In winter, both the game reserve and the ranch showed records of similar grass tuft density and distance between tufts, whereas these values were nil for communal areas, because, there were no grasses recorded. Herbaceous plant dry matter was significantly greater (P < 0.05) in the game reserve followed by the ranch and the least in the communal areas. Results on biomass showed remarkably higher values (P < 0.001) in summer than winter in all land management systems. The total woody plant density was significantly higher (P < 0.001) in the ranch (542 TE ha-1) than the game reserve (449 TE ha-1) and communal area (324 TE ha-1). However, percentage of canopy cover did not differ significantly (P > 0.05) between the three land management systems. Woody plant density of height classes were significantly different (P < 0.05) between three land management systems. The abundance of seedlings, saplings and young shrubs were significantly greater (P < 0.05) in the ranch than the game reserve and communal area. The mature trees had a significantly greater density (P < 0.05) in the game reserve than the ranch and communal area. Soil analysis results showed that Magnesium (Mg), Potassium (K), Manganese (Mn) and Copper (Cu) had similar (P > 0.05) concentrations in soils obtained from all land management systems in both seasons. Soil Calcium (Ca) levels showed differences between land management systems in winter only being greater (P < 0.001) in the game reserve than the ranch and the communal lands. Soil Phosphorus (P) and Iron (Fe) also showed variations between land management systems in winter being significantly greater (P < 0.001) in the ranch than the other land management systems. The concentration of soil K differed between the two seasons in soils collected from the ranch and the communal lands, being greater (P < 0.001) in winter than summer seasons. Soil Zinc (Zn) also showed differences between land management systems in summer being greater (P < 0.001) in the game reserve than in the ranch and communal land. Seasonal variations were observed in soil P level of samples collected from the ranch being greater (P < 0.001) in winter than summer season. The concentration of soil Zn was higher (P < 0.001) in the soil collected from the game reserve and the ranch in summer than winter season. Woody forage analysis results showed that browse samples harvested from the ranch had greater (P < 0.001) Nitrogen (N) level than the other land management systems in both seasons. The browse samples harvested from the game reserve had greater (P < 0.001) Ca level than the other land management systems in winter season only. The level of P showed variations (P < 0.05) between land management systems in samples harvested during winter only being greater (P < 0.001) in samples from the ranch than the other land management systems. Similarly, browse harvested during winter showed significant differences (P < 0.05) in K levels being lowest in samples collected from game reserves, where the Ca level was greatest. Browse samples collected from the communal land and the ranch had the lowest Mg levels in summer and winter seasons, respectively. In all management systems, browse harvested during summer had greater (P < 0.001) N and P levels than those harvested in winter, and the reverse holds true for K and Ca levels. Browse samples harvested during winter had greater (P < 0.001) Mn levels in samples from the communal area and game reserve than the ranch, but in summer, the game reserve had higher Mn level than the other two sites. Browse samples harvested during winter only showed differences (P < 0.05) in Cu and Zn levels being greatest (P < 0.001) in samples collected from ranch and game reserves. In all management systems, browse samples harvested during winter had greater (P < 0.001) Fe, Mn, Zn and Cu (except for the game reserve and communal land) levels than those harvested in summer. Herbaceous analysis results showed that samples harvested in summer from the game reserve and ranch had greater (P < 0.001) TOC levels than the communal area, but in winter, samples from the game reserve and ranch had similar TOC levels, except for communal areas that had no herbaceous vegetation. Herbaceous samples harvested in winter from the ranch had greater (P < 0.001) TN levels than the game reserve, and that made the C:N ratio higher (P < 0.001) in the game reserve. Woody foliar samples harvested in winter from the game reserve and communal lands had greater (P < 0.001) TOC than the ranch. Values on C:N ratio showed that in winter, the communal and ranch had greater (P < 0.001) C:N than the game reserve, but in summer, the ranch had higher (P < 0.001) C:N than the game reserve and communal area. The vegetation TOC (kg ha-1) showed the order of the game reserve > ranch > communal area and the trend was similar in both seasons. In summer, the game reserve had the greatest (P < 0.001) TN (kg ha-1) followed by the ranch and the lowest in the communal area, but in winter the game reserve and ranch had similar and higher (P < 0.001) TN (kg ha-1) than the communal areas. In summer, both the game reserve and ranch recorded greater (P < 0.001) herbaceous δ13C and lowest δ15N than the communal area, but in winter, the game reserve had higher (P < 0.001) δ13C than the ranch, though both the game reserve and ranch had similar (P > 0.001) δ15N values. In summer, both the communal and ranch had slightly higher (P < 0.001) woody foliar δ13C than the game reserve, but in winter the ranch had greater (P < 0.001) δ13C than game reserve and communal areas. Woody foliar samples harvested from the ranch showed variations (P < 0.05) in δ15N between seasons being higher (P < 0.001) in summer than winter. The TOC was greatest in summer, in soils collected from the game reserve followed by the ranch and least in the communal land, but in winter, the lowest TOC was recorded in soils collected from the ranch. The soil C:N ratio varied between land management systems in soils collected during summer only being greater (P < 0.001) in the game and ranch than the communal area. The soil TOC (kg ha-1) and TN (kg ha-1) did not show (P > 0.05) differences between land management systems. Soil δ13C level was remarkably (P < 0.05) affected by land management systems, but did not interact with seasons. In both seasons, the communal land had slightly higher (P < 0.001) δ13C level than the other two land management systems. In both seasons, δ15N levels showed great differences (P < 0.001) between land management systems, with highest soil δ15N levels observed in the communal area than the ranch and game reserve. Results on social survey showed that the majority of the interviewed households in Omaandi (63percent), Oshitutuma (53percent) and Epukunoyana (50percent) were female headed families and the remaining were male headed. The mean population of goats and cattle were significantly higher (P < 0.05) in Omaandi and Epukunoyana than in Oshitutuma village, respectively. In this study, household respondents in all villages indicated that all livestock species were primarily kept for wealth status and provision of meat for consumption. Respondents in all villages also indicated that lack of grazing lands and shortage of feed were the primary constraints of livestock production followed by water scarcity and recurring droughts. Elder respondents in all villages perceived overgrazing and climate change as the primary cause of rangeland degradation. Elder interviewees in Omaandi and Oshitutuma villages regarded low grass cover and dominance of poor quality grass (Epukunoyana only) as the primary vegetation indicators of rangeland degradation. The animal related indicators such as stunted animal body as a result of mineral deficiency, high livestock mortality, emaciated body and animals traveling long distance for grazing and water (Oshitutuma only) were regarded in all villages as the primary livestock related indicators of rangeland degradation. Elders from Epukunoyana village ranked low rainfall, high soil and atmospheric temperatures as the primary climate related indicators of rangeland degradation, although in Omaandi and Oshitutuma, high soil and atmospheric temperatures were considered as the primary climate related indicators of rangeland degradation. Based on the findings, this study concludes that land management systems had great influences on the distribution and production of herbaceous and woody vegetation in summer and winter seasons. This study also observed that land management systems interacted strongly with season to influence most vegetation and soil variables. Lastly, based on the study findings, the study concludes that all three communal rangelands are degraded and degradation led to a gradual declining trend in the livestock population over the past 10 to 20 years in the communal areas as a result of feed shortage.
