Evaluation of various proteomic techniques to identify proteins involved in cereal stress responses to aphid infestation
- Authors: Nqumla, Ntombekhaya
- Date: 2012
- Subjects: Aphids , Wheat , Plant proteomics , Rice
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11270 , http://hdl.handle.net/10353/d1004572 , Aphids , Wheat , Plant proteomics , Rice
- Description: All plants are exposed to abiotic and biotic stresses and have developed intricate signalling responses to survive. They respond to cell-structure disruption caused by herbivore probing and feeding by the formation of callose. Callose is a linear homopolymer made up of β-1,3-linked glucose residues with some β-1,6-branches. Plant responses to abiotic or biotic stress share events such as phosphorylation, membrane depolarization, calcium influx and the release of reactive oxygen species such as hydrogen peroxide. These events lead to the up-regulation of several pathways leading to biosynthesis of signalling molecules such as salicylic acid, jasmonate, abscisic acid and ethylene pathways. The aim of this study was to determine the most suitable proteomic approach for identifying proteins and signalling pathways involved in cereal response to aphid infestation. An in silico approach was first evaluated in which the 5ʹ upstream regulatory region of proteins belonging to the family of callose synthases was scanned for cis-regulatory elements in order to identify which callose synthases are possibly expressed in plants during biotic or abiotic stresses. Bioinformatics tools were used in the identification of twelve Arabidopsis and ten rice callose synthase coding regions. Genome sequences for rice and Arabidopsis were scanned for the 2000 bp 5ʹ region upstream of the start codon of each callose synthase coding region. PlantCare, PLACE and Athena software were used to identify putative cis-regulatory elements present in the 2000 bp 5ʹ upstream sequences. The majority of cis-acting elements identified were involved in drought and high temperature responses and only one cis-acting element was involved in wound stress. These results therefore indicated a probable role for plant callose synthases in drought stress responses rather than in biotic stress responses. Genevestigator analysis of Arabidopsis results of micro-array experiments indicated that AtGSL10 is highly up-regulated, with AtGSL1, 3, 5, 6, 7, 8, 11 and 12 showing medium up-regulation and AtGSL2, 4 and 9 no up-regulation during aphid infestation of Arabidopsis plants, implicating a possible role for AtGSL10 in the plant response to aphid infestation. An LC/MS/MS approach was used to identify specific signalling pathways involved in wheat resistance or stress response to aphid infestation. Eight proteins were identified as being up-regulated during aphid feeding in wheat, and 11 proteins were identified as possibly involved in the wheat resistance mechanism against aphid infestation. Several proteins were also identified as constitutively expressed proteins, during normal conditions and aphid infestation. Most pathways identified with proteins up-regulated in the resistance mechanisms of TugelaDN plants, were related to energy metabolism and located in the chloroplast. Evaluation of two dimensional gel electrophoresis to identify phosphoproteins differentially regulated in wheat during aphid infestation, revealed the up-regulation of three proteins namely photosystem II oxygen-evolving complex protein 2, HVUNKNOWN from Hordeum vulgare subsp vulgare and HSKERAT9 NID from Homo sapiens. Additional 57 proteins were partially identified as involved in the stress response but due to low protein levels, the percentage of matching peptides to these proteins was below the required confidence level. Although these protein identifications were below the confidence level, it is interesting to note that several of the proteins are known stress response proteins, and therefore could serve as potential targets for future investigations. In conclusion, the down and up-regulation of wheat proteins after aphid feeding reported in this study suggest that several signalling pathways are involved in the cereal stress response to aphid feeding. In silico approaches require knowledge or identification of potential proteins whereas 2D and LC/MS can identify numerous proteins still unknown to be involved in specific stress responses. The 2D approach is also limited in that the proteins of interest may be in low abundance and therefore not detected in the gels due to the presence of high abundant proteins. Therefore the best approach to identify proteins and signalling pathways involved in the stress response of wheat to aphid infestation, is the LC/MS/MS approach, as this proved to be the most sensitive and robust, identifying the most proteins with a high degree of confidence.
- Full Text:
- Date Issued: 2012
- Authors: Nqumla, Ntombekhaya
- Date: 2012
- Subjects: Aphids , Wheat , Plant proteomics , Rice
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11270 , http://hdl.handle.net/10353/d1004572 , Aphids , Wheat , Plant proteomics , Rice
- Description: All plants are exposed to abiotic and biotic stresses and have developed intricate signalling responses to survive. They respond to cell-structure disruption caused by herbivore probing and feeding by the formation of callose. Callose is a linear homopolymer made up of β-1,3-linked glucose residues with some β-1,6-branches. Plant responses to abiotic or biotic stress share events such as phosphorylation, membrane depolarization, calcium influx and the release of reactive oxygen species such as hydrogen peroxide. These events lead to the up-regulation of several pathways leading to biosynthesis of signalling molecules such as salicylic acid, jasmonate, abscisic acid and ethylene pathways. The aim of this study was to determine the most suitable proteomic approach for identifying proteins and signalling pathways involved in cereal response to aphid infestation. An in silico approach was first evaluated in which the 5ʹ upstream regulatory region of proteins belonging to the family of callose synthases was scanned for cis-regulatory elements in order to identify which callose synthases are possibly expressed in plants during biotic or abiotic stresses. Bioinformatics tools were used in the identification of twelve Arabidopsis and ten rice callose synthase coding regions. Genome sequences for rice and Arabidopsis were scanned for the 2000 bp 5ʹ region upstream of the start codon of each callose synthase coding region. PlantCare, PLACE and Athena software were used to identify putative cis-regulatory elements present in the 2000 bp 5ʹ upstream sequences. The majority of cis-acting elements identified were involved in drought and high temperature responses and only one cis-acting element was involved in wound stress. These results therefore indicated a probable role for plant callose synthases in drought stress responses rather than in biotic stress responses. Genevestigator analysis of Arabidopsis results of micro-array experiments indicated that AtGSL10 is highly up-regulated, with AtGSL1, 3, 5, 6, 7, 8, 11 and 12 showing medium up-regulation and AtGSL2, 4 and 9 no up-regulation during aphid infestation of Arabidopsis plants, implicating a possible role for AtGSL10 in the plant response to aphid infestation. An LC/MS/MS approach was used to identify specific signalling pathways involved in wheat resistance or stress response to aphid infestation. Eight proteins were identified as being up-regulated during aphid feeding in wheat, and 11 proteins were identified as possibly involved in the wheat resistance mechanism against aphid infestation. Several proteins were also identified as constitutively expressed proteins, during normal conditions and aphid infestation. Most pathways identified with proteins up-regulated in the resistance mechanisms of TugelaDN plants, were related to energy metabolism and located in the chloroplast. Evaluation of two dimensional gel electrophoresis to identify phosphoproteins differentially regulated in wheat during aphid infestation, revealed the up-regulation of three proteins namely photosystem II oxygen-evolving complex protein 2, HVUNKNOWN from Hordeum vulgare subsp vulgare and HSKERAT9 NID from Homo sapiens. Additional 57 proteins were partially identified as involved in the stress response but due to low protein levels, the percentage of matching peptides to these proteins was below the required confidence level. Although these protein identifications were below the confidence level, it is interesting to note that several of the proteins are known stress response proteins, and therefore could serve as potential targets for future investigations. In conclusion, the down and up-regulation of wheat proteins after aphid feeding reported in this study suggest that several signalling pathways are involved in the cereal stress response to aphid feeding. In silico approaches require knowledge or identification of potential proteins whereas 2D and LC/MS can identify numerous proteins still unknown to be involved in specific stress responses. The 2D approach is also limited in that the proteins of interest may be in low abundance and therefore not detected in the gels due to the presence of high abundant proteins. Therefore the best approach to identify proteins and signalling pathways involved in the stress response of wheat to aphid infestation, is the LC/MS/MS approach, as this proved to be the most sensitive and robust, identifying the most proteins with a high degree of confidence.
- Full Text:
- Date Issued: 2012
Farmers` perceptions of livestock feeding and rangeland management: dynamics of soil, forage and cattle blood serum mineral levels in two communal areas of the Eastern Cape, South Africa
- Authors: Gwelo, Farai Alice
- Date: 2012
- Subjects: Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11581 , http://hdl.handle.net/10353/d1006785 , Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Description: This study was conducted to determine livestock production, rangeland management and the mineral levels of soils, grass and cattle blood serum in two communal areas (Kwezana and Dikidikana). A total of 77 farmers from both Kwezana and Dikidikana were interviewed to determine farmers’ perceptions. Soil and grass sampling was done at three sites in each communal area. Soil and grass samples were analysed for N, Ca, Mg, K, P, Fe, Cu, Zn, Mn and Bo. Three, two and half year old Nguni heifers were randomly selected from each communal area and blood samples were collected for the analysis of Ca, Mg, K, Cu and Fe. Soil, grass and blood samples were all collected in two seasons (winter and summer). The results of the study revealed that feed availability was the major constraint in livestock production as indicated by 83 percent of thefarmers at Kwezana and 88 percent at Dikidikana. At both villages less than 20 percent practiced supplementation and grazing management. From both villages, 83 percent of the farmers did not know the forage species preferred by their cattle. The second study revealed significant seasonal variations in soil N in both study areas while forage N exhibited seasonal variations (P<0.05) only at Dikidikana. Spatial variation (P<0.05) in soil Mn was apparent in both seasons at Dikidikana and in summer at Kwezana. At Dikidikana forage P varied (P<0.05) both seasonally and spatially. In both study areas, there was a positive correlation (P<0.05) between soil and forage levels of Cu and Zn. The blood serum of animals from both study areas had higher (P<0.05) K and Na in winter than in summer. Farmers do not understand the composition of their rangelands but are concerned about cattle nutrition during winter. Indeed the mineral status of soils, forages and Nguni cattle blood serum tend to vary not only seasonally but also spatially. There is need therefore to assist the farmers to understand these changes in order to find ways of managing the rangelands in a way that will manipulate both seasonal and spatial variations in soil nutrients for the benefit of the grazing livestock. Further research is required to determine the digestibility of the forages and the amount of energy available from these forages for the grazing livestock.
- Full Text:
- Date Issued: 2012
- Authors: Gwelo, Farai Alice
- Date: 2012
- Subjects: Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11581 , http://hdl.handle.net/10353/d1006785 , Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Description: This study was conducted to determine livestock production, rangeland management and the mineral levels of soils, grass and cattle blood serum in two communal areas (Kwezana and Dikidikana). A total of 77 farmers from both Kwezana and Dikidikana were interviewed to determine farmers’ perceptions. Soil and grass sampling was done at three sites in each communal area. Soil and grass samples were analysed for N, Ca, Mg, K, P, Fe, Cu, Zn, Mn and Bo. Three, two and half year old Nguni heifers were randomly selected from each communal area and blood samples were collected for the analysis of Ca, Mg, K, Cu and Fe. Soil, grass and blood samples were all collected in two seasons (winter and summer). The results of the study revealed that feed availability was the major constraint in livestock production as indicated by 83 percent of thefarmers at Kwezana and 88 percent at Dikidikana. At both villages less than 20 percent practiced supplementation and grazing management. From both villages, 83 percent of the farmers did not know the forage species preferred by their cattle. The second study revealed significant seasonal variations in soil N in both study areas while forage N exhibited seasonal variations (P<0.05) only at Dikidikana. Spatial variation (P<0.05) in soil Mn was apparent in both seasons at Dikidikana and in summer at Kwezana. At Dikidikana forage P varied (P<0.05) both seasonally and spatially. In both study areas, there was a positive correlation (P<0.05) between soil and forage levels of Cu and Zn. The blood serum of animals from both study areas had higher (P<0.05) K and Na in winter than in summer. Farmers do not understand the composition of their rangelands but are concerned about cattle nutrition during winter. Indeed the mineral status of soils, forages and Nguni cattle blood serum tend to vary not only seasonally but also spatially. There is need therefore to assist the farmers to understand these changes in order to find ways of managing the rangelands in a way that will manipulate both seasonal and spatial variations in soil nutrients for the benefit of the grazing livestock. Further research is required to determine the digestibility of the forages and the amount of energy available from these forages for the grazing livestock.
