Image processing and data analysis tools of a remote sensing-based euthrophication monitoring system
- Authors: Chamunorwa, Brighton
- Date: 2018
- Subjects: Eutrophication Image processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10210 , vital:35376
- Description: Numerous surface water bodies in South Africa face serious challenges of eutrophication despite several initiatives from government to solve the problem. Government efforts have not been successful particularly because of three issues: 1) insufficient and inconsistent water quality data and 2) the costly nature of collecting this data. Third, the limited uptake of remote sensing based technologies in water quality management due to lack of skills, as well as the lengthy and complex procedures involved in retrieving water quality parameters. This thesis aims to explore the possibilities of using satellite data and simple software for mapping and collecting water quality data. The broad goal was to determine the function of software dedicated to meet the requirements of a remote sensing-based eutrophication-monitoring system. Two specific goal were set in this study: 1. To extract software requirements from available eutrophication management documentation. This was necessary to determine the functions of the dedicated software that matches the legislative requirements and 2. To determine a design capable of handling spatial and temporal requirement of a remote sensing based eutrophication-monitoring system. The study applied Goal Based Requirement Analysis Model [GBRAM] model to extract goals from the National Eutrophication Monitoring Programme [NEMP] implementation plan document and recent publication on remote sensing of water quality monitoring conducted in South Africa. Afterwards, the study used object-oriented concepts to model suitable data objects and processes to implement spatial-temporal requirements of a remote sensing-based eutrophication-monitoring system. Based on the study findings the following are essential functions of a remote sensing based eutrophication-monitoring system. A graphical user interface that allows the user to set up a monitoring programming. Automated image processing procedures. Data assessment methods used to generate eutrophication status information. Numerous display options for viewing data in several perfectives.
- Full Text:
- Date Issued: 2018
Image processing and data analysis tools of a remote sensing-based euthrophication monitoring system
- Authors: Chamunorwa, Brighton
- Date: 2018
- Subjects: Eutrophication Image processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10210 , vital:35376
- Description: Numerous surface water bodies in South Africa face serious challenges of eutrophication despite several initiatives from government to solve the problem. Government efforts have not been successful particularly because of three issues: 1) insufficient and inconsistent water quality data and 2) the costly nature of collecting this data. Third, the limited uptake of remote sensing based technologies in water quality management due to lack of skills, as well as the lengthy and complex procedures involved in retrieving water quality parameters. This thesis aims to explore the possibilities of using satellite data and simple software for mapping and collecting water quality data. The broad goal was to determine the function of software dedicated to meet the requirements of a remote sensing-based eutrophication-monitoring system. Two specific goal were set in this study: 1. To extract software requirements from available eutrophication management documentation. This was necessary to determine the functions of the dedicated software that matches the legislative requirements and 2. To determine a design capable of handling spatial and temporal requirement of a remote sensing based eutrophication-monitoring system. The study applied Goal Based Requirement Analysis Model [GBRAM] model to extract goals from the National Eutrophication Monitoring Programme [NEMP] implementation plan document and recent publication on remote sensing of water quality monitoring conducted in South Africa. Afterwards, the study used object-oriented concepts to model suitable data objects and processes to implement spatial-temporal requirements of a remote sensing-based eutrophication-monitoring system. Based on the study findings the following are essential functions of a remote sensing based eutrophication-monitoring system. A graphical user interface that allows the user to set up a monitoring programming. Automated image processing procedures. Data assessment methods used to generate eutrophication status information. Numerous display options for viewing data in several perfectives.
- Full Text:
- Date Issued: 2018
In silico analysis, isolation and kinetic characterisation of red algae (Rhodophyta) catalases
- Authors: Nodangala, Sinovuyo
- Date: 2018
- Subjects: Red algae Marine algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14626 , vital:40024
- Description: Catalase (EC: 1.11.1.6) is produced by almost all aerobic organism ranging from bacteria to human and is an essential antioxidant enzyme that catalyses the conversion of hydrogen peroxide to water and molecular oxygen, therefore neutralising hydrogen peroxide toxicity. The present study aimed to purify and characterise catalase from Pachymenia orbitosa, a marine red algae found in the Algoa Bay region of South Africa. Bioinformatics analysis was performed to confirm the presence of a catalase gene in the red algae genome. In silico analysis of the Chondrus crispus genome was performed to predict the functional and structural characterisation of the protein encoded by the gene. The Pachymenia orbitosa catalase enzyme was purified to homogeneity using 60% ammonium sulphate precipitation and Sephacryl S-200 gel filtration chromatography. InterProScan confirmed that the Chondrus crispus genome encodes a catalase protein, which is from the mono-functional and heme-dependent catalase-like superfamily. The purified Pachymenia orbitosa catalase enzyme displayed a specific activity of 23 000 units per mg of protein with a 14.94% recovery and 222.91 fold purification. Sodium dodecyl sulphatepolyacrylamide gel electrophoresis indicated a single band, with a molecular weight of around 50kDa. The catalase enzyme exhibited a maximum activity at pH 7 and a temperature of 30℃. It was stable up to 40℃ and rapidly denatured at temperatures above this. The Km and Vmax values for the purified catalase, using hydrogen peroxide as a substrate, were determined from the Lineweaver-Burk plot to be 22.22mM and 1.11x10-4mM.min-1 , respectively, while from the Hanes-Woolf plot, to be 23.4mM and 1.17x10-4mM.min-1 , respectively. The Heme catalase inhibitor (ferricyanide) inhibited the enzyme activity markedly, while sodium chloride and citric acid had only a slight inhibitory effect. Copper sulphate showed a slight stimulatory effect. The physiochemical properties suggest a good application potential in both the pharmaceutical and food industries
- Full Text:
- Date Issued: 2018
- Authors: Nodangala, Sinovuyo
- Date: 2018
- Subjects: Red algae Marine algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14626 , vital:40024
- Description: Catalase (EC: 1.11.1.6) is produced by almost all aerobic organism ranging from bacteria to human and is an essential antioxidant enzyme that catalyses the conversion of hydrogen peroxide to water and molecular oxygen, therefore neutralising hydrogen peroxide toxicity. The present study aimed to purify and characterise catalase from Pachymenia orbitosa, a marine red algae found in the Algoa Bay region of South Africa. Bioinformatics analysis was performed to confirm the presence of a catalase gene in the red algae genome. In silico analysis of the Chondrus crispus genome was performed to predict the functional and structural characterisation of the protein encoded by the gene. The Pachymenia orbitosa catalase enzyme was purified to homogeneity using 60% ammonium sulphate precipitation and Sephacryl S-200 gel filtration chromatography. InterProScan confirmed that the Chondrus crispus genome encodes a catalase protein, which is from the mono-functional and heme-dependent catalase-like superfamily. The purified Pachymenia orbitosa catalase enzyme displayed a specific activity of 23 000 units per mg of protein with a 14.94% recovery and 222.91 fold purification. Sodium dodecyl sulphatepolyacrylamide gel electrophoresis indicated a single band, with a molecular weight of around 50kDa. The catalase enzyme exhibited a maximum activity at pH 7 and a temperature of 30℃. It was stable up to 40℃ and rapidly denatured at temperatures above this. The Km and Vmax values for the purified catalase, using hydrogen peroxide as a substrate, were determined from the Lineweaver-Burk plot to be 22.22mM and 1.11x10-4mM.min-1 , respectively, while from the Hanes-Woolf plot, to be 23.4mM and 1.17x10-4mM.min-1 , respectively. The Heme catalase inhibitor (ferricyanide) inhibited the enzyme activity markedly, while sodium chloride and citric acid had only a slight inhibitory effect. Copper sulphate showed a slight stimulatory effect. The physiochemical properties suggest a good application potential in both the pharmaceutical and food industries
- Full Text:
- Date Issued: 2018
Incidence and antibiogram fingerprints of members of the Enterobacteriaceae family recovered from river water, hospital effluents and vegetables in Chris Hani and Amathole District Municipalities in the Eastern Cape Province
- Authors: Mpaka, Lindelwa
- Date: 2018
- Subjects: Enterobacteriaceae
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14549 , vital:40003
- Description: The worldwide problem of antimicrobial resistance has limited the spectrum of the current affordable and effective antimicrobials. Infections associated with resistant microorganisms impose a major threat to public health and economic stability. Globally, about 700 000 deaths every year can be accredited to antimicrobial resistance. The leading mechanism of resistance amid bacterial pathogens is the extended spectrum beta-lactamases production, which inhibits spectrum activity of several antimicrobial agents. The rise in antimicrobial resistance has compelled an urgent need of developing means of combatting resistance issue amid diseasecausing microbes. The main aim of this study is to evaluate the incidence and antibiogram fingerprints of Enterobacteriaceae recovered from hospital effluents, river water and vegetables in the Eastern Cape Province. A total of eighteen antibiotics from ten different antimicrobial classes were used to determine antibiogram profiles of the MALDI-TOF confirmed isolates. From the MALDI-TOF confirmed isolates, 60% of Enterobacter spp. and E. coli isolates displayed resistance against colistin, while Citrobacter spp. and Klebsiella spp. displayed 90% and 60% resistance against this antimicrobial respectively. These findings outline the need for the development of new antimicrobials. About 75.5% (25/33) of the presumptive Enterobacter spp. were confirmed by MALDI-TOF with 79.2% (19/24), 66.7% (2/3), 66.7% (4/6) been confirmed vegetables, hospital effluents and river water samples respectively. Likewise, about 77.8% (21/27) were confirmed as Citrobacter spp. of which 92.3% (12/13), 66.7% (2/3) and 63.6% (7/11) were from vegetables, hospital effluents and river water samples respectively. These results show that the selected vegetables were highly contaminated with resistant bacteria and thus unsafe to consume uncooked vegetable. Also river water was higly contaminated with resistant microbes, which also shows that these rivers are not fit to be used 17 as drinking water sources and recreational activities. Colistin is an antimicrobial used as a last resort of antibiotics because it exhibits broad-spectrum activity. However from the findings of the work at present, this is no longer the case. The spectrum of this antimicrobial is now reduced by Enterobacteriaceae members. To the best of my knowledge; relatively few resources have been provided to understanding, preventing, and controlling increasing antimicrobial resistance on global, national and local levels.
- Full Text:
- Date Issued: 2018
- Authors: Mpaka, Lindelwa
- Date: 2018
- Subjects: Enterobacteriaceae
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14549 , vital:40003
- Description: The worldwide problem of antimicrobial resistance has limited the spectrum of the current affordable and effective antimicrobials. Infections associated with resistant microorganisms impose a major threat to public health and economic stability. Globally, about 700 000 deaths every year can be accredited to antimicrobial resistance. The leading mechanism of resistance amid bacterial pathogens is the extended spectrum beta-lactamases production, which inhibits spectrum activity of several antimicrobial agents. The rise in antimicrobial resistance has compelled an urgent need of developing means of combatting resistance issue amid diseasecausing microbes. The main aim of this study is to evaluate the incidence and antibiogram fingerprints of Enterobacteriaceae recovered from hospital effluents, river water and vegetables in the Eastern Cape Province. A total of eighteen antibiotics from ten different antimicrobial classes were used to determine antibiogram profiles of the MALDI-TOF confirmed isolates. From the MALDI-TOF confirmed isolates, 60% of Enterobacter spp. and E. coli isolates displayed resistance against colistin, while Citrobacter spp. and Klebsiella spp. displayed 90% and 60% resistance against this antimicrobial respectively. These findings outline the need for the development of new antimicrobials. About 75.5% (25/33) of the presumptive Enterobacter spp. were confirmed by MALDI-TOF with 79.2% (19/24), 66.7% (2/3), 66.7% (4/6) been confirmed vegetables, hospital effluents and river water samples respectively. Likewise, about 77.8% (21/27) were confirmed as Citrobacter spp. of which 92.3% (12/13), 66.7% (2/3) and 63.6% (7/11) were from vegetables, hospital effluents and river water samples respectively. These results show that the selected vegetables were highly contaminated with resistant bacteria and thus unsafe to consume uncooked vegetable. Also river water was higly contaminated with resistant microbes, which also shows that these rivers are not fit to be used 17 as drinking water sources and recreational activities. Colistin is an antimicrobial used as a last resort of antibiotics because it exhibits broad-spectrum activity. However from the findings of the work at present, this is no longer the case. The spectrum of this antimicrobial is now reduced by Enterobacteriaceae members. To the best of my knowledge; relatively few resources have been provided to understanding, preventing, and controlling increasing antimicrobial resistance on global, national and local levels.