- Full Text:
- Date Issued: 2018
- Authors: Kahumba, Absalom
- Date: 2018
- Subjects: Rural development Land use Land tenure
- Language: English
- Type: Thesis , Doctoral , Pasture Science
- Identifier: http://hdl.handle.net/10353/11718 , vital:39100
- Description: This study was conducted in Ogongo district, situated in Omusati Region of the central northern Namibia. The objectives of this study were to assess the impact of land use practices on 1) vegetation distribution and status; 2) soil properties; 3) carbon-nitrogen sequestration potential, and 4) investigate the indigenous pastoralists’ knowledge and perceptions on livestock production, rangeland degradation and its indicators in three villages (Omaandi, Epukunoyana and Oshitutuma) in Mopane savannah rangelands of central northern Namibia. For vegetation and soil assessment, three grazing land management systems (communal, game reserve and cattle ranch) were identified adjacent to each other. In each grazing system, three sites (for game reserve and cattle ranch, these were camps) were selected. In each site, three belt transects of 50 m x 5 m2 were marked to record vegetation and soil data as well as to collect vegetation samples for analysis. Grass species composition was recorded using step point methods from 250 points per belt transect. A total of five 0.25 m2 quadrats were randomly laid within each 250 m2 belt transect to record the herbaceous plant density, tuft diameter, tuft distance and biomass. All woody plants in the belt transect (250 m2) were measured and recorded for species plant height and canopy diameters. Three soil samples per belt transect were collected at the time of forage sampling down to a depth of 20 cm using a soil auger. Soil and plant samples were analysed for macro and micro minerals, total organic carbon, total nitrogen, carbon-nitrogen ratios, and carbon and nitrogen isotopes. For bulk density, soil samples were collected using soil core samplers. In the social study, a total of 90 households were randomly selected from three villages and a total of 48 elders were purposefully selected based on the age, time spent in the village and livestock ownership. A combination of structured and semi-structured questionnaires were used to gather household information, while a structured questionnaire and open ended discussion were used to interview elders on the constraints of livestock production, rangeland degradation related issues and their consequences on livelihood. Field vegetation and soil data were analyzed using a General Linear Model (GLM) in SAS (2007), whereas the social data were analyzed using SPSS version 21 (2014). A total of 23 grass species were identified in all three land management systems, of which 48% were perennials and the remaining 52% were annuals. Aristida meridionalis dominated the game reserve and the ranch, whereas Eragrostis trichophora was dominant in all land management systems. Forbs occurred commonly in the game reserve and the ranch, but were dominant in the communal areas. The abundance of A. meridionalis responded significantly (P < 0.001) to land management systems with the game reserve showing remarkably greater abundance than the ranch. In summer, the abundance of E. trichophora was high (P < 0.001) in the game reserve followed by the communal and ranch sites, whereas in winter, the species had still greater abundance in the game reserve followed by the ranch. In summer, the mean grass density was greatest (P < 0.001) in the game reserve and least in the communal lands, but vice versa for the tuft distance. In summer, the average distance between tufts showed great variations (P < 0.001) with the communal areas having greater values than the ranch and game reserve. In winter, both the game reserve and the ranch showed records of similar grass tuft density and distance between tufts, whereas these values were nil for communal areas, because, there were no grasses recorded. Herbaceous plant dry matter was significantly greater (P < 0.05) in the game reserve followed by the ranch and the least in the communal areas. Results on biomass showed remarkably higher values (P < 0.001) in summer than winter in all land management systems. The total woody plant density was significantly higher (P < 0.001) in the ranch (542 TE ha-1) than the game reserve (449 TE ha-1) and communal area (324 TE ha-1). However, percentage of canopy cover did not differ significantly (P > 0.05) between the three land management systems. Woody plant density of height classes were significantly different (P < 0.05) between three land management systems. The abundance of seedlings, saplings and young shrubs were significantly greater (P < 0.05) in the ranch than the game reserve and communal area. The mature trees had a significantly greater density (P < 0.05) in the game reserve than the ranch and communal area. Soil analysis results showed that Magnesium (Mg), Potassium (K), Manganese (Mn) and Copper (Cu) had similar (P > 0.05) concentrations in soils obtained from all land management systems in both seasons. Soil Calcium (Ca) levels showed differences between land management systems in winter only being greater (P < 0.001) in the game reserve than the ranch and the communal lands. Soil Phosphorus (P) and Iron (Fe) also showed variations between land management systems in winter being significantly greater (P < 0.001) in the ranch than the other land management systems. The concentration of soil K differed between the two seasons in soils collected from the ranch and the communal lands, being greater (P < 0.001) in winter than summer seasons. Soil Zinc (Zn) also showed differences between land management systems in summer being greater (P < 0.001) in the game reserve than in the ranch and communal land. Seasonal variations were observed in soil P level of samples collected from the ranch being greater (P < 0.001) in winter than summer season. The concentration of soil Zn was higher (P < 0.001) in the soil collected from the game reserve and the ranch in summer than winter season. Woody forage analysis results showed that browse samples harvested from the ranch had greater (P < 0.001) Nitrogen (N) level than the other land management systems in both seasons. The browse samples harvested from the game reserve had greater (P < 0.001) Ca level than the other land management systems in winter season only. The level of P showed variations (P < 0.05) between land management systems in samples harvested during winter only being greater (P < 0.001) in samples from the ranch than the other land management systems. Similarly, browse harvested during winter showed significant differences (P < 0.05) in K levels being lowest in samples collected from game reserves, where the Ca level was greatest. Browse samples collected from the communal land and the ranch had the lowest Mg levels in summer and winter seasons, respectively. In all management systems, browse harvested during summer had greater (P < 0.001) N and P levels than those harvested in winter, and the reverse holds true for K and Ca levels. Browse samples harvested during winter had greater (P < 0.001) Mn levels in samples from the communal area and game reserve than the ranch, but in summer, the game reserve had higher Mn level than the other two sites. Browse samples harvested during winter only showed differences (P < 0.05) in Cu and Zn levels being greatest (P < 0.001) in samples collected from ranch and game reserves. In all management systems, browse samples harvested during winter had greater (P < 0.001) Fe, Mn, Zn and Cu (except for the game reserve and communal land) levels than those harvested in summer. Herbaceous analysis results showed that samples harvested in summer from the game reserve and ranch had greater (P < 0.001) TOC levels than the communal area, but in winter, samples from the game reserve and ranch had similar TOC levels, except for communal areas that had no herbaceous vegetation. Herbaceous samples harvested in winter from the ranch had greater (P < 0.001) TN levels than the game reserve, and that made the C:N ratio higher (P < 0.001) in the game reserve. Woody foliar samples harvested in winter from the game reserve and communal lands had greater (P < 0.001) TOC than the ranch. Values on C:N ratio showed that in winter, the communal and ranch had greater (P < 0.001) C:N than the game reserve, but in summer, the ranch had higher (P < 0.001) C:N than the game reserve and communal area. The vegetation TOC (kg ha-1) showed the order of the game reserve > ranch > communal area and the trend was similar in both seasons. In summer, the game reserve had the greatest (P < 0.001) TN (kg ha-1) followed by the ranch and the lowest in the communal area, but in winter the game reserve and ranch had similar and higher (P < 0.001) TN (kg ha-1) than the communal areas. In summer, both the game reserve and ranch recorded greater (P < 0.001) herbaceous δ13C and lowest δ15N than the communal area, but in winter, the game reserve had higher (P < 0.001) δ13C than the ranch, though both the game reserve and ranch had similar (P > 0.001) δ15N values. In summer, both the communal and ranch had slightly higher (P < 0.001) woody foliar δ13C than the game reserve, but in winter the ranch had greater (P < 0.001) δ13C than game reserve and communal areas. Woody foliar samples harvested from the ranch showed variations (P < 0.05) in δ15N between seasons being higher (P < 0.001) in summer than winter. The TOC was greatest in summer, in soils collected from the game reserve followed by the ranch and least in the communal land, but in winter, the lowest TOC was recorded in soils collected from the ranch. The soil C:N ratio varied between land management systems in soils collected during summer only being greater (P < 0.001) in the game and ranch than the communal area. The soil TOC (kg ha-1) and TN (kg ha-1) did not show (P > 0.05) differences between land management systems. Soil δ13C level was remarkably (P < 0.05) affected by land management systems, but did not interact with seasons. In both seasons, the communal land had slightly higher (P < 0.001) δ13C level than the other two land management systems. In both seasons, δ15N levels showed great differences (P < 0.001) between land management systems, with highest soil δ15N levels observed in the communal area than the ranch and game reserve. Results on social survey showed that the majority of the interviewed households in Omaandi (63percent), Oshitutuma (53percent) and Epukunoyana (50percent) were female headed families and the remaining were male headed. The mean population of goats and cattle were significantly higher (P < 0.05) in Omaandi and Epukunoyana than in Oshitutuma village, respectively. In this study, household respondents in all villages indicated that all livestock species were primarily kept for wealth status and provision of meat for consumption. Respondents in all villages also indicated that lack of grazing lands and shortage of feed were the primary constraints of livestock production followed by water scarcity and recurring droughts. Elder respondents in all villages perceived overgrazing and climate change as the primary cause of rangeland degradation. Elder interviewees in Omaandi and Oshitutuma villages regarded low grass cover and dominance of poor quality grass (Epukunoyana only) as the primary vegetation indicators of rangeland degradation. The animal related indicators such as stunted animal body as a result of mineral deficiency, high livestock mortality, emaciated body and animals traveling long distance for grazing and water (Oshitutuma only) were regarded in all villages as the primary livestock related indicators of rangeland degradation. Elders from Epukunoyana village ranked low rainfall, high soil and atmospheric temperatures as the primary climate related indicators of rangeland degradation, although in Omaandi and Oshitutuma, high soil and atmospheric temperatures were considered as the primary climate related indicators of rangeland degradation. Based on the findings, this study concludes that land management systems had great influences on the distribution and production of herbaceous and woody vegetation in summer and winter seasons. This study also observed that land management systems interacted strongly with season to influence most vegetation and soil variables. Lastly, based on the study findings, the study concludes that all three communal rangelands are degraded and degradation led to a gradual declining trend in the livestock population over the past 10 to 20 years in the communal areas as a result of feed shortage.
- Full Text:
- Date Issued: 2018
Bayesian spatial modelling of tuberculosis and its effects on socio-economic and demographic factors in South Africa : a case study of the Eastern Cape Province
- Authors: Obaromi, Abiodun Davies
- Date: 2018
- Subjects: Tuberculosis -- South Africa -- Eastern Cape Tuberculosis -- Epidemiology -- Statistics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9648 , vital:34813
- Description: This dissertation is concerned with evolving and extending statistical models in the area of Bayesian spatial modelling, an increasingly important field of spatial epidemiology with particular interest towards application to Tuberculosis data in the Eastern Cape province of South Africa. In spatial epidemiology, the diseases to be examined usually occur within a map that needs spatial statistical methods that are appropriate, to model the observed data in the presence of some covariates and also cater for the variation of the disease. In this thesis, the Bayesian models were developed in such a way that they allowed several factors classified as fixed and random effects, to be included in the models and using the Bayesian approach. The basic model used in disease mapping is the Besag, York and Mollie model, which incorporates two random effects; one which is spatially structured and the other random effect which is spatially unstructured. The effects (fixed and random) were the covariate effects, socio-economic and demographic variability and the spatial variability respectively, which were all investigated in seven different hierarchical/multilevel Bayesian models. These factors showed varying and substantial effects in the posterior relative risk estimation of the disease. We assumed a negative binomial and generalized Poisson distributions to the response variable or relative risk estimate, 𝑦𝑖 ,to capture the over-dispersion phenomenon that is common and inherent with Poisson density for counts data. Spatial and non-spatial models were developed to model over-dispersion with all the distributions; Poisson, negative binomial and generalized Poisson. Negative binomial and generalized Poisson showed varying properties from comparisons with DIC values and parameter estimates to standard errors, which made either of them fit depending on the choice of model selection. It was found that a lower DIC value could be insufficient to determine a best fit model, if other models present estimates with lower variances even at higher DIC values. The generalized Poisson, a two parameter distribution like the negative binomial, which also has the ability to capture both under-dispersion and over-dispersion, was found to perform better in the results than the negative binomial on the basis of a lower variance and with more exact parameter estimates. A new weighted prior distribution, the “Besag2” ICAR model for the structured spatial random effects, which is an extension of the traditional ICAR prior model with two hyperparameters, was also developed and compared with some existing prior models; BYM and ICAR, to measure for spatial dependency in the regions. This new prior distribution was found to show a better fit, when compared to the basic ICAR prior usually assumed for the spatial random effect in the BYM model. This newly parameterized prior distribution in the Besag, York and Mollie model also led to improved parameter control, as the hyperparameters can be seen independently from each other. The result also showed that the new model performed well, both presenting good learning abilities and good shrinkage behaviour. In terms of model choice criteria, the proposed model performed at least equally well and better than the existing models, and the new formulation also gave parameters that are interpretable and have a clearer meaning. To interpolate scattered or regularly distributed data, there are imprecise or exact methods, but there are some of these methods that could be used for interpolating data in a regular grid and others in an irregular grid. Linear and biharmonic spline methods were implemented in MATLAB, to compare for smoothing in the distribution patterns of tuberculosis in the province. This smoothing spline is a method of fitting a smooth curve to a set of noisy observations using a spline function. This new method is rarely used in disease mapping applications, but it has a superior advantage to be assessed at subjective locations rather than only on a rectangular grid as seen in most traditional GIS methods of geospatial analyses. The proposed new models and methods in this thesis were found to be flexible and robust, since they can be reduced or extended according to the nature of the data. Nevertheless, great care must be considered in the choice of prior densities. The approaches developed in this dissertation helped to broaden the scope for spatial analysis and disease mapping applications in epidemiology and public health studies.