- Full Text:
- Date Issued: 2012
Impact of animal traction power on agricultural productivity: case of lowlands of Mohale's Hoek district of Lesotho
- Rampokanyo, Lepolesa Michael
- Authors: Rampokanyo, Lepolesa Michael
- Date: 2012
- Subjects: Animal traction -- Lesotho , Agricultural productivity -- Lesotho , Draft animals -- Lesotho , Food security -- Lesotho , Farm produce -- Lesotho
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11178 , http://hdl.handle.net/10353/483 , Animal traction -- Lesotho , Agricultural productivity -- Lesotho , Draft animals -- Lesotho , Food security -- Lesotho , Farm produce -- Lesotho
- Description: Most farming at subsistence level is located in rural areas where the majority of smallholder farmers have low productivity which results in high rate of food insecurity. The areas are characterised by animal traction and poor farming practises, and monoculture is mostly preferred. In light of this, this study analyzed the impact of animal power on agricultural productivity. Smallholder farmers in the lowlands of Mohale’s Hoek district of Lesotho were investigated by means of a case study methodology. The aim of the study was to inform agricultural policy about the level and key determinants of inefficiency in the smallholder farming system so as to contribute to policy designed to raise productivity of smallholder farmers. The sampling frame comprised farmers and extension workers in the lowlands of Mohale’s Hoek district. From this frame, 118 farmers and 4 extension workers were randomly selected from four villages, namely‘Mapotsane, Potsane, Tsoloane and Siloe. The four groups of farmers include; the farmers owning and using cattle for ploughing, farmers owning tractor and cattle and using them for ploughing, farmers owning tractor only and using it for ploughing, and farmers who owned neither cattle nor tractor and normally hire these when ploughing operations are to be done on the farm. The interviews of these farmers and extension workers were conducted by means of semi-structured questionnaire which consisted of both open and close ended questions. The study used the stochastic frontier production model for the production efficiencies and linear regression model for the impact of animal traction on agricultural productivity. Both procedures provided insights into the relative contributions of animal power and traditional systems to poverty alleviation and food security in the project areas. Descriptive statistics were employed for farming systems and challenges facing small scale farmers. Gross Margins analysis was conducted for the animal power and tractor power yield levels for maize crop to compare the two types of power. Some diagnostic tests to detect serial correlation and heteroskedasticity and t-tests were also performed. The significant variables include the area of sorghum ploughed, members of the household that assist with family labour, education, quantity of fertilizer applied, time taken by the farmers in farming, members who are formally employed, household size, area of land ploughed, old age, costs of tractor and animal, marital status, income, area of maize ploughed, area of sorghum ploughed, quantity of fertilizers applied, costs of seeds and fertilizers applied, maize and sorghum yield and amount sold and consumed. The study revealed that monoculture is mainly practised and many smallholder farmers used traditional technologies that fail to replace nutrients in the soil. Nonetheless family labour was not a problem. During the farming season, tractors were used as the main source of power for ploughing. Most farmers hired these for maize production as it is a staple food crop even where animal power is available. It was noted that the tractors were few and in most cases old and malfunctioning. The cost of using animals in farming obviouslyplayed a role in the production of both maize v and sorghum in the lowland areas of Mohale’s Hoek district. Smallholder farmers who owned both tractors and animals produced more but they were mainly affected by high costs of maintaining the aging tractors, generally purchased on the used-equipment market. The increased challenges resulted in lower productivity of the smallholder farmers, including: unhealthy animals, drought, marketing problems, late ploughing, poor soils, lack of extension services, low yields, low income, lack of information, lack of appropriate implements, lack of support services, nutrition inadequacy, inappropriate farming systems. The study recommended the adoption and promotion of low-cost mechanization in the lowlands of Mohale’s Hoek district so as to increase the production of the smallholder farmers. Increased productivity will in turn improve household food security.
- Full Text:
- Date Issued: 2012
- Authors: Rampokanyo, Lepolesa Michael
- Date: 2012
- Subjects: Animal traction -- Lesotho , Agricultural productivity -- Lesotho , Draft animals -- Lesotho , Food security -- Lesotho , Farm produce -- Lesotho
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11178 , http://hdl.handle.net/10353/483 , Animal traction -- Lesotho , Agricultural productivity -- Lesotho , Draft animals -- Lesotho , Food security -- Lesotho , Farm produce -- Lesotho
- Description: Most farming at subsistence level is located in rural areas where the majority of smallholder farmers have low productivity which results in high rate of food insecurity. The areas are characterised by animal traction and poor farming practises, and monoculture is mostly preferred. In light of this, this study analyzed the impact of animal power on agricultural productivity. Smallholder farmers in the lowlands of Mohale’s Hoek district of Lesotho were investigated by means of a case study methodology. The aim of the study was to inform agricultural policy about the level and key determinants of inefficiency in the smallholder farming system so as to contribute to policy designed to raise productivity of smallholder farmers. The sampling frame comprised farmers and extension workers in the lowlands of Mohale’s Hoek district. From this frame, 118 farmers and 4 extension workers were randomly selected from four villages, namely‘Mapotsane, Potsane, Tsoloane and Siloe. The four groups of farmers include; the farmers owning and using cattle for ploughing, farmers owning tractor and cattle and using them for ploughing, farmers owning tractor only and using it for ploughing, and farmers who owned neither cattle nor tractor and normally hire these when ploughing operations are to be done on the farm. The interviews of these farmers and extension workers were conducted by means of semi-structured questionnaire which consisted of both open and close ended questions. The study used the stochastic frontier production model for the production efficiencies and linear regression model for the impact of animal traction on agricultural productivity. Both procedures provided insights into the relative contributions of animal power and traditional systems to poverty alleviation and food security in the project areas. Descriptive statistics were employed for farming systems and challenges facing small scale farmers. Gross Margins analysis was conducted for the animal power and tractor power yield levels for maize crop to compare the two types of power. Some diagnostic tests to detect serial correlation and heteroskedasticity and t-tests were also performed. The significant variables include the area of sorghum ploughed, members of the household that assist with family labour, education, quantity of fertilizer applied, time taken by the farmers in farming, members who are formally employed, household size, area of land ploughed, old age, costs of tractor and animal, marital status, income, area of maize ploughed, area of sorghum ploughed, quantity of fertilizers applied, costs of seeds and fertilizers applied, maize and sorghum yield and amount sold and consumed. The study revealed that monoculture is mainly practised and many smallholder farmers used traditional technologies that fail to replace nutrients in the soil. Nonetheless family labour was not a problem. During the farming season, tractors were used as the main source of power for ploughing. Most farmers hired these for maize production as it is a staple food crop even where animal power is available. It was noted that the tractors were few and in most cases old and malfunctioning. The cost of using animals in farming obviouslyplayed a role in the production of both maize v and sorghum in the lowland areas of Mohale’s Hoek district. Smallholder farmers who owned both tractors and animals produced more but they were mainly affected by high costs of maintaining the aging tractors, generally purchased on the used-equipment market. The increased challenges resulted in lower productivity of the smallholder farmers, including: unhealthy animals, drought, marketing problems, late ploughing, poor soils, lack of extension services, low yields, low income, lack of information, lack of appropriate implements, lack of support services, nutrition inadequacy, inappropriate farming systems. The study recommended the adoption and promotion of low-cost mechanization in the lowlands of Mohale’s Hoek district so as to increase the production of the smallholder farmers. Increased productivity will in turn improve household food security.
- Full Text:
- Date Issued: 2012
Implications of food value chain support structures for water resource management by smallholder farmers in the Eastern Cape Province
- Authors: Arowolo, Steven Alaba
- Date: 2012
- Subjects: Agricultural assistance -- South Africa -- Eastern Cape , Agricultural productivity -- South Africa -- Eastern Cape , Agricultural extension work -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Farm produce -- South Africa -- Eastern Cape -- Marketing , Sustainable development -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11181 , http://hdl.handle.net/10353/d1001027 , Agricultural assistance -- South Africa -- Eastern Cape , Agricultural productivity -- South Africa -- Eastern Cape , Agricultural extension work -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Farm produce -- South Africa -- Eastern Cape -- Marketing , Sustainable development -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Description: Smallholder agriculture is faced with so many challenges despite all the policies and programmes that have been channelled towards ensuring improvement in this sector. Improving smallholder agricultural productivity requires that smallholder farmers gain access to reliable and adequate farmer support services such as physical infrastructures like good road network, functional irrigation facilities, extension services, finance and efficient marketing system. However, these support services are lacking in a vast majority of the rural communities in which the smallholder farmers live and work. This study is centred on governance within the food value chains, with specific focus on butternuts and chicken value chains;with a view to identifying those factors preventing smallholder farmers from accessing the mainstream market. Ciko and Mbozi villages in Mbashe local municipality were used as the research sites for the study. Data were collected across the two villages through sampling of 100 individual farming households based on random selection; questionnaires and checklist of questions were used as tools to access information from farmers through focus group discussions, personal interviews and key informants. In addition,Ciko Santrini project and foundation community project, which are the two agricultural community projects located within the study area were also investigated. Conceptual and analytical frameworks were employed in the research analysis. Williamson’s 4-level of social analysis and the sustainable livelihood frameworks were used to conceptualize the analysis. Inferential analysis was carried out using binary logistic regression and discriminant analysis with focus on butternuts and cSmallholder agriculture is faced with so many challenges despite all the policies and programmes that have been channelled towards ensuring improvement in this sector. Improving smallholder agricultural productivity requires that smallholder farmers gain access to reliable and adequate farmer support services such as physical infrastructures like good road network, functional irrigation facilities, extension services, finance and efficient marketing system. However, these support services are lacking in a vast majority of the rural communities in which the smallholder farmers live and work. This study is centred on governance within the food value chains, with specific focus on butternuts and chicken value chains;with a view to identifying those factors preventing smallholder farmers from accessing the mainstream market. Ciko and Mbozi villages in Mbashe local municipality were used as the research sites for the study. Data were collected across the two villages through sampling of 100 individual farming households based on random selection; questionnaires and checklist of questions were used as tools to access information from farmers through focus group discussions, personal interviews and key informants. In addition,Ciko Santrini project and foundation community project, which are the two agricultural community projects located within the study area were also investigated. Conceptual and analytical frameworks were employed in the research analysis. Williamson’s 4-level of social analysis and the sustainable livelihood frameworks were used to conceptualize the analysis. Inferential analysis was carried out using binary logistic regression and discriminant analysis with focus on butternuts and chicken production among the smallholder farmers in the study area to determine factors that could encourage farmers ‘access markets. The results showed that factors such as; assistance from government agency, partnerships with private and public institutions and farmers’ decision due to access to information were significant at 1% level for both butternuts and chicken production. On the other hand, factors such as provision of input subsidy and farmers’ membership of agricultural development projects are significant at 5% level. The findings suggest that adoption of any or combination of the significant factors could serve as good support structures for farmers and they could directly help them market their produce efficiently.
- Full Text:
- Date Issued: 2012
- Authors: Arowolo, Steven Alaba
- Date: 2012
- Subjects: Agricultural assistance -- South Africa -- Eastern Cape , Agricultural productivity -- South Africa -- Eastern Cape , Agricultural extension work -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Farm produce -- South Africa -- Eastern Cape -- Marketing , Sustainable development -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11181 , http://hdl.handle.net/10353/d1001027 , Agricultural assistance -- South Africa -- Eastern Cape , Agricultural productivity -- South Africa -- Eastern Cape , Agricultural extension work -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Farm produce -- South Africa -- Eastern Cape -- Marketing , Sustainable development -- South Africa -- Eastern Cape , Water resources development -- South Africa -- Eastern Cape
- Description: Smallholder agriculture is faced with so many challenges despite all the policies and programmes that have been channelled towards ensuring improvement in this sector. Improving smallholder agricultural productivity requires that smallholder farmers gain access to reliable and adequate farmer support services such as physical infrastructures like good road network, functional irrigation facilities, extension services, finance and efficient marketing system. However, these support services are lacking in a vast majority of the rural communities in which the smallholder farmers live and work. This study is centred on governance within the food value chains, with specific focus on butternuts and chicken value chains;with a view to identifying those factors preventing smallholder farmers from accessing the mainstream market. Ciko and Mbozi villages in Mbashe local municipality were used as the research sites for the study. Data were collected across the two villages through sampling of 100 individual farming households based on random selection; questionnaires and checklist of questions were used as tools to access information from farmers through focus group discussions, personal interviews and key informants. In addition,Ciko Santrini project and foundation community project, which are the two agricultural community projects located within the study area were also investigated. Conceptual and analytical frameworks were employed in the research analysis. Williamson’s 4-level of social analysis and the sustainable livelihood frameworks were used to conceptualize the analysis. Inferential analysis was carried out using binary logistic regression and discriminant analysis with focus on butternuts and cSmallholder agriculture is faced with so many challenges despite all the policies and programmes that have been channelled towards ensuring improvement in this sector. Improving smallholder agricultural productivity requires that smallholder farmers gain access to reliable and adequate farmer support services such as physical infrastructures like good road network, functional irrigation facilities, extension services, finance and efficient marketing system. However, these support services are lacking in a vast majority of the rural communities in which the smallholder farmers live and work. This study is centred on governance within the food value chains, with specific focus on butternuts and chicken value chains;with a view to identifying those factors preventing smallholder farmers from accessing the mainstream market. Ciko and Mbozi villages in Mbashe local municipality were used as the research sites for the study. Data were collected across the two villages through sampling of 100 individual farming households based on random selection; questionnaires and checklist of questions were used as tools to access information from farmers through focus group discussions, personal interviews and key informants. In addition,Ciko Santrini project and foundation community project, which are the two agricultural community projects located within the study area were also investigated. Conceptual and analytical frameworks were employed in the research analysis. Williamson’s 4-level of social analysis and the sustainable livelihood frameworks were used to conceptualize the analysis. Inferential analysis was carried out using binary logistic regression and discriminant analysis with focus on butternuts and chicken production among the smallholder farmers in the study area to determine factors that could encourage farmers ‘access markets. The results showed that factors such as; assistance from government agency, partnerships with private and public institutions and farmers’ decision due to access to information were significant at 1% level for both butternuts and chicken production. On the other hand, factors such as provision of input subsidy and farmers’ membership of agricultural development projects are significant at 5% level. The findings suggest that adoption of any or combination of the significant factors could serve as good support structures for farmers and they could directly help them market their produce efficiently.