- Full Text:
- Date Issued: 2018
Influence of family structure on food security status of farming households in Alice, South Africa
- Authors: Ijila, Olusegun Jeremiah
- Date: 2018
- Subjects: Food security Families--South Africa--Eastern Cape Farms, Small
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11537 , vital:39081
- Description: Achieving food security in sub-Saharan Africa remains a major challenge despite efforts made by a majority of the countries to reduce abject poverty and food insecurity. Just as these countries prioritized food security under the Millennium Development Goals (MDGs), they are equally putting it on top of the agenda under the Sustainable Development Goals (SDGs). In the face of the political and economic developments seen in the country since 1994, South Africa is overwhelmed by poverty and unemployment. But efforts to address these problems have not given due recognition to the question of family structure which is complex and varied, with immense potential implications for ownership and distribution of resources and the bargaining strength that are likely to determine the food security status of various farming households. Furthermore, the contribution of households towards agricultural production differs according to the way family organizes itself. This study was carried out to determine the influence of family structures on food security status of farming households in Alice, South Africa. Data were collected from 120 farming households’ selected using purposive sampling method. To collect data, a well-structured questionnaire was administered through face-to-face interviews. Consequent to that, the data were analyzed using descriptive statistics, and binary logistic regression model. The dominant family structures are nuclear, single-parent, working parent and cohabiting. The analysis revealed that nuclear family where father, mother and their children have access to labour and financial resources could be more comfortable than single parent family. Working parents would probably be more food secure because both parents are able to combine incomes while food insecurity might exist within cohabiting families since the union is less stable because of scarce resources occasioned by their inability to combine their resources to pursue a common goal. The results further revealed that single parent family structures and socio-economic characteristics like age, marital status and year of education of the household head were significant in terms of their influence on food security. The study therefore, recommends that old people should be encouraged to participate in agricultural production due to the wealth of experience gathered over the years. It is probably safe to conclude that encouraging marriage would provide better opportunities to raise the necessary capital to support positive productivity changes that would have implications for enhanced food availability and affordability.
- Full Text:
- Date Issued: 2018
- Authors: Ijila, Olusegun Jeremiah
- Date: 2018
- Subjects: Food security Families--South Africa--Eastern Cape Farms, Small
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11537 , vital:39081
- Description: Achieving food security in sub-Saharan Africa remains a major challenge despite efforts made by a majority of the countries to reduce abject poverty and food insecurity. Just as these countries prioritized food security under the Millennium Development Goals (MDGs), they are equally putting it on top of the agenda under the Sustainable Development Goals (SDGs). In the face of the political and economic developments seen in the country since 1994, South Africa is overwhelmed by poverty and unemployment. But efforts to address these problems have not given due recognition to the question of family structure which is complex and varied, with immense potential implications for ownership and distribution of resources and the bargaining strength that are likely to determine the food security status of various farming households. Furthermore, the contribution of households towards agricultural production differs according to the way family organizes itself. This study was carried out to determine the influence of family structures on food security status of farming households in Alice, South Africa. Data were collected from 120 farming households’ selected using purposive sampling method. To collect data, a well-structured questionnaire was administered through face-to-face interviews. Consequent to that, the data were analyzed using descriptive statistics, and binary logistic regression model. The dominant family structures are nuclear, single-parent, working parent and cohabiting. The analysis revealed that nuclear family where father, mother and their children have access to labour and financial resources could be more comfortable than single parent family. Working parents would probably be more food secure because both parents are able to combine incomes while food insecurity might exist within cohabiting families since the union is less stable because of scarce resources occasioned by their inability to combine their resources to pursue a common goal. The results further revealed that single parent family structures and socio-economic characteristics like age, marital status and year of education of the household head were significant in terms of their influence on food security. The study therefore, recommends that old people should be encouraged to participate in agricultural production due to the wealth of experience gathered over the years. It is probably safe to conclude that encouraging marriage would provide better opportunities to raise the necessary capital to support positive productivity changes that would have implications for enhanced food availability and affordability.
- Full Text:
- Date Issued: 2018
Institutions, Production and Marketing of maize in Zimbabwe. Case of Marondera District of Mashonaland East Province
- Authors: Mafuse, Never
- Date: 2018
- Subjects: Food security Food supply
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15687 , vital:40506
- Description: Food security situation in Zimbabwe is deteriorating despite the efforts made by the government for embarking on agrarian reforms in terms of redressing colonial imbalances and taking on the major trading investment risks. The government assured the resettled farmers that if they invest in maize production, they would not be stranded by lack of marketing services as the markets are liberalized. However, this market liberalization policy occurring in maize sector has resulted in A1 resettled farmers becoming more vulnerable to traders preying on their weaknesses as the policy is not living up to expectations and is failing to bring dramatic increases in agricultural growth. This may mean that sending children to school is a nightmare for those who depend on farming for educating their children, inadequate food in the home, unpaid loans and subsequent impoverishment. The resettled A1farmers will remain trapped in the poverty cycle as long as institutions are not corrected. The general aim of the study was to evaluate institutional factors influencing maize production and marketing by A1 resettled farmers of Marondera district in Mashonaland East province of Zimbabwe. Using a sample of 343 farmers randomly selected in Marondera District, different econometric models like Data envelopment Analysis, Cob Douglas, Binary logistic, and Tobit as well as descriptive statistics were used to analyse the data. Institutional variables were captured in two ways: as a dummy showing whether farmers have access to institutional variables and as a continuous variable indicating importance of institutions on maize production and marketing. The study found out that, most of the A1 farmers are old, with a mean age of 47 years and a maximum of 55 years of farming experience. It is also dominated by male farmers who are literate. Results also showed that most of A1 farmers from the sample are married and very few separated. These farmers sell most their maize and keep little for consumption though they are still using convectional farming methods. Most of the farmers from the sample generate their incomes from farming activities only and they have good access to market and production information as well as extension xvi messages through training .They however have poor access to financial credit and weak social capital as well as low contract farming. Results also indicated that A1 farmers pursue the formal supply chains than informal supply chains. It is noted that, A1 farmers participate in a number of markets that include agricultural inputs markets seed, fertilizers, chemicals.; credit markets which includes banks as well as labour markets which can in the form of (maricho). In terms production and marketing efficiency, the study found out that A1 farmers are technically, allocatively and economically inefficient. The maximum efficient score is 1 while the minimum score is 0.01 for both production and marketing stage. The mean scores for production stage are 0.195, 0.504 and 0.072 for technical, allocative and economic efficient respectively. The mean scores for marketing are 0.103, 0.688, and 0.068 for technical, allocative and economic efficiency respectively. Farmers are performing better at production stage than at marketing technically while there is better allocative and economic efficiency at marketing stage. Results for determinants of technical, allocative and economic efficiency at production stage showed that, cattle ownership, farming experience, access to financial credit and (member of farmer organisation) which was used as a proxy indicator for social capital ,access to information, contract farming, distance to input market ,area planted to maize and quantity of seed used influences marketing efficiency of A1 maize farmers in Marondera District. Access to credit, Access to market, distance to market, road infrastructure, farming experience and access to information influences technical, allocative and economic efficiency at marketing stage. Cooperative membership, road infrastructure, contractual farming arrangements, and access to financial credit and transport cost to market influence choice of marketing channel respectively. Finally results from the non linear cob Douglas reveals that, maize production is significantly influenced by contract with value chain actors, access to market xvii information, access to financial credit, total topdressing used , total basal fertilizer used, total herbicides used, and total area put under maize production. The results showed that, future of A1 resettled farmers depends on correcting the institutions which are of paramount importance for maize production and marketing. The study therefore recommended the government to improve institutional environment that has direct link with institutional innovations necessary for sustainable maize production and marketing. This can be done through correcting inefficiencies and ineffective institutions by creating and maintaining both environment and arrangement that will transform maize production and marketing systems to operate efficiently. The study presents policy options to address both production and marketing of maize arguing that new direction of production and marketing of maize depends on correcting dysfunctional institutions. Policy options include increasing A1 farmers access to financial credit by removing the stringent collateral requirements which are not attainable by most A1 farmers as their asset endowment is limited to non capital. Addressing imperfections in the input markets by improving the supply of chemical fertilisers and seed at affordable prices as this influences total area put under maize production. The other policy is for private companies and NGOs to offer contract farming to A1 maize farmers as this will help them to increase total area put under maize production, access to market, access to credit, and access to information and reduces long distances to purchase inputs. Introducing focused training to motivate resettled A1 farmers on formation farmer organisations as this assists in social capital which is an important asset in maize production and marketing.Improving road infrastructure by creating a fund that would be used to maintain the road rather waiting for DDF only.
- Full Text:
- Date Issued: 2018
- Authors: Mafuse, Never
- Date: 2018
- Subjects: Food security Food supply
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15687 , vital:40506
- Description: Food security situation in Zimbabwe is deteriorating despite the efforts made by the government for embarking on agrarian reforms in terms of redressing colonial imbalances and taking on the major trading investment risks. The government assured the resettled farmers that if they invest in maize production, they would not be stranded by lack of marketing services as the markets are liberalized. However, this market liberalization policy occurring in maize sector has resulted in A1 resettled farmers becoming more vulnerable to traders preying on their weaknesses as the policy is not living up to expectations and is failing to bring dramatic increases in agricultural growth. This may mean that sending children to school is a nightmare for those who depend on farming for educating their children, inadequate food in the home, unpaid loans and subsequent impoverishment. The resettled A1farmers will remain trapped in the poverty cycle as long as institutions are not corrected. The general aim of the study was to evaluate institutional factors influencing maize production and marketing by A1 resettled farmers of Marondera district in Mashonaland East province of Zimbabwe. Using a sample of 343 farmers randomly selected in Marondera District, different econometric models like Data envelopment Analysis, Cob Douglas, Binary logistic, and Tobit as well as descriptive statistics were used to analyse the data. Institutional variables were captured in two ways: as a dummy showing whether farmers have access to institutional variables and as a continuous variable indicating importance of institutions on maize production and marketing. The study found out that, most of the A1 farmers are old, with a mean age of 47 years and a maximum of 55 years of farming experience. It is also dominated by male farmers who are literate. Results also showed that most of A1 farmers from the sample are married and very few separated. These farmers sell most their maize and keep little for consumption though they are still using convectional farming methods. Most of the farmers from the sample generate their incomes from farming activities only and they have good access to market and production information as well as extension xvi messages through training .They however have poor access to financial credit and weak social capital as well as low contract farming. Results also indicated that A1 farmers pursue the formal supply chains than informal supply chains. It is noted that, A1 farmers participate in a number of markets that include agricultural inputs markets seed, fertilizers, chemicals.; credit markets which includes banks as well as labour markets which can in the form of (maricho). In terms production and marketing efficiency, the study found out that A1 farmers are technically, allocatively and economically inefficient. The maximum efficient score is 1 while the minimum score is 0.01 for both production and marketing stage. The mean scores for production stage are 0.195, 0.504 and 0.072 for technical, allocative and economic efficient respectively. The mean scores for marketing are 0.103, 0.688, and 0.068 for technical, allocative and economic efficiency respectively. Farmers are performing better at production stage than at marketing technically while there is better allocative and economic efficiency at marketing stage. Results for determinants of technical, allocative and economic efficiency at production stage showed that, cattle ownership, farming experience, access to financial credit and (member of farmer organisation) which was used as a proxy indicator for social capital ,access to information, contract farming, distance to input market ,area planted to maize and quantity of seed used influences marketing efficiency of A1 maize farmers in Marondera District. Access to credit, Access to market, distance to market, road infrastructure, farming experience and access to information influences technical, allocative and economic efficiency at marketing stage. Cooperative membership, road infrastructure, contractual farming arrangements, and access to financial credit and transport cost to market influence choice of marketing channel respectively. Finally results from the non linear cob Douglas reveals that, maize production is significantly influenced by contract with value chain actors, access to market xvii information, access to financial credit, total topdressing used , total basal fertilizer used, total herbicides used, and total area put under maize production. The results showed that, future of A1 resettled farmers depends on correcting the institutions which are of paramount importance for maize production and marketing. The study therefore recommended the government to improve institutional environment that has direct link with institutional innovations necessary for sustainable maize production and marketing. This can be done through correcting inefficiencies and ineffective institutions by creating and maintaining both environment and arrangement that will transform maize production and marketing systems to operate efficiently. The study presents policy options to address both production and marketing of maize arguing that new direction of production and marketing of maize depends on correcting dysfunctional institutions. Policy options include increasing A1 farmers access to financial credit by removing the stringent collateral requirements which are not attainable by most A1 farmers as their asset endowment is limited to non capital. Addressing imperfections in the input markets by improving the supply of chemical fertilisers and seed at affordable prices as this influences total area put under maize production. The other policy is for private companies and NGOs to offer contract farming to A1 maize farmers as this will help them to increase total area put under maize production, access to market, access to credit, and access to information and reduces long distances to purchase inputs. Introducing focused training to motivate resettled A1 farmers on formation farmer organisations as this assists in social capital which is an important asset in maize production and marketing.Improving road infrastructure by creating a fund that would be used to maintain the road rather waiting for DDF only.