- Full Text:
- Date Issued: 2018
- Authors: Obaromi, Abiodun Davies
- Date: 2018
- Subjects: Tuberculosis -- South Africa -- Eastern Cape Tuberculosis -- Epidemiology -- Statistics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9648 , vital:34813
- Description: This dissertation is concerned with evolving and extending statistical models in the area of Bayesian spatial modelling, an increasingly important field of spatial epidemiology with particular interest towards application to Tuberculosis data in the Eastern Cape province of South Africa. In spatial epidemiology, the diseases to be examined usually occur within a map that needs spatial statistical methods that are appropriate, to model the observed data in the presence of some covariates and also cater for the variation of the disease. In this thesis, the Bayesian models were developed in such a way that they allowed several factors classified as fixed and random effects, to be included in the models and using the Bayesian approach. The basic model used in disease mapping is the Besag, York and Mollie model, which incorporates two random effects; one which is spatially structured and the other random effect which is spatially unstructured. The effects (fixed and random) were the covariate effects, socio-economic and demographic variability and the spatial variability respectively, which were all investigated in seven different hierarchical/multilevel Bayesian models. These factors showed varying and substantial effects in the posterior relative risk estimation of the disease. We assumed a negative binomial and generalized Poisson distributions to the response variable or relative risk estimate, 𝑦𝑖 ,to capture the over-dispersion phenomenon that is common and inherent with Poisson density for counts data. Spatial and non-spatial models were developed to model over-dispersion with all the distributions; Poisson, negative binomial and generalized Poisson. Negative binomial and generalized Poisson showed varying properties from comparisons with DIC values and parameter estimates to standard errors, which made either of them fit depending on the choice of model selection. It was found that a lower DIC value could be insufficient to determine a best fit model, if other models present estimates with lower variances even at higher DIC values. The generalized Poisson, a two parameter distribution like the negative binomial, which also has the ability to capture both under-dispersion and over-dispersion, was found to perform better in the results than the negative binomial on the basis of a lower variance and with more exact parameter estimates. A new weighted prior distribution, the “Besag2” ICAR model for the structured spatial random effects, which is an extension of the traditional ICAR prior model with two hyperparameters, was also developed and compared with some existing prior models; BYM and ICAR, to measure for spatial dependency in the regions. This new prior distribution was found to show a better fit, when compared to the basic ICAR prior usually assumed for the spatial random effect in the BYM model. This newly parameterized prior distribution in the Besag, York and Mollie model also led to improved parameter control, as the hyperparameters can be seen independently from each other. The result also showed that the new model performed well, both presenting good learning abilities and good shrinkage behaviour. In terms of model choice criteria, the proposed model performed at least equally well and better than the existing models, and the new formulation also gave parameters that are interpretable and have a clearer meaning. To interpolate scattered or regularly distributed data, there are imprecise or exact methods, but there are some of these methods that could be used for interpolating data in a regular grid and others in an irregular grid. Linear and biharmonic spline methods were implemented in MATLAB, to compare for smoothing in the distribution patterns of tuberculosis in the province. This smoothing spline is a method of fitting a smooth curve to a set of noisy observations using a spline function. This new method is rarely used in disease mapping applications, but it has a superior advantage to be assessed at subjective locations rather than only on a rectangular grid as seen in most traditional GIS methods of geospatial analyses. The proposed new models and methods in this thesis were found to be flexible and robust, since they can be reduced or extended according to the nature of the data. Nevertheless, great care must be considered in the choice of prior densities. The approaches developed in this dissertation helped to broaden the scope for spatial analysis and disease mapping applications in epidemiology and public health studies.
- Full Text:
- Date Issued: 2018
Chemical transformation and phytochemical studies of bioactive constituents from extract of callistemon citrinus (curtis) skeels
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
- Full Text:
- Date Issued: 2018
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
- Full Text:
- Date Issued: 2018
Evaluation and identification of microbial contaminants in polyherbal medicines used for the treatment of tuberculosis in Amathole District Municipality, Eastern Cape Province, South Africa
- Authors: Famewo, Elizabeth Bosede
- Date: 2018
- Subjects: Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9680 , vital:34818
- Description: Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Famewo, Elizabeth Bosede
- Date: 2018
- Subjects: Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9680 , vital:34818
- Description: Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2018
Farmers' vulnerability to climate change and variability and adaptation strategies : a case study of commercial tobacco farmers in Zimbabwe
- Authors: Nyathi, Confidence G
- Date: 2018
- Subjects: Climatic changes Global environmental change
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9111 , vital:34269
- Description: The fast track land reform program (FTRLP) of 2000 in Zimbabwe resulted in a dynamic change of Zimbabwe’s agricultural landscape. It resulted in the conversion of white owned commercial farms into resettlement models A1 and A2. Model A1 was intended to decongest communal areas and was targeted at land-constrained farmers in communal areas. Model A2 on the other hand was a commercial settlement scheme comprising small, medium and large scale commercial settlement, intended to create a cadre of black commercial farmers. This model was in principle, targeted at any Zimbabwean citizen who could prove farming experience and/or resource availability and was based on the concept of full cost recovery from the beneficiary (Musemwa, 2011) This study looked at the demographic that constitutes of commercial tobacco farmers, in Zimbabwe after the FTLRP, how they are affected by climate change and variability and how they adapt to these climate extremes; in particular, their uptake of crop insurance. The study was quantitative and utilised a structured pre-coded questionnaire to interview 158 farmers that are into commercial tobacco farming in Manicaland, Mashonaland Central, Mashonaland West and Mashonaland East Provinces of Zimbabwe. The focus was on two central themes. The first was an investigation of the commercial tobacco farmers’ vulnerability to climate change and variability in Zimbabwe. The second theme analysed the factors influencing the farmers’ adoption of crop insurance and the challenges faced by both the farmers and insurance companies in its adoption. Three approaches were used to address the above objectives. Firstly to analyze the vulnerability of commercial tobacco farmers to climate change and variability, the integrated vulnerability assessment approach using vulnerability indicators from four tobacco producing provinces in Zimbabwe was used. The vulnerability indicators used included a series of different socio-economic, institutional and biophysical attributes which were further categorized into three classes, based on the Intergovernmental Panel on Climate Change’s (IPCC 2001) definition of vulnerability, which consists of adaptive capacity, sensitivity and exposure. The LV Index and LVI-IPCC Index (Ms Excel) were then used to determine the farmer’s vulnerability index. Secondly, descriptive statistics were used to determine the manner in which farmers have been adapting to climate change and variability and lastly, the study used the binary logistic regression model to determine factors that influence the adoption of crop insurance by these farmers. The results from the analysis show that the net effect of exposure, sensitivity and adaptive capacity is moderate for the provinces of Mashonaland East, Mashonaland Central, Mashonaland West and Manicaland. Through the LVI Index and LVI-IPCC index, the study found indices of 0.566 and 0.100 respectively showing that the commercial farmers in these provinces are moderately vulnerable to the effects of climate change and variability. The factors that contributed the most to this vulnerability were aspects of finance, knowledge and skills, support services, and the state of the environment. In terms of adaptation, the majority of farmers indicated that they were aware of climate change and were aware of increased climate variability and had observed an increase in temperature and rainfall variability. The different ways in which the farmers adapted included, off-farm income, enterprise diversification, irrigation, crop rotation, conservation tillage practices, establishing woodlots and using alternative fuel for curing such as coal. The binary logistic regression model showed that the factors that were significant with a positive effect on the uptake of crop insurance are; subscription to contract farming which was the major determinant, access to crop insurance information, farm tenure and area under tobacco. Factors that had a significant but negative effect, and led to a reduction in the uptake of crop insurance were level of education, perception of crop insurance premiums and enterprise diversification. The farmers were found to be highly diversified either with off-farm income, crop diversification and or enterprise diversification. The study recommended that the farmers should promote sustainable development through their production activities and adaptation strategies adopted to increase their resilience to climate change and variability. Strengthening of social networks and institutional capacities was also recommended to; increase bargaining power, for information dissemination and provision of technical support and extension services to enable the farmers to take on appropriate measues to reduce their vulnerability. In terms of crop insurance uptake, the study recommended improvement in the dialogue between the farmers and insurance companies, and periodic training and education of farmers to improve knowledge and encourage uptake.
