A mobile based user centred integrated remote patient monitoring framework for low resource settings
- Authors: Ndlovu, Nkanyiso
- Date: 2017
- Subjects: Health services accessibility Medical telematics Patient monitoring -- Remote sensing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8563 , vital:33128
- Description: There is a gap in healthcare service delivery within low resource settings of South Africa. These areas are under-serviced because of poor health infrastructure and few available medical experts. This contributes immensely to poor health care delivery especially to chronically ill diabetic patients and increases mortality rates. However, innovative remote patient monitoring (RPM) systems have been developed to curb the above challenge in recent years. Unfortunately, most of these systems are standalone and are incompatible with one another. Most of them relay on Internet for connectivity which is imminent in low resource settings. This makes continuity of care of chronic ill patients a great challenge. Additional, the efficacy and feasibility of RPM using mobile phones in low resource settings of South Africa are still unknown. It was also noted that none of these systems have been developed for a clinical trial. The goal of this study was to provide a standard framework that allows optimal design of mobile RPM systems which are interoperable. The objectives were to investigate the RPM system efficacy and reliability in low resource settings and determine its effects on clinical management, self-care and health outcomes. The framework was validated with a clinical trial to remotely monitor diabetic adults in Limpopo province of South Africa. A prototype system was developed based on sound user centric design process and enterprise architectural principles to remotely monitor diabetic elderly patients using cellular technologies and existing hospital infrastructure. It was evaluated using a controlled, randomized clinical trial for 6 months. There were 120 patients who took part in the study and were categorized into two groups, the intervention Group X and the control Group Y. Each group comprised of 60 participants. Evidence from this study justified the feasibility and possibility of long term implementation of RPM system to cater for chronic ill patients in low resource settings worldwide. Results showed that the self-care and normal blood glucose levels improved for both groups whereas quality of life improved only for Group X. It was shown that extensive self-care knowledge with the help of RPM system improved self-care and helped normalize their glucose levels. The hospital admissions and mortality between the two groups did not differ much. However, the intervention group had more hospital visits than the control group because the participants were requested to visit the hospitals in case of emergency. The users perceived the RPM system as feasible and effective way of clinical management and self-care. Due to wide acceptance, some patients were even willing to continue using the system after the trial. Home measurements proved to be reliable and helped improve self-care. In future, a standardized and unified framework based on rule set would provide comprehensive remote healthcare allowing continuous patient monitoring at a reduced overall cost thereby decreasing mortality rates.
- Full Text:
- Date Issued: 2017
A mobile based user centred integrated remote patient monitoring framework for low resource settings
- Authors: Ndlovu, Nkanyiso
- Date: 2017
- Subjects: Health services accessibility Medical telematics Patient monitoring -- Remote sensing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8563 , vital:33128
- Description: There is a gap in healthcare service delivery within low resource settings of South Africa. These areas are under-serviced because of poor health infrastructure and few available medical experts. This contributes immensely to poor health care delivery especially to chronically ill diabetic patients and increases mortality rates. However, innovative remote patient monitoring (RPM) systems have been developed to curb the above challenge in recent years. Unfortunately, most of these systems are standalone and are incompatible with one another. Most of them relay on Internet for connectivity which is imminent in low resource settings. This makes continuity of care of chronic ill patients a great challenge. Additional, the efficacy and feasibility of RPM using mobile phones in low resource settings of South Africa are still unknown. It was also noted that none of these systems have been developed for a clinical trial. The goal of this study was to provide a standard framework that allows optimal design of mobile RPM systems which are interoperable. The objectives were to investigate the RPM system efficacy and reliability in low resource settings and determine its effects on clinical management, self-care and health outcomes. The framework was validated with a clinical trial to remotely monitor diabetic adults in Limpopo province of South Africa. A prototype system was developed based on sound user centric design process and enterprise architectural principles to remotely monitor diabetic elderly patients using cellular technologies and existing hospital infrastructure. It was evaluated using a controlled, randomized clinical trial for 6 months. There were 120 patients who took part in the study and were categorized into two groups, the intervention Group X and the control Group Y. Each group comprised of 60 participants. Evidence from this study justified the feasibility and possibility of long term implementation of RPM system to cater for chronic ill patients in low resource settings worldwide. Results showed that the self-care and normal blood glucose levels improved for both groups whereas quality of life improved only for Group X. It was shown that extensive self-care knowledge with the help of RPM system improved self-care and helped normalize their glucose levels. The hospital admissions and mortality between the two groups did not differ much. However, the intervention group had more hospital visits than the control group because the participants were requested to visit the hospitals in case of emergency. The users perceived the RPM system as feasible and effective way of clinical management and self-care. Due to wide acceptance, some patients were even willing to continue using the system after the trial. Home measurements proved to be reliable and helped improve self-care. In future, a standardized and unified framework based on rule set would provide comprehensive remote healthcare allowing continuous patient monitoring at a reduced overall cost thereby decreasing mortality rates.