- Full Text:
- Date Issued: 2018
Investigation of strategies employed in rural households to improve food security in Raymond Mhlaba Local Municipality : a case of Zihlahleni Location in Middledrift, Eastern Cape Province
- Authors: Gqozo, Odwa
- Date: 2018
- Subjects: Food security -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10758 , vital:35752
- Description: Eastern Cape is one of the provinces experiencing a rapid increase in food prices while household income is increasing at a slower rate. Against this background, the main objective of this study was to investigate strategies used by rural households to improve food security in Raymond Mhlaba Local Municipality formally known as Nkonkobe in the Eastern Cape Province, South Africa. Data were collected from 100 households using a questionnaire as the main instrument by using simple random sampling. Data were analyzed by employing simple descriptive statistics to describe household food security. Results revealed that most (50.3percent) households that were interviewed were male headed and unemployment was high (73.6percent). Moreover, the average age of the interviewed household heads was 59 years. Most (68percent) of the households owned home gardens and had access to arable land which was not being cultivated. Most (87percent) households indicated that lack of capital was the main cause of food security and depended on government grants. Most (100percent) of the interviewed household heads depend mostly on food purchases rather than their own production. The recommendation is that the government should continue fostering its agenda of improving agriculture as a strategy in rural households for curbing food insecurity.
- Full Text:
- Date Issued: 2018
- Authors: Gqozo, Odwa
- Date: 2018
- Subjects: Food security -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10758 , vital:35752
- Description: Eastern Cape is one of the provinces experiencing a rapid increase in food prices while household income is increasing at a slower rate. Against this background, the main objective of this study was to investigate strategies used by rural households to improve food security in Raymond Mhlaba Local Municipality formally known as Nkonkobe in the Eastern Cape Province, South Africa. Data were collected from 100 households using a questionnaire as the main instrument by using simple random sampling. Data were analyzed by employing simple descriptive statistics to describe household food security. Results revealed that most (50.3percent) households that were interviewed were male headed and unemployment was high (73.6percent). Moreover, the average age of the interviewed household heads was 59 years. Most (68percent) of the households owned home gardens and had access to arable land which was not being cultivated. Most (87percent) households indicated that lack of capital was the main cause of food security and depended on government grants. Most (100percent) of the interviewed household heads depend mostly on food purchases rather than their own production. The recommendation is that the government should continue fostering its agenda of improving agriculture as a strategy in rural households for curbing food insecurity.
- Full Text:
- Date Issued: 2018
Investigation of the subsurface geology using time domain, magnetic and electrical resistivity geophysical techniques in the Karoo basin at Beaufort west, Western Cape Province, South Africa
- Authors: Ntunja, Asanda
- Date: 2018
- Subjects: Geology Geophysics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14659 , vital:40034
- Description: Beaufort West lies in the Central Karoo Basin and is specifically situated in the Poortjie Member of the Teekloof Formation in the Beaufort Group. The Teekloof Formation was deposited in a floodplain environment and it consists of alternating bluish grey mudstone and very fine to medium grained sandstone. The sediments of the Karoo Basin were intruded by numerous dolerite sills and dykes during a period of extensive magmatic activity over the whole South African subcontinent when the break-up of Gondwanda occurred. This led to a continuous jointing of the sedimentary rocks and the jointing resulted in rocks that are prone to weathering. Weathering that occurred in Beaufort West resulted in the formation of alluvium, calcrete, scree and hard pan deposits which overlay most of the ground surface. The joints in rocks paved way for groundwater storage in the sedimentary beds as sediments of the Karoo Basin lack significant primary porosity. Geophysical surveys were done in order to determine a suitable site to locate and drill a deep borehole to the White Hill Formation in order to extract shale gas that is proposed to be present in the area, thereafter determine sites for monitoring boreholes for groundwater and also look for area where potential groundwater might be present. This then requires geophysical investigations of the surface and subsurface geology of the area prior to drilling so as to locate any features such as dolerite intrusions which may hinder the drilling process and locate shallow aquifers, which will tend to be monitored before and during fracking. Five lines of varying lengths from 2-6 km and different orientation were surveyed using geophysical techniques which included the time domain, electrical resistivity as well as the magnetic methods. The geophysical investigations were conducted in order to fulfil the main vii objectives and aims of the study. The techniques were then complemented by XRF, petrography and density analyses. The time domain method reveals that Lines 1 and Line 2 comprises of rocks with low resistivity values of less than 30 Ωm. These two lines were more conductive towards the east and northeast side of the study site and the resistivity tends to increase towards the south and west. Line 4 appeared to be more conductive towards the south-east of the line. Lines 3 and 5 showed high resistivity values with Line 5 being the most resistive suggesting that the underlying strata is consolidated, dry and hard. The resistivity in all the lines surveyed showed an increase with increasing depth. The depth of investigation was approximately up to 150 m. The electrical resistivity results were only obtained from Line 1 and Line 2. The results, which complement the time domain results, suggest that the two lines indeed comprise of rocks which exhibit low resistivity values. This then implies that the rocks in the vicinity are fractured and the fractures might be field with groundwater and possibly contain some conductive minerals such as sodium oxide (Na2O) as supported by XRF results. This method also reveals that along Line 1, there are individual bodies of high resistivity values. The probing depth of about 78 m was achieved for the electrical resistivity survey. The magnetic data indicate that the magnetic intensity does not vary much across lines 3, 4 and 5 and there is not much change in lithology with depth and lateral extent. The area covered by Lines 1 and 2, and the additional eleven fill in lines has several prominent magnetic highs that are inferred to be due to dolerite intrusions in the sandstones and these bodies may be connected at depth. One of these anomalies which trends east-west direction partially coincides with a mapped dolerite intrusion. Some areas with sandstones also exhibit high viii magnetism which is due to about 3.3% content of Fe2O3 present in the sandstones as seen from XRF. This is probably resulted from weathering of magnetite in dolerite intrusions. Petrography results obtained from samples collected in the field reveal that there is an abundance of quartz in sandstones and siltstones. Quartz arenite also contained about 50% of feldspar, containing both plagioclase and K-feldspar. The sandstones of the Teekloof Formation (Beaufort West) have undergone calcite replacement where the calcite matrix replaced most or all of the clay matrix between the mineral grains. The fractures in rocks were seen and it was inferred that they are due to the present cleavages in feldspar and weathering of feldspar in sandstones. Through X-ray Fluorescence (XRF) analysis, it was revealed that the rocks contained a high percentage of Na2O. XRF also showed that these rocks were under low chemical weathering which led to the formation of new minerals in rock as other minerals such as feldspar weather away. This resulted in quartz being the most dominant mineral present as it is not prone to chemical weathering and thus the rocks were proven to be chemically matured. Thirty one rock samples were collected from the field in order to determine the density and porosity measurements. The fine to medium grained grey sandstones show an average density of 2.597 g/cm3 and a porosity of 1.4 %. The brownish grey sandstone have an average density of 2.546 g/cm3 and porosity of 2.9 % and the brown sandstones exhibit an average of 2.584 g/cm3 and a porosity 1.46 %. Dolerite has an average density of 2.970 g/cm3 and porosity of 0.5 % and siltstones have a density of 2.595 g/cm3 and porosity of 1.38 %. The brownish grey sandstones have the highest porosity and the grey sandstone and siltstone have the least porosity after the dolerite.
- Full Text:
- Date Issued: 2018
- Authors: Ntunja, Asanda
- Date: 2018
- Subjects: Geology Geophysics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14659 , vital:40034
- Description: Beaufort West lies in the Central Karoo Basin and is specifically situated in the Poortjie Member of the Teekloof Formation in the Beaufort Group. The Teekloof Formation was deposited in a floodplain environment and it consists of alternating bluish grey mudstone and very fine to medium grained sandstone. The sediments of the Karoo Basin were intruded by numerous dolerite sills and dykes during a period of extensive magmatic activity over the whole South African subcontinent when the break-up of Gondwanda occurred. This led to a continuous jointing of the sedimentary rocks and the jointing resulted in rocks that are prone to weathering. Weathering that occurred in Beaufort West resulted in the formation of alluvium, calcrete, scree and hard pan deposits which overlay most of the ground surface. The joints in rocks paved way for groundwater storage in the sedimentary beds as sediments of the Karoo Basin lack significant primary porosity. Geophysical surveys were done in order to determine a suitable site to locate and drill a deep borehole to the White Hill Formation in order to extract shale gas that is proposed to be present in the area, thereafter determine sites for monitoring boreholes for groundwater and also look for area where potential groundwater might be present. This then requires geophysical investigations of the surface and subsurface geology of the area prior to drilling so as to locate any features such as dolerite intrusions which may hinder the drilling process and locate shallow aquifers, which will tend to be monitored before and during fracking. Five lines of varying lengths from 2-6 km and different orientation were surveyed using geophysical techniques which included the time domain, electrical resistivity as well as the magnetic methods. The geophysical investigations were conducted in order to fulfil the main vii objectives and aims of the study. The techniques were then complemented by XRF, petrography and density analyses. The time domain method reveals that Lines 1 and Line 2 comprises of rocks with low resistivity values of less than 30 Ωm. These two lines were more conductive towards the east and northeast side of the study site and the resistivity tends to increase towards the south and west. Line 4 appeared to be more conductive towards the south-east of the line. Lines 3 and 5 showed high resistivity values with Line 5 being the most resistive suggesting that the underlying strata is consolidated, dry and hard. The resistivity in all the lines surveyed showed an increase with increasing depth. The depth of investigation was approximately up to 150 m. The electrical resistivity results were only obtained from Line 1 and Line 2. The results, which complement the time domain results, suggest that the two lines indeed comprise of rocks which exhibit low resistivity values. This then implies that the rocks in the vicinity are fractured and the fractures might be field with groundwater and possibly contain some conductive minerals such as sodium oxide (Na2O) as supported by XRF results. This method also reveals that along Line 1, there are individual bodies of high resistivity values. The probing depth of about 78 m was achieved for the electrical resistivity survey. The magnetic data indicate that the magnetic intensity does not vary much across lines 3, 4 and 5 and there is not much change in lithology with depth and lateral extent. The area covered by Lines 1 and 2, and the additional eleven fill in lines has several prominent magnetic highs that are inferred to be due to dolerite intrusions in the sandstones and these bodies may be connected at depth. One of these anomalies which trends east-west direction partially coincides with a mapped dolerite intrusion. Some areas with sandstones also exhibit high viii magnetism which is due to about 3.3% content of Fe2O3 present in the sandstones as seen from XRF. This is probably resulted from weathering of magnetite in dolerite intrusions. Petrography results obtained from samples collected in the field reveal that there is an abundance of quartz in sandstones and siltstones. Quartz arenite also contained about 50% of feldspar, containing both plagioclase and K-feldspar. The sandstones of the Teekloof Formation (Beaufort West) have undergone calcite replacement where the calcite matrix replaced most or all of the clay matrix between the mineral grains. The fractures in rocks were seen and it was inferred that they are due to the present cleavages in feldspar and weathering of feldspar in sandstones. Through X-ray Fluorescence (XRF) analysis, it was revealed that the rocks contained a high percentage of Na2O. XRF also showed that these rocks were under low chemical weathering which led to the formation of new minerals in rock as other minerals such as feldspar weather away. This resulted in quartz being the most dominant mineral present as it is not prone to chemical weathering and thus the rocks were proven to be chemically matured. Thirty one rock samples were collected from the field in order to determine the density and porosity measurements. The fine to medium grained grey sandstones show an average density of 2.597 g/cm3 and a porosity of 1.4 %. The brownish grey sandstone have an average density of 2.546 g/cm3 and porosity of 2.9 % and the brown sandstones exhibit an average of 2.584 g/cm3 and a porosity 1.46 %. Dolerite has an average density of 2.970 g/cm3 and porosity of 0.5 % and siltstones have a density of 2.595 g/cm3 and porosity of 1.38 %. The brownish grey sandstones have the highest porosity and the grey sandstone and siltstone have the least porosity after the dolerite.