- Full Text:
- Date Issued: 2018
- Authors: Nyathi, Confidence G
- Date: 2018
- Subjects: Climatic changes Global environmental change
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9111 , vital:34269
- Description: The fast track land reform program (FTRLP) of 2000 in Zimbabwe resulted in a dynamic change of Zimbabwe’s agricultural landscape. It resulted in the conversion of white owned commercial farms into resettlement models A1 and A2. Model A1 was intended to decongest communal areas and was targeted at land-constrained farmers in communal areas. Model A2 on the other hand was a commercial settlement scheme comprising small, medium and large scale commercial settlement, intended to create a cadre of black commercial farmers. This model was in principle, targeted at any Zimbabwean citizen who could prove farming experience and/or resource availability and was based on the concept of full cost recovery from the beneficiary (Musemwa, 2011) This study looked at the demographic that constitutes of commercial tobacco farmers, in Zimbabwe after the FTLRP, how they are affected by climate change and variability and how they adapt to these climate extremes; in particular, their uptake of crop insurance. The study was quantitative and utilised a structured pre-coded questionnaire to interview 158 farmers that are into commercial tobacco farming in Manicaland, Mashonaland Central, Mashonaland West and Mashonaland East Provinces of Zimbabwe. The focus was on two central themes. The first was an investigation of the commercial tobacco farmers’ vulnerability to climate change and variability in Zimbabwe. The second theme analysed the factors influencing the farmers’ adoption of crop insurance and the challenges faced by both the farmers and insurance companies in its adoption. Three approaches were used to address the above objectives. Firstly to analyze the vulnerability of commercial tobacco farmers to climate change and variability, the integrated vulnerability assessment approach using vulnerability indicators from four tobacco producing provinces in Zimbabwe was used. The vulnerability indicators used included a series of different socio-economic, institutional and biophysical attributes which were further categorized into three classes, based on the Intergovernmental Panel on Climate Change’s (IPCC 2001) definition of vulnerability, which consists of adaptive capacity, sensitivity and exposure. The LV Index and LVI-IPCC Index (Ms Excel) were then used to determine the farmer’s vulnerability index. Secondly, descriptive statistics were used to determine the manner in which farmers have been adapting to climate change and variability and lastly, the study used the binary logistic regression model to determine factors that influence the adoption of crop insurance by these farmers. The results from the analysis show that the net effect of exposure, sensitivity and adaptive capacity is moderate for the provinces of Mashonaland East, Mashonaland Central, Mashonaland West and Manicaland. Through the LVI Index and LVI-IPCC index, the study found indices of 0.566 and 0.100 respectively showing that the commercial farmers in these provinces are moderately vulnerable to the effects of climate change and variability. The factors that contributed the most to this vulnerability were aspects of finance, knowledge and skills, support services, and the state of the environment. In terms of adaptation, the majority of farmers indicated that they were aware of climate change and were aware of increased climate variability and had observed an increase in temperature and rainfall variability. The different ways in which the farmers adapted included, off-farm income, enterprise diversification, irrigation, crop rotation, conservation tillage practices, establishing woodlots and using alternative fuel for curing such as coal. The binary logistic regression model showed that the factors that were significant with a positive effect on the uptake of crop insurance are; subscription to contract farming which was the major determinant, access to crop insurance information, farm tenure and area under tobacco. Factors that had a significant but negative effect, and led to a reduction in the uptake of crop insurance were level of education, perception of crop insurance premiums and enterprise diversification. The farmers were found to be highly diversified either with off-farm income, crop diversification and or enterprise diversification. The study recommended that the farmers should promote sustainable development through their production activities and adaptation strategies adopted to increase their resilience to climate change and variability. Strengthening of social networks and institutional capacities was also recommended to; increase bargaining power, for information dissemination and provision of technical support and extension services to enable the farmers to take on appropriate measues to reduce their vulnerability. In terms of crop insurance uptake, the study recommended improvement in the dialogue between the farmers and insurance companies, and periodic training and education of farmers to improve knowledge and encourage uptake.
- Full Text:
- Date Issued: 2018
Institutions, Production and Marketing of maize in Zimbabwe. Case of Marondera District of Mashonaland East Province
- Authors: Mafuse, Never
- Date: 2018
- Subjects: Food security Food supply
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15687 , vital:40506
- Description: Food security situation in Zimbabwe is deteriorating despite the efforts made by the government for embarking on agrarian reforms in terms of redressing colonial imbalances and taking on the major trading investment risks. The government assured the resettled farmers that if they invest in maize production, they would not be stranded by lack of marketing services as the markets are liberalized. However, this market liberalization policy occurring in maize sector has resulted in A1 resettled farmers becoming more vulnerable to traders preying on their weaknesses as the policy is not living up to expectations and is failing to bring dramatic increases in agricultural growth. This may mean that sending children to school is a nightmare for those who depend on farming for educating their children, inadequate food in the home, unpaid loans and subsequent impoverishment. The resettled A1farmers will remain trapped in the poverty cycle as long as institutions are not corrected. The general aim of the study was to evaluate institutional factors influencing maize production and marketing by A1 resettled farmers of Marondera district in Mashonaland East province of Zimbabwe. Using a sample of 343 farmers randomly selected in Marondera District, different econometric models like Data envelopment Analysis, Cob Douglas, Binary logistic, and Tobit as well as descriptive statistics were used to analyse the data. Institutional variables were captured in two ways: as a dummy showing whether farmers have access to institutional variables and as a continuous variable indicating importance of institutions on maize production and marketing. The study found out that, most of the A1 farmers are old, with a mean age of 47 years and a maximum of 55 years of farming experience. It is also dominated by male farmers who are literate. Results also showed that most of A1 farmers from the sample are married and very few separated. These farmers sell most their maize and keep little for consumption though they are still using convectional farming methods. Most of the farmers from the sample generate their incomes from farming activities only and they have good access to market and production information as well as extension xvi messages through training .They however have poor access to financial credit and weak social capital as well as low contract farming. Results also indicated that A1 farmers pursue the formal supply chains than informal supply chains. It is noted that, A1 farmers participate in a number of markets that include agricultural inputs markets seed, fertilizers, chemicals.; credit markets which includes banks as well as labour markets which can in the form of (maricho). In terms production and marketing efficiency, the study found out that A1 farmers are technically, allocatively and economically inefficient. The maximum efficient score is 1 while the minimum score is 0.01 for both production and marketing stage. The mean scores for production stage are 0.195, 0.504 and 0.072 for technical, allocative and economic efficient respectively. The mean scores for marketing are 0.103, 0.688, and 0.068 for technical, allocative and economic efficiency respectively. Farmers are performing better at production stage than at marketing technically while there is better allocative and economic efficiency at marketing stage. Results for determinants of technical, allocative and economic efficiency at production stage showed that, cattle ownership, farming experience, access to financial credit and (member of farmer organisation) which was used as a proxy indicator for social capital ,access to information, contract farming, distance to input market ,area planted to maize and quantity of seed used influences marketing efficiency of A1 maize farmers in Marondera District. Access to credit, Access to market, distance to market, road infrastructure, farming experience and access to information influences technical, allocative and economic efficiency at marketing stage. Cooperative membership, road infrastructure, contractual farming arrangements, and access to financial credit and transport cost to market influence choice of marketing channel respectively. Finally results from the non linear cob Douglas reveals that, maize production is significantly influenced by contract with value chain actors, access to market xvii information, access to financial credit, total topdressing used , total basal fertilizer used, total herbicides used, and total area put under maize production. The results showed that, future of A1 resettled farmers depends on correcting the institutions which are of paramount importance for maize production and marketing. The study therefore recommended the government to improve institutional environment that has direct link with institutional innovations necessary for sustainable maize production and marketing. This can be done through correcting inefficiencies and ineffective institutions by creating and maintaining both environment and arrangement that will transform maize production and marketing systems to operate efficiently. The study presents policy options to address both production and marketing of maize arguing that new direction of production and marketing of maize depends on correcting dysfunctional institutions. Policy options include increasing A1 farmers access to financial credit by removing the stringent collateral requirements which are not attainable by most A1 farmers as their asset endowment is limited to non capital. Addressing imperfections in the input markets by improving the supply of chemical fertilisers and seed at affordable prices as this influences total area put under maize production. The other policy is for private companies and NGOs to offer contract farming to A1 maize farmers as this will help them to increase total area put under maize production, access to market, access to credit, and access to information and reduces long distances to purchase inputs. Introducing focused training to motivate resettled A1 farmers on formation farmer organisations as this assists in social capital which is an important asset in maize production and marketing.Improving road infrastructure by creating a fund that would be used to maintain the road rather waiting for DDF only.