- Full Text:
- Date Issued: 2017
An optimum wind power output model for concentrator augmented wind turbines (CAWTs)
- Authors: Shonhiwa, Chipo
- Date: 2017
- Subjects: Wind power Wind turbines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8692 , vital:33427
- Description: The aim of this study was to develop an optimum wind power output model for concentrator augmented wind turbines (CAWTs), which can operate in low wind speed areas. This study was done using computational fluid dynamics modelling (CFD), theoretical and experimental work. Currently the wind resource is contributing 2.5percent of the global electricity supply and is anticipated to increase to by 2050. Despite this, the contribution to wind energy consumption share by South Africa is still low having just exceeded in 2015. Like many other countries, South Africa agrees that climate change is one of the biggest challenges currently being faced by mankind and acknowledges that tackling it requires collaborative effort from all. The Integrated Resource Plan (IRP 2010-2030) passed in 2010 targets 26.3percent renewable energy contribution to national energy consumption by the year 2030 with 10.3percent coming from wind energy hence contributing to abatement of climate change. 1518percent 1 000 MW Small wind turbines are known for their vital contribution to providing electricity in remote areas. Their power output is mainly influenced by the turbine rotor diameter and wind speed which depend on tower height. A cost benefit analysis conducted basing on increasing wind speed by increasing the turbine tower height revealed that for small wind turbines, the optimal height is . Concentrator Augmented Wind Turbines (CAWTs) are one of several concepts that have been suggested to increase the power output per unit rotor cross-sectional area by increasing the wind speed upstream of the turbine. Although some research effort has been put in this area, the major drawback is that the effect of concentrator geometry and environmental conditions on the aerodynamics and hence ultimate performance of CAWTs is still not clear. Also, the CAWTs systems that have been made so far, do not track the wind resulting in CAWT systems receiving wind from one direction thus limiting their performance. 25 m Wind has a very low energy density in nature implying that a bigger rotor area is required to harness kinetic energy for generation of meaningful electrical energy. This has resulted in higher costs of producing energy from wind than conventional sources of energy such as fossil fuels and hydro. To lower the cost of wind energy, researchers have come up with several initiatives to boost wind turbine power output. A brief review of various concepts that have been used in this study included: history of wind turbines, South Africa’s political will to abatement of climate change, wind resource assessment, power output augmentation, estimation of air density, historical development of CAWTs, fundamental parameters influencing the performance of CAWTs, mathematical modelling of wind turbines and dynamic similarity. Some facts were borrowed from these concepts to come up with the current study and explain the observations. With a view to assess any concept, it is necessary to study the fundamental basis from which it originates. Thus, it was vital to develop a fundamental basis of CAWT performance from which solutions to currently prevailing questions on the relationships among the governing parameters were obtained. The momentum theory of bare wind turbines, which is also found in literature was described. A similar approach was then used for developing the theory of CAWT systems. The theories of concentrator losses, density variation with weather conditions and turbulence modelling were also described. It was of utmost significance to evaluate the wind power potential of the Western part of the Eastern Cape Province to assess whether there would be a need for the concentrator augmented wind turbines (CAWTs) in the province and all other regions with similar or lower wind speeds in the country. In this study, five-year-long, hourly average wind speed series between January 2009 and December 2013 for six weather stations in the western part of the Eastern Cape (Bisho, Fort Beaufort, Graaff–Reinet, Grahamstown, Port Elizabeth and Queenstown) were statistically analysed using the Weibull distribution function. The dimensionless Weibull shape parameter varied from 1.7 to 2.2. All the values were low indicating that there is widely dispersed data. This means that the data tend to be distributed uniformly over a relatively wide range wind speed. Therefore, this has a positive implication on wind power generation in all the studied areas because if a suitable turbine is installed, it would get enough wind speed to run for the greater part of the year. The scale parameter varied between 3.5 and 6.3. The values for all the sites except Port Elizabeth were relatively low implying that the days of high wind speeds are few. Therefore, wind turbines that require high wind speeds for operation are not suitable here.