- Full Text:
- Date Issued: 2012
Inhibitory potential of honey on the enzymatic activity of Helicobacter pylori urease
- Authors: Matongo, Fredrick
- Date: 2012
- Subjects: Honey , Helicobacter pylori infections , Enzyme inhibitors , Traditional medicine , Antifungal agents
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11253 , http://hdl.handle.net/10353/431 , Honey , Helicobacter pylori infections , Enzyme inhibitors , Traditional medicine , Antifungal agents
- Description: Urease of Helicobacter pylori is an important virulence factor implicated in the pathogenesis of many clinical conditions, such as chronic gastritis, peptic ulceration, and gastric cancer. Many urease inhibitors have been discovered, like phosphorodiamidates, hydroxamic acid derivatives, and imidazoles. Despite good activities at the enzyme level and excellent kinetic properties most of them have not been used as therapeutic agents in vivo because of their side effects, toxicity and instability. This has led to much attention to focus on exploring the novel urease inhibitory activities of natural products because of their low toxicity and good bioavailability. Honey, a natural product has been used in folk medicine due to its antitumor, antioxidant, antimicrobial and anti-inflammatory properties. The aims of this study were to isolate, characterise, purify urease produced by H. pylori and investigate the inhibitory effects of solvent honey extracts on its enzymatic activity. Urease was found to be both surface-associated and cytoplasmic. Maximum cytoplasmic urease activity was found to occur after 72 hr whereas maximum extracellular urease activities were found to occur after 96 hr. Characterization of the crude cytoplasmic urease revealed optimal activity at a pH of 7.5 and temperature of 40°C. The kinetic parameters Vmax and Km were 45.32 U ml-1 and 61.11 mM respectively.The honey extracts inhibited the activity of the crude urease in a concentration dependent manner. The Lineweaver-Burk plots indicated a non-competitive type of inhibition against H. pylori urease. The two honey extracts gave promising inhibitory activities against urease of H. pylori. Thus the results of this study delineates that inhibition of urease can ease development in therapeutic and preventative approaches based on the enzymatic activity of this Helicobacter protein.
- Full Text:
- Date Issued: 2012
- Authors: Matongo, Fredrick
- Date: 2012
- Subjects: Honey , Helicobacter pylori infections , Enzyme inhibitors , Traditional medicine , Antifungal agents
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11253 , http://hdl.handle.net/10353/431 , Honey , Helicobacter pylori infections , Enzyme inhibitors , Traditional medicine , Antifungal agents
- Description: Urease of Helicobacter pylori is an important virulence factor implicated in the pathogenesis of many clinical conditions, such as chronic gastritis, peptic ulceration, and gastric cancer. Many urease inhibitors have been discovered, like phosphorodiamidates, hydroxamic acid derivatives, and imidazoles. Despite good activities at the enzyme level and excellent kinetic properties most of them have not been used as therapeutic agents in vivo because of their side effects, toxicity and instability. This has led to much attention to focus on exploring the novel urease inhibitory activities of natural products because of their low toxicity and good bioavailability. Honey, a natural product has been used in folk medicine due to its antitumor, antioxidant, antimicrobial and anti-inflammatory properties. The aims of this study were to isolate, characterise, purify urease produced by H. pylori and investigate the inhibitory effects of solvent honey extracts on its enzymatic activity. Urease was found to be both surface-associated and cytoplasmic. Maximum cytoplasmic urease activity was found to occur after 72 hr whereas maximum extracellular urease activities were found to occur after 96 hr. Characterization of the crude cytoplasmic urease revealed optimal activity at a pH of 7.5 and temperature of 40°C. The kinetic parameters Vmax and Km were 45.32 U ml-1 and 61.11 mM respectively.The honey extracts inhibited the activity of the crude urease in a concentration dependent manner. The Lineweaver-Burk plots indicated a non-competitive type of inhibition against H. pylori urease. The two honey extracts gave promising inhibitory activities against urease of H. pylori. Thus the results of this study delineates that inhibition of urease can ease development in therapeutic and preventative approaches based on the enzymatic activity of this Helicobacter protein.
- Full Text:
- Date Issued: 2012
Interaction of terpenes and oxygenated terpenes with some drugs
- Authors: Ajayi, Emmanuel Olusegun
- Date: 2012
- Subjects: Terpenes -- Essences and essential oils , Lavenders -- Monoterpenes -- Drug interactions , Drugs -- Camphor -- Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11332 , http://hdl.handle.net/10353/418 , Terpenes -- Essences and essential oils , Lavenders -- Monoterpenes -- Drug interactions , Drugs -- Camphor -- Medicinal plants
- Description: SFME and HD for the extraction of essential oil in Lavandula officinalis in Alice have been reported. A total of 59 compounds were identified with the major compound being 1,8-cineole, an oxygenated monoterpene, with 46.89% and 44.84% yield obtained for HD and SFME respectively. Charge transfer (CT) complexes formed between α-pinene, 1,8-cineole and camphor as electron donors with iodine as the electron acceptor have been studied spectrophotometrically in methylene chloride solution. The Benesi- Hildebrand equation has been applied to estimate the formation constant (Kf) and molecular extinction coefficient (εCT). The value of Kf is the highest in camphor-I2 complex compared to the other two complexes. Antibacterial assessment was carried out on the various reagents, determining the MIC of individual reagents and in combination. The results show an improvement, on combination of the various reagents than when tested alone.
- Full Text:
- Date Issued: 2012
- Authors: Ajayi, Emmanuel Olusegun
- Date: 2012
- Subjects: Terpenes -- Essences and essential oils , Lavenders -- Monoterpenes -- Drug interactions , Drugs -- Camphor -- Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11332 , http://hdl.handle.net/10353/418 , Terpenes -- Essences and essential oils , Lavenders -- Monoterpenes -- Drug interactions , Drugs -- Camphor -- Medicinal plants
- Description: SFME and HD for the extraction of essential oil in Lavandula officinalis in Alice have been reported. A total of 59 compounds were identified with the major compound being 1,8-cineole, an oxygenated monoterpene, with 46.89% and 44.84% yield obtained for HD and SFME respectively. Charge transfer (CT) complexes formed between α-pinene, 1,8-cineole and camphor as electron donors with iodine as the electron acceptor have been studied spectrophotometrically in methylene chloride solution. The Benesi- Hildebrand equation has been applied to estimate the formation constant (Kf) and molecular extinction coefficient (εCT). The value of Kf is the highest in camphor-I2 complex compared to the other two complexes. Antibacterial assessment was carried out on the various reagents, determining the MIC of individual reagents and in combination. The results show an improvement, on combination of the various reagents than when tested alone.
- Full Text:
- Date Issued: 2012
Lithostratigraphic correlation, mineralogy and geochemistry of the lower manganese orebody at the Kalagadi Manganese Mine in the Northern Cape Province of South Africa
- Authors: Rasmeni, Sonwabile
- Date: 2012
- Subjects: Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11526 , http://hdl.handle.net/10353/d1016155 , Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Description: The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly 0.01wt% and 0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.
- Full Text:
- Date Issued: 2012
- Authors: Rasmeni, Sonwabile
- Date: 2012
- Subjects: Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11526 , http://hdl.handle.net/10353/d1016155 , Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Description: The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly 0.01wt% and 0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.
- Full Text:
- Date Issued: 2012
Major spoligotype families of Mycobacterium tuberculosis strains isolated from tuberculosis patients in Port Elizabeth, Eastern Cape, South Africa
- Authors: Nqini, Babalwa J
- Date: 2012
- Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Tuberculosis -- Patients -- South Africa -- Eastern Cape , Drug resistance , Multidrug-resistant tuberculosis -- South Africa -- Eastern Cape , HIV infections -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11271 , http://hdl.handle.net/10353/d1006877 , Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Tuberculosis -- Patients -- South Africa -- Eastern Cape , Drug resistance , Multidrug-resistant tuberculosis -- South Africa -- Eastern Cape , HIV infections -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape
- Description: South Africa is burdened with tuberculosis (TB) which is aggravated by the concurrent epidemic of HIV as well as the emergence of drug resistance. In most developed countries molecular techniques have been used to look at the dynamics of the TB epidemic however, despite the prevalence that is high in sub-Saharan Africa, there is little data on strain types that are available in Port Elizabeth. This study aims to find the major clades of M. tuberculosis that are circulating in Port Elizabeth. Two hundred MDR-TB DNA samples were obtained from the National Health Laboratory Services TB laboratory in Port Elizabeth. Spoligotyping and MIRU-VNTR were used to genotype the strains. Two hundred strains were sent to the University of Stellenbosch for spoligotyping and 179 of those were typed. Spoligotype defined families were further typed by MIRU-VNTR typing, so as to further differentiate and assess clonal diversity within the spoligotype families. The Beijing family was the dominant family and the MANU family being the least dominant, with percentages of 71 percent and 0.5 percent respectively. A comparison of spoligotyping results with the international spoligotyping database (SITVIT2) showed a total of 15 shared international types. Forty four percent (44 percent) of the isolates that were typed by MIRU-VNTR showed similarities, suggesting epidemiological relatedness. Thirty eight percent of isolates from spoligotyping were from the same family, the Beijing family, with the same shared international type STI1, but when typed by 12 MIRU-VNTR they showed no epidemiological relatedness and 18 percent of the isolates showed no relatedness when typed by 12 MIRU-VNTR but spoligotyping showed that they were from the LAM family. Results from our study illustrate the effectiveness of MIRU-VNTR typing together with spoligotyping in epidemiological studies in the region of Port Elizabeth.
- Full Text:
- Date Issued: 2012
- Authors: Nqini, Babalwa J
- Date: 2012
- Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Tuberculosis -- Patients -- South Africa -- Eastern Cape , Drug resistance , Multidrug-resistant tuberculosis -- South Africa -- Eastern Cape , HIV infections -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11271 , http://hdl.handle.net/10353/d1006877 , Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Tuberculosis -- Patients -- South Africa -- Eastern Cape , Drug resistance , Multidrug-resistant tuberculosis -- South Africa -- Eastern Cape , HIV infections -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape
- Description: South Africa is burdened with tuberculosis (TB) which is aggravated by the concurrent epidemic of HIV as well as the emergence of drug resistance. In most developed countries molecular techniques have been used to look at the dynamics of the TB epidemic however, despite the prevalence that is high in sub-Saharan Africa, there is little data on strain types that are available in Port Elizabeth. This study aims to find the major clades of M. tuberculosis that are circulating in Port Elizabeth. Two hundred MDR-TB DNA samples were obtained from the National Health Laboratory Services TB laboratory in Port Elizabeth. Spoligotyping and MIRU-VNTR were used to genotype the strains. Two hundred strains were sent to the University of Stellenbosch for spoligotyping and 179 of those were typed. Spoligotype defined families were further typed by MIRU-VNTR typing, so as to further differentiate and assess clonal diversity within the spoligotype families. The Beijing family was the dominant family and the MANU family being the least dominant, with percentages of 71 percent and 0.5 percent respectively. A comparison of spoligotyping results with the international spoligotyping database (SITVIT2) showed a total of 15 shared international types. Forty four percent (44 percent) of the isolates that were typed by MIRU-VNTR showed similarities, suggesting epidemiological relatedness. Thirty eight percent of isolates from spoligotyping were from the same family, the Beijing family, with the same shared international type STI1, but when typed by 12 MIRU-VNTR they showed no epidemiological relatedness and 18 percent of the isolates showed no relatedness when typed by 12 MIRU-VNTR but spoligotyping showed that they were from the LAM family. Results from our study illustrate the effectiveness of MIRU-VNTR typing together with spoligotyping in epidemiological studies in the region of Port Elizabeth.
- Full Text:
- Date Issued: 2012
Modelling and mapping the suitability of land for crop production using a combination of GIS and remote sensing in the Eastern Cape: a case study of Mbashe and Mquma local municipalities-South Africa
- Authors: Vuso, Solly
- Date: 2012
- Language: English
- Type: Thesis , Masters , MSc (Geographic Information System)
- Identifier: vital:11534 , http://hdl.handle.net/10353/d1019872
- Description: In order to achieve sustainable agriculture, decision makers require appropriate and fully detailed spatial information on land resources. Crop-land suitability analysis is a prerequisite to achieve optimum utilization of the available land resources for sustainable agriculture rural production (T.R. Nisar Ahamed et al., 2000). It is indeed of paramount importance to identify suitable land for cropping while causing minimum impact to the environment. The Food and Agriculture Organization (FAO, 1976), recommended an approach of land suitability evaluation for crops in terms of suitable land based on climatic and terrain data and soil properties. In this study, an attempt was made to identify suitable areas for massive crop production using remote sensing and GIS methodologies and the knowledge from extension officers. The primary method aims at generating land cover data using SPOT 5 satellite imagery and modeling with the existing land capability. The research purpose was to map the map the number hectares suitable areas for crop production number hectares suitable areas for crop production number hectares suitable areas for crop production number hectares suitable areas for crop production. Spatial modeling techniques were utilized to model land suitability model in an effective and efficiently way. The spatial modeling extension from ESRI product was used to model the crop suitability areas. The model run on ArcGIS platform and due to the fact that modeling only uses raster formats, all the data sets were projected and converted to raster format. The weighted overlay model was used to create land suitability map. The model results revealed that 4046251.79 hectares were suitable for cropping in the study area. The final outputs of suitable areas were calculated and each ward was given a value of suitable area as well as unsuitable area. The validation of the final maps compliments the 500 000 hectares that were mapped by Dept of Agriculture EC using 8% slope as the best potential areas. The method provides a cheap, effective and efficient way to map suitable areas over a large area and it also uses remote sensing data. It is hoped that decision makers will make use of the information produced in this paper as the whole world is in crisis of food security.