- Full Text:
- Date Issued: 2018
Isolation and characterization of E. coli and Campylobacter spp. from diarrhoeal samples collected from selected hospitals in Amathole District Municipality, Eastern Cape, South Africa
- Authors: Omolajaiye, Sunday Abraham
- Date: 2018
- Subjects: Escherichia coli infections Campylobacter infections Diarrhea
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6213 , vital:29515
- Description: Approximately 2-4 billion cases of infectious diarrhoea occur every year, with the highest numbers recorded in sub-Saharan Africa. It remains the most common public health issue among children in developing nations. The purpose of this research was to unfold the prevalence of diarrhoeagenic E. coli and Campylobacter pathotypes as well as elucidate their antibiogram characteristics in diarrhoeal stool samples collected in some medical facilities in Eastern Cape Province, South Africa. Two hundred stool samples were collected from both inpatients and outpatients from male and females of all age groups attending selected medical facilities in the study area. Isolation and characterization of both organisms were done using culture based and molecular methods. Antibiotic susceptibility patterns of identified isolates were determined against a panel of 12 antimicrobial agents. One hundred and twenty presumptive E. coli isolates and 42 presumptive isolates of Campylobacter spp. Were isolated. Eighty-two percent (82 percent) of the presumptive E. coli isolates were confirmed as E. coli while 46.3 percent belonged to Campylobacter spp. Pathotyping of the diarrhoeagenic E. coli isolates by Polymerase chain reaction (PCR) showed the following prevalences: DAEC 43 (32 percent), EHEC 18 (17 percent), EIEC 11 (10 percent) and EPEC 18 (17 percent). EAEC and ETEC were not detected, while for Campylobacter spp. 37 (88 percent) were C. jejuni, and C. coli was not detected. A total of 12 (32.4 percent) of the confirmed Campylobacter jejuni isolates were found to possess the fliM gene, 9 (24.3 percent) possessed the flhA gene and only 6 (16.2 percent) harboured the gene flgE2. None were positive for the flaA, flab and flhB genes.The antibiotic resistance patterns observed among the E. coli isolates were high against ampicillin (98.1 percent), chloramphenicol (94.3 percent) and tetracycline (90.6 percent). For Campylobacter spp., resistance observed were: chloramphenicol (91.6 percent), tetracycline (25.2 percent), erythromycin (49.6 percent) and gentamycin (56.4 percent). A lesser resistance against imipenem (35.9 percent) and quinolone (ciprofloxacin) (45.5 percent) were exhibited by the E.coli isolates. 10.8 percent and 20.3 percent of the Campylobacter isolates were resistant to imipenem and ciprofloxacin respectively. The presence of chloramphenicol (CatA1) and tetracycline (tetA) resistance genes were detected in 94 percent and 89 percent of E. coli isolates respectively while 98 percent of Campylobacter spp. Harboured the catA1 resistance gene. It could be deduced from this study that E. coli and Campylobacter spp. are predomiant enteric pathogens as the etiologic agents of diarrhoea in the study community, and that their antimicrobial resistance is high in the study location. The need to develop strategies to prevent infection and control resistant organisms is evident.
- Full Text:
- Date Issued: 2018
- Authors: Omolajaiye, Sunday Abraham
- Date: 2018
- Subjects: Escherichia coli infections Campylobacter infections Diarrhea
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6213 , vital:29515
- Description: Approximately 2-4 billion cases of infectious diarrhoea occur every year, with the highest numbers recorded in sub-Saharan Africa. It remains the most common public health issue among children in developing nations. The purpose of this research was to unfold the prevalence of diarrhoeagenic E. coli and Campylobacter pathotypes as well as elucidate their antibiogram characteristics in diarrhoeal stool samples collected in some medical facilities in Eastern Cape Province, South Africa. Two hundred stool samples were collected from both inpatients and outpatients from male and females of all age groups attending selected medical facilities in the study area. Isolation and characterization of both organisms were done using culture based and molecular methods. Antibiotic susceptibility patterns of identified isolates were determined against a panel of 12 antimicrobial agents. One hundred and twenty presumptive E. coli isolates and 42 presumptive isolates of Campylobacter spp. Were isolated. Eighty-two percent (82 percent) of the presumptive E. coli isolates were confirmed as E. coli while 46.3 percent belonged to Campylobacter spp. Pathotyping of the diarrhoeagenic E. coli isolates by Polymerase chain reaction (PCR) showed the following prevalences: DAEC 43 (32 percent), EHEC 18 (17 percent), EIEC 11 (10 percent) and EPEC 18 (17 percent). EAEC and ETEC were not detected, while for Campylobacter spp. 37 (88 percent) were C. jejuni, and C. coli was not detected. A total of 12 (32.4 percent) of the confirmed Campylobacter jejuni isolates were found to possess the fliM gene, 9 (24.3 percent) possessed the flhA gene and only 6 (16.2 percent) harboured the gene flgE2. None were positive for the flaA, flab and flhB genes.The antibiotic resistance patterns observed among the E. coli isolates were high against ampicillin (98.1 percent), chloramphenicol (94.3 percent) and tetracycline (90.6 percent). For Campylobacter spp., resistance observed were: chloramphenicol (91.6 percent), tetracycline (25.2 percent), erythromycin (49.6 percent) and gentamycin (56.4 percent). A lesser resistance against imipenem (35.9 percent) and quinolone (ciprofloxacin) (45.5 percent) were exhibited by the E.coli isolates. 10.8 percent and 20.3 percent of the Campylobacter isolates were resistant to imipenem and ciprofloxacin respectively. The presence of chloramphenicol (CatA1) and tetracycline (tetA) resistance genes were detected in 94 percent and 89 percent of E. coli isolates respectively while 98 percent of Campylobacter spp. Harboured the catA1 resistance gene. It could be deduced from this study that E. coli and Campylobacter spp. are predomiant enteric pathogens as the etiologic agents of diarrhoea in the study community, and that their antimicrobial resistance is high in the study location. The need to develop strategies to prevent infection and control resistant organisms is evident.
- Full Text:
- Date Issued: 2018
Metabolic Systems Biology: Uncovering operations of cell and metabolism
- Authors: Marange , Israel Yeukai
- Date: 2018
- Subjects: Systems biology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19120 , vital:39881
- Description: The aim of this work is to analyse the technique for formulating cellular metabolism in living organisms. It also focuses on developing models of cellular metabolic systems. A sequence of biochemical reactions termed metabolic branched pathways that occur inside a cell, are of particular interest.Mathematical modelling is used as a tool to examine and analyse the metabolism of viral dynamics for the ends of this research. Dynamic mathematical models provide an important means with which to investigate the cell cycle control system. The derivation of the ordinary differential equations (ODEs) is useful in describing and analysing the metabolic network structures of branched flux pathways, as well as enzyme-substrate,reciprocal-action networks which control the cell cycle. Different general and specific factors affecting metabolic rate are identified and explained
- Full Text:
- Date Issued: 2018
- Authors: Marange , Israel Yeukai
- Date: 2018
- Subjects: Systems biology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19120 , vital:39881
- Description: The aim of this work is to analyse the technique for formulating cellular metabolism in living organisms. It also focuses on developing models of cellular metabolic systems. A sequence of biochemical reactions termed metabolic branched pathways that occur inside a cell, are of particular interest.Mathematical modelling is used as a tool to examine and analyse the metabolism of viral dynamics for the ends of this research. Dynamic mathematical models provide an important means with which to investigate the cell cycle control system. The derivation of the ordinary differential equations (ODEs) is useful in describing and analysing the metabolic network structures of branched flux pathways, as well as enzyme-substrate,reciprocal-action networks which control the cell cycle. Different general and specific factors affecting metabolic rate are identified and explained
- Full Text:
- Date Issued: 2018
Molecular characterization of streptococcus agalactiae isolated from pregnant women in the Eastern Cape, South Africa and Windhoek, Namibia and antibacterial activities of some medicinal plant extracts on the isolates
- Authors: Mukesi, Munyaradzi
- Date: 2018
- Subjects: Streptococcus Medicinal plants Pregnant women
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13034 , vital:39437
- Description: Streptococcus agalactiae (S. agalactiae) also known as group B Streptococcus (GBS) is one of the leading causes of bacterial morbidity and mortality among neonates worldwide. It is the cause of invasive Early Onset Disease (EOD), which occurs in the first 7 days of life and characterised by sepsis, pneumonia and meningitis and Late Onset Disease (LOD) occurring between 7 and 89 days of life. Late onset disease is characterised by meningitis and long term neurological sequelae such as cerebral palsy, hearing impairment and cognitive challenges. S. agalactiae does not only infect neonates, it also infects the elderly, immunocompromised individuals and pregnant and non-pregnant women, causing invasive disease. In the world, 10-40 percent of healthy women are rectally or vaginally colonised with GBS and they face the risk of passing it to their babies during the process of childbirth. During parturition, a GBS colonized pregnant woman transfers the bacterium to her new-born as the baby passes through the ruptured membrane, thus infecting the child. However, GBS has been reported to be transferred even without rupture of membranes. Once it infects the membranes, it is transferred into the amniotic fluid and subsequently infects the baby. It can be aspirated into the lungs causing pneumonia or it can infect the blood stream and disseminated round the body causing septicaemia, meningitis and other infections. Once in the neonate’s body, the bacteria is able to evade the immune system as the host immune system is not yet fully developed. Bacterial evasion of the immune system is enhanced by its various virulence factors which are deployed to help it escape the immune system. These include the polysaccharide capsule, haemolysin and the release of complement inactivating factors such C5a peptidase. The World Health Organisation (WHO) (2010) recommends universal screening of pregnant women to identify those colonised and who are at risk of passing the bacterium to their babies during birth. WHO also recommends identification of at risk women and providing Intrapartum Antibiotic Prophylaxis (IAP) using penicillin. However, problems arise in penicillin allergic women and while alternatives for IAP include erythromycin and clindamycin, there is increasing resistance to these drugs thereby limiting therapeutic options. Antimicrobial susceptibility testing is also not always possible in most resource constrained countries due to poor infrastructure, limited access to health care and the logistical problems in implementing the WHO guidelines. Alternative therapeutic options to GBS infection include developing new and potent antibiotics, development of a vaccine, use of medicinal plants and the use of bacteriophage therapy. While these look like better alternatives there is massive scientific work to be carried out to ensure proper characterisation and efficiency of such alternatives. This process should be followed by in vitro diagnostic testing, experiments with animal models and clinical trials. The problems encountered during vaccine development to curtail GBS infection are compounded by the multiplicity of S. agalactiae capsular types which vary in different geographic locations. Medicinal plants are a cheap and convenient option since they are widely used in communities but the phytochemical components of the plants have to be identified and subjected to in vitro testing to evaluate their therapeutic efficacy as antimicrobial agents. This study therefore sought to isolate GBS from pregnant women between 35 and 37 weeks gestation in Windhoek (Namibia) and the Eastern Cape (South Africa), to determine the prevalence of GBS colonisation in the vagina and rectum of the pregnant women, characterise the isolates by molecular techniques, determine the antimicrobial resistance profiles and genes of the isolates and explore the efficacies of medicinal plant extracts as possible candidates for therapeutic options.
- Full Text:
- Date Issued: 2018
- Authors: Mukesi, Munyaradzi
- Date: 2018
- Subjects: Streptococcus Medicinal plants Pregnant women
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13034 , vital:39437
- Description: Streptococcus agalactiae (S. agalactiae) also known as group B Streptococcus (GBS) is one of the leading causes of bacterial morbidity and mortality among neonates worldwide. It is the cause of invasive Early Onset Disease (EOD), which occurs in the first 7 days of life and characterised by sepsis, pneumonia and meningitis and Late Onset Disease (LOD) occurring between 7 and 89 days of life. Late onset disease is characterised by meningitis and long term neurological sequelae such as cerebral palsy, hearing impairment and cognitive challenges. S. agalactiae does not only infect neonates, it also infects the elderly, immunocompromised individuals and pregnant and non-pregnant women, causing invasive disease. In the world, 10-40 percent of healthy women are rectally or vaginally colonised with GBS and they face the risk of passing it to their babies during the process of childbirth. During parturition, a GBS colonized pregnant woman transfers the bacterium to her new-born as the baby passes through the ruptured membrane, thus infecting the child. However, GBS has been reported to be transferred even without rupture of membranes. Once it infects the membranes, it is transferred into the amniotic fluid and subsequently infects the baby. It can be aspirated into the lungs causing pneumonia or it can infect the blood stream and disseminated round the body causing septicaemia, meningitis and other infections. Once in the neonate’s body, the bacteria is able to evade the immune system as the host immune system is not yet fully developed. Bacterial evasion of the immune system is enhanced by its various virulence factors which are deployed to help it escape the immune system. These include the polysaccharide capsule, haemolysin and the release of complement inactivating factors such C5a peptidase. The World Health Organisation (WHO) (2010) recommends universal screening of pregnant women to identify those colonised and who are at risk of passing the bacterium to their babies during birth. WHO also recommends identification of at risk women and providing Intrapartum Antibiotic Prophylaxis (IAP) using penicillin. However, problems arise in penicillin allergic women and while alternatives for IAP include erythromycin and clindamycin, there is increasing resistance to these drugs thereby limiting therapeutic options. Antimicrobial susceptibility testing is also not always possible in most resource constrained countries due to poor infrastructure, limited access to health care and the logistical problems in implementing the WHO guidelines. Alternative therapeutic options to GBS infection include developing new and potent antibiotics, development of a vaccine, use of medicinal plants and the use of bacteriophage therapy. While these look like better alternatives there is massive scientific work to be carried out to ensure proper characterisation and efficiency of such alternatives. This process should be followed by in vitro diagnostic testing, experiments with animal models and clinical trials. The problems encountered during vaccine development to curtail GBS infection are compounded by the multiplicity of S. agalactiae capsular types which vary in different geographic locations. Medicinal plants are a cheap and convenient option since they are widely used in communities but the phytochemical components of the plants have to be identified and subjected to in vitro testing to evaluate their therapeutic efficacy as antimicrobial agents. This study therefore sought to isolate GBS from pregnant women between 35 and 37 weeks gestation in Windhoek (Namibia) and the Eastern Cape (South Africa), to determine the prevalence of GBS colonisation in the vagina and rectum of the pregnant women, characterise the isolates by molecular techniques, determine the antimicrobial resistance profiles and genes of the isolates and explore the efficacies of medicinal plant extracts as possible candidates for therapeutic options.