- Full Text:
- Date Issued: 2018
- Authors: Mafuse, Never
- Date: 2018
- Subjects: Food security Food supply
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15687 , vital:40506
- Description: Food security situation in Zimbabwe is deteriorating despite the efforts made by the government for embarking on agrarian reforms in terms of redressing colonial imbalances and taking on the major trading investment risks. The government assured the resettled farmers that if they invest in maize production, they would not be stranded by lack of marketing services as the markets are liberalized. However, this market liberalization policy occurring in maize sector has resulted in A1 resettled farmers becoming more vulnerable to traders preying on their weaknesses as the policy is not living up to expectations and is failing to bring dramatic increases in agricultural growth. This may mean that sending children to school is a nightmare for those who depend on farming for educating their children, inadequate food in the home, unpaid loans and subsequent impoverishment. The resettled A1farmers will remain trapped in the poverty cycle as long as institutions are not corrected. The general aim of the study was to evaluate institutional factors influencing maize production and marketing by A1 resettled farmers of Marondera district in Mashonaland East province of Zimbabwe. Using a sample of 343 farmers randomly selected in Marondera District, different econometric models like Data envelopment Analysis, Cob Douglas, Binary logistic, and Tobit as well as descriptive statistics were used to analyse the data. Institutional variables were captured in two ways: as a dummy showing whether farmers have access to institutional variables and as a continuous variable indicating importance of institutions on maize production and marketing. The study found out that, most of the A1 farmers are old, with a mean age of 47 years and a maximum of 55 years of farming experience. It is also dominated by male farmers who are literate. Results also showed that most of A1 farmers from the sample are married and very few separated. These farmers sell most their maize and keep little for consumption though they are still using convectional farming methods. Most of the farmers from the sample generate their incomes from farming activities only and they have good access to market and production information as well as extension xvi messages through training .They however have poor access to financial credit and weak social capital as well as low contract farming. Results also indicated that A1 farmers pursue the formal supply chains than informal supply chains. It is noted that, A1 farmers participate in a number of markets that include agricultural inputs markets seed, fertilizers, chemicals.; credit markets which includes banks as well as labour markets which can in the form of (maricho). In terms production and marketing efficiency, the study found out that A1 farmers are technically, allocatively and economically inefficient. The maximum efficient score is 1 while the minimum score is 0.01 for both production and marketing stage. The mean scores for production stage are 0.195, 0.504 and 0.072 for technical, allocative and economic efficient respectively. The mean scores for marketing are 0.103, 0.688, and 0.068 for technical, allocative and economic efficiency respectively. Farmers are performing better at production stage than at marketing technically while there is better allocative and economic efficiency at marketing stage. Results for determinants of technical, allocative and economic efficiency at production stage showed that, cattle ownership, farming experience, access to financial credit and (member of farmer organisation) which was used as a proxy indicator for social capital ,access to information, contract farming, distance to input market ,area planted to maize and quantity of seed used influences marketing efficiency of A1 maize farmers in Marondera District. Access to credit, Access to market, distance to market, road infrastructure, farming experience and access to information influences technical, allocative and economic efficiency at marketing stage. Cooperative membership, road infrastructure, contractual farming arrangements, and access to financial credit and transport cost to market influence choice of marketing channel respectively. Finally results from the non linear cob Douglas reveals that, maize production is significantly influenced by contract with value chain actors, access to market xvii information, access to financial credit, total topdressing used , total basal fertilizer used, total herbicides used, and total area put under maize production. The results showed that, future of A1 resettled farmers depends on correcting the institutions which are of paramount importance for maize production and marketing. The study therefore recommended the government to improve institutional environment that has direct link with institutional innovations necessary for sustainable maize production and marketing. This can be done through correcting inefficiencies and ineffective institutions by creating and maintaining both environment and arrangement that will transform maize production and marketing systems to operate efficiently. The study presents policy options to address both production and marketing of maize arguing that new direction of production and marketing of maize depends on correcting dysfunctional institutions. Policy options include increasing A1 farmers access to financial credit by removing the stringent collateral requirements which are not attainable by most A1 farmers as their asset endowment is limited to non capital. Addressing imperfections in the input markets by improving the supply of chemical fertilisers and seed at affordable prices as this influences total area put under maize production. The other policy is for private companies and NGOs to offer contract farming to A1 maize farmers as this will help them to increase total area put under maize production, access to market, access to credit, and access to information and reduces long distances to purchase inputs. Introducing focused training to motivate resettled A1 farmers on formation farmer organisations as this assists in social capital which is an important asset in maize production and marketing.Improving road infrastructure by creating a fund that would be used to maintain the road rather waiting for DDF only.
- 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
Production and molecular characterization of peroxidases from novel ligninolytic proteobacteria and bacillus strains
- Authors: Falade, Ayodeji Osmund
- Date: 2018
- Subjects: Peroxidase Catalase
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9702 , vital:34823
- Description: Inadequate quantity is a major impediment to the industrial application of peroxidase and other industrial enzymes. Consequently, efforts are geared towards increasing peroxidase production by searching for new microbes with enhanced production capacity. In this study, three novel ligninolytic bacteria: Raoultella ornithinolytica OKOH-1 (KX640917), Ensifer adhaerens NWODO-2 (KX640918) and Bacillus sp. FALADE-1 (KX640922) were optimized for peroxidase production and their peroxidases characterized using molecular and biochemical approaches. Molecular analysis confirmed the presence of peroxidase genes in the three bacteria. BLAST result and phylogenetic analysis of the deduced amino acid sequences suggested that Raoultella ornithinolytica OKOH-1 peroxidase (RaoPrx) belongs to a DyP-type peroxidase family while peroxidases from Ensifer adhaerens NWODO-2 and Bacillus sp. FALADE-1 are catalase-peroxidases. The peroxidase genes are available in the GenBank with MF370527, MF374336 and MF407314 as respective accession numbers. Upon optimization, Raoultella ornithinolytica OKOH-1 exhibited the highest peroxidase production at pH 5, 35 oC and 150 rpm. Biochemical characterization showed that RaoPrx had a wide substrate specificity as it was able to oxidize all the tested substrates in this study (ABTS, veratryl alcohol, guaiacol and pyrogallol), except 2, 6-Dimethoxyphenol. However, highest activity by the enzyme was recorded with pyrogallol as substrate. The enzyme had an optimum activity at pH 6 and 50 oC and was very stable at high temperatures (50 oC – 70 oC). Its pH stability was over a pH range of 5.0 – 7.0. Moreover, RaoPrx activity was significantly enhanced by Ag+, Cu2+, Zn2+and Fe2+ while Ca2+, Mg2+, Ba2+, Al3+, Co2+, NaN3 and EDTA inhibited the activity of the enzyme. Nevertheless, RaoPrx exhibited a remarkable dye-decolourizing activity on congo red and melanin, indicating the biotechnological potential of the enzyme in dye decolourization and development of cosmetic agent. Generally, the results from this study suggest that ligninolytic bacteria hold a great potential for enhanced peroxidase production that could meet the increasing industrial demand.
- Full Text:
- Date Issued: 2018
- Authors: Falade, Ayodeji Osmund
- Date: 2018
- Subjects: Peroxidase Catalase
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9702 , vital:34823
- Description: Inadequate quantity is a major impediment to the industrial application of peroxidase and other industrial enzymes. Consequently, efforts are geared towards increasing peroxidase production by searching for new microbes with enhanced production capacity. In this study, three novel ligninolytic bacteria: Raoultella ornithinolytica OKOH-1 (KX640917), Ensifer adhaerens NWODO-2 (KX640918) and Bacillus sp. FALADE-1 (KX640922) were optimized for peroxidase production and their peroxidases characterized using molecular and biochemical approaches. Molecular analysis confirmed the presence of peroxidase genes in the three bacteria. BLAST result and phylogenetic analysis of the deduced amino acid sequences suggested that Raoultella ornithinolytica OKOH-1 peroxidase (RaoPrx) belongs to a DyP-type peroxidase family while peroxidases from Ensifer adhaerens NWODO-2 and Bacillus sp. FALADE-1 are catalase-peroxidases. The peroxidase genes are available in the GenBank with MF370527, MF374336 and MF407314 as respective accession numbers. Upon optimization, Raoultella ornithinolytica OKOH-1 exhibited the highest peroxidase production at pH 5, 35 oC and 150 rpm. Biochemical characterization showed that RaoPrx had a wide substrate specificity as it was able to oxidize all the tested substrates in this study (ABTS, veratryl alcohol, guaiacol and pyrogallol), except 2, 6-Dimethoxyphenol. However, highest activity by the enzyme was recorded with pyrogallol as substrate. The enzyme had an optimum activity at pH 6 and 50 oC and was very stable at high temperatures (50 oC – 70 oC). Its pH stability was over a pH range of 5.0 – 7.0. Moreover, RaoPrx activity was significantly enhanced by Ag+, Cu2+, Zn2+and Fe2+ while Ca2+, Mg2+, Ba2+, Al3+, Co2+, NaN3 and EDTA inhibited the activity of the enzyme. Nevertheless, RaoPrx exhibited a remarkable dye-decolourizing activity on congo red and melanin, indicating the biotechnological potential of the enzyme in dye decolourization and development of cosmetic agent. Generally, the results from this study suggest that ligninolytic bacteria hold a great potential for enhanced peroxidase production that could meet the increasing industrial demand.