- Full Text:
- Date Issued: 2012
- Authors: Vuso, Solly
- Date: 2012
- Language: English
- Type: Thesis , Masters , MSc (Geographic Information System)
- Identifier: vital:11534 , http://hdl.handle.net/10353/d1019872
- Description: In order to achieve sustainable agriculture, decision makers require appropriate and fully detailed spatial information on land resources. Crop-land suitability analysis is a prerequisite to achieve optimum utilization of the available land resources for sustainable agriculture rural production (T.R. Nisar Ahamed et al., 2000). It is indeed of paramount importance to identify suitable land for cropping while causing minimum impact to the environment. The Food and Agriculture Organization (FAO, 1976), recommended an approach of land suitability evaluation for crops in terms of suitable land based on climatic and terrain data and soil properties. In this study, an attempt was made to identify suitable areas for massive crop production using remote sensing and GIS methodologies and the knowledge from extension officers. The primary method aims at generating land cover data using SPOT 5 satellite imagery and modeling with the existing land capability. The research purpose was to map the map the number hectares suitable areas for crop production number hectares suitable areas for crop production number hectares suitable areas for crop production number hectares suitable areas for crop production. Spatial modeling techniques were utilized to model land suitability model in an effective and efficiently way. The spatial modeling extension from ESRI product was used to model the crop suitability areas. The model run on ArcGIS platform and due to the fact that modeling only uses raster formats, all the data sets were projected and converted to raster format. The weighted overlay model was used to create land suitability map. The model results revealed that 4046251.79 hectares were suitable for cropping in the study area. The final outputs of suitable areas were calculated and each ward was given a value of suitable area as well as unsuitable area. The validation of the final maps compliments the 500 000 hectares that were mapped by Dept of Agriculture EC using 8% slope as the best potential areas. The method provides a cheap, effective and efficient way to map suitable areas over a large area and it also uses remote sensing data. It is hoped that decision makers will make use of the information produced in this paper as the whole world is in crisis of food security.
- Full Text:
- Date Issued: 2012
Parent characterization of quality protein maize (Zea mays L.) and combining ability for tolerance to drought stress
- Authors: Pfunde, Cleopatra Nyaradzo
- Date: 2012
- Subjects: Corn -- Quality , Corn as food , Corn -- Effect of stress on , Corn -- Effect of drought on , Cluster analysis , Crops -- Effect of drought on , Corn -- Drought tolerance , Corn -- Breeding , Crops -- Drought tolerance
- Language: English
- Type: Thesis , Masters , MSc Agric (Crop Science)
- Identifier: vital:11869 , http://hdl.handle.net/10353/d1007536 , Corn -- Quality , Corn as food , Corn -- Effect of stress on , Corn -- Effect of drought on , Cluster analysis , Crops -- Effect of drought on , Corn -- Drought tolerance , Corn -- Breeding , Crops -- Drought tolerance
- Description: Quality protein maize (QPM) has enhanced levels of two essential amino acids, lysine and tryptophan compared to normal maize. This makes QPM an important cereal crop in communities where maize is a staple crop. The main abiotic factor to QPM production is drought stress. Little information is available on the effect of drought stress on QPM. Therefore, the objectives of this study were to: (i) conduct diversity analysis of QPM inbred lines using morpho-agronomic and simple sequence repeat markers, (ii) screen available QPM inbred lines and F1 progeny for tolerance to seedling drought stress, (iii) determine the combining ability and type of gene action of QPM inbred lines for tolerance to seedling drought stress, grain yield and endosperm modification. The study was conducted in South Africa, at the University of Fort Hare. Morphological characterisation of 21 inbred lines was done using quantitative and qualitative traits. A randomised complete block design with three replicates was used for characterizing the inbred lines in the field. Genstat statistical software, version 12 (Genstat ®, 2009) was used for analysis of variance (ANOVA) and descriptive statistics. Analysis of variance was performed on all quantitative data for morphological traits. Data for qualitative traits was tabulated in their nominal classes. Traits that contributed most to the variation were days to anthesis, days to silking, anthesis-silking interval, plant height, number of kernel rows, ear length and grain yield. Cluster analysis grouped the inbred lines into three main clusters. The first cluster was characterised by tall and average yielding lines, while the second cluster showed the least anthesis-silking interval, and had the highest yield. Cluster three consisted of lines that were early maturing, but were the least yielding. Genetic distances between maize inbred lines were quantified by using 27 simple sequence repeat markers. The genetic distances between genotypes was computed using Roger’s (1972) genetic distances. Cluster analysis was then carried out using the neighbour-joining tree method using Power Marker software version 3.25. A dendrogram generated from the genetic study of the inbred lines revealed three groups that concurred with expectations based upon pedigree data. These groups were not identical to the groups generated using morpho-agronomic characterisation. Twenty one QPM inbred lines were crossed using a North Carolina design II mating scheme. These were divided into seven sets, each with three inbred lines. The three inbred lines in one set were used as females and crossed with three inbred lines in another set consisting of males. Each inbred line was used as a female in one set, and as a male in a second set. Sixty three hybrids (7 sets x 9 hybrids) were formed and evaluated in October 2011, using a 6x8 alpha-lattice incomplete block design with three replicates under glasshouse and optimum field conditions. A randomised complete block design with three replicates was used for the 21 parental inbred lines. Traits recorded for the glasshouse study were, canopy temperature, chlorophyll content, leaf roll, stem diameter, plant height, leaf number, leaf area, fresh and dry root and shoot weights. Data for the various traits for each environment, 25 percent (stress treatment) and 75 percent (non-stress) of field capacity, were subjected to analysis of variance using the unbalanced treatment design in Genstat statistical package Edition 12. Where varietal differences were found, means were separated using Tukey’s test. Genetic analyses for grain yield and agronomic traits were performed using a fixed effects model in JMP 10 following Residual Maximum Likelihood procedure (REML). From the results, inbred lines that were not previously classified into heterotic groups and drought tolerance categories were classified based on their total dry weight performance and drought susceptibility index. Inbred lines L18, L9, L8, L6 and L3, in order of their drought tolerance index were the best performers under greenhouse conditions and could be recommended for breeding new varieties that are tolerant to seedling drought stress. Evaluation of maize seedlings tolerant to drought stress under glasshouse conditions revealed that cross combination L18 x L11 was drought tolerant, while cross L20 x L7 was susceptible. Total dry weight was used as the major criteria for classifying F1 maize seedlings as being resistant or susceptible. General combining ability effects accounted for 67.43 percent of the genetic variation for total dry weight, while specific combining ability effects contributed 37.57 percent. This indicated that additive gene effects were more important than non-additive gene action in controlling this trait. In the field study (non-drought), the experimental design was a 6x8 alpha lattice incomplete block design with three replicates. On an adjacent field a randomised complete block design with three replicates was used to evaluate the parental inbred lines. The following variables were recorded: plant height, ear height, ears per plant, endosperm modification, days to silking and days to anthesis, anthesis-silking interval, number of kernels per row, number of rows per ear and grain yield. General analyses for the incomplete lattice block design and randomised complete block design for hybrid and inbred data respectively were performed using JMP 10 statistical software. Means were separated using the Tukey's test. Genetic analyses of data for grain yield and agronomic traits were conducted using a fixed effects model using REML in JMP 10. The importance of both GCA (51 percent) and SCA (49 percent) was observed for grain yield. A preponderance of GCA existed for ear height, days to anthesis, anthesis-silking interval, ears per plant and number of kernels per row, indicating that predominantly, additive gene effects controlled hybrid performance under optimum field conditions. The highest heritability was observed for days to silking (48.27 percent) suggesting that yield could be improved through selection for this trait. Under field conditions, variation in time to maturity was observed. This implies that these inbred lines can be recommended for utilisation in different agro-ecologies. Early maturing lines such as L18 can be used to introduce earliness in local cultivars, while early maturing single crosses such as L18 x L2, L5 x L9, L3 x L4 and L2 x L21 could be recommended for maize growers in drought prone areas such as the former Ciskei. Single crosses L18xL11, L16xL18, L8xL21 and L9xL6 had good tolerance to seedling drought stress. On the other hand, single crosses L18xL11 and L11xL13 had high grain yield and good endosperm modification. All these single crosses could be recommended for commercial production after evaluation across locations in the Eastern Cape Province. Alternatively they can be crossed with other superior inbreds to generate three or four way hybrids, which could then be evaluated for potential use by farmers in the Eastern Cape.
- Full Text:
- Date Issued: 2012
- Authors: Pfunde, Cleopatra Nyaradzo
- Date: 2012
- Subjects: Corn -- Quality , Corn as food , Corn -- Effect of stress on , Corn -- Effect of drought on , Cluster analysis , Crops -- Effect of drought on , Corn -- Drought tolerance , Corn -- Breeding , Crops -- Drought tolerance
- Language: English
- Type: Thesis , Masters , MSc Agric (Crop Science)
- Identifier: vital:11869 , http://hdl.handle.net/10353/d1007536 , Corn -- Quality , Corn as food , Corn -- Effect of stress on , Corn -- Effect of drought on , Cluster analysis , Crops -- Effect of drought on , Corn -- Drought tolerance , Corn -- Breeding , Crops -- Drought tolerance
- Description: Quality protein maize (QPM) has enhanced levels of two essential amino acids, lysine and tryptophan compared to normal maize. This makes QPM an important cereal crop in communities where maize is a staple crop. The main abiotic factor to QPM production is drought stress. Little information is available on the effect of drought stress on QPM. Therefore, the objectives of this study were to: (i) conduct diversity analysis of QPM inbred lines using morpho-agronomic and simple sequence repeat markers, (ii) screen available QPM inbred lines and F1 progeny for tolerance to seedling drought stress, (iii) determine the combining ability and type of gene action of QPM inbred lines for tolerance to seedling drought stress, grain yield and endosperm modification. The study was conducted in South Africa, at the University of Fort Hare. Morphological characterisation of 21 inbred lines was done using quantitative and qualitative traits. A randomised complete block design with three replicates was used for characterizing the inbred lines in the field. Genstat statistical software, version 12 (Genstat ®, 2009) was used for analysis of variance (ANOVA) and descriptive statistics. Analysis of variance was performed on all quantitative data for morphological traits. Data for qualitative traits was tabulated in their nominal classes. Traits that contributed most to the variation were days to anthesis, days to silking, anthesis-silking interval, plant height, number of kernel rows, ear length and grain yield. Cluster analysis grouped the inbred lines into three main clusters. The first cluster was characterised by tall and average yielding lines, while the second cluster showed the least anthesis-silking interval, and had the highest yield. Cluster three consisted of lines that were early maturing, but were the least yielding. Genetic distances between maize inbred lines were quantified by using 27 simple sequence repeat markers. The genetic distances between genotypes was computed using Roger’s (1972) genetic distances. Cluster analysis was then carried out using the neighbour-joining tree method using Power Marker software version 3.25. A dendrogram generated from the genetic study of the inbred lines revealed three groups that concurred with expectations based upon pedigree data. These groups were not identical to the groups generated using morpho-agronomic characterisation. Twenty one QPM inbred lines were crossed using a North Carolina design II mating scheme. These were divided into seven sets, each with three inbred lines. The three inbred lines in one set were used as females and crossed with three inbred lines in another set consisting of males. Each inbred line was used as a female in one set, and as a male in a second set. Sixty three hybrids (7 sets x 9 hybrids) were formed and evaluated in October 2011, using a 6x8 alpha-lattice incomplete block design with three replicates under glasshouse and optimum field conditions. A randomised complete block design with three replicates was used for the 21 parental inbred lines. Traits recorded for the glasshouse study were, canopy temperature, chlorophyll content, leaf roll, stem diameter, plant height, leaf number, leaf area, fresh and dry root and shoot weights. Data for the various traits for each environment, 25 percent (stress treatment) and 75 percent (non-stress) of field capacity, were subjected to analysis of variance using the unbalanced treatment design in Genstat statistical package Edition 12. Where varietal differences were found, means were separated using Tukey’s test. Genetic analyses for grain yield and agronomic traits were performed using a fixed effects model in JMP 10 following Residual Maximum Likelihood procedure (REML). From the results, inbred lines that were not previously classified into heterotic groups and drought tolerance categories were classified based on their total dry weight performance and drought susceptibility index. Inbred lines L18, L9, L8, L6 and L3, in order of their drought tolerance index were the best performers under greenhouse conditions and could be recommended for breeding new varieties that are tolerant to seedling drought stress. Evaluation of maize seedlings tolerant to drought stress under glasshouse conditions revealed that cross combination L18 x L11 was drought tolerant, while cross L20 x L7 was susceptible. Total dry weight was used as the major criteria for classifying F1 maize seedlings as being resistant or susceptible. General combining ability effects accounted for 67.43 percent of the genetic variation for total dry weight, while specific combining ability effects contributed 37.57 percent. This indicated that additive gene effects were more important than non-additive gene action in controlling this trait. In the field study (non-drought), the experimental design was a 6x8 alpha lattice incomplete block design with three replicates. On an adjacent field a randomised complete block design with three replicates was used to evaluate the parental inbred lines. The following variables were recorded: plant height, ear height, ears per plant, endosperm modification, days to silking and days to anthesis, anthesis-silking interval, number of kernels per row, number of rows per ear and grain yield. General analyses for the incomplete lattice block design and randomised complete block design for hybrid and inbred data respectively were performed using JMP 10 statistical software. Means were separated using the Tukey's test. Genetic analyses of data for grain yield and agronomic traits were conducted using a fixed effects model using REML in JMP 10. The importance of both GCA (51 percent) and SCA (49 percent) was observed for grain yield. A preponderance of GCA existed for ear height, days to anthesis, anthesis-silking interval, ears per plant and number of kernels per row, indicating that predominantly, additive gene effects controlled hybrid performance under optimum field conditions. The highest heritability was observed for days to silking (48.27 percent) suggesting that yield could be improved through selection for this trait. Under field conditions, variation in time to maturity was observed. This implies that these inbred lines can be recommended for utilisation in different agro-ecologies. Early maturing lines such as L18 can be used to introduce earliness in local cultivars, while early maturing single crosses such as L18 x L2, L5 x L9, L3 x L4 and L2 x L21 could be recommended for maize growers in drought prone areas such as the former Ciskei. Single crosses L18xL11, L16xL18, L8xL21 and L9xL6 had good tolerance to seedling drought stress. On the other hand, single crosses L18xL11 and L11xL13 had high grain yield and good endosperm modification. All these single crosses could be recommended for commercial production after evaluation across locations in the Eastern Cape Province. Alternatively they can be crossed with other superior inbreds to generate three or four way hybrids, which could then be evaluated for potential use by farmers in the Eastern Cape.