- Full Text:
- Date Issued: 2018
Molecular epidemiology of vibrio pathogens in selected surface waters and treated final effluents of wastewater treatment plants in Chris Hani District Municipality in the Eastern Cape Province, South Africa
- Authors: Ayodeji, Onsula Charles
- Date: 2018
- Subjects: Sewage disposal plants Sewage -- Purification Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/10464 , vital:35478
- Description: Access to clean and safe water is essential for the survival of human beings. Nevertheless pollution from wastewater treatment plants (WWTPs) effluents often impacts the microbiological qualities of surface waters. Availability of freshwater resources is indispensable for preventing waterborne diseases. The current study evaluated the physicochemical properties and abundance of Vibrio species in selected rivers and WWTPs in the Eastern Cape Province of South Africa, over a one year sampling regime (December, 2016 to November, 2017). Water samples were collected monthly at designated locations along the banks of two rivers, treated effluents from 500 m upstream and downstream discharge points of two WWTPs and examined for physicochemical qualities, prevalence of Vibrio pathogens and their antibiogram profiles using both cultural and molecular techniques. The findings reveal the qualities of Tsomo and Great Fish river qualities with respect to electrical conductivity (EC) (137.75 – 377.69 mg/l), total suspended solids (TSS) (52.00 – 725.19 mg/l) and temperature (12.7 – 23 oC) and the treated effluents of WW-AD and WW-CR WWTPs with respect to EC (525.73 – 1071.89 mg/l), free chlorine (0.00 mg/l – 0.68 mg/l), temperature (12.4 – 28.8 oC), TSS (14.67 – 276.44 mg/l) exceeds the permissible limits set for effluent discharged to freshwater by South Africa guidelines. Other physicochemical qualities such as turbidity (63.11 – 797.17 NTU), BOD (3.30 – 5.26 mg/l) and TDS (68.88 – 148.14 mg/l) for Tsomo and Great Fish river and turbidity (20.33 – 310 NTU), biological oxygen demand (BOD) (1.28 – 4.96 mg/l), and total dissolve solid (TDS) (262.89 – 534.89 mg/l) for WWTPs WW-AD and WW-CR did not comply with WHO and EU standards as no regulation is set for them in the South African guidelines for domestic water usage. Statistical analysis revealed that pH, electrical conductivities, dissolved oxygen and total dissolved solid were significantly different whereas temperature did not differ significantly with respect to the four seasons (P < 0.05). The Vibrio densities for Great Fish river ranged between 0 and 3.29 log10 CFU/ml with the highest obtained in the spring. The Tsomo River Vibrio densities varied between 0 to 3.56 log10 CFU/ml and the maximum densities recorded during summer. The presumptive Vibrio densities in WW-AD and WW-CR WWTPs ranged from 0 to 3.67 log10 CFU/ml and 0 to 4.42 log10 CFU/ml with autumn and spring having the highest loads respectively. Molecular identification of the presumptive Vibrio species revealed 424 positive for the Vibrio genus. Of these, 21.69 percent, 11.79 percent, 8.25 percent and 2.12 percent were confirmed as V. cholerae, V. mimicus, V. parahaemolyticus and V. fluvialis respectively. The presence of potentially Vibrio pathogens in the rivers and treated effluents suggests potential public health threat to the communities relying on receiving watersheds where the effluents are discharged. Results of antibiotic sensitivity testing revealed high sensitivities against Ofloxacin (85.54 percent), Cefuroxime (81.93 percent), and Ciprofloxacin (74.70 percent), whereas resistance against other antibiotics follow this order: Imipenem (42.17 percent), Amoxicillin-Clavulanic Acid (54.17 percent), Ampicillin (63.54 percent), Nitrofurantoin (71.79 percent) and Polymyxin B (97.44 percent). Surprisingly, the resistance of Vibrio species against the known effective Carbapenems was relatively high (Meropenem (38.54 percent) and Imipenem (58.88 percent). Multiple antibiotic resistance phenotypes (MARP) of the isolates were resistant to two or more antibiotics whereas the calculated multiple antibiotic resistance index (MARI) ranged from 0.2 to 0.7. The observed high multiple antibiotics index suggest the recovered Vibrio pathogens are of high antimicrobial usage origin. Increase in antimicrobial resistance profiles towards conventionally used antibiotics as indicated in this study calls for adequate sanitation facilities and proper surveillance programs towards monitoring of antimicrobial resistance determinants in wastewater treatment effluents and receiving watersheds. This will in turn enhance early detection of resistant strains of public health importance, and supports the prompt notification and investigation of outbreaks. It further advocates the need for constant monitoring programme by the relevant regulatory agencies to ensure total compliance of the wastewater treatment facilities to the stipulated standards.
- Full Text:
- Date Issued: 2018
- Authors: Ayodeji, Onsula Charles
- Date: 2018
- Subjects: Sewage disposal plants Sewage -- Purification Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/10464 , vital:35478
- Description: Access to clean and safe water is essential for the survival of human beings. Nevertheless pollution from wastewater treatment plants (WWTPs) effluents often impacts the microbiological qualities of surface waters. Availability of freshwater resources is indispensable for preventing waterborne diseases. The current study evaluated the physicochemical properties and abundance of Vibrio species in selected rivers and WWTPs in the Eastern Cape Province of South Africa, over a one year sampling regime (December, 2016 to November, 2017). Water samples were collected monthly at designated locations along the banks of two rivers, treated effluents from 500 m upstream and downstream discharge points of two WWTPs and examined for physicochemical qualities, prevalence of Vibrio pathogens and their antibiogram profiles using both cultural and molecular techniques. The findings reveal the qualities of Tsomo and Great Fish river qualities with respect to electrical conductivity (EC) (137.75 – 377.69 mg/l), total suspended solids (TSS) (52.00 – 725.19 mg/l) and temperature (12.7 – 23 oC) and the treated effluents of WW-AD and WW-CR WWTPs with respect to EC (525.73 – 1071.89 mg/l), free chlorine (0.00 mg/l – 0.68 mg/l), temperature (12.4 – 28.8 oC), TSS (14.67 – 276.44 mg/l) exceeds the permissible limits set for effluent discharged to freshwater by South Africa guidelines. Other physicochemical qualities such as turbidity (63.11 – 797.17 NTU), BOD (3.30 – 5.26 mg/l) and TDS (68.88 – 148.14 mg/l) for Tsomo and Great Fish river and turbidity (20.33 – 310 NTU), biological oxygen demand (BOD) (1.28 – 4.96 mg/l), and total dissolve solid (TDS) (262.89 – 534.89 mg/l) for WWTPs WW-AD and WW-CR did not comply with WHO and EU standards as no regulation is set for them in the South African guidelines for domestic water usage. Statistical analysis revealed that pH, electrical conductivities, dissolved oxygen and total dissolved solid were significantly different whereas temperature did not differ significantly with respect to the four seasons (P < 0.05). The Vibrio densities for Great Fish river ranged between 0 and 3.29 log10 CFU/ml with the highest obtained in the spring. The Tsomo River Vibrio densities varied between 0 to 3.56 log10 CFU/ml and the maximum densities recorded during summer. The presumptive Vibrio densities in WW-AD and WW-CR WWTPs ranged from 0 to 3.67 log10 CFU/ml and 0 to 4.42 log10 CFU/ml with autumn and spring having the highest loads respectively. Molecular identification of the presumptive Vibrio species revealed 424 positive for the Vibrio genus. Of these, 21.69 percent, 11.79 percent, 8.25 percent and 2.12 percent were confirmed as V. cholerae, V. mimicus, V. parahaemolyticus and V. fluvialis respectively. The presence of potentially Vibrio pathogens in the rivers and treated effluents suggests potential public health threat to the communities relying on receiving watersheds where the effluents are discharged. Results of antibiotic sensitivity testing revealed high sensitivities against Ofloxacin (85.54 percent), Cefuroxime (81.93 percent), and Ciprofloxacin (74.70 percent), whereas resistance against other antibiotics follow this order: Imipenem (42.17 percent), Amoxicillin-Clavulanic Acid (54.17 percent), Ampicillin (63.54 percent), Nitrofurantoin (71.79 percent) and Polymyxin B (97.44 percent). Surprisingly, the resistance of Vibrio species against the known effective Carbapenems was relatively high (Meropenem (38.54 percent) and Imipenem (58.88 percent). Multiple antibiotic resistance phenotypes (MARP) of the isolates were resistant to two or more antibiotics whereas the calculated multiple antibiotic resistance index (MARI) ranged from 0.2 to 0.7. The observed high multiple antibiotics index suggest the recovered Vibrio pathogens are of high antimicrobial usage origin. Increase in antimicrobial resistance profiles towards conventionally used antibiotics as indicated in this study calls for adequate sanitation facilities and proper surveillance programs towards monitoring of antimicrobial resistance determinants in wastewater treatment effluents and receiving watersheds. This will in turn enhance early detection of resistant strains of public health importance, and supports the prompt notification and investigation of outbreaks. It further advocates the need for constant monitoring programme by the relevant regulatory agencies to ensure total compliance of the wastewater treatment facilities to the stipulated standards.
- Full Text:
- Date Issued: 2018
Multi-temporal analysis of changes in vegetation distribution in the Great Fish River Game Reserve, Eastern Cape Province, South Africa :1982-2012
- Authors: Dikweni, Sipho
- Date: 2018
- Subjects: Climatic changes -- South Africa|zEastern Cape Biodiversity conservation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10511 , vital:35550
- Description: Great Fish River Game Reserve plays an important role in curtailing the ever-increasing biodiversity declines in Eastern Cape Province and South Africa at large. Though this area plays an important role in the conservation of natural biodiversity, it has been observed that it is undergoing considerable changes with regards to conditions and composition of vegetation cover. These changes signal a decline in the capacity of the Great Fish River Game Reserve to support wildlife population. In this study, remote sensing was used to investigate multi-temporal changes in vegetation distribution in this particular reserve over a period of 30 years (1982-2012). A supervised classification was carried out to classify four Landsat images including; Landsat TM, Landsat ETM and Landsat 8 imagery of 1984, 1992, 2002 and 2013 respectively to map historical and present vegetation conditions and distribution in the Great Fish River Game Reserve. A comparative examination of the classified images showed that there were significant changes in the composition and structure of vegetation with much of the palatable plant species being driven to extinction. The results showed that herbivory pressure inconjuction with climate variability has subsequently resulted in a decrease of the supporting potential of the reserve to sustain wildlife due to mortality of the most preferred plant species and abundant increase of non-palatable plant species. As grazing and browsing intensity increased, there was a decline in regenerative potential of the selected plant species by wild herbivores and successful increase in abundance of the non-palatable plant species. The results of this investigation suggest that the current increase in wildlife population will facilitate the deterioration of habitat condition to support wildlife up to the point of no recovery.