- Full Text:
- Date Issued: 2018
Spatial and seasonal variations of water quality determinants and pollutants as fitness-for-use and compliance assessments of the Mzimvubu catchment water resources for the proposed Mzimvubu Water Project, South Africa
- Authors: Mutingwende, Nhamo
- Date: 2018
- Subjects: Water quality -- South Africa Water quality management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9308 , vital:34320
- Description: The Department of Water Affairs as of late reported plans to build two substantial stockpiling dams in the Mzimvubu Catchment. The Mzimvubu stream basin is probably one of most prominent and undeveloped basin in South Africa. This is notwithstanding high yearly rainfall, high ecological status, high tourism potential, and appropriateness for afforestation, dryland/rainfed and water system agribusiness. Hence, the Department of Water Affairs researched the capability of building a multipurpose dam in the Mzimvubu catchment to catalyse financial and social improvement. The proposed dam will be based on the Tsitsa River. Often, scientific studies related to dam construction concentrate more on discovering the most, in fact, accessible place to construct it, than on the long haul socio-natural issues that come in its preparation. The water quality of the Tsitsa River, its tributaries and the underground drinking water sources within the Mzimvubu catchment are most likely to change once the dam wall is completed. Surface water resources are susceptible to chemical, physical, microbiological contamination and the so-called emerging pollutants either, through human or natural activities. A comprehensive baseline study on the water quality of the Mzimvubu water resources regarding traces of emerging pollutants and water quality determinants (physical, chemical and microbial) pre-dam construction is therefore essential. The objective of the water quality section of this study was to perform an in-depth analysis of water quality in the study area to form a baseline for future studies on how the built dam may affect these. The approach was to assess the spatial and seasonal variations of the pollutants (pharmaceuticals and pesticides) and water quality determinants for all water sources most likely to be affected by the development of the dam. The fitness-for-use and compliance assessments were conducted to assess if the current water resources are fit-for-use for various categories of use and if they comply with various water quality standards and guidelines as determined by the Department of Water Affairs and Forestry. Department of Water Affairs and Forestry is the overseer of South Africa's water assets, and its central goal is to keep up the fitness-for-use of water on a sustained basis. Water samples (500ml) were collected from sixteen (16) sample points, ranging from the proposed mouth of the dam to the N2 bridge point of the Tsitsa River. Points were selected where the Tsitsa River was accessible using the dam project development roads or where tributaries to the Tsitsa River were accessible using dam development roads. Taps/groundwater sources were sampled from the five selected villages. Monthly samples were collected upstream and downstream of the proposed dam wall, from June 2015 to April 2017.Seventeen (17) water quality indices were therefore analysed at sixteen sampling sites, over a two year period. The AB SCIEX TripleTOF™5600 LC/MS/MS was used to screen for pharmaceutical and pesticide pollutants. All the water quality indices were analysed using the AL400 Aqua lytic photometer, and the microbial analysis was done using the Rand Water Method Number 1.2.2.09.1 for enumerating the amount of E. coli and coliforms in the water samples (Rand Water, 2010f). The South African Water Quality Guidelines, Volumes 1 to 7 (DWS, 1996a-g) were used to assess the fitness-for-use of the water sources. To confirm the compliance of the water resources to various standards and guidelines, the water quality data were assessed against international and national guidelines and standards i.e. the WHO guideline, South African water quality guidelines (domestic, irrigation, livestock and watering, aquaculture, and aquatic ecosystems), and the SANS: 241 (2015) standard for drinking water. Non-parametric statistics were utilised to ascertain the changeability, which is a measure of how water quality may vary after some time. With non-parametric insights, the interquartile extent, which lies between the 25th and the 75th percentile, was utilised to depict inconstancy. The median value (50th percentile) was used as an indication of the central tendency or average. The 90th percentile was included as it can be used to assess the frequency of excursions into higher and possibly unacceptable water quality conditions. 3D Sigma plot was used to graphical present the spatial and seasonal variations of water quality indices and emerging pollutants against their concentrations. Fundamental statistical properties and correlations of water quality variables from the Tsitsa River, Tsitsa River tributaries and the drinking water sources were examined using SAS descriptive statistics. The water quality was determined to be of relatively sound quality, based on the comparison with guidelines and standards for the various intended uses, even though some of the water quality determinants were non-compliant and were “unacceptable” regarding fitness for purpose. The water quality of the Ntabalenga dam would most probably be affected by natural influences (for example rainfall, weathering and geological composition) and anthropogenic factors through non-point source pollution from agriculture activities, human settlements (pit latrines and open defecation) as well as industrial activities in the Maclear and Tsolo towns (wastewater treatments plants effluent, hospital effluent). The Tsitsa River had the highest number of non-compliances, especially to the World Health Organisation and Department of Water and Sanitation aquaculture guidelines. Therefore, the Tsitsa River’s water quality would be a significant factor that could compromise the water quality of the water collected in the dam. The human settlement conditions and agricultural inputs seem to be the factors contributing most to contamination of the surface water of the catchment area. The lack of sanitation systems and facilities means that community members have to use the bush and rivers for ablutions, thus contributing to microbial contamination of the environment. The direct application of manure and fertilisers on the fields by farmers further exacerbates microbial contamination and high nutrient inputs into the environment as observed in elevated microbial and phosphate contaminants during the study period. The data obtained from the analysis of pesticides and pharmaceuticals confirmed the contamination of the drinking water sources, the Tsitsa River and its tributaries with pesticides and pharmaceuticals through non-point source pollution. The origins of these pharmaceutical contaminants were identified as the pit latrines, open defecation and wastewater treatment plant effluent, while agricultural application of pesticides was identified as the source of pesticides in surface waters. If not monitored closely, the presence of these emerging pollutants will negatively affect the quality of the dam water both at spatial and temporal scales once the dam wall is completed. Pit latrines and wastewater treatment plants are a significant source of non-point source pollution. The results of this study will add to the ongoing efforts on water quality remediation by recording the spatial and seasonal variations in water quality across various water sources within the study area. The study also provides a baseline for future water quality fitness-for-use and compliance assessments. By these findings and conclusions, it is recommended that a long-term continuous monitoring programme be implemented, especially in areas where increased agricultural activities have been observed. Monitoring should be implemented for the Tsitsa River, its tributaries, and selected drinking water sources which showed the highest number of non-compliances and microbial contamination. All anthropogenic activities in the catchment areas of these sources, both upstream and downstream of the proposed dam wall, must be monitored and strictly managed to prevent and mitigate their possible impacts. Specific emphasis should be placed on agricultural development, which should be controlled to ensure sustainable livestock and cropping practises. Sanitation facilities, systems and community programmes should be put in place to minimise microbial contamination. It would be beneficial for the Department of Water and Sanitation office responsible for the Mzimvubu water resources to establish a central database for all information concerning the water quality of their water resources including the findings in this report. The database must be freely accessible to the residents of the Mzimvubu catchment.
- Full Text:
- Date Issued: 2018
- Authors: Mutingwende, Nhamo
- Date: 2018
- Subjects: Water quality -- South Africa Water quality management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9308 , vital:34320
- Description: The Department of Water Affairs as of late reported plans to build two substantial stockpiling dams in the Mzimvubu Catchment. The Mzimvubu stream basin is probably one of most prominent and undeveloped basin in South Africa. This is notwithstanding high yearly rainfall, high ecological status, high tourism potential, and appropriateness for afforestation, dryland/rainfed and water system agribusiness. Hence, the Department of Water Affairs researched the capability of building a multipurpose dam in the Mzimvubu catchment to catalyse financial and social improvement. The proposed dam will be based on the Tsitsa River. Often, scientific studies related to dam construction concentrate more on discovering the most, in fact, accessible place to construct it, than on the long haul socio-natural issues that come in its preparation. The water quality of the Tsitsa River, its tributaries and the underground drinking water sources within the Mzimvubu catchment are most likely to change once the dam wall is completed. Surface water resources are susceptible to chemical, physical, microbiological contamination and the so-called emerging pollutants either, through human or natural activities. A comprehensive baseline study on the water quality of the Mzimvubu water resources regarding traces of emerging pollutants and water quality determinants (physical, chemical and microbial) pre-dam construction is therefore essential. The objective of the water quality section of this study was to perform an in-depth analysis of water quality in the study area to form a baseline for future studies on how the built dam may affect these. The approach was to assess the spatial and seasonal variations of the pollutants (pharmaceuticals and pesticides) and water quality determinants for all water sources most likely to be affected by the development of the dam. The fitness-for-use and compliance assessments were conducted to assess if the current water resources are fit-for-use for various categories of use and if they comply with various water quality standards and guidelines as determined by the Department of Water Affairs and Forestry. Department of Water Affairs and Forestry is the overseer of South Africa's water assets, and its central goal is to keep up the fitness-for-use of water on a sustained basis. Water samples (500ml) were collected from sixteen (16) sample points, ranging from the proposed mouth of the dam to the N2 bridge point of the Tsitsa River. Points were selected where the Tsitsa River was accessible using the dam project development roads or where tributaries to the Tsitsa River were accessible using dam development roads. Taps/groundwater sources were sampled from the five selected villages. Monthly samples were collected upstream and downstream of the proposed dam wall, from June 2015 to April 2017.Seventeen (17) water quality indices were therefore analysed at sixteen sampling sites, over a two year period. The AB SCIEX TripleTOF™5600 LC/MS/MS was used to screen for pharmaceutical and pesticide pollutants. All the water quality indices were analysed using the AL400 Aqua lytic photometer, and the microbial analysis was done using the Rand Water Method Number 1.2.2.09.1 for enumerating the amount of E. coli and coliforms in the water samples (Rand Water, 2010f). The South African Water Quality Guidelines, Volumes 1 to 7 (DWS, 1996a-g) were used to assess the fitness-for-use of the water sources. To confirm the compliance of the water resources to various standards and guidelines, the water quality data were assessed against international and national guidelines and standards i.e. the WHO guideline, South African water quality guidelines (domestic, irrigation, livestock and watering, aquaculture, and aquatic ecosystems), and the SANS: 241 (2015) standard for drinking water. Non-parametric statistics were utilised to ascertain the changeability, which is a measure of how water quality may vary after some time. With non-parametric insights, the interquartile extent, which lies between the 25th and the 75th percentile, was utilised to depict inconstancy. The median value (50th percentile) was used as an indication of the central tendency or average. The 90th percentile was included as it can be used to assess the frequency of excursions into higher and possibly unacceptable water quality conditions. 3D Sigma plot was used to graphical present the spatial and seasonal variations of water quality indices and emerging pollutants against their concentrations. Fundamental statistical properties and correlations of water quality variables from the Tsitsa River, Tsitsa River tributaries and the drinking water sources were examined using SAS descriptive statistics. The water quality was determined to be of relatively sound quality, based on the comparison with guidelines and standards for the various intended uses, even though some of the water quality determinants were non-compliant and were “unacceptable” regarding fitness for purpose. The water quality of the Ntabalenga dam would most probably be affected by natural influences (for example rainfall, weathering and geological composition) and anthropogenic factors through non-point source pollution from agriculture activities, human settlements (pit latrines and open defecation) as well as industrial activities in the Maclear and Tsolo towns (wastewater treatments plants effluent, hospital effluent). The Tsitsa River had the highest number of non-compliances, especially to the World Health Organisation and Department of Water and Sanitation aquaculture guidelines. Therefore, the Tsitsa River’s water quality would be a significant factor that could compromise the water quality of the water collected in the dam. The human settlement conditions and agricultural inputs seem to be the factors contributing most to contamination of the surface water of the catchment area. The lack of sanitation systems and facilities means that community members have to use the bush and rivers for ablutions, thus contributing to microbial contamination of the environment. The direct application of manure and fertilisers on the fields by farmers further exacerbates microbial contamination and high nutrient inputs into the environment as observed in elevated microbial and phosphate contaminants during the study period. The data obtained from the analysis of pesticides and pharmaceuticals confirmed the contamination of the drinking water sources, the Tsitsa River and its tributaries with pesticides and pharmaceuticals through non-point source pollution. The origins of these pharmaceutical contaminants were identified as the pit latrines, open defecation and wastewater treatment plant effluent, while agricultural application of pesticides was identified as the source of pesticides in surface waters. If not monitored closely, the presence of these emerging pollutants will negatively affect the quality of the dam water both at spatial and temporal scales once the dam wall is completed. Pit latrines and wastewater treatment plants are a significant source of non-point source pollution. The results of this study will add to the ongoing efforts on water quality remediation by recording the spatial and seasonal variations in water quality across various water sources within the study area. The study also provides a baseline for future water quality fitness-for-use and compliance assessments. By these findings and conclusions, it is recommended that a long-term continuous monitoring programme be implemented, especially in areas where increased agricultural activities have been observed. Monitoring should be implemented for the Tsitsa River, its tributaries, and selected drinking water sources which showed the highest number of non-compliances and microbial contamination. All anthropogenic activities in the catchment areas of these sources, both upstream and downstream of the proposed dam wall, must be monitored and strictly managed to prevent and mitigate their possible impacts. Specific emphasis should be placed on agricultural development, which should be controlled to ensure sustainable livestock and cropping practises. Sanitation facilities, systems and community programmes should be put in place to minimise microbial contamination. It would be beneficial for the Department of Water and Sanitation office responsible for the Mzimvubu water resources to establish a central database for all information concerning the water quality of their water resources including the findings in this report. The database must be freely accessible to the residents of the Mzimvubu catchment.