- Full Text:
- Date Issued: 2012
Perceptions of rural consumers and the quality of mutton at purchase points in the Eastern Cape Province, South Africa
- Authors: Rani, Zikhona Theodora
- Date: 2012
- Subjects: Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11823 , http://hdl.handle.net/10353/d1007562 , Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Description: The objective of the study was to determine perceptions of rural consumers on mutton quality, and the quality of mutton at purchase points in the Eastern Cape Province, South Africa. The study was conducted in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi). A survey was conducted where a sample of 215 consumers were randomly selected and interviewed, either at point of purchase or as they left the shops. The survey was not limited to the shoppers only but also extended to households from the villages. Questions on some of the most important meat quality cues were compiled. The physico-chemical quality of mutton purchased from different shops was also determined. Forty different shops and butcheries selling mutton from all the selected municipalities were visited. Different parts of mutton samples were bought. Physico-chemical qualities of mutton such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at points of purchase. Cooking loss and tenderness evaluations were later done at the Meat Science laboratory at the University of Fort Hare. The results indicated that price was one of the major factors affecting the purchasing decisions of consumers. Thirty four percent of the consumers preferred mutton as compared to other protein sources, even though they were not buying this type of meat because it was not affordable to them. Both male and female consumers suggested that more sheep farmers need to be established in order to reduce the levels of imported mutton into South Africa. They also highlighted that selection programmes that will result in efficient sheep production and reduced mutton prices need to be implemented. Meat at points of purchase was affected by season resulting in lower lightness (L*24.7±0.49) values in winter and higher (L* 32.2±0.49) in Spring. The class of shop did not have an effect on meat quality attributes. Trotter had high values of lightness (L*30.4±2.78a), redness (a*30.4±2.78a), yellowness (13.1±1.08a), pH (6.3±0.12a), tenderness (24.9±3.69b) and cooking loss (39.5±4.38ab). The number of days from when the meat was put on the shelves to the time when it was purchased for consumption (days to purchase) had a significant (P<0.05) negative correlation with the Warner Braztler Shear Force (WBSF)values and lightness of the meat. Significant negative (P < 0.05) correlations between pH and colour of the meat (L*, a* and b*) were also observed. It was concluded that rural consumers perceive the quality of mutton as the best and that the physico-chemical quality of meat purchased from different shops was different, largely based on the part of meat, meat storage conditions and not necessarily on the class of the shop.
- Full Text:
- Date Issued: 2012
- Authors: Rani, Zikhona Theodora
- Date: 2012
- Subjects: Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11823 , http://hdl.handle.net/10353/d1007562 , Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Description: The objective of the study was to determine perceptions of rural consumers on mutton quality, and the quality of mutton at purchase points in the Eastern Cape Province, South Africa. The study was conducted in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi). A survey was conducted where a sample of 215 consumers were randomly selected and interviewed, either at point of purchase or as they left the shops. The survey was not limited to the shoppers only but also extended to households from the villages. Questions on some of the most important meat quality cues were compiled. The physico-chemical quality of mutton purchased from different shops was also determined. Forty different shops and butcheries selling mutton from all the selected municipalities were visited. Different parts of mutton samples were bought. Physico-chemical qualities of mutton such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at points of purchase. Cooking loss and tenderness evaluations were later done at the Meat Science laboratory at the University of Fort Hare. The results indicated that price was one of the major factors affecting the purchasing decisions of consumers. Thirty four percent of the consumers preferred mutton as compared to other protein sources, even though they were not buying this type of meat because it was not affordable to them. Both male and female consumers suggested that more sheep farmers need to be established in order to reduce the levels of imported mutton into South Africa. They also highlighted that selection programmes that will result in efficient sheep production and reduced mutton prices need to be implemented. Meat at points of purchase was affected by season resulting in lower lightness (L*24.7±0.49) values in winter and higher (L* 32.2±0.49) in Spring. The class of shop did not have an effect on meat quality attributes. Trotter had high values of lightness (L*30.4±2.78a), redness (a*30.4±2.78a), yellowness (13.1±1.08a), pH (6.3±0.12a), tenderness (24.9±3.69b) and cooking loss (39.5±4.38ab). The number of days from when the meat was put on the shelves to the time when it was purchased for consumption (days to purchase) had a significant (P<0.05) negative correlation with the Warner Braztler Shear Force (WBSF)values and lightness of the meat. Significant negative (P < 0.05) correlations between pH and colour of the meat (L*, a* and b*) were also observed. It was concluded that rural consumers perceive the quality of mutton as the best and that the physico-chemical quality of meat purchased from different shops was different, largely based on the part of meat, meat storage conditions and not necessarily on the class of the shop.
- Full Text:
- Date Issued: 2012
Photocatalytic activity and antibacterial properties of Ag/N-doped TiO2 nanoparticles on PVAE-CS nanofibre support
- Authors: Ocwelwang, Atsile Rosy
- Date: 2012
- Subjects: Nanocomposites (Materials) , Nanofibers , Electrospinning
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11337 , http://hdl.handle.net/10353/d1006794 , Nanocomposites (Materials) , Nanofibers , Electrospinning
- Description: Lack of potable water is one of the major challenges that the world faces currently and the effects of this are mainly experienced by people in developing countries. This has therefore propelled research in advanced oxidation technologies AOTs to improve the current water treatment methods using cost effective, non toxic and efficient treatment methods. Hence, in this study the sol-gel synthesis method was used to prepare TiO2 nanoparticles that were photocatalytically active under UV and visible solar light as well as possessing antibacterial properties. Silver and nitrogen doping was carried out to extend the optical absorption of TiO2. For easy removal and reuse of the photocatalyst the nanoparticles were immobilized on chitosan and poly (vinyl-alcohol-co-ethylene) using the electrospining technique. The synthesized nanomaterials were characterized by FTIR, XRD, SEM/EDS, TEM, DRS, and TGA. FTIR and EDS analysis confirmed the formation and composition of TiO2 nanopowders for the doped and undoped nanoparticles. XRD analysis showed that the anatase phase was the dominant crystalline phase of the synthesized nanopowders. SEM and TEM respectively illustrated the distribution and size of the electrospun nanofibers and the nanoparticles of TiO2. DRS results showed that there was a significant shift in the absorption band edge and wavelength of Ag-TiO2 to 397 nm, followed by N-TiO2 at 396 nm compared to the commercial titania which was at 359 nm. The photocatalytic activities and antibacterial properties of these materials were tested on methylene blue dye and E.coli microorganism respectively. Ag-TiO2 immobilized on nanofibers of chitosan and PVAE had the highest photocatalytic activity compared to N-TiO2. Similar results were observed when the biocide properties of these materials were tested on E. coli.
- Full Text:
- Date Issued: 2012
- Authors: Ocwelwang, Atsile Rosy
- Date: 2012
- Subjects: Nanocomposites (Materials) , Nanofibers , Electrospinning
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11337 , http://hdl.handle.net/10353/d1006794 , Nanocomposites (Materials) , Nanofibers , Electrospinning
- Description: Lack of potable water is one of the major challenges that the world faces currently and the effects of this are mainly experienced by people in developing countries. This has therefore propelled research in advanced oxidation technologies AOTs to improve the current water treatment methods using cost effective, non toxic and efficient treatment methods. Hence, in this study the sol-gel synthesis method was used to prepare TiO2 nanoparticles that were photocatalytically active under UV and visible solar light as well as possessing antibacterial properties. Silver and nitrogen doping was carried out to extend the optical absorption of TiO2. For easy removal and reuse of the photocatalyst the nanoparticles were immobilized on chitosan and poly (vinyl-alcohol-co-ethylene) using the electrospining technique. The synthesized nanomaterials were characterized by FTIR, XRD, SEM/EDS, TEM, DRS, and TGA. FTIR and EDS analysis confirmed the formation and composition of TiO2 nanopowders for the doped and undoped nanoparticles. XRD analysis showed that the anatase phase was the dominant crystalline phase of the synthesized nanopowders. SEM and TEM respectively illustrated the distribution and size of the electrospun nanofibers and the nanoparticles of TiO2. DRS results showed that there was a significant shift in the absorption band edge and wavelength of Ag-TiO2 to 397 nm, followed by N-TiO2 at 396 nm compared to the commercial titania which was at 359 nm. The photocatalytic activities and antibacterial properties of these materials were tested on methylene blue dye and E.coli microorganism respectively. Ag-TiO2 immobilized on nanofibers of chitosan and PVAE had the highest photocatalytic activity compared to N-TiO2. Similar results were observed when the biocide properties of these materials were tested on E. coli.
- Full Text:
- Date Issued: 2012
Phytochemical analysis and bioactivity of Garcinia Kola (Heckel) seeds on selected bacterial pathogens
- Seanego, Christinah Tshephisho
- Authors: Seanego, Christinah Tshephisho
- Date: 2012
- Subjects: Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants , Microbial sensitivity tests , Streptococcal infections , Streptococcus , Staphylococcus aureus infections , Salmonella typhimurium , Traditional medicine
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11259 , http://hdl.handle.net/10353/420 , Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants , Microbial sensitivity tests , Streptococcal infections , Streptococcus , Staphylococcus aureus infections , Salmonella typhimurium , Traditional medicine
- Description: Garcinia kola is one of the plants used in folklore remedies for the treatment of microbial infections. Bacterial resistance to commonly used antibiotics has necessitated the search for newer and alternative compounds for the treatment of drug resistant microbial infections. This study focuses on the bioactivity of G. kola seeds on Streptococcus pyogenes (ATCC 49399), Staphylococcus aureus (NCTC 6571), Plesiomonas Shigelloides (ATCC 51903) and Salmonella typhimurium (ATCC 13311), organisms which can cause illnesses from mild to severe with potentially fatal outcomes. The crude ethyl acetate, ethanol, methanol, acetone and aqueous extracts were screened by agar-well diffusion method and the activities of the extract were further determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The inhibition zones ranged from 0 - 24 mm, while MIC and MBC of the extract ranged between 0.04 - 1.25 mg/mL and 0.081 - 2.5 mg/mL respectively. Chloroform/ Ethyl Acetate/ Formic acid (CEF) solvent system separated more active compounds followed by Ethyl Acetate/ Methanol/ Water (EMW) and Benzene/ Ethanol/ Ammonium Hydroxide (BEA). The extracts were fractionated by Thin Layer Chromatography (TLC). Bioautography was used to assess the activity of the possible classes of compounds present in the more active extracts. Column chromatography was used to purify the active compounds from the mixture while Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the phyto components of the fractions. The MIC of the fractions ranged between 0.0006 - 2.5 mg/mL. CEF 3 (F3), CEF 11 (F11) and CEF 12 (F12) revealed the presence of high levels fatty acids Linoleic acid, 1, 2-Benzenedicarboxylic acid and 2, 3-Dihydro-3, 5-dihydroxy-6-methyl, respectively. The results obtained from this study justify the use of this plant in traditional medicine and provide leads which could be further exploited for the development of new and potent antimicrobials.
- Full Text:
- Date Issued: 2012
- Authors: Seanego, Christinah Tshephisho
- Date: 2012
- Subjects: Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants , Microbial sensitivity tests , Streptococcal infections , Streptococcus , Staphylococcus aureus infections , Salmonella typhimurium , Traditional medicine
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11259 , http://hdl.handle.net/10353/420 , Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants , Microbial sensitivity tests , Streptococcal infections , Streptococcus , Staphylococcus aureus infections , Salmonella typhimurium , Traditional medicine
- Description: Garcinia kola is one of the plants used in folklore remedies for the treatment of microbial infections. Bacterial resistance to commonly used antibiotics has necessitated the search for newer and alternative compounds for the treatment of drug resistant microbial infections. This study focuses on the bioactivity of G. kola seeds on Streptococcus pyogenes (ATCC 49399), Staphylococcus aureus (NCTC 6571), Plesiomonas Shigelloides (ATCC 51903) and Salmonella typhimurium (ATCC 13311), organisms which can cause illnesses from mild to severe with potentially fatal outcomes. The crude ethyl acetate, ethanol, methanol, acetone and aqueous extracts were screened by agar-well diffusion method and the activities of the extract were further determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The inhibition zones ranged from 0 - 24 mm, while MIC and MBC of the extract ranged between 0.04 - 1.25 mg/mL and 0.081 - 2.5 mg/mL respectively. Chloroform/ Ethyl Acetate/ Formic acid (CEF) solvent system separated more active compounds followed by Ethyl Acetate/ Methanol/ Water (EMW) and Benzene/ Ethanol/ Ammonium Hydroxide (BEA). The extracts were fractionated by Thin Layer Chromatography (TLC). Bioautography was used to assess the activity of the possible classes of compounds present in the more active extracts. Column chromatography was used to purify the active compounds from the mixture while Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the phyto components of the fractions. The MIC of the fractions ranged between 0.0006 - 2.5 mg/mL. CEF 3 (F3), CEF 11 (F11) and CEF 12 (F12) revealed the presence of high levels fatty acids Linoleic acid, 1, 2-Benzenedicarboxylic acid and 2, 3-Dihydro-3, 5-dihydroxy-6-methyl, respectively. The results obtained from this study justify the use of this plant in traditional medicine and provide leads which could be further exploited for the development of new and potent antimicrobials.