- Full Text:
- Date Issued: 2018
- Authors: Dikweni, Sipho
- Date: 2018
- Subjects: Climatic changes -- South Africa|zEastern Cape Biodiversity conservation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10511 , vital:35550
- Description: Great Fish River Game Reserve plays an important role in curtailing the ever-increasing biodiversity declines in Eastern Cape Province and South Africa at large. Though this area plays an important role in the conservation of natural biodiversity, it has been observed that it is undergoing considerable changes with regards to conditions and composition of vegetation cover. These changes signal a decline in the capacity of the Great Fish River Game Reserve to support wildlife population. In this study, remote sensing was used to investigate multi-temporal changes in vegetation distribution in this particular reserve over a period of 30 years (1982-2012). A supervised classification was carried out to classify four Landsat images including; Landsat TM, Landsat ETM and Landsat 8 imagery of 1984, 1992, 2002 and 2013 respectively to map historical and present vegetation conditions and distribution in the Great Fish River Game Reserve. A comparative examination of the classified images showed that there were significant changes in the composition and structure of vegetation with much of the palatable plant species being driven to extinction. The results showed that herbivory pressure inconjuction with climate variability has subsequently resulted in a decrease of the supporting potential of the reserve to sustain wildlife due to mortality of the most preferred plant species and abundant increase of non-palatable plant species. As grazing and browsing intensity increased, there was a decline in regenerative potential of the selected plant species by wild herbivores and successful increase in abundance of the non-palatable plant species. The results of this investigation suggest that the current increase in wildlife population will facilitate the deterioration of habitat condition to support wildlife up to the point of no recovery.
- Full Text:
- Date Issued: 2018
Perceptions, determinants and consumption patterns of indigenous fruits and vegetables in rural areas : evidence from Mutale Local Municipality, Limpopo Province, South Africa
- Authors: Nengovhela, Rudzani
- Date: 2018
- Subjects: Vegetables in human nutrition Indigenous crops Food security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10123 , vital:35356
- Description: Rural households across South Africa experience food and nutrition insecurity. Given the fact that indigenous fruits and vegetables (IF&Vs) have numerous health benefits including their wide availability and accessibility in rural areas, these indigenous varieties can significantly contribute to food and nutrition security in rural household. However, the consumption of IF&Vs in recent years has generally remained low and has been declining. The present study investigated the perceptions of IF&Vs, consumption patterns and determinants of IF&V consumption among 200 rural households (n = 200) from 10 villages within the Mutale Local Municipality of Limpopo Province, South Africa. The results revealed that, respondents held overwhelmingly positive perceptions of IF&Vs. The majority of the respondents believed that IF&Vs were healthier, less expensive and more visually attractive than exotic varieties. Consumption of the selected IF&Vs was generally high among the sample size. There were more households that consumed each of the selected IF&Vs than those that did not consume. Most of the selected IF&Vs were consumed only in summer and consumed on a weekly basis rather than daily or monthly basis. Age, marital status, occupation, education level and household size, as well as, perceptions of indigenous fruits’ longevity promotion, health beneficiation and relative visual attractiveness were found to be significant determinants of indigenous fruit consumption. On the other hand, the education level, in addition to perceptions of indigenous vegetables’ comparative healthiness, longevity promotion, health beneficiation and preparative ease were significant determinants of respondents’ indigenous vegetable consumption.
- Full Text:
- Date Issued: 2018
- Authors: Nengovhela, Rudzani
- Date: 2018
- Subjects: Vegetables in human nutrition Indigenous crops Food security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10123 , vital:35356
- Description: Rural households across South Africa experience food and nutrition insecurity. Given the fact that indigenous fruits and vegetables (IF&Vs) have numerous health benefits including their wide availability and accessibility in rural areas, these indigenous varieties can significantly contribute to food and nutrition security in rural household. However, the consumption of IF&Vs in recent years has generally remained low and has been declining. The present study investigated the perceptions of IF&Vs, consumption patterns and determinants of IF&V consumption among 200 rural households (n = 200) from 10 villages within the Mutale Local Municipality of Limpopo Province, South Africa. The results revealed that, respondents held overwhelmingly positive perceptions of IF&Vs. The majority of the respondents believed that IF&Vs were healthier, less expensive and more visually attractive than exotic varieties. Consumption of the selected IF&Vs was generally high among the sample size. There were more households that consumed each of the selected IF&Vs than those that did not consume. Most of the selected IF&Vs were consumed only in summer and consumed on a weekly basis rather than daily or monthly basis. Age, marital status, occupation, education level and household size, as well as, perceptions of indigenous fruits’ longevity promotion, health beneficiation and relative visual attractiveness were found to be significant determinants of indigenous fruit consumption. On the other hand, the education level, in addition to perceptions of indigenous vegetables’ comparative healthiness, longevity promotion, health beneficiation and preparative ease were significant determinants of respondents’ indigenous vegetable consumption.
- Full Text:
- Date Issued: 2018
Performance comparison of the residential types of air source heat pump water heaters in South Africa due to the refrigerant thermo-physical properties
- Authors: Sikhonza, Mandlenkosi
- Date: 2018
- Subjects: Heat pumps Water heaters
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9275 , vital:34317
- Description: Globally hot water heating contributes enormously to the increase in energy consumption in the residential sector. Coal being a fossil fuel and non-renewable source of energy remains the major source used for electricity generation. The burning of coal is the primary cause of CO2 emission into the environment which causes climate change and global warming. Energy efficiency and renewable energy technologies were employed as one of the alternative ways of reducing global warming. In most residential areas in South Africa, the water heating generates 30 -50percent of the monthly electricity bill (Zhang and Huan, 2013). In this light, residential load management (RLM) is a significant part of the load management programme of Eskom’s overall demand side management strategy. Through RLM, the electricity load is being transferred from peak times to off times by switching the geysers during peak hours because geysers consume more electricity and contribute significantly to the national grid constraint problem (Eskom, 2012).
- Full Text:
- Date Issued: 2018
- Authors: Sikhonza, Mandlenkosi
- Date: 2018
- Subjects: Heat pumps Water heaters
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9275 , vital:34317
- Description: Globally hot water heating contributes enormously to the increase in energy consumption in the residential sector. Coal being a fossil fuel and non-renewable source of energy remains the major source used for electricity generation. The burning of coal is the primary cause of CO2 emission into the environment which causes climate change and global warming. Energy efficiency and renewable energy technologies were employed as one of the alternative ways of reducing global warming. In most residential areas in South Africa, the water heating generates 30 -50percent of the monthly electricity bill (Zhang and Huan, 2013). In this light, residential load management (RLM) is a significant part of the load management programme of Eskom’s overall demand side management strategy. Through RLM, the electricity load is being transferred from peak times to off times by switching the geysers during peak hours because geysers consume more electricity and contribute significantly to the national grid constraint problem (Eskom, 2012).
- Full Text:
- Date Issued: 2018
Pollution potential of on-site dry sanitation systems associated with the Mzimvubu Water Project, Eastern Cape, South Africa
- Authors: Mamera, Matthew
- Date: 2018
- Subjects: Water resources development Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6038 , vital:29485
- Description: Protecting the environment requires tools that can be used to monitor environmental conditions for proper sustainable management of water resources. The Mzimvubu River is the largest undeveloped river, in the poorest region of South Africa. The South African government announced plans to construct two large storage dams (Ntabelanga and Laleni) in the Tsitsa River, one of the largest tributaries to the Mzimvubu River. The dams and associated infrastructure is termed the Mzimvubu Water Project (MWP). In developing countries like South Africa, several households use pit latrines. Moreover, many people also rely upon untreated groundwater supplies for their drinking water. The shared utilization of both pit latrines and groundwater resources, can lead to human and ecological health risks from microbial and chemical pollutants. These threats can be accelerated due to a permanent rise in the water table associated with dam constructions. Four hillslope sites with pit latrines (MT1, MT2, MT3 and MT4) above 1st order tributaries to the Tsitsa River, in the vicinity of the proposed MWP were chosen for this study. The soils were described and classified at selected locations below the pit latrine and above the tributary. Undisturbed core samples were from representative soil horizons on which hydraulic properties were determined in the laboratory. Samples were also collected to determine the feacal coliform and other bacterial concentrations during a winter and summer period. Mechanistic modelling with Hydrus 2D for a 121 day period was conducted to determine the risk of pollution to surface and groundwater from the various sites. Apedal soils of the Clovelly form dominated upper slopes of MT1 and the lower slopes of MT2. A Clovelly form is hydropedologically termed a recharge soil, as morphological indicators of saturation are absent. Hydromorphic soil properties were observed in the sub-surface B horizons of a Tukulu form in MT1-3 and MT4. High clay contents and strong structure soils of the Sepane form were dominant in MT3. The soils of MT1 and MT2 are relatively sandy with slightly higher hydraulic conductivities compared to MT3 and MT4. In general higher measured faecal coliform concentrations were higher in winter as compared to summer seasons but in most sites both winter and summer seasons had counts < 1 CFU/g. The highest concentrations of total bacteria (9 x 106 CFU/ g soil) was observed in MT3-1. Other sites with potential pollution include MT3-3, with a count above 4 x 104 CFU /g soil in winter and MT1-1 with a count above 2.2 X 104 CFU /g soil in summer. In most of the sites, the E. coli bacteria detections were low (< 1 CFU/g) during both seasons. The highest value in summer of 1.8 x 102 CFU/g was observed in MT3-3 which increased from 1.2 x102 CFU/g in winter. As the soil water flow rate increase the mobility of bacteria increase as well. Hydrus simulations showed that surface water resources are threatened by pollution from MT3 and MT4 due to the prominence of lateral flow. Groundwater pollution is more likely to occur on MT1 and MT2 as the soils are freely drained. Future work should focus on the more direct measurements and modelling of the migration of bacterial pollutants from pit latrines to various water resources.
- Full Text:
- Date Issued: 2018
- Authors: Mamera, Matthew
- Date: 2018
- Subjects: Water resources development Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6038 , vital:29485
- Description: Protecting the environment requires tools that can be used to monitor environmental conditions for proper sustainable management of water resources. The Mzimvubu River is the largest undeveloped river, in the poorest region of South Africa. The South African government announced plans to construct two large storage dams (Ntabelanga and Laleni) in the Tsitsa River, one of the largest tributaries to the Mzimvubu River. The dams and associated infrastructure is termed the Mzimvubu Water Project (MWP). In developing countries like South Africa, several households use pit latrines. Moreover, many people also rely upon untreated groundwater supplies for their drinking water. The shared utilization of both pit latrines and groundwater resources, can lead to human and ecological health risks from microbial and chemical pollutants. These threats can be accelerated due to a permanent rise in the water table associated with dam constructions. Four hillslope sites with pit latrines (MT1, MT2, MT3 and MT4) above 1st order tributaries to the Tsitsa River, in the vicinity of the proposed MWP were chosen for this study. The soils were described and classified at selected locations below the pit latrine and above the tributary. Undisturbed core samples were from representative soil horizons on which hydraulic properties were determined in the laboratory. Samples were also collected to determine the feacal coliform and other bacterial concentrations during a winter and summer period. Mechanistic modelling with Hydrus 2D for a 121 day period was conducted to determine the risk of pollution to surface and groundwater from the various sites. Apedal soils of the Clovelly form dominated upper slopes of MT1 and the lower slopes of MT2. A Clovelly form is hydropedologically termed a recharge soil, as morphological indicators of saturation are absent. Hydromorphic soil properties were observed in the sub-surface B horizons of a Tukulu form in MT1-3 and MT4. High clay contents and strong structure soils of the Sepane form were dominant in MT3. The soils of MT1 and MT2 are relatively sandy with slightly higher hydraulic conductivities compared to MT3 and MT4. In general higher measured faecal coliform concentrations were higher in winter as compared to summer seasons but in most sites both winter and summer seasons had counts < 1 CFU/g. The highest concentrations of total bacteria (9 x 106 CFU/ g soil) was observed in MT3-1. Other sites with potential pollution include MT3-3, with a count above 4 x 104 CFU /g soil in winter and MT1-1 with a count above 2.2 X 104 CFU /g soil in summer. In most of the sites, the E. coli bacteria detections were low (< 1 CFU/g) during both seasons. The highest value in summer of 1.8 x 102 CFU/g was observed in MT3-3 which increased from 1.2 x102 CFU/g in winter. As the soil water flow rate increase the mobility of bacteria increase as well. Hydrus simulations showed that surface water resources are threatened by pollution from MT3 and MT4 due to the prominence of lateral flow. Groundwater pollution is more likely to occur on MT1 and MT2 as the soils are freely drained. Future work should focus on the more direct measurements and modelling of the migration of bacterial pollutants from pit latrines to various water resources.