- Full Text:
- Date Issued: 2017
- Authors: Shonhiwa, Chipo
- Date: 2017
- Subjects: Wind power Wind turbines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8692 , vital:33427
- Description: The aim of this study was to develop an optimum wind power output model for concentrator augmented wind turbines (CAWTs), which can operate in low wind speed areas. This study was done using computational fluid dynamics modelling (CFD), theoretical and experimental work. Currently the wind resource is contributing 2.5percent of the global electricity supply and is anticipated to increase to by 2050. Despite this, the contribution to wind energy consumption share by South Africa is still low having just exceeded in 2015. Like many other countries, South Africa agrees that climate change is one of the biggest challenges currently being faced by mankind and acknowledges that tackling it requires collaborative effort from all. The Integrated Resource Plan (IRP 2010-2030) passed in 2010 targets 26.3percent renewable energy contribution to national energy consumption by the year 2030 with 10.3percent coming from wind energy hence contributing to abatement of climate change. 1518percent 1 000 MW Small wind turbines are known for their vital contribution to providing electricity in remote areas. Their power output is mainly influenced by the turbine rotor diameter and wind speed which depend on tower height. A cost benefit analysis conducted basing on increasing wind speed by increasing the turbine tower height revealed that for small wind turbines, the optimal height is . Concentrator Augmented Wind Turbines (CAWTs) are one of several concepts that have been suggested to increase the power output per unit rotor cross-sectional area by increasing the wind speed upstream of the turbine. Although some research effort has been put in this area, the major drawback is that the effect of concentrator geometry and environmental conditions on the aerodynamics and hence ultimate performance of CAWTs is still not clear. Also, the CAWTs systems that have been made so far, do not track the wind resulting in CAWT systems receiving wind from one direction thus limiting their performance. 25 m Wind has a very low energy density in nature implying that a bigger rotor area is required to harness kinetic energy for generation of meaningful electrical energy. This has resulted in higher costs of producing energy from wind than conventional sources of energy such as fossil fuels and hydro. To lower the cost of wind energy, researchers have come up with several initiatives to boost wind turbine power output. A brief review of various concepts that have been used in this study included: history of wind turbines, South Africa’s political will to abatement of climate change, wind resource assessment, power output augmentation, estimation of air density, historical development of CAWTs, fundamental parameters influencing the performance of CAWTs, mathematical modelling of wind turbines and dynamic similarity. Some facts were borrowed from these concepts to come up with the current study and explain the observations. With a view to assess any concept, it is necessary to study the fundamental basis from which it originates. Thus, it was vital to develop a fundamental basis of CAWT performance from which solutions to currently prevailing questions on the relationships among the governing parameters were obtained. The momentum theory of bare wind turbines, which is also found in literature was described. A similar approach was then used for developing the theory of CAWT systems. The theories of concentrator losses, density variation with weather conditions and turbulence modelling were also described. It was of utmost significance to evaluate the wind power potential of the Western part of the Eastern Cape Province to assess whether there would be a need for the concentrator augmented wind turbines (CAWTs) in the province and all other regions with similar or lower wind speeds in the country. In this study, five-year-long, hourly average wind speed series between January 2009 and December 2013 for six weather stations in the western part of the Eastern Cape (Bisho, Fort Beaufort, Graaff–Reinet, Grahamstown, Port Elizabeth and Queenstown) were statistically analysed using the Weibull distribution function. The dimensionless Weibull shape parameter varied from 1.7 to 2.2. All the values were low indicating that there is widely dispersed data. This means that the data tend to be distributed uniformly over a relatively wide range wind speed. Therefore, this has a positive implication on wind power generation in all the studied areas because if a suitable turbine is installed, it would get enough wind speed to run for the greater part of the year. The scale parameter varied between 3.5 and 6.3. The values for all the sites except Port Elizabeth were relatively low implying that the days of high wind speeds are few. Therefore, wind turbines that require high wind speeds for operation are not suitable here.