- Full Text:
- Date Issued: 2012
Prevalence, seasonal trends and incidences of cattle tuberculosis and brucellosis in the Cacadu municipality, Eastern Cape, South Africa
- Authors: Nombebe, Thobeka
- Date: 2012
- Subjects: Tuberculosis in cattle -- South Africa -- Eastern Cape , Brucellosis in animals -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Mycobacterium tuberculosis -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11783 , http://hdl.handle.net/10353/d1016200 , Tuberculosis in cattle -- South Africa -- Eastern Cape , Brucellosis in animals -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Mycobacterium tuberculosis -- South Africa -- Eastern Cape
- Description: A cross-sectional study was conducted from February 2011 to August 2012 to investigate the status and identify risk factors for Bovine Tuberculosis (BTB) and cattle Brucellosis. A total of 1277 cattle from 6 selected dairy farms were tested. The farms were purposively selected on suspected risk. Samples were analysed using Rose Bengal Test (RBPT) and Complement Fixation Test (CFT) for Brucellosis and Comparative Intradermal Tuberculin Test (CITT) for BTB. The results revealed the overall prevalence of 1.6% for Brucellosis and no BTB was found. Logistic regression analysis revealed that age of cattle, herd size and number of calves a cow has had significant association with Brucellosis with p-values 0.0071, 0.0490 and 0.000 respectively. The role of location (p>0.05), gender (p>0.05) and breed (p>0.05) in the occurrence of the disease was not statistically significant at α=0.05, although higher rates were obtained in females and Jersey breed. Questionnaires were also administered to 47 individuals a total of 12 females and 35 males. Most respondents were not aware about cattle brucellosis and cattle tuberculosis. Consumption of raw or unpasteurized milk still occurs with 74.75% of respondents revealed.
- Full Text:
- Date Issued: 2012
- Authors: Nombebe, Thobeka
- Date: 2012
- Subjects: Tuberculosis in cattle -- South Africa -- Eastern Cape , Brucellosis in animals -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Mycobacterium tuberculosis -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11783 , http://hdl.handle.net/10353/d1016200 , Tuberculosis in cattle -- South Africa -- Eastern Cape , Brucellosis in animals -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Mycobacterium tuberculosis -- South Africa -- Eastern Cape
- Description: A cross-sectional study was conducted from February 2011 to August 2012 to investigate the status and identify risk factors for Bovine Tuberculosis (BTB) and cattle Brucellosis. A total of 1277 cattle from 6 selected dairy farms were tested. The farms were purposively selected on suspected risk. Samples were analysed using Rose Bengal Test (RBPT) and Complement Fixation Test (CFT) for Brucellosis and Comparative Intradermal Tuberculin Test (CITT) for BTB. The results revealed the overall prevalence of 1.6% for Brucellosis and no BTB was found. Logistic regression analysis revealed that age of cattle, herd size and number of calves a cow has had significant association with Brucellosis with p-values 0.0071, 0.0490 and 0.000 respectively. The role of location (p>0.05), gender (p>0.05) and breed (p>0.05) in the occurrence of the disease was not statistically significant at α=0.05, although higher rates were obtained in females and Jersey breed. Questionnaires were also administered to 47 individuals a total of 12 females and 35 males. Most respondents were not aware about cattle brucellosis and cattle tuberculosis. Consumption of raw or unpasteurized milk still occurs with 74.75% of respondents revealed.
- Full Text:
- Date Issued: 2012
Productions of high quality wastewater final effluents remain a challenge in the Eastern Cape Province of South Africa
- Authors: Gusha, Siyabulela Stability
- Date: 2012
- Subjects: Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11265 , http://hdl.handle.net/10353/489 , Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Description: Water is an indispensible and yet a difficult resource to be renewed, thus water scarcity has become one of the major challenges faced worldwide, with the Southern regions of Africa being the most impacted and affected, especially the Eastern Cape Province of South Africa where rural communities depend on receiving waterbodies that are often negatively impacted by wastewater final effluents. This present study was conducted between August and December 2010 to assess the physicochemical and microbial qualities of the final effluents of peri-urban and rural communities based wastewater treatment plants in the Eastern Cape Province. The physicochemical parameters were determined on site and in the laboratory, while bacteriological qualities were determined using culture based techniques. The virological qualities were determined by molecular methods using reverse transcriptase polymerase chain reaction for the target RNA virus and the conventional polymerase chain reaction for the target DNA virus. For both wastewater treatment plants, the physicochemical parameters ranged as follows: chemical oxygen demand (5.95-45 mg/L); total dissolved solids (114.5-187.0 mg/L); salinity (0.12-0.20 psu); temperature (14.2-25.7oC); pH (6.0-7.6); nitrate and nitrites (1.55-6.7 mg/L and 0.023-1.15 mg/L respectively); biological oxygen demand (3.5-7.8 mg/L); turbidity (1.49-6.98 NTU); and chlorine residual (0-2.97 mg/L). Feacal indicator bacteria counts ranged as follows: feacal coliforms (0-1.25×104 cfu/100 ml); total coliforms (0-3.95×104 cfu/100 ml); and enterococci (0-5.0×103 cfu/100 ml). xviii Seventy five percent of the rural community based plant and 80 percent of the peri-urban community based plant were positive for coxsackie A virus, while hepatitis A virus was detected in all the rural community based plant 80 percent of the peri-urban community based plant. This study suggests the need for intervention by appropriate regulatory agencies to ensure regular monitoring of the qualities of final effluents of wastewater treatment facilities in the Eastern Cape Province and ensure compliance to established guidelines.
- Full Text:
- Date Issued: 2012
- Authors: Gusha, Siyabulela Stability
- Date: 2012
- Subjects: Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11265 , http://hdl.handle.net/10353/489 , Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Description: Water is an indispensible and yet a difficult resource to be renewed, thus water scarcity has become one of the major challenges faced worldwide, with the Southern regions of Africa being the most impacted and affected, especially the Eastern Cape Province of South Africa where rural communities depend on receiving waterbodies that are often negatively impacted by wastewater final effluents. This present study was conducted between August and December 2010 to assess the physicochemical and microbial qualities of the final effluents of peri-urban and rural communities based wastewater treatment plants in the Eastern Cape Province. The physicochemical parameters were determined on site and in the laboratory, while bacteriological qualities were determined using culture based techniques. The virological qualities were determined by molecular methods using reverse transcriptase polymerase chain reaction for the target RNA virus and the conventional polymerase chain reaction for the target DNA virus. For both wastewater treatment plants, the physicochemical parameters ranged as follows: chemical oxygen demand (5.95-45 mg/L); total dissolved solids (114.5-187.0 mg/L); salinity (0.12-0.20 psu); temperature (14.2-25.7oC); pH (6.0-7.6); nitrate and nitrites (1.55-6.7 mg/L and 0.023-1.15 mg/L respectively); biological oxygen demand (3.5-7.8 mg/L); turbidity (1.49-6.98 NTU); and chlorine residual (0-2.97 mg/L). Feacal indicator bacteria counts ranged as follows: feacal coliforms (0-1.25×104 cfu/100 ml); total coliforms (0-3.95×104 cfu/100 ml); and enterococci (0-5.0×103 cfu/100 ml). xviii Seventy five percent of the rural community based plant and 80 percent of the peri-urban community based plant were positive for coxsackie A virus, while hepatitis A virus was detected in all the rural community based plant 80 percent of the peri-urban community based plant. This study suggests the need for intervention by appropriate regulatory agencies to ensure regular monitoring of the qualities of final effluents of wastewater treatment facilities in the Eastern Cape Province and ensure compliance to established guidelines.
- Full Text:
- Date Issued: 2012
Risk preferences and consumption decisions in organic production: the case of Kwazulu-Natal and Eastern Cape provinces of South Africa
- Authors: Kisaka-Lwayo, Maggie
- Date: 2012
- Subjects: Food security -- South Africa , Sustainable development -- South Africa , Organic farming -- South Africa , Natural foods industry -- South Africa , Risk management -- South Africa , Consumers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11188 , http://hdl.handle.net/10353/492 , Food security -- South Africa , Sustainable development -- South Africa , Organic farming -- South Africa , Natural foods industry -- South Africa , Risk management -- South Africa , Consumers -- South Africa
- Description: Despite phenomenal success of the commercial agricultural sector in South Africa and significant progress in integrating smallholders since democratic reforms, food security concerns remain. Recent global increases in food prices have further exacerbated vulnerabilities and made it imperative to examine alternative food production questions in the country. Organic agriculture is identified as one of the sustainable approaches to farming and offers insights towards a paradigm shift in food and nutritional security. Notwithstanding, consumer awareness, knowledge and consumption of organic foods are significantly lower in developing than developed countries. Risks associated with adoption of organic practices need to be explored to address the supply and demand constraints. Similarly, while consumer awareness of organic foods is the first step in developing demand for organic products, it does not necessarily translate to consumption. Therefore it is important to investigate these issues. The objectives of this study were to: (i) describe the demographic and socio-economic characteristics of organic farmers and consumers; (ii) establish the determinants of farmers‘ decision to participate in organic farming distinguishing between the fully-certified organic, partially-certified organic and non-organic farmers; (iii) elicit farmers risk preferences and empirically analyse farmers sources of risk and risk management strategies; (iv) explore consumer awareness, perceptions and attitudes regarding organic products; and (v) identify the factors that influence consumer‘s preference and consumption of organic products. A total of 400 respondents were surveyed, consisting of 200 smallholder farmers in KwaZulu-Natal and 200 consumers in the Eastern Cape. The KwaZulu-Natal study was conducted earlier and identified the following as major sources of risk, lack of consumer awareness of organic products and lack of information among producers about consumer preferences for organic products. This informed the need to undertake a consumer awareness and preference study, in order to inform producers. The Eastern Cape is a bordering province to KwaZulu-Natal with similar socio economic conditions and a major consumer of produce from KwaZulu-Natal. It was also expected that in the intervening period there could have been awareness about the product. An vii indication of its appeal would not be in the consumption of the product by the people who grow it, but by consumers who reside in bordering regions. Producer and household questionnaires were used to record household activities, socio-economic and institutional data as well as household demographics through personal interviews. The Arrow Pratt Absolute Risk Aversion (APARA) coefficient was used to measure the farmer‘s degree of risk aversion and the experimental gambling approach to establish the risk classification. Consumers were also asked about their awareness and knowledge about organics, attitudes and perceptions towards organics, preference and consumption patterns. The ordered probit results indicate that older farmers, who are less risk averse and reside in the sub-ward Ogagwini, Ezigani, and Hwayi were more likely to be certified organic farmers. Similarly, the propensity to adopt organic farming is positively correlated to household size, livestock ownership, asset base and tenure security. The risk analysis indicates that at higher pay-offs most farmers are intermediate to moderately risk-averse, with little variation according to personal characteristics, and that non-organic farmers tend to be more risk averse than fully-certified and partially-certified farmers. In general, price, production and financial risks were perceived as the most important sources of risk. Using Principal Component Analysis (PCA), seven principal components (PCs) explaining 66.13% of the variation were extracted. Socio economic factors having a significant effect on the various sources of risk are age, gender, education, location, information access and risk taking ability. The most important traditional risk management strategies used by the surveyed farmers are crop diversification, precautionary savings and participating in social networks. There was general awareness of what constituted organic foods with many consumers associating organic foods with health and nutrition, chemical free and produced using indigenous methods of production. However, there was low awareness of organic products among consumers with little or no knowledge of organic certification and standards. According to the logit model the major factors influencing consumer awareness of organic products are: gender, education, employment status, and location of the respondents, person/household member responsible for shopping and the price perception of the decision maker. The discriminant analysis showed that the consumption of organic products is significantly affected by age of the consumer, viii location, person/household member responsible for shopping, consumer awareness of organics, price perception and label trust. The findings from this study provides useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of organic practices, increase smallholder farmers capacity to manage risk and drive growth in the organic food market.
- Full Text:
- Date Issued: 2012
- Authors: Kisaka-Lwayo, Maggie
- Date: 2012
- Subjects: Food security -- South Africa , Sustainable development -- South Africa , Organic farming -- South Africa , Natural foods industry -- South Africa , Risk management -- South Africa , Consumers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11188 , http://hdl.handle.net/10353/492 , Food security -- South Africa , Sustainable development -- South Africa , Organic farming -- South Africa , Natural foods industry -- South Africa , Risk management -- South Africa , Consumers -- South Africa
- Description: Despite phenomenal success of the commercial agricultural sector in South Africa and significant progress in integrating smallholders since democratic reforms, food security concerns remain. Recent global increases in food prices have further exacerbated vulnerabilities and made it imperative to examine alternative food production questions in the country. Organic agriculture is identified as one of the sustainable approaches to farming and offers insights towards a paradigm shift in food and nutritional security. Notwithstanding, consumer awareness, knowledge and consumption of organic foods are significantly lower in developing than developed countries. Risks associated with adoption of organic practices need to be explored to address the supply and demand constraints. Similarly, while consumer awareness of organic foods is the first step in developing demand for organic products, it does not necessarily translate to consumption. Therefore it is important to investigate these issues. The objectives of this study were to: (i) describe the demographic and socio-economic characteristics of organic farmers and consumers; (ii) establish the determinants of farmers‘ decision to participate in organic farming distinguishing between the fully-certified organic, partially-certified organic and non-organic farmers; (iii) elicit farmers risk preferences and empirically analyse farmers sources of risk and risk management strategies; (iv) explore consumer awareness, perceptions and attitudes regarding organic products; and (v) identify the factors that influence consumer‘s preference and consumption of organic products. A total of 400 respondents were surveyed, consisting of 200 smallholder farmers in KwaZulu-Natal and 200 consumers in the Eastern Cape. The KwaZulu-Natal study was conducted earlier and identified the following as major sources of risk, lack of consumer awareness of organic products and lack of information among producers about consumer preferences for organic products. This informed the need to undertake a consumer awareness and preference study, in order to inform producers. The Eastern Cape is a bordering province to KwaZulu-Natal with similar socio economic conditions and a major consumer of produce from KwaZulu-Natal. It was also expected that in the intervening period there could have been awareness about the product. An vii indication of its appeal would not be in the consumption of the product by the people who grow it, but by consumers who reside in bordering regions. Producer and household questionnaires were used to record household activities, socio-economic and institutional data as well as household demographics through personal interviews. The Arrow Pratt Absolute Risk Aversion (APARA) coefficient was used to measure the farmer‘s degree of risk aversion and the experimental gambling approach to establish the risk classification. Consumers were also asked about their awareness and knowledge about organics, attitudes and perceptions towards organics, preference and consumption patterns. The ordered probit results indicate that older farmers, who are less risk averse and reside in the sub-ward Ogagwini, Ezigani, and Hwayi were more likely to be certified organic farmers. Similarly, the propensity to adopt organic farming is positively correlated to household size, livestock ownership, asset base and tenure security. The risk analysis indicates that at higher pay-offs most farmers are intermediate to moderately risk-averse, with little variation according to personal characteristics, and that non-organic farmers tend to be more risk averse than fully-certified and partially-certified farmers. In general, price, production and financial risks were perceived as the most important sources of risk. Using Principal Component Analysis (PCA), seven principal components (PCs) explaining 66.13% of the variation were extracted. Socio economic factors having a significant effect on the various sources of risk are age, gender, education, location, information access and risk taking ability. The most important traditional risk management strategies used by the surveyed farmers are crop diversification, precautionary savings and participating in social networks. There was general awareness of what constituted organic foods with many consumers associating organic foods with health and nutrition, chemical free and produced using indigenous methods of production. However, there was low awareness of organic products among consumers with little or no knowledge of organic certification and standards. According to the logit model the major factors influencing consumer awareness of organic products are: gender, education, employment status, and location of the respondents, person/household member responsible for shopping and the price perception of the decision maker. The discriminant analysis showed that the consumption of organic products is significantly affected by age of the consumer, viii location, person/household member responsible for shopping, consumer awareness of organics, price perception and label trust. The findings from this study provides useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of organic practices, increase smallholder farmers capacity to manage risk and drive growth in the organic food market.