- Full Text:
- Date Issued: 2018
Preparation, characterization and in vitro analysis of polyamidoamine drug conjugates containing ferrocene and platinum analogues
- Authors: Mugogodi, Ansley
- Date: 2018
- Subjects: Ferrocene
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10145 , vital:35360
- Description: Polyamidoamine drug conjugates were prepared from analogues of ferrocene and platinum. Standard reaction procedures were followed in the synthesis of platinum and ferrocene analogues. Michael addition reaction of amines to the activated double bonds of methylenebisacrylamide was applied for preparation of the water soluble polyamidoamine carriers onto which drug analogues were attached. The drug release studies of the conjugates were evaluated at different pH environments. The results obtained from drug release studies showed that rate of drug release was variable depending on the conjugate and pH environment. Mathematical drug release models by Korsmeyer-Peppas were used to determine the drug release characteristics of the ferrocene and platinum based drugs from polyamidoamine drug conjugates. Cytotoxicity potential of the analogues and polyamidoamine drug conjugates was tested on selected cell lines. Cisplatin was used as the standard for comparison of the IC50 values obtained for the compounds tested for cytotoxicity activity. The results from six polymer drug conjugates tested for cytotoxicity activity showed that conjugation of analogues to polyamidoamine carrier enhanced the activity of the analogues in some of the polyamidoamine drug conjugates. Various techniques such as Fourier Transform Infrared (FTIR) spectroscopy, Proton Nuclear Magnetic Resonance spectroscopy (1H NMR), Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) spectroscopy were employed for the characterization of the ferrocene and platinum analogues, polyamidoamine carriers and drug conjugates.
- Full Text:
- Date Issued: 2018
- Authors: Mugogodi, Ansley
- Date: 2018
- Subjects: Ferrocene
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10145 , vital:35360
- Description: Polyamidoamine drug conjugates were prepared from analogues of ferrocene and platinum. Standard reaction procedures were followed in the synthesis of platinum and ferrocene analogues. Michael addition reaction of amines to the activated double bonds of methylenebisacrylamide was applied for preparation of the water soluble polyamidoamine carriers onto which drug analogues were attached. The drug release studies of the conjugates were evaluated at different pH environments. The results obtained from drug release studies showed that rate of drug release was variable depending on the conjugate and pH environment. Mathematical drug release models by Korsmeyer-Peppas were used to determine the drug release characteristics of the ferrocene and platinum based drugs from polyamidoamine drug conjugates. Cytotoxicity potential of the analogues and polyamidoamine drug conjugates was tested on selected cell lines. Cisplatin was used as the standard for comparison of the IC50 values obtained for the compounds tested for cytotoxicity activity. The results from six polymer drug conjugates tested for cytotoxicity activity showed that conjugation of analogues to polyamidoamine carrier enhanced the activity of the analogues in some of the polyamidoamine drug conjugates. Various techniques such as Fourier Transform Infrared (FTIR) spectroscopy, Proton Nuclear Magnetic Resonance spectroscopy (1H NMR), Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX) spectroscopy were employed for the characterization of the ferrocene and platinum analogues, polyamidoamine carriers and drug conjugates.
- Full Text:
- Date Issued: 2018
Production and molecular characterization of peroxidases from novel ligninolytic proteobacteria and bacillus strains
- Authors: Falade, Ayodeji Osmund
- Date: 2018
- Subjects: Peroxidase Catalase
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9702 , vital:34823
- Description: Inadequate quantity is a major impediment to the industrial application of peroxidase and other industrial enzymes. Consequently, efforts are geared towards increasing peroxidase production by searching for new microbes with enhanced production capacity. In this study, three novel ligninolytic bacteria: Raoultella ornithinolytica OKOH-1 (KX640917), Ensifer adhaerens NWODO-2 (KX640918) and Bacillus sp. FALADE-1 (KX640922) were optimized for peroxidase production and their peroxidases characterized using molecular and biochemical approaches. Molecular analysis confirmed the presence of peroxidase genes in the three bacteria. BLAST result and phylogenetic analysis of the deduced amino acid sequences suggested that Raoultella ornithinolytica OKOH-1 peroxidase (RaoPrx) belongs to a DyP-type peroxidase family while peroxidases from Ensifer adhaerens NWODO-2 and Bacillus sp. FALADE-1 are catalase-peroxidases. The peroxidase genes are available in the GenBank with MF370527, MF374336 and MF407314 as respective accession numbers. Upon optimization, Raoultella ornithinolytica OKOH-1 exhibited the highest peroxidase production at pH 5, 35 oC and 150 rpm. Biochemical characterization showed that RaoPrx had a wide substrate specificity as it was able to oxidize all the tested substrates in this study (ABTS, veratryl alcohol, guaiacol and pyrogallol), except 2, 6-Dimethoxyphenol. However, highest activity by the enzyme was recorded with pyrogallol as substrate. The enzyme had an optimum activity at pH 6 and 50 oC and was very stable at high temperatures (50 oC – 70 oC). Its pH stability was over a pH range of 5.0 – 7.0. Moreover, RaoPrx activity was significantly enhanced by Ag+, Cu2+, Zn2+and Fe2+ while Ca2+, Mg2+, Ba2+, Al3+, Co2+, NaN3 and EDTA inhibited the activity of the enzyme. Nevertheless, RaoPrx exhibited a remarkable dye-decolourizing activity on congo red and melanin, indicating the biotechnological potential of the enzyme in dye decolourization and development of cosmetic agent. Generally, the results from this study suggest that ligninolytic bacteria hold a great potential for enhanced peroxidase production that could meet the increasing industrial demand.
- Full Text:
- Date Issued: 2018
- Authors: Falade, Ayodeji Osmund
- Date: 2018
- Subjects: Peroxidase Catalase
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9702 , vital:34823
- Description: Inadequate quantity is a major impediment to the industrial application of peroxidase and other industrial enzymes. Consequently, efforts are geared towards increasing peroxidase production by searching for new microbes with enhanced production capacity. In this study, three novel ligninolytic bacteria: Raoultella ornithinolytica OKOH-1 (KX640917), Ensifer adhaerens NWODO-2 (KX640918) and Bacillus sp. FALADE-1 (KX640922) were optimized for peroxidase production and their peroxidases characterized using molecular and biochemical approaches. Molecular analysis confirmed the presence of peroxidase genes in the three bacteria. BLAST result and phylogenetic analysis of the deduced amino acid sequences suggested that Raoultella ornithinolytica OKOH-1 peroxidase (RaoPrx) belongs to a DyP-type peroxidase family while peroxidases from Ensifer adhaerens NWODO-2 and Bacillus sp. FALADE-1 are catalase-peroxidases. The peroxidase genes are available in the GenBank with MF370527, MF374336 and MF407314 as respective accession numbers. Upon optimization, Raoultella ornithinolytica OKOH-1 exhibited the highest peroxidase production at pH 5, 35 oC and 150 rpm. Biochemical characterization showed that RaoPrx had a wide substrate specificity as it was able to oxidize all the tested substrates in this study (ABTS, veratryl alcohol, guaiacol and pyrogallol), except 2, 6-Dimethoxyphenol. However, highest activity by the enzyme was recorded with pyrogallol as substrate. The enzyme had an optimum activity at pH 6 and 50 oC and was very stable at high temperatures (50 oC – 70 oC). Its pH stability was over a pH range of 5.0 – 7.0. Moreover, RaoPrx activity was significantly enhanced by Ag+, Cu2+, Zn2+and Fe2+ while Ca2+, Mg2+, Ba2+, Al3+, Co2+, NaN3 and EDTA inhibited the activity of the enzyme. Nevertheless, RaoPrx exhibited a remarkable dye-decolourizing activity on congo red and melanin, indicating the biotechnological potential of the enzyme in dye decolourization and development of cosmetic agent. Generally, the results from this study suggest that ligninolytic bacteria hold a great potential for enhanced peroxidase production that could meet the increasing industrial demand.
- Full Text:
- Date Issued: 2018
Productivity and profitability of different maize varieties and cropping systems used in the smallholder sector of the Eastern Cape Province of South Africa : implication on food security
- Authors: Kambanje, Ardinesh
- Date: 2018
- Subjects: Crop yields Crops and climate Cropping systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6237 , vital:29528
- Description: Low maize yields in the midst of abundant arable land, favourable climatic conditions, input and financial support programs, plagues smallholder maize farming in Eastern Cape Province. These scenarios have led the province to be a net importer of maize. In essence, low production may signify a mis-match between maize varieties being promoted amongst smallholder farmers and their farming system. Thus, the main objective of the study was to investigate the productivity and profitability of different maize varieties and cropping system under smallholder agriculture in selected villages of the Eastern Cape Province of South Africa as well as, the implications posed on the household food security. The study sought to assess: (i) the productivity of different maize varieties and cropping systems, (ii) the effect of GM maize adoption on food security among smallholder farmers, (iii) the profitability of GM, conventional hybrids and OPV maize varieties produced by farmers under different agro-ecological conditions and (iv) the impact of different maize varieties and cropping systems on food security in the smallholder agriculture. A cross sectional quantitative-based survey study was carried out to obtain information from a total of 650 small holder farmers. The study was conducted in three local municipalities in Oliver Reginald (OR) Tambo District Municipality of the Eastern Cape Province of South Africa. Descriptive statistics, partial factor productivity, gross margin analysis, household food insecurity access score (HFIAS), ordinal logistic and linear regression were the analytical techniques used in establishing correlations among variables. Results obtained from the survey indicated that under mono-cropping system, Genetically Modified (GM) maize variety was highly productive with an average yield of 1.9 t/ha whilst, improved OPV maize variety was productive (with an average yield of 1.6 t/ha) under mixed cropping system. Furthermore, GM maize (GM = -R418.10), and landrace (GM = -R1 140.29) maize varieties had negative gross margins whilst, conventional hybrids (GM = R5 181.21) and improved OPV (GM = R1 457.41) were profitable. There was a significant and negative correlation between use of GM maize variety and reduction of household food insecurity. GM maize varieties, improved OPV, white maize, white as well as yellow GM maize varieties had a significant impact in reducing household food insecurity; whilst using more than one variety of maize (landraces and GMO) positively influenced household food insecurity. In light of these research findings, it is recommended that, there is need to address household food security by growing improved OPVs under a mixed cropping system and GM maize under monocropping system.
- Full Text:
- Date Issued: 2018
- Authors: Kambanje, Ardinesh
- Date: 2018
- Subjects: Crop yields Crops and climate Cropping systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6237 , vital:29528
- Description: Low maize yields in the midst of abundant arable land, favourable climatic conditions, input and financial support programs, plagues smallholder maize farming in Eastern Cape Province. These scenarios have led the province to be a net importer of maize. In essence, low production may signify a mis-match between maize varieties being promoted amongst smallholder farmers and their farming system. Thus, the main objective of the study was to investigate the productivity and profitability of different maize varieties and cropping system under smallholder agriculture in selected villages of the Eastern Cape Province of South Africa as well as, the implications posed on the household food security. The study sought to assess: (i) the productivity of different maize varieties and cropping systems, (ii) the effect of GM maize adoption on food security among smallholder farmers, (iii) the profitability of GM, conventional hybrids and OPV maize varieties produced by farmers under different agro-ecological conditions and (iv) the impact of different maize varieties and cropping systems on food security in the smallholder agriculture. A cross sectional quantitative-based survey study was carried out to obtain information from a total of 650 small holder farmers. The study was conducted in three local municipalities in Oliver Reginald (OR) Tambo District Municipality of the Eastern Cape Province of South Africa. Descriptive statistics, partial factor productivity, gross margin analysis, household food insecurity access score (HFIAS), ordinal logistic and linear regression were the analytical techniques used in establishing correlations among variables. Results obtained from the survey indicated that under mono-cropping system, Genetically Modified (GM) maize variety was highly productive with an average yield of 1.9 t/ha whilst, improved OPV maize variety was productive (with an average yield of 1.6 t/ha) under mixed cropping system. Furthermore, GM maize (GM = -R418.10), and landrace (GM = -R1 140.29) maize varieties had negative gross margins whilst, conventional hybrids (GM = R5 181.21) and improved OPV (GM = R1 457.41) were profitable. There was a significant and negative correlation between use of GM maize variety and reduction of household food insecurity. GM maize varieties, improved OPV, white maize, white as well as yellow GM maize varieties had a significant impact in reducing household food insecurity; whilst using more than one variety of maize (landraces and GMO) positively influenced household food insecurity. In light of these research findings, it is recommended that, there is need to address household food security by growing improved OPVs under a mixed cropping system and GM maize under monocropping system.