- Full Text:
- Date Issued: 2018
Synthesis, characterization and evaluation of photophysical and electrochemical properties of ruthenium(II) complexes for dye-sensitized solar cells
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
The classification of fuzzy groups of finite cyclic groups Zpn Zqm Zr and Zp1 Zp2 Zpn for distinct prime numbers p; q; r; p1; p2; ; pn and n;m 2 Z+
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
The effect of replacing antibiotic growth promoters with moringa oleifera leaf powder on growth performance, carcass characteristics, immune organ indices, gut microflora, physicochemical and sensory quality of broiler meat
- Nantapo, Carlos Wyson Tawanda
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2018
- Subjects: Moringa oleifera Meat--Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/17749 , vital:41197
- Description: The objective of the study was to determine the effect of feeding graded levels of Moringa oleifera leaf meal powder (MOLP) on growth performance, carcass characteristics, economic analysis, health status, physicochemical, sensory properties, mineral composition and retention values of meat. A total of 1600 Comb-500 day-old unsexed chicks were allotted to 4 dietary treatment groups, with 4 replicate pens of 100 birds each in a completely randomised design. The dietary treatments were basal diets supplemented with different levels of MOLP as follows; Treatment 1/ control: Basal diet with antibiotic Zinc bacitracin and coccidiostatic Maxiban and no MOLP (0MOLP); Treatment 2: Basal diet included 1percent MOLP (1MOLP); Treatment 3: Basal diet included 3.0 percent MOLP (3MOLP); Treatment 4: Basal diet included 5 percent MOLP (5MOLP). Birds fed basal diets plus 5percent MOLP at starter phase achieved the least FCR 1.53 (P < 0.037), whilst consuming significantly less feed ADFI 47.4 g (P < 0.05). For the entire feeding period, birds fed 5 percent MOLP achieved a favourable FCR of 1.80 among all treatment groups (P < 0.001), but achieved the lowest final live weight (1416 g), carcass weights (1044g) (P < 0.05). Birds fed 0 percent MOLP recorded highest final weight, carcass weight (1339) and the best dressing percentages (76.8percent) (P < 0.05). Abdominal fat levels were reduced by elevating MOLP in diets (P < 0.05). Improvements in proportions of giblets, gizzard, liver and intestine were observed with increase in dietary MOLP. Feed costs increased, while gross and net returns and economic efficiency decreased as dietary MOLP increased. Organ indices of spleen, Bursa of Fabricius and liver were significantly increased by 5percent MOLP in the diet (P < 0.05). Macroscopic lesions scores (P < 0.05) were significantly higher in duodenum, jejunum and ileum of birds in the 1MOLP treatment group on d 28 and d 35. Control and 5MOLP groups recorded the least bloody excreta scores among all treatment groups (P < 0.05). Highest total aerobic bacteria (TAB), E. coli, C. perfringens counts and the lowest lactobacillus spp counts were observed in all intestinal segments in birds in the 1MOLP treatment group. Lower E. coli and C. perfringens but higher lactobacillus spp counts were observed in control and 5MOLP groups (P < 0.05) in the duodenum and jejunum. Increasing MOLP levels in diets led to lower pH and pHu in both breast and leg muscles (P < 0.05). pH was consistently lower in leg muscles than in breast cuts in all treatments and a large decline in post-mortem pH was observed in all muscles of birds in control group. A dietary increase in MOLP level led to a significant increase in L* and b* (P < 0.05) negative correlation between pH and L* (r = -0.463) (P < 0.05) and a weak but significant (P < 0.001) correlation (r = 0.176) between pH and drip loss. Herb flavour (P = 0.0029), appearance (P = 0.0156), aroma (P = 0.0011), colour (P = 0.0375), taste (P = 0.0032) and overall acceptability (P = 0.0192) were improved by grilling, microwave cooking and pan-frying in olive oil. These changes were more pronounced in breast muscle, thus following the trend; microwave > pan-frying in olive oil > grilled samples > boiling for best cooked product based on overall acceptability. Grilling and frying heart muscles resulted in the highest Ca (45.9 mg/kg) and Mg (98.9 mg/kg), whereas boiling led to the lowest Ca (41.1 mg/kg) and Mg (91.4 mg/kg) concentration. The highest concentrations of Fe and Zn these minerals were recorded in grilled (32.7 mg/kg) and fried samples (75.2 mg/kg). Zinc and Fe concentration observed in liver and heart muscles were higher than those found in breast and leg muscle. In conclusion, the results confirm the potential of MOLP for use as an alternative to antibiotics in maintaining broiler health, reducing mortalities and improving carcass characteristics and some meat quality traits.
- Full Text:
- Date Issued: 2018
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2018
- Subjects: Moringa oleifera Meat--Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/17749 , vital:41197
- Description: The objective of the study was to determine the effect of feeding graded levels of Moringa oleifera leaf meal powder (MOLP) on growth performance, carcass characteristics, economic analysis, health status, physicochemical, sensory properties, mineral composition and retention values of meat. A total of 1600 Comb-500 day-old unsexed chicks were allotted to 4 dietary treatment groups, with 4 replicate pens of 100 birds each in a completely randomised design. The dietary treatments were basal diets supplemented with different levels of MOLP as follows; Treatment 1/ control: Basal diet with antibiotic Zinc bacitracin and coccidiostatic Maxiban and no MOLP (0MOLP); Treatment 2: Basal diet included 1percent MOLP (1MOLP); Treatment 3: Basal diet included 3.0 percent MOLP (3MOLP); Treatment 4: Basal diet included 5 percent MOLP (5MOLP). Birds fed basal diets plus 5percent MOLP at starter phase achieved the least FCR 1.53 (P < 0.037), whilst consuming significantly less feed ADFI 47.4 g (P < 0.05). For the entire feeding period, birds fed 5 percent MOLP achieved a favourable FCR of 1.80 among all treatment groups (P < 0.001), but achieved the lowest final live weight (1416 g), carcass weights (1044g) (P < 0.05). Birds fed 0 percent MOLP recorded highest final weight, carcass weight (1339) and the best dressing percentages (76.8percent) (P < 0.05). Abdominal fat levels were reduced by elevating MOLP in diets (P < 0.05). Improvements in proportions of giblets, gizzard, liver and intestine were observed with increase in dietary MOLP. Feed costs increased, while gross and net returns and economic efficiency decreased as dietary MOLP increased. Organ indices of spleen, Bursa of Fabricius and liver were significantly increased by 5percent MOLP in the diet (P < 0.05). Macroscopic lesions scores (P < 0.05) were significantly higher in duodenum, jejunum and ileum of birds in the 1MOLP treatment group on d 28 and d 35. Control and 5MOLP groups recorded the least bloody excreta scores among all treatment groups (P < 0.05). Highest total aerobic bacteria (TAB), E. coli, C. perfringens counts and the lowest lactobacillus spp counts were observed in all intestinal segments in birds in the 1MOLP treatment group. Lower E. coli and C. perfringens but higher lactobacillus spp counts were observed in control and 5MOLP groups (P < 0.05) in the duodenum and jejunum. Increasing MOLP levels in diets led to lower pH and pHu in both breast and leg muscles (P < 0.05). pH was consistently lower in leg muscles than in breast cuts in all treatments and a large decline in post-mortem pH was observed in all muscles of birds in control group. A dietary increase in MOLP level led to a significant increase in L* and b* (P < 0.05) negative correlation between pH and L* (r = -0.463) (P < 0.05) and a weak but significant (P < 0.001) correlation (r = 0.176) between pH and drip loss. Herb flavour (P = 0.0029), appearance (P = 0.0156), aroma (P = 0.0011), colour (P = 0.0375), taste (P = 0.0032) and overall acceptability (P = 0.0192) were improved by grilling, microwave cooking and pan-frying in olive oil. These changes were more pronounced in breast muscle, thus following the trend; microwave > pan-frying in olive oil > grilled samples > boiling for best cooked product based on overall acceptability. Grilling and frying heart muscles resulted in the highest Ca (45.9 mg/kg) and Mg (98.9 mg/kg), whereas boiling led to the lowest Ca (41.1 mg/kg) and Mg (91.4 mg/kg) concentration. The highest concentrations of Fe and Zn these minerals were recorded in grilled (32.7 mg/kg) and fried samples (75.2 mg/kg). Zinc and Fe concentration observed in liver and heart muscles were higher than those found in breast and leg muscle. In conclusion, the results confirm the potential of MOLP for use as an alternative to antibiotics in maintaining broiler health, reducing mortalities and improving carcass characteristics and some meat quality traits.