- Full Text:
- Date Issued: 2017
Antidiabetic activity and mechanism of action of extracts of Brachylaena elliptica (Thurb.) DC. and Brachylaena ilicifolia (Lam) Phill & Schweick
- Authors: Sagbo, Idowu Jonas
- Date: 2017
- Subjects: Herbs -- Therapeutic use Pharmacognosy Diabetes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8154 , vital:31624
- Description: International Diabetes Federation (IDF) estimated that there are 415 million people globally that are suffering from diabetes and this figure is likely to double by 2040. In South Africa, the number of people suffering from diabetes is believed to be rising steadily and the current antidiabetic therapies include the use of expensive pharmaceutical drugs which after display numerous adverse side effects. Herbal medicine is an alternative treatment strategy used by many rural populations for the management of diabetes, which is cost-effective and with minimal reported side effects. The aim of this study was to validate the antidiabetic activity and to elucidate the possible mechanisms of action of the aqueous leaf extracts prepared from two plants, Brachylaena elliptica and Brachylaena ilicifolia, used by traditional healers in the Eastern Cape, South Africa for the treatment of diabetes. The current pharmaceutical drugs target site, including carbohydrate digestion, regulation of blood glucose levels through insulin levels or activating glucose uptake in liver and muscle. The plants extracts were therefore evaluated for their potential to mimic or replace these drugs. The inhibibitory effects on alpha amylase, alpha glucosidase, DPP-IV activity and pancreatic lipase were evaluated at various concentrations of the plant extracts. To evaluate the suitability of these extracts for cell based in vitro assay as well as to determine the safety of the plant extracts for human consumption, cytotoxicity towards HepG2 cells was assessed using the MTT assay. The effect of both plant extracts on glucose uptake in HepG2 and L6 cells, lipid accumulation in 3T3-L1 preadipocytes and NO production in RAW macrophages were investigated. Both plant extracts were also tested for INS-1 proliferation using the imageXpress®Micro XLS analysis. The MTT reduction assay was also used to investigate the effect of extracts on INS-1 glucose metabolism and as a reflection of insulin secretion. The inhibitory activity of the crude extracts of both plants on protein glycation, collagenase activity and CYP3A4 interaction were also evaluated The crude extracts of both plants displayed no significant inhibition on alpha amylase, alpha glucosidase, dipeptidyl peptidase-IV, lipase, protein glycation and collagenase compared to relevant standard inhibitors, acarbose, EGCG, Diprotin A, Orlistart and aminoguanidine. The mild inhibition of B. elliptica on alpha glucosidase activity at the highest concentration of the extract tested, was considered as not physiologically relevant. The aqueous extracts of bothplants showed < 40 percent cell death in HepG2 cells even at high concentration and hence support the use of the plants by traditional healers. The extracts of B. ellipticaat 25 µg/ml, displayed a proliferative effect on INS-1 cells when compared to the negative control and B. ilicifolia at 25 μg/ml. The treatment of HepG2 cells with 100 µg/mlB. elliptica and B. ilicifolia extracts revealed a higher glucose uptake of 121 percent and 123 percent respectively when compared to the pharmaceutical drug berberine. However, both plants extracts displayed weak significant glucose uptake in L6 muscle cell line at all the tested concentrations when compared to insulin at 6 μg/ml. The crude extracts of both plants demonstrated no significant effect on 3T3-L1 lipid accumulation and INS-1 glucose metabolism. The extracts of both plants strongly reduced NO production in RAW macrophages at the highest concentration (100 μg/ml) tested in this study, which at least in part, may be explained by the flavanoids and phenols content of these plants. In addition, the crude extracts of both plants displayed weak significant inhibition on the CYP3A4 activity indicating that both plant extracts do not interfere with the cytochrome P450 activation or metabolism of anti-diabetic drugs, that may be taken together with the plant extracts. In conclusion, the results obtained from this study revealed that both plants could possibly exert their hypoglycemic effect via interactions with insulin receptor, thereby enhancing glucose metabolism as well as maintaining and repairing the health state and function of the pancreatic beta cells. The findings in this study, therefore provide evidence that B. elliptica and B. ilicifolia possess antidiabetic properties, and support their folkloric use for the management of diabetes. However, due to the potential toxicity of both plant extracts, they must be prescribed with caution.