- Full Text:
- Date Issued: 2018
Regional and community food systems for rural households :|bthe case of maize in Mqanduli, Eastern Cape Province, South Africa
- Authors: Qangule, Mondli
- Date: 2018
- Subjects: Sustainable agriculture -- South Africa -- Eastern Cape Food supply -- South Africa -- Eastern Cape Agricultural systems -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10232 , vital:35383
- Description: Smallholder farmers have been growing food in their communities, but some are still food insecure. Therefore, appropriate food systems are very important for smallholder farmers’ self-reliance as well as food and nutrition security. The study focuses only on community and regional maize food systems for rural households. The main aim of this study was to investigate the regional and community food systems for smallholder maize farmers in Mqanduli. The objectives of the study were to profile smallholder maize farmers, describing the existing maize food systems and patterns in Mqanduli and also to determine factors that influence farmers’ participation in local or regional markets. Availability or convenient sampling and random sampling techniques were used to collect primary data from smallholder maize farmers. Descriptive statistics was used to profile smallholder farmers, as well as, in describing the existing maize food systems at Mqanduli. The binary logistic regression model was used to analyse the variables that had influenced the smallholder famers’ participation in markets. Descriptive results revealed that, smallholder maize farmers in Mqanduli are characterised by high participation in both local and regional markets. Moreover, they utilized both community and regional food systems. Logistic regression results indicated that, out of 11 variables included in the analysis as factors influencing farmers’ participation, 6 of them (age, level of education, market information, distance, access to credit and extension visit) were found to be significant and 5 (gender, amount of land, transport availability etc) were not significant. However, access to credit and distance were found to be the most significant variables, showing a positive relationship to smallholder maize producer`s market participation. Therefore, it was recommended that, there must be more investment in research by government and policy makers when it comes to food systems especially in rural areas, to enhance smallholders’ livelihood. More access to credit is also needed by farmers in order to be able to market their produces.
- Full Text:
- Date Issued: 2018
- Authors: Qangule, Mondli
- Date: 2018
- Subjects: Sustainable agriculture -- South Africa -- Eastern Cape Food supply -- South Africa -- Eastern Cape Agricultural systems -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10232 , vital:35383
- Description: Smallholder farmers have been growing food in their communities, but some are still food insecure. Therefore, appropriate food systems are very important for smallholder farmers’ self-reliance as well as food and nutrition security. The study focuses only on community and regional maize food systems for rural households. The main aim of this study was to investigate the regional and community food systems for smallholder maize farmers in Mqanduli. The objectives of the study were to profile smallholder maize farmers, describing the existing maize food systems and patterns in Mqanduli and also to determine factors that influence farmers’ participation in local or regional markets. Availability or convenient sampling and random sampling techniques were used to collect primary data from smallholder maize farmers. Descriptive statistics was used to profile smallholder farmers, as well as, in describing the existing maize food systems at Mqanduli. The binary logistic regression model was used to analyse the variables that had influenced the smallholder famers’ participation in markets. Descriptive results revealed that, smallholder maize farmers in Mqanduli are characterised by high participation in both local and regional markets. Moreover, they utilized both community and regional food systems. Logistic regression results indicated that, out of 11 variables included in the analysis as factors influencing farmers’ participation, 6 of them (age, level of education, market information, distance, access to credit and extension visit) were found to be significant and 5 (gender, amount of land, transport availability etc) were not significant. However, access to credit and distance were found to be the most significant variables, showing a positive relationship to smallholder maize producer`s market participation. Therefore, it was recommended that, there must be more investment in research by government and policy makers when it comes to food systems especially in rural areas, to enhance smallholders’ livelihood. More access to credit is also needed by farmers in order to be able to market their produces.
- Full Text:
- Date Issued: 2018
Rose-scented geranium oil yield and composition as affected by leaf age, herbage drying and paclobutrazol
- Authors: Dyafta, Viwe
- Date: 2018
- Subjects: Essences and essential oils Rose geranium oil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10747 , vital:35733
- Description: Essential oil of rose scented-geranium is highly versatile and this makes it a very important essential oil in aromatherapy, medicine and cosmetics as well as in flavouring of food and drinks for different industries. The value of the essential oil is directly related to the quality of the oil. Therefore, it is important that the geranium growers take good care of agricultural practices in the production of essential oils as it is a crucial step where oil quality and yield is either obtained or lost. Thus, growing conditions and harvesting time must be cautiously established and controlled including herbage drying to ensure optimum yields and high quality of rose-scented geranium oil. The geranium oil production industry in South Africa is still expanding and oil yield & quality variation is important. This study was undertaken to determine the effects of herbage drying and method, leaf age and paclobutrazol concentrations on oil yield and quality of rose-scented geranium. The responses of oil yield and quality to drying effect was conducted on plant materials which were harvested from the University of Fort Hare Research Farm and glasshouse in December 2014 and October 2015. To determine the effect of drying method on essential oil yield and composition of rose-scented geranium the harvested leaves were dried in direct sunlight (20-35℃) and in a shade conditions (25℃/room temperature). Essential oil was obtained by hydro-distillation using a Clevenger apparatus. The oil samples were analysed by gas chromatography (GC) at the Dohne Agricultural institute. The major components of the oil conducted under the shade method were Linalool (5.58 percent), Menthone (0.68 percent), Citronellol (36.14 percent), Geraniol (7.29 percent), CitronellylFormate (15.39 percent) and GeranylFormate (3.30 percent), whereas those that were sun dried comprised of Linalool (3.56percent), Menthone (0.76 percent), Citronellol (32.25 percent), Geraniol (6.49 percent), CitronellylFormate (14.84 percent) and GeranylFormate (3.15 percent). The analysis of variance showed that freshly dried herbage followed by shade drying is suitable for highest oil yield. In addition, changes in essential oil composition and oil yield with leaf age in rose-scented geranium (Pelargonium capitatum x P. radens cv. Rose) were investigated in a glasshouse of the University of Fort Hare, during January to April and April to August 2012. The plants were allowed to grow to about 12-leaf stage. From top to bottom, the leaves were put into five groups (each group comprising two successive leaves, Pairs 1, 2, 3, 4 and 5). Leaf growth (leaf fresh and dry mass), and essential oil yield and composition data were collected and compared. The results indicated that, leaf fresh and dry mass data were significantly lower in the top-most (youngest leaves) as compared with the rest of the leaf pairs harvested. Essential oil in the youngest leaves was colourless, but as the leaves advanced with age, the oil tended to have a blue-green colour. Oil content (on dry mass basis) from the top to bottom, for Leaf Pairs 1, 2, 3, 4, and 5 were about 7.0, 4.9, 3.2, 2.4, 1.9 percent, respectively. Oil yield showed a significant increase in the second youngest pair of leaves and progressively declined, resulting in a significant lower yield in the oldest leaves. Leaf Pairs 1, 2, 3, 4 and 5, contributed about 19.3, 22.0, 17.71, 12.03 and 8.5 percent of the total yield per branch, respectively. Citronellol:Geraniol ratio was significantly lower in the young leaves than in the old leaves. Linalool and Geranylformate concentrations were the highest in the youngest leaves, and the opposite was observed in isomenthone. Other essential oil components did respond to leaf age. In support of research by Góra et al. (2002), Motsa et al. (2006) and Southwell and Stiff (1989), the current results indicate that early leaf age affects essential oil yield and composition. Thus, shorter regrowth cycles would increase essential oil yield and quality of rose-scented geranium. The paclobutrazol experiment was conducted in a glasshouse at the University of Fort Hare, Alice. A randomized complete block design with four replications was applied. One month after cutting back of the plants, PBZ was applied at the rates of 0, 100, 200 and 300 mg/l on the regrowth and harvested at four months of age. Data, such as chlorophyll content, plant circumference, plant height, fresh and dry mass and oil composition, were determined. The results highlighted that with an increase in PBZ concentration, total herbage mass and plant height tended to decline (Esmaielpour et al., 2011). Thus, in most cases herbage fresh and dry weight of treated plants had lower weight than the control. Paclobutrazol significantly reduced canopy circumference. There was no significant difference (P< 0.05) in oil yield and composition. Furthermore, observations showed that plants receiving PBZ had a deep green colour although the chlorophyll data did not show a significant difference. These results clearly show that PBZ helps geranium plants with compact canopy, which would enable farmers to increase income by increasing planting density, reducing distillation cost of the herbage volume and mass without reducing oil yield per plant. The findings, add another dimension to practical use of this hormone for commercial cultivation.
- Full Text:
- Date Issued: 2018
- Authors: Dyafta, Viwe
- Date: 2018
- Subjects: Essences and essential oils Rose geranium oil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10747 , vital:35733
- Description: Essential oil of rose scented-geranium is highly versatile and this makes it a very important essential oil in aromatherapy, medicine and cosmetics as well as in flavouring of food and drinks for different industries. The value of the essential oil is directly related to the quality of the oil. Therefore, it is important that the geranium growers take good care of agricultural practices in the production of essential oils as it is a crucial step where oil quality and yield is either obtained or lost. Thus, growing conditions and harvesting time must be cautiously established and controlled including herbage drying to ensure optimum yields and high quality of rose-scented geranium oil. The geranium oil production industry in South Africa is still expanding and oil yield & quality variation is important. This study was undertaken to determine the effects of herbage drying and method, leaf age and paclobutrazol concentrations on oil yield and quality of rose-scented geranium. The responses of oil yield and quality to drying effect was conducted on plant materials which were harvested from the University of Fort Hare Research Farm and glasshouse in December 2014 and October 2015. To determine the effect of drying method on essential oil yield and composition of rose-scented geranium the harvested leaves were dried in direct sunlight (20-35℃) and in a shade conditions (25℃/room temperature). Essential oil was obtained by hydro-distillation using a Clevenger apparatus. The oil samples were analysed by gas chromatography (GC) at the Dohne Agricultural institute. The major components of the oil conducted under the shade method were Linalool (5.58 percent), Menthone (0.68 percent), Citronellol (36.14 percent), Geraniol (7.29 percent), CitronellylFormate (15.39 percent) and GeranylFormate (3.30 percent), whereas those that were sun dried comprised of Linalool (3.56percent), Menthone (0.76 percent), Citronellol (32.25 percent), Geraniol (6.49 percent), CitronellylFormate (14.84 percent) and GeranylFormate (3.15 percent). The analysis of variance showed that freshly dried herbage followed by shade drying is suitable for highest oil yield. In addition, changes in essential oil composition and oil yield with leaf age in rose-scented geranium (Pelargonium capitatum x P. radens cv. Rose) were investigated in a glasshouse of the University of Fort Hare, during January to April and April to August 2012. The plants were allowed to grow to about 12-leaf stage. From top to bottom, the leaves were put into five groups (each group comprising two successive leaves, Pairs 1, 2, 3, 4 and 5). Leaf growth (leaf fresh and dry mass), and essential oil yield and composition data were collected and compared. The results indicated that, leaf fresh and dry mass data were significantly lower in the top-most (youngest leaves) as compared with the rest of the leaf pairs harvested. Essential oil in the youngest leaves was colourless, but as the leaves advanced with age, the oil tended to have a blue-green colour. Oil content (on dry mass basis) from the top to bottom, for Leaf Pairs 1, 2, 3, 4, and 5 were about 7.0, 4.9, 3.2, 2.4, 1.9 percent, respectively. Oil yield showed a significant increase in the second youngest pair of leaves and progressively declined, resulting in a significant lower yield in the oldest leaves. Leaf Pairs 1, 2, 3, 4 and 5, contributed about 19.3, 22.0, 17.71, 12.03 and 8.5 percent of the total yield per branch, respectively. Citronellol:Geraniol ratio was significantly lower in the young leaves than in the old leaves. Linalool and Geranylformate concentrations were the highest in the youngest leaves, and the opposite was observed in isomenthone. Other essential oil components did respond to leaf age. In support of research by Góra et al. (2002), Motsa et al. (2006) and Southwell and Stiff (1989), the current results indicate that early leaf age affects essential oil yield and composition. Thus, shorter regrowth cycles would increase essential oil yield and quality of rose-scented geranium. The paclobutrazol experiment was conducted in a glasshouse at the University of Fort Hare, Alice. A randomized complete block design with four replications was applied. One month after cutting back of the plants, PBZ was applied at the rates of 0, 100, 200 and 300 mg/l on the regrowth and harvested at four months of age. Data, such as chlorophyll content, plant circumference, plant height, fresh and dry mass and oil composition, were determined. The results highlighted that with an increase in PBZ concentration, total herbage mass and plant height tended to decline (Esmaielpour et al., 2011). Thus, in most cases herbage fresh and dry weight of treated plants had lower weight than the control. Paclobutrazol significantly reduced canopy circumference. There was no significant difference (P< 0.05) in oil yield and composition. Furthermore, observations showed that plants receiving PBZ had a deep green colour although the chlorophyll data did not show a significant difference. These results clearly show that PBZ helps geranium plants with compact canopy, which would enable farmers to increase income by increasing planting density, reducing distillation cost of the herbage volume and mass without reducing oil yield per plant. The findings, add another dimension to practical use of this hormone for commercial cultivation.
- Full Text:
- Date Issued: 2018