- Full Text:
- Date Issued: 2012
Sedimentary environments and provenance of the Balfour Formation (Beaufort Group) in the area between Bedford and Adelaide, Eastern Cape Province, South Africa
- Authors: Oghenekome, Monica Enifome
- Date: 2012
- Subjects: Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11524 , http://hdl.handle.net/10353/d1004354 , Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Description: The research examines the sedimentary environments and provenance of the Balfour Formation of the Beaufort Group (Karoo Supergroup) in the Eastern Cape Province, South Africa. This Formation occurs in the southeastern part of the Karoo Basin. It consists of sedimentary rocks, which are an alternating siltstone, shale and mudstone succession with subordinate interbedded sandstone and subsequently intruded by Karoo dolerite in the form of sills and dykes. ithostratigraphically, the Balfour Formation is subdivided into five units namely, from the base to the top, the Oudeberg, Daggaboersnek, Barberskrans, Elandsberg and Palingkloof Members. The Balfour Formation is overlain by the Katberg Formation. This study involved field investigations in the vicinity of the towns of Bedford and Adelaide with integrated stratigraphical, sedimentological and petrological studies. A geological map was constructed after field investigations. Lithofacies of the Balfour Formation that were studied are characterised by sandstone facies (Sh, Sm, St, Sr, Sp) and fine-grained sediments (Fl or Fsm) which reflect point-bar, cut-bank, channel and floodplain deposits. Lithologically, the Oudeberg Member consists of sandstone of which some units are internally massive alternating with thin laminated siltstone and mudstone. The Daggaboersnek Member is characterised by regular, generally non-lenticular, overall stratification, in the Barberkrans Member consists of sandstone lithosomes, while the Elandsberg Member is an argillaceous unit, similar to the Daggaboersnek Member. The Palingkloof Member is composed predominantly of red mudstone that can be used to distinguish the Balfour Formation from the overlying Katberg Formation, which consists predominantly of sandstone. The stratigraphic sequence displays two fining upward megacycles of sedimentary deposits with change in the sediment supply pattern from low-sinuosity to high-sinuosity river systems which reflect both braid and meandering deposits, respectively. Sedimentary structures in the sandstone units and the provenance of the Balfour Formation indicate that these deposits were produced by rivers flowing from the southeast with minor drift towards the northwest. According to the composition of the sediments and their sequence of deposition the Formation represents a fluvial environment. Mineralogical and grain size data from the sandstones of the various members of the Balfour Formation indicate the same source area of granitic, metamorphic and older sedimentary rocks and show no significant petrographic differences. The petrographic and geochemical investigations confirmed the sandstone to be feldspathic litharenite and ultralithofeldspathic sandstone. The palaeocurrent investigation indicates the main provenance to have been situated to the southeast of the Karoo basin. Heavy-mineral concentrations within the sandstones also give an indication that the source had a transitional arc plate tectonic setting.
- Full Text:
- Date Issued: 2012
- Authors: Oghenekome, Monica Enifome
- Date: 2012
- Subjects: Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11524 , http://hdl.handle.net/10353/d1004354 , Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Description: The research examines the sedimentary environments and provenance of the Balfour Formation of the Beaufort Group (Karoo Supergroup) in the Eastern Cape Province, South Africa. This Formation occurs in the southeastern part of the Karoo Basin. It consists of sedimentary rocks, which are an alternating siltstone, shale and mudstone succession with subordinate interbedded sandstone and subsequently intruded by Karoo dolerite in the form of sills and dykes. ithostratigraphically, the Balfour Formation is subdivided into five units namely, from the base to the top, the Oudeberg, Daggaboersnek, Barberskrans, Elandsberg and Palingkloof Members. The Balfour Formation is overlain by the Katberg Formation. This study involved field investigations in the vicinity of the towns of Bedford and Adelaide with integrated stratigraphical, sedimentological and petrological studies. A geological map was constructed after field investigations. Lithofacies of the Balfour Formation that were studied are characterised by sandstone facies (Sh, Sm, St, Sr, Sp) and fine-grained sediments (Fl or Fsm) which reflect point-bar, cut-bank, channel and floodplain deposits. Lithologically, the Oudeberg Member consists of sandstone of which some units are internally massive alternating with thin laminated siltstone and mudstone. The Daggaboersnek Member is characterised by regular, generally non-lenticular, overall stratification, in the Barberkrans Member consists of sandstone lithosomes, while the Elandsberg Member is an argillaceous unit, similar to the Daggaboersnek Member. The Palingkloof Member is composed predominantly of red mudstone that can be used to distinguish the Balfour Formation from the overlying Katberg Formation, which consists predominantly of sandstone. The stratigraphic sequence displays two fining upward megacycles of sedimentary deposits with change in the sediment supply pattern from low-sinuosity to high-sinuosity river systems which reflect both braid and meandering deposits, respectively. Sedimentary structures in the sandstone units and the provenance of the Balfour Formation indicate that these deposits were produced by rivers flowing from the southeast with minor drift towards the northwest. According to the composition of the sediments and their sequence of deposition the Formation represents a fluvial environment. Mineralogical and grain size data from the sandstones of the various members of the Balfour Formation indicate the same source area of granitic, metamorphic and older sedimentary rocks and show no significant petrographic differences. The petrographic and geochemical investigations confirmed the sandstone to be feldspathic litharenite and ultralithofeldspathic sandstone. The palaeocurrent investigation indicates the main provenance to have been situated to the southeast of the Karoo basin. Heavy-mineral concentrations within the sandstones also give an indication that the source had a transitional arc plate tectonic setting.
- Full Text:
- Date Issued: 2012
Soil fertility enhancement through appropriate fertilizer management on winter cover crops in a conservation agriculture system
- Authors: Dube, Ernest
- Date: 2012
- Subjects: Fertilizers , Soil fertility , Crops -- Nutrition , Soil productivity , Range management , Grazing -- Management , Forage plants , Humus
- Language: English
- Type: Thesis , Doctoral , PhD (Crop Science)
- Identifier: vital:11239 , http://hdl.handle.net/10353/d1001044 , Fertilizers , Soil fertility , Crops -- Nutrition , Soil productivity , Range management , Grazing -- Management , Forage plants , Humus
- Description: A study was carried out to determine the effects of oat (Avena sativa) and grazing vetch (Vicia darsycapa) winter cover crops and fertilizer application on SOM, phosphorus (P) pools, nutrient availability, nutrient uptake, maize yield and seedbanks of problematic weeds in an irrigated maize-based conservation agriculture (CA) system. A separate experiment was carried out to investigate the effects of the winter cover crops on nitrogen (N) management, N use efficiency and profitability. After four years of continuous rotation, the winter cover crops significantly (p<0.05) increased particulate SOM and hot water soluble carbon in the 0 – 5 and 5 – 20 cm soil depths. When fertilized, oat was better able to support SOM sequestration in water stable aggregates at 0 – 20 cm whilst grazing vetch was more effective at 20 – 50 cm. Where no fertilizer was invested, there were significant (p<0.01) reductions in biomass input and SOM on oat-maize and weedy fallow-maize rotations whereas vetch-maize rotations did not respond, both at 0 – 5 and 5 – 20 cm. Targeting fertilizer to the winter cover crop required less fertilizer, and yet gave a similar SOM response as targeting the fertilizer to the maize crop. In addition to increasing SOM in the surface soil (0 – 5 cm), the winter cover crops significantly (p<0.05) increased labile pools of P, including microbial P. The cover crops also significantly (p<0.05) increased maize P concentration during early growth, extractable soil P, Cu, Mn, and Zn but had no effect on Ca and K. Grazing vetch increased soil mineral N but reduced extractable soil Mg. Without fertilizer, there were sharp declines in maize grain yield on oat and weedy fallow rotations over the four year period, but less so, on the grazing vetch. Grazing vetch increased maize growth, grain yield response to N fertilizer, nitrogen use efficiency (NUE) and profitability for fertilizer rates below 180 kg N ha-1. Oat effects however on maize yield and NUE were generally similar to weedy fallow. Based on the partial factor productivity of N, the highest efficiencies in utilization of fertilizer N for maize yield improvement under grazing vetch and oat are obtained at 60 kg N ha-1 and would decline thereafter with any increases in fertilizer application rate. Grazing vetch gave N fertilizer replacement values of up to 120 kg N ha-1 as well as the highest marginal rates of return to increasing N fertilizer rate. The cover crops were more effective than the weedy fallow in reducing seedbank density of Digitaria sanguinalis, Eleusine indica, Amaranthus retroflexus and Datura stramonium at 0 – 5 cm soil depth, causing weed seed reductions of 30 - 70%. The winter cover crops however, selectively allowed emergence of the narrow leafed weeds; Cyperus esculentus and Digitaria sanguinalis in the maize crop. The findings of this study suggested that grazing vetch is suited for SOM improvement in low fertilizer input systems and that fertilizer is better invested on winter cover crops as opposed to maize crops. Oat, on the other hand, when fertilized, would be ideal for C sequestration in water stable aggregates of the surface soil. Grazing vetch is ideal for resource poor farmers who cannot afford mineral fertilizers as it gives grain yield improvement and high fertilizer replacement value. Grazing vetch can produce enough maize yield response to pay its way in the maize-based systems and oat may not require additional N than that applied to the weedy fallow. Phosphorus and Zn are some of the major limiting essential plant nutrients on South African soils and the winter cover crops could make a contribution. The cover crops also hasten depletion of some problematic weeds from seedbanks, leading to reduced weed pressure during maize growth.
- Full Text:
- Date Issued: 2012
- Authors: Dube, Ernest
- Date: 2012
- Subjects: Fertilizers , Soil fertility , Crops -- Nutrition , Soil productivity , Range management , Grazing -- Management , Forage plants , Humus
- Language: English
- Type: Thesis , Doctoral , PhD (Crop Science)
- Identifier: vital:11239 , http://hdl.handle.net/10353/d1001044 , Fertilizers , Soil fertility , Crops -- Nutrition , Soil productivity , Range management , Grazing -- Management , Forage plants , Humus
- Description: A study was carried out to determine the effects of oat (Avena sativa) and grazing vetch (Vicia darsycapa) winter cover crops and fertilizer application on SOM, phosphorus (P) pools, nutrient availability, nutrient uptake, maize yield and seedbanks of problematic weeds in an irrigated maize-based conservation agriculture (CA) system. A separate experiment was carried out to investigate the effects of the winter cover crops on nitrogen (N) management, N use efficiency and profitability. After four years of continuous rotation, the winter cover crops significantly (p<0.05) increased particulate SOM and hot water soluble carbon in the 0 – 5 and 5 – 20 cm soil depths. When fertilized, oat was better able to support SOM sequestration in water stable aggregates at 0 – 20 cm whilst grazing vetch was more effective at 20 – 50 cm. Where no fertilizer was invested, there were significant (p<0.01) reductions in biomass input and SOM on oat-maize and weedy fallow-maize rotations whereas vetch-maize rotations did not respond, both at 0 – 5 and 5 – 20 cm. Targeting fertilizer to the winter cover crop required less fertilizer, and yet gave a similar SOM response as targeting the fertilizer to the maize crop. In addition to increasing SOM in the surface soil (0 – 5 cm), the winter cover crops significantly (p<0.05) increased labile pools of P, including microbial P. The cover crops also significantly (p<0.05) increased maize P concentration during early growth, extractable soil P, Cu, Mn, and Zn but had no effect on Ca and K. Grazing vetch increased soil mineral N but reduced extractable soil Mg. Without fertilizer, there were sharp declines in maize grain yield on oat and weedy fallow rotations over the four year period, but less so, on the grazing vetch. Grazing vetch increased maize growth, grain yield response to N fertilizer, nitrogen use efficiency (NUE) and profitability for fertilizer rates below 180 kg N ha-1. Oat effects however on maize yield and NUE were generally similar to weedy fallow. Based on the partial factor productivity of N, the highest efficiencies in utilization of fertilizer N for maize yield improvement under grazing vetch and oat are obtained at 60 kg N ha-1 and would decline thereafter with any increases in fertilizer application rate. Grazing vetch gave N fertilizer replacement values of up to 120 kg N ha-1 as well as the highest marginal rates of return to increasing N fertilizer rate. The cover crops were more effective than the weedy fallow in reducing seedbank density of Digitaria sanguinalis, Eleusine indica, Amaranthus retroflexus and Datura stramonium at 0 – 5 cm soil depth, causing weed seed reductions of 30 - 70%. The winter cover crops however, selectively allowed emergence of the narrow leafed weeds; Cyperus esculentus and Digitaria sanguinalis in the maize crop. The findings of this study suggested that grazing vetch is suited for SOM improvement in low fertilizer input systems and that fertilizer is better invested on winter cover crops as opposed to maize crops. Oat, on the other hand, when fertilized, would be ideal for C sequestration in water stable aggregates of the surface soil. Grazing vetch is ideal for resource poor farmers who cannot afford mineral fertilizers as it gives grain yield improvement and high fertilizer replacement value. Grazing vetch can produce enough maize yield response to pay its way in the maize-based systems and oat may not require additional N than that applied to the weedy fallow. Phosphorus and Zn are some of the major limiting essential plant nutrients on South African soils and the winter cover crops could make a contribution. The cover crops also hasten depletion of some problematic weeds from seedbanks, leading to reduced weed pressure during maize growth.