- Full Text:
- Date Issued: 2017
- Authors: Sagbo, Idowu Jonas
- Date: 2017
- Subjects: Herbs -- Therapeutic use Pharmacognosy Diabetes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8154 , vital:31624
- Description: International Diabetes Federation (IDF) estimated that there are 415 million people globally that are suffering from diabetes and this figure is likely to double by 2040. In South Africa, the number of people suffering from diabetes is believed to be rising steadily and the current antidiabetic therapies include the use of expensive pharmaceutical drugs which after display numerous adverse side effects. Herbal medicine is an alternative treatment strategy used by many rural populations for the management of diabetes, which is cost-effective and with minimal reported side effects. The aim of this study was to validate the antidiabetic activity and to elucidate the possible mechanisms of action of the aqueous leaf extracts prepared from two plants, Brachylaena elliptica and Brachylaena ilicifolia, used by traditional healers in the Eastern Cape, South Africa for the treatment of diabetes. The current pharmaceutical drugs target site, including carbohydrate digestion, regulation of blood glucose levels through insulin levels or activating glucose uptake in liver and muscle. The plants extracts were therefore evaluated for their potential to mimic or replace these drugs. The inhibibitory effects on alpha amylase, alpha glucosidase, DPP-IV activity and pancreatic lipase were evaluated at various concentrations of the plant extracts. To evaluate the suitability of these extracts for cell based in vitro assay as well as to determine the safety of the plant extracts for human consumption, cytotoxicity towards HepG2 cells was assessed using the MTT assay. The effect of both plant extracts on glucose uptake in HepG2 and L6 cells, lipid accumulation in 3T3-L1 preadipocytes and NO production in RAW macrophages were investigated. Both plant extracts were also tested for INS-1 proliferation using the imageXpress®Micro XLS analysis. The MTT reduction assay was also used to investigate the effect of extracts on INS-1 glucose metabolism and as a reflection of insulin secretion. The inhibitory activity of the crude extracts of both plants on protein glycation, collagenase activity and CYP3A4 interaction were also evaluated The crude extracts of both plants displayed no significant inhibition on alpha amylase, alpha glucosidase, dipeptidyl peptidase-IV, lipase, protein glycation and collagenase compared to relevant standard inhibitors, acarbose, EGCG, Diprotin A, Orlistart and aminoguanidine. The mild inhibition of B. elliptica on alpha glucosidase activity at the highest concentration of the extract tested, was considered as not physiologically relevant. The aqueous extracts of bothplants showed < 40 percent cell death in HepG2 cells even at high concentration and hence support the use of the plants by traditional healers. The extracts of B. ellipticaat 25 µg/ml, displayed a proliferative effect on INS-1 cells when compared to the negative control and B. ilicifolia at 25 μg/ml. The treatment of HepG2 cells with 100 µg/mlB. elliptica and B. ilicifolia extracts revealed a higher glucose uptake of 121 percent and 123 percent respectively when compared to the pharmaceutical drug berberine. However, both plants extracts displayed weak significant glucose uptake in L6 muscle cell line at all the tested concentrations when compared to insulin at 6 μg/ml. The crude extracts of both plants demonstrated no significant effect on 3T3-L1 lipid accumulation and INS-1 glucose metabolism. The extracts of both plants strongly reduced NO production in RAW macrophages at the highest concentration (100 μg/ml) tested in this study, which at least in part, may be explained by the flavanoids and phenols content of these plants. In addition, the crude extracts of both plants displayed weak significant inhibition on the CYP3A4 activity indicating that both plant extracts do not interfere with the cytochrome P450 activation or metabolism of anti-diabetic drugs, that may be taken together with the plant extracts. In conclusion, the results obtained from this study revealed that both plants could possibly exert their hypoglycemic effect via interactions with insulin receptor, thereby enhancing glucose metabolism as well as maintaining and repairing the health state and function of the pancreatic beta cells. The findings in this study, therefore provide evidence that B. elliptica and B. ilicifolia possess antidiabetic properties, and support their folkloric use for the management of diabetes. However, due to the potential toxicity of both plant extracts, they must be prescribed with caution.