- Full Text:
- Date Issued: 2018
The role of assisted reproduction technologies in improving cattle production under communal and emerging farming systems in Limpopo, Mpumalanga and KwaZulu-Natal, South Africa
- Mugwabana, Thinawanga Joseph
- Authors: Mugwabana, Thinawanga Joseph
- Date: 2018
- Subjects: Beef cattle -- Breeding -- South Africa Beef cattle breeds -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9100 , vital:34262
- Description: The aim of the study was to determine the effect of assisted reproductive technologies (ARTs) in improving cattle production with the purpose of providing policy directives for the successful implementation of the ART project among communal and emerging livestock systems. The study was conducted under communal and emerging cattle farming systems in Limpopo, Mpumalanga and KwaZulu-Natal provinces. The selected districts in Limpopo were Vhembe, Capricorn, Mopani and Waterberg, in Mpumalanga were Gert Sibande and Ehlanzeni while in KwaZulu-Natal the selected districts were Zululand and Harry Gwala. A total of 282 cows were selected for the study, 38 percent in Limpopo, 32 percent in Mpumalanga and 30 percent in KwaZuluNatal. The cow parameters evaluated were breed type, parity, age, body condition score, frame size and lactation status. An ovsynch protocol which allows for fixed-time artificial insemination (FTAI) was used during the oestrous synchronisation process. A heat mount detector (Karma®) was used to detect oestrous synchronisation response. The dominant cattle breed types were the Bonsmara, Brahman and Nguni. All experimental cows that responded positively to oestrous synchronisation protocol and were inseminated with semen from a Nguni bull. Chi-Square Test of Independence were computed to determine the association among factors. Data was further modelled using the logistic regression model of SAS, establishing the probability of success. Districts, breed type, parity, age, and lactation status did not significantly influence (P > 0.05) conception rate following oestrous synchronisation and timed artificial insemination. However, conception rate was not independent (P < 0.05) of provinces, body condition score and body frame size. Cows in KwaZulu-Natal (66 percent) had significantly higher (P < 0.05) conception rates than those in Limpopo (44 percent) and Mpumalanga (60 percent). Cows of body condition score of ≥ 3.5 (72 percent) had a significantly higher (P < 0.05) conception rate than those of body condition score of ≤ 2.5 (66 percent) and 3 (48 percent). Large (82 percent) framed cows had a significantly higher (P < 0.05) conception rate than small (49 percent) and medium (55 percent) framed cows. Cows in Mpumalanga had more chances to conceive than those of Limpopo and KwaZulu-Natal with odds ratio of 0.605 and 0.863, respectively. Cows in KwaZulu-Natal were in much better body conditions than those from the other two provinces. Cows of body condition score of ≥ 3.5 had more chances to conceive than those of body condition score of ≤ 2.5 and 3 with odds ratio of 0.592 and 0.388, respectively, and the difference was significant (P < 0.05). The study recorded a 100 percent calf survival rate following synchronisation and timed artificial insemination. The breed type, parity, age frame size and lactation status did not significantly influence calving response following oestrous synchronisation and timed artificial insemination (P > 0.05). However, calving rate was not independent of provinces, districts and body condition score (P < 0.05). Calving rate in Mpumalanga (58 percent) and KwaZulu-Natal (54 percent) was significantly higher (P < 0.05) than that recorded in Limpopo Province (36 percent). Calving rate of Gert Sibande (61 percent) and Ehlanzeni (50 percent) districts in Mpumalanga and Zululand (50 percent) and Harry Gwala (61 percent) in KwaZulu-Natal was significantly higher (P < 0.05) than that of the Capricorn (32 percent), Mopani (23 percent and Waterberg (30 percent) in Limpopo Province with the exception of Vhembe (44 percent). Cows with body condition score of ≤ 2.5 (60 percent) had a significantly higher (P < 0.05) calving rate than those with a body condition score of 3 (43 percent). Cows in Mpumalanga had more chances to calve than those in Limpopo and KwaZulu-Natal with odds ratio of 0.076 and 0.537, respectively. Additionally, quantitative data was collected through in-depth interviews using a semi-structured questionnaire. Data collected was managed and coded into themes using the Nvivo Version 11 software programme. Themes and issues that emerged were analysed and interpreted using critical social thinking and systems thinking. The results of the study revealed many factors that could compromise the implementation and adoption of ARTs in the study areas. The general feeling amongst cattle farmers interviewed was that government should address these challenges. A shortage of bulls was the main cause of the low cattle reproduction rate. The Nguni breed type cattle was perceived as the ideal cattle breed for rural areas by respondents. Oestrous synchronisation and artificial insemination can be applied under communal and emerging farming systems with success. From the study results, breeding with small framed animals such as the Nguni type breed under communal and emerging farming systems makes a lot of sense because the breed is known for its low feed maintenance requirement. Furthermore, cattle stakeholders should co-operate and work together to address many of the constraints facing cattle productivity and the implementation and adoption of ARTs in rural areas.
- Full Text:
- Date Issued: 2018
- Authors: Mugwabana, Thinawanga Joseph
- Date: 2018
- Subjects: Beef cattle -- Breeding -- South Africa Beef cattle breeds -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9100 , vital:34262
- Description: The aim of the study was to determine the effect of assisted reproductive technologies (ARTs) in improving cattle production with the purpose of providing policy directives for the successful implementation of the ART project among communal and emerging livestock systems. The study was conducted under communal and emerging cattle farming systems in Limpopo, Mpumalanga and KwaZulu-Natal provinces. The selected districts in Limpopo were Vhembe, Capricorn, Mopani and Waterberg, in Mpumalanga were Gert Sibande and Ehlanzeni while in KwaZulu-Natal the selected districts were Zululand and Harry Gwala. A total of 282 cows were selected for the study, 38 percent in Limpopo, 32 percent in Mpumalanga and 30 percent in KwaZuluNatal. The cow parameters evaluated were breed type, parity, age, body condition score, frame size and lactation status. An ovsynch protocol which allows for fixed-time artificial insemination (FTAI) was used during the oestrous synchronisation process. A heat mount detector (Karma®) was used to detect oestrous synchronisation response. The dominant cattle breed types were the Bonsmara, Brahman and Nguni. All experimental cows that responded positively to oestrous synchronisation protocol and were inseminated with semen from a Nguni bull. Chi-Square Test of Independence were computed to determine the association among factors. Data was further modelled using the logistic regression model of SAS, establishing the probability of success. Districts, breed type, parity, age, and lactation status did not significantly influence (P > 0.05) conception rate following oestrous synchronisation and timed artificial insemination. However, conception rate was not independent (P < 0.05) of provinces, body condition score and body frame size. Cows in KwaZulu-Natal (66 percent) had significantly higher (P < 0.05) conception rates than those in Limpopo (44 percent) and Mpumalanga (60 percent). Cows of body condition score of ≥ 3.5 (72 percent) had a significantly higher (P < 0.05) conception rate than those of body condition score of ≤ 2.5 (66 percent) and 3 (48 percent). Large (82 percent) framed cows had a significantly higher (P < 0.05) conception rate than small (49 percent) and medium (55 percent) framed cows. Cows in Mpumalanga had more chances to conceive than those of Limpopo and KwaZulu-Natal with odds ratio of 0.605 and 0.863, respectively. Cows in KwaZulu-Natal were in much better body conditions than those from the other two provinces. Cows of body condition score of ≥ 3.5 had more chances to conceive than those of body condition score of ≤ 2.5 and 3 with odds ratio of 0.592 and 0.388, respectively, and the difference was significant (P < 0.05). The study recorded a 100 percent calf survival rate following synchronisation and timed artificial insemination. The breed type, parity, age frame size and lactation status did not significantly influence calving response following oestrous synchronisation and timed artificial insemination (P > 0.05). However, calving rate was not independent of provinces, districts and body condition score (P < 0.05). Calving rate in Mpumalanga (58 percent) and KwaZulu-Natal (54 percent) was significantly higher (P < 0.05) than that recorded in Limpopo Province (36 percent). Calving rate of Gert Sibande (61 percent) and Ehlanzeni (50 percent) districts in Mpumalanga and Zululand (50 percent) and Harry Gwala (61 percent) in KwaZulu-Natal was significantly higher (P < 0.05) than that of the Capricorn (32 percent), Mopani (23 percent and Waterberg (30 percent) in Limpopo Province with the exception of Vhembe (44 percent). Cows with body condition score of ≤ 2.5 (60 percent) had a significantly higher (P < 0.05) calving rate than those with a body condition score of 3 (43 percent). Cows in Mpumalanga had more chances to calve than those in Limpopo and KwaZulu-Natal with odds ratio of 0.076 and 0.537, respectively. Additionally, quantitative data was collected through in-depth interviews using a semi-structured questionnaire. Data collected was managed and coded into themes using the Nvivo Version 11 software programme. Themes and issues that emerged were analysed and interpreted using critical social thinking and systems thinking. The results of the study revealed many factors that could compromise the implementation and adoption of ARTs in the study areas. The general feeling amongst cattle farmers interviewed was that government should address these challenges. A shortage of bulls was the main cause of the low cattle reproduction rate. The Nguni breed type cattle was perceived as the ideal cattle breed for rural areas by respondents. Oestrous synchronisation and artificial insemination can be applied under communal and emerging farming systems with success. From the study results, breeding with small framed animals such as the Nguni type breed under communal and emerging farming systems makes a lot of sense because the breed is known for its low feed maintenance requirement. Furthermore, cattle stakeholders should co-operate and work together to address many of the constraints facing cattle productivity and the implementation and adoption of ARTs in rural areas.
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- Date Issued: 2018
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