- Full Text:
- Date Issued: 2012
Spatio-temporal ecology of the yellow mongoose Cynictis penicillata in the Great Fish River Reserve (Eastern Cape, South Africa)
- Authors: Mbatyoti, Owen A
- Date: 2012
- Subjects: Carnivorous animals -- South Africa -- Eastern Cape , Spatial behavior -- South Africa -- Eastern Cape , Great Fish River Reserve (South Africa) , Mongooses -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11792 , http://hdl.handle.net/10353/d1006856 , Carnivorous animals -- South Africa -- Eastern Cape , Spatial behavior -- South Africa -- Eastern Cape , Great Fish River Reserve (South Africa) , Mongooses -- South Africa -- Eastern Cape
- Description: Very little is known about the spatio-temporal ecology of the yellow mongoose Cynictis penicillata, despite this small carnivore being widely distributed in the southern African subregion. Until the present study, activity patterns and daily movement distances had only been investigated over a single season, and information on home range sizes was only available from a few populations. Here, I aimed at determining the activity patterns and the space use of yellow mongooses over the different seasons of the year in the Great Fish River Reserve (Eastern Cape, South Africa). In addition, I tested some predictions related to environmental factors (variations in photoperiod, climatic conditions and food availability over the year), as well as life cycle (reproduction) and morphological and physiological characteristics (sexual dimorphism and thermoregulatory aspects associated to the possession of an elongated body). From September 2005 to August 2011, spatio-temporal data were collected through 102 continuous tracking sessions (84 during the day and 18 during the night) of 12 adult individuals (seven males and five females) fitted with motion-sensor radio-collars. Additional data were obtained through semi-continuous tracking sessions and random locations. Yellow mongooses were essentially diurnal and crepuscular. Activity levels averaged 57 percent during the day (n = 11,807 fixes) and only 11 percent at night (n = 3,623 fixes). Yellow mongooses emerged from their burrows on average (± SD) 85 ± 62 min after sunrise (range: –11 to +369 min) and returned 21 ± 84 min before sunset (range: –518 to +225 min). The duration of the daily activity period varied between 12 min and 15 h 36 min, with a mean of 9 h 28 min. Both sexes exhibited some overground activity after sunset, but this was most pronounced in males than in females. Nocturnal activity outside the activity period was generally restricted to short underground bouts of activity occurring at anytime of the night. Diurnal resting, with up to 11 bouts per activity period, occurred in 98.8 percent of activity periods. Overall, yellow mongooses were active during 68 ± 17 percent of the time spent outside the burrow. Photoperiod acted as a zeitgeber and activity was negatively affected by adverse climatic conditions (very hot or conversely low temperatures, rain, wet soil) and probably low terrestrial arthropod activity/availability. No intersexual difference in activity levels was found, although the higher body mass of males (on average 16 oercent) implies higher metabolic demands. The total home range size (MCP 100 percent ) averaged 0.55 ± 0.65 km2 (range: 0.10–2.36 km2) and the related total perimeter measured on average 2.80 ± 1.71 km (range: 1.17–7.36 km). Male home ranges were on average more than twice large than those of females, but this difference did not reach statistical significance. However, males had larger daily home ranges (0.13 ± 0.15 km2) than females (0.05 ± 0.05 km2). In addition, daily movement distances of males were longer (1.99 ± 1.07 km) than those of females (1.29 ± 0.66 km). Males also travelled at a faster speed (0.29 ± 0.13 km/h) than females (0.18 ± 0.07 km/h). Overall, sex clearly appeared to play a role in the spatial ecology of yellow mongooses, but the underlying explanation does not seem to be linked to sexual dimorphism (body mass) or reproductive activity. Whilst the role of food availability on the space use of yellow mongooses is unclear, it is likely that low temperatures negatively affect yellow mongoose movements, as they do for their activity levels.
- Full Text:
- Date Issued: 2012
- Authors: Mbatyoti, Owen A
- Date: 2012
- Subjects: Carnivorous animals -- South Africa -- Eastern Cape , Spatial behavior -- South Africa -- Eastern Cape , Great Fish River Reserve (South Africa) , Mongooses -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11792 , http://hdl.handle.net/10353/d1006856 , Carnivorous animals -- South Africa -- Eastern Cape , Spatial behavior -- South Africa -- Eastern Cape , Great Fish River Reserve (South Africa) , Mongooses -- South Africa -- Eastern Cape
- Description: Very little is known about the spatio-temporal ecology of the yellow mongoose Cynictis penicillata, despite this small carnivore being widely distributed in the southern African subregion. Until the present study, activity patterns and daily movement distances had only been investigated over a single season, and information on home range sizes was only available from a few populations. Here, I aimed at determining the activity patterns and the space use of yellow mongooses over the different seasons of the year in the Great Fish River Reserve (Eastern Cape, South Africa). In addition, I tested some predictions related to environmental factors (variations in photoperiod, climatic conditions and food availability over the year), as well as life cycle (reproduction) and morphological and physiological characteristics (sexual dimorphism and thermoregulatory aspects associated to the possession of an elongated body). From September 2005 to August 2011, spatio-temporal data were collected through 102 continuous tracking sessions (84 during the day and 18 during the night) of 12 adult individuals (seven males and five females) fitted with motion-sensor radio-collars. Additional data were obtained through semi-continuous tracking sessions and random locations. Yellow mongooses were essentially diurnal and crepuscular. Activity levels averaged 57 percent during the day (n = 11,807 fixes) and only 11 percent at night (n = 3,623 fixes). Yellow mongooses emerged from their burrows on average (± SD) 85 ± 62 min after sunrise (range: –11 to +369 min) and returned 21 ± 84 min before sunset (range: –518 to +225 min). The duration of the daily activity period varied between 12 min and 15 h 36 min, with a mean of 9 h 28 min. Both sexes exhibited some overground activity after sunset, but this was most pronounced in males than in females. Nocturnal activity outside the activity period was generally restricted to short underground bouts of activity occurring at anytime of the night. Diurnal resting, with up to 11 bouts per activity period, occurred in 98.8 percent of activity periods. Overall, yellow mongooses were active during 68 ± 17 percent of the time spent outside the burrow. Photoperiod acted as a zeitgeber and activity was negatively affected by adverse climatic conditions (very hot or conversely low temperatures, rain, wet soil) and probably low terrestrial arthropod activity/availability. No intersexual difference in activity levels was found, although the higher body mass of males (on average 16 oercent) implies higher metabolic demands. The total home range size (MCP 100 percent ) averaged 0.55 ± 0.65 km2 (range: 0.10–2.36 km2) and the related total perimeter measured on average 2.80 ± 1.71 km (range: 1.17–7.36 km). Male home ranges were on average more than twice large than those of females, but this difference did not reach statistical significance. However, males had larger daily home ranges (0.13 ± 0.15 km2) than females (0.05 ± 0.05 km2). In addition, daily movement distances of males were longer (1.99 ± 1.07 km) than those of females (1.29 ± 0.66 km). Males also travelled at a faster speed (0.29 ± 0.13 km/h) than females (0.18 ± 0.07 km/h). Overall, sex clearly appeared to play a role in the spatial ecology of yellow mongooses, but the underlying explanation does not seem to be linked to sexual dimorphism (body mass) or reproductive activity. Whilst the role of food availability on the space use of yellow mongooses is unclear, it is likely that low temperatures negatively affect yellow mongoose movements, as they do for their activity levels.
- Full Text:
- Date Issued: 2012
Strategies used by professional nurses to manage newly diagnosed HIV positive pregnant women who fail to return within a month for further management and care
- Authors: Jama, Nontembiso Mary
- Date: 2012
- Subjects: HIV-positive women -- Medical care -- South Africa -- Eastern Cape , AIDS (Disease) in women -- South Africa -- Eastern Cape , Prenatal care -- South Africa -- Eastern Cape , Antiretroviral agents -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11899 , http://hdl.handle.net/10353/444 , HIV-positive women -- Medical care -- South Africa -- Eastern Cape , AIDS (Disease) in women -- South Africa -- Eastern Cape , Prenatal care -- South Africa -- Eastern Cape , Antiretroviral agents -- South Africa -- Eastern Cape
- Description: This study explored and described the strategies used by nurses to manage newly diagnosed HIV positive pregnant women who do not return to the clinic within a month following diagnosis, for continuity of care. The main aim was to prevent mother-to-child transmission of HIV (PMTCT). Method: The study sites were two accredited antiretroviral- ante-natal care (ARV-ANC) clinics at the Dimbaza community health centre (CHC) and the East London Hospital Complex (ELHC) which comprises of Cecilia Makiwane and Frere hospitals, in the Buffalo City Metropolitan Municipality (BCM). The majority of health personnel at these clinics are professional nurses. An in-depth semi structured interview guide was used to collect data through focus group interviews from professional nurses who work in these units. They were required to share their experiences about intervention strategies used for newly diagnosed HIV- positive, pregnant women who fail to return for continuity of care within a month after diagnosis. Results: Follow up of these women is done by tracking them (by calling them; calling the clinic nearest to their homes and doing home visits). Decentralisation of further management and care to the nearest clinic was also cited, especially for the patients who stay far from these accredited sites. Family support was also mentioned as a strategy to intervene for the non-compliant patients. Challenges: The challenges that were encountered with these interventions include wrong contact details, wrong addresses and being evasive when visited at home. Another challenge cited was related to the stigma attached to the diagnosis and the tracking devices used, for example, the car as it is familiar to the community it serves. Despite known benefits for early initiation of HIV treatment newly diagnosed HIV- positive, pregnant women continue to refrain from accessing care after diagnosis, thus posing a risk to the transmission of HIV to the baby and further comprising their own health. They miss out on general HIV management and ante-natal care. Conclusion: The identified intervention strategies used by nurses to follow up newly diagnosed HIV- positive, pregnant women need to be reinforced and strategies put in place to control the related challenges for a better response by the patients.
- Full Text:
- Date Issued: 2012
- Authors: Jama, Nontembiso Mary
- Date: 2012
- Subjects: HIV-positive women -- Medical care -- South Africa -- Eastern Cape , AIDS (Disease) in women -- South Africa -- Eastern Cape , Prenatal care -- South Africa -- Eastern Cape , Antiretroviral agents -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11899 , http://hdl.handle.net/10353/444 , HIV-positive women -- Medical care -- South Africa -- Eastern Cape , AIDS (Disease) in women -- South Africa -- Eastern Cape , Prenatal care -- South Africa -- Eastern Cape , Antiretroviral agents -- South Africa -- Eastern Cape
- Description: This study explored and described the strategies used by nurses to manage newly diagnosed HIV positive pregnant women who do not return to the clinic within a month following diagnosis, for continuity of care. The main aim was to prevent mother-to-child transmission of HIV (PMTCT). Method: The study sites were two accredited antiretroviral- ante-natal care (ARV-ANC) clinics at the Dimbaza community health centre (CHC) and the East London Hospital Complex (ELHC) which comprises of Cecilia Makiwane and Frere hospitals, in the Buffalo City Metropolitan Municipality (BCM). The majority of health personnel at these clinics are professional nurses. An in-depth semi structured interview guide was used to collect data through focus group interviews from professional nurses who work in these units. They were required to share their experiences about intervention strategies used for newly diagnosed HIV- positive, pregnant women who fail to return for continuity of care within a month after diagnosis. Results: Follow up of these women is done by tracking them (by calling them; calling the clinic nearest to their homes and doing home visits). Decentralisation of further management and care to the nearest clinic was also cited, especially for the patients who stay far from these accredited sites. Family support was also mentioned as a strategy to intervene for the non-compliant patients. Challenges: The challenges that were encountered with these interventions include wrong contact details, wrong addresses and being evasive when visited at home. Another challenge cited was related to the stigma attached to the diagnosis and the tracking devices used, for example, the car as it is familiar to the community it serves. Despite known benefits for early initiation of HIV treatment newly diagnosed HIV- positive, pregnant women continue to refrain from accessing care after diagnosis, thus posing a risk to the transmission of HIV to the baby and further comprising their own health. They miss out on general HIV management and ante-natal care. Conclusion: The identified intervention strategies used by nurses to follow up newly diagnosed HIV- positive, pregnant women need to be reinforced and strategies put in place to control the related challenges for a better response by the patients.
- Full Text:
- Date Issued: 2012