- Full Text:
- Date Issued: 2017
Antidiabetic and toxicological properties of Dianthus thunbergii (Caryophyllaceae) roots and Hypoxis argentea (Hypoxidaceae) corms
- Authors: Akinrinde, Akinleye Stephen
- Date: 2017
- Subjects: Medicinal plants--South Africa--Eastern Cape Traditional medicine--South Africa--Eastern Cape Diabetics--Alternative treatment--South Africa
- Language: English
- Type: Thesis , Doctoral , Biochemistry
- Identifier: http://hdl.handle.net/10353/16036 , vital:40606
- Description: Diabetes mellitus is a chronic metabolic disorder primarily characterized by elevated blood glucose levels. Its rapidly increasing prevalence as a major non-communicable disease is now a growing concern for both developed and developing countries. The development of safe, cost-effective and pharmacologically-effective medications continues to a major challenge of antidiabetic management. Since most conventional antidiabetic drugs are costly and present with numerous adverse effects, alternatives are increasingly being sought from natural sources, most notably medicinal plants, as viable approaches to tackling the scourge of this disease. In the Eastern Cape Province of South Africa, the roots of Dianthus thunbergii and corms of Hypoxis argentea are frequently used traditionally for the treatment of diabetes mellitus, although no scientific evidence exists to validate their effectiveness for diabetes management. The studies conducted in the resent research were, therefore, aimed at investigating the antidiabetic and toxicological properties of these plants, in an attempt to providing data towards validating their use in traditional management of diabetes mellitus. Aqueous and ethanol extracts of the underground parts of D. thunbergii and H. argentea were initially subjected to analysis of their phytochemical composition, relative to standard compounds, and the nature of their in-vitro antioxidant activities using standard spectrophotometric methods. The potentials of these extracts for cytotoxicity and/or cell proliferation were evaluated using MTT assay in HepG2 cells and Crystal violet assay in INS-1 cells. These activities were further examined in INS-1 cells using live cell fluorescence imaging techniques. To evaluate the antidiabetic properties of the extracts, they were screened for their inhibitory effects on the activities of different enzymes including α-amylase, α-glucosidase, porcine pancreatic lipase, Dipeptidyl peptidase IV (DPP-IV), collagenase and the drug metabolizing enzyme, CYP3A4, while also assessing their effects on protein glycation using in- vitro visible and fluorescence spectrophotometric approaches. Cell culture procedures were carried out to evaluate the effects of the extracts on glucose utilization in HepG2 cells and L6 myotubes; nitric oxide production in RAW 264.7 macrophages; glucose metabolism in INS-1 cells, as well as triglyceride accumulation in 3T3-L1 pre-adipocytes. Furthermore, identification of compounds present in the aqueous and ethanol extracts was carried out by Liquid chromatography- Mass spectrometry (LC-MS), while volatile oils extracted from fresh and dried parts of the two plants by hydrodistillation were also analyzed by Gas chromatography-Mass spectrometry (GC-MS). The ethanol extracts of both D. thunbergii and H. argentea contained higher amounts of total phenols, flavonoids, tannins, proanthocyanidins and alkaloids, when compared with the aqueous extracts. This finding was in direct correlation with the antioxidant activities of the extracts, with the ethanol extracts of both plants demonstrating stronger scavenging activities against hydrogen peroxide, nitric oxide, ABTS and DPPH radicals, while also exhibiting higher ferric reducing antioxidant potentials, when compared with the aqueous extracts, and in some cases, the standard antioxidants, Vitamin C, butylated hydroxytoluene and rutin. The aqueous extracts of D. thunbergii exhibited the highest toxicity in HepG2 cells with IC50 < 50 μg/ml, while also producing a concentration-dependent reduction in the viability of INS-1 cells up to 41.81percent at 50 μg/ml. Both extracts of H. argentea, however, did not produce any significant toxicity in these cells. Fluorescence imaging of live INS-1 cells using Hoechst and propidium iodide staining revealed stimulation of cell proliferation by H. argentea, while the cytotoxicity of D. thunbergii was further confirmed. H. argentea caused stimulation of glucose uptake in HepG2 cells up to 119.58 percent at 100 μg/ml and as much as 116.96 percent in L6 myotubes at 50 μg/ml, without showing toxicity to these cells. D. thunbergii produced 18.39 percent increase in L6 glucose uptake above untreated control; although its effect on HepG2 glucose uptake was irrelevant as significant toxicity was produced in these cells. H. argentea produced a concentration-dependent reduction in nitric oxide production in RAW macrophages, although not as effectively as the positive control, aminoguanidine. Again, the toxicity of D. thunbergii to this cell line precludes the relevance of nitric oxide inhibition as an antidiabetic mechanism for this plant. D. thunbergii produced a concentration-dependent increase in 3T3-L1 triglyceride accumulation, as measured by Oil red O staining, compared to untreated cells, while H. argentea exerted no significant alterations in pre- adipocyte differentiation. Generally, the two plants produced weak inhibition of the activities of the various enzymes measured, suggesting that this mechanism may not play a major role in the activities of these plants as possible antidiabetic agents. GC-MS analysis revealed major differences in the volatile oil composition between fresh and dried plant parts for both plants. Most notably, total terpenoid content of D. thunbergii oils reduced significantly from 77.17 percent in the fresh root oil to 47.58 percent in the dried root oil. Total terpenoid content was much lower in H. argentea oils, but similarly reduced from 10.58 percent in the fresh corm oil to 4.00 percent in the dried corm oil. LC-MS analysis enabled the tentative identification of compounds including phenolic glycosides, flavonoids, alkaloids, terpenoids saponins and sapogenins, many of which have been reported in literature to exert bioactivities relevant to the ones elucidated in the present study. Overall, H. argentea exhibited antidiabetic properties that may be mediated by its stimulation of glucose uptake in HepG2 and L6 cells; stimulation of proliferation in INS-1 cells; lack of stimulation of 3T3-L1 triglyceride accumulation and a tendency to reduce nitric oxide production in RAW macrophages. These activities suggest that H. argentea has promise for further investigations as an antidiabetic agent. On the contrary, D. thunbergii exhibited significant toxicity to HepG2 cells, INS-1 cells and RAW macrophages. Its cytotoxicity at the concentrations investigated in the present studies raises significant concerns about any potential antidiabetic applications for this plant.
- Full Text:
- Date Issued: 2017
- Authors: Akinrinde, Akinleye Stephen
- Date: 2017
- Subjects: Medicinal plants--South Africa--Eastern Cape Traditional medicine--South Africa--Eastern Cape Diabetics--Alternative treatment--South Africa
- Language: English
- Type: Thesis , Doctoral , Biochemistry
- Identifier: http://hdl.handle.net/10353/16036 , vital:40606
- Description: Diabetes mellitus is a chronic metabolic disorder primarily characterized by elevated blood glucose levels. Its rapidly increasing prevalence as a major non-communicable disease is now a growing concern for both developed and developing countries. The development of safe, cost-effective and pharmacologically-effective medications continues to a major challenge of antidiabetic management. Since most conventional antidiabetic drugs are costly and present with numerous adverse effects, alternatives are increasingly being sought from natural sources, most notably medicinal plants, as viable approaches to tackling the scourge of this disease. In the Eastern Cape Province of South Africa, the roots of Dianthus thunbergii and corms of Hypoxis argentea are frequently used traditionally for the treatment of diabetes mellitus, although no scientific evidence exists to validate their effectiveness for diabetes management. The studies conducted in the resent research were, therefore, aimed at investigating the antidiabetic and toxicological properties of these plants, in an attempt to providing data towards validating their use in traditional management of diabetes mellitus. Aqueous and ethanol extracts of the underground parts of D. thunbergii and H. argentea were initially subjected to analysis of their phytochemical composition, relative to standard compounds, and the nature of their in-vitro antioxidant activities using standard spectrophotometric methods. The potentials of these extracts for cytotoxicity and/or cell proliferation were evaluated using MTT assay in HepG2 cells and Crystal violet assay in INS-1 cells. These activities were further examined in INS-1 cells using live cell fluorescence imaging techniques. To evaluate the antidiabetic properties of the extracts, they were screened for their inhibitory effects on the activities of different enzymes including α-amylase, α-glucosidase, porcine pancreatic lipase, Dipeptidyl peptidase IV (DPP-IV), collagenase and the drug metabolizing enzyme, CYP3A4, while also assessing their effects on protein glycation using in- vitro visible and fluorescence spectrophotometric approaches. Cell culture procedures were carried out to evaluate the effects of the extracts on glucose utilization in HepG2 cells and L6 myotubes; nitric oxide production in RAW 264.7 macrophages; glucose metabolism in INS-1 cells, as well as triglyceride accumulation in 3T3-L1 pre-adipocytes. Furthermore, identification of compounds present in the aqueous and ethanol extracts was carried out by Liquid chromatography- Mass spectrometry (LC-MS), while volatile oils extracted from fresh and dried parts of the two plants by hydrodistillation were also analyzed by Gas chromatography-Mass spectrometry (GC-MS). The ethanol extracts of both D. thunbergii and H. argentea contained higher amounts of total phenols, flavonoids, tannins, proanthocyanidins and alkaloids, when compared with the aqueous extracts. This finding was in direct correlation with the antioxidant activities of the extracts, with the ethanol extracts of both plants demonstrating stronger scavenging activities against hydrogen peroxide, nitric oxide, ABTS and DPPH radicals, while also exhibiting higher ferric reducing antioxidant potentials, when compared with the aqueous extracts, and in some cases, the standard antioxidants, Vitamin C, butylated hydroxytoluene and rutin. The aqueous extracts of D. thunbergii exhibited the highest toxicity in HepG2 cells with IC50 < 50 μg/ml, while also producing a concentration-dependent reduction in the viability of INS-1 cells up to 41.81percent at 50 μg/ml. Both extracts of H. argentea, however, did not produce any significant toxicity in these cells. Fluorescence imaging of live INS-1 cells using Hoechst and propidium iodide staining revealed stimulation of cell proliferation by H. argentea, while the cytotoxicity of D. thunbergii was further confirmed. H. argentea caused stimulation of glucose uptake in HepG2 cells up to 119.58 percent at 100 μg/ml and as much as 116.96 percent in L6 myotubes at 50 μg/ml, without showing toxicity to these cells. D. thunbergii produced 18.39 percent increase in L6 glucose uptake above untreated control; although its effect on HepG2 glucose uptake was irrelevant as significant toxicity was produced in these cells. H. argentea produced a concentration-dependent reduction in nitric oxide production in RAW macrophages, although not as effectively as the positive control, aminoguanidine. Again, the toxicity of D. thunbergii to this cell line precludes the relevance of nitric oxide inhibition as an antidiabetic mechanism for this plant. D. thunbergii produced a concentration-dependent increase in 3T3-L1 triglyceride accumulation, as measured by Oil red O staining, compared to untreated cells, while H. argentea exerted no significant alterations in pre- adipocyte differentiation. Generally, the two plants produced weak inhibition of the activities of the various enzymes measured, suggesting that this mechanism may not play a major role in the activities of these plants as possible antidiabetic agents. GC-MS analysis revealed major differences in the volatile oil composition between fresh and dried plant parts for both plants. Most notably, total terpenoid content of D. thunbergii oils reduced significantly from 77.17 percent in the fresh root oil to 47.58 percent in the dried root oil. Total terpenoid content was much lower in H. argentea oils, but similarly reduced from 10.58 percent in the fresh corm oil to 4.00 percent in the dried corm oil. LC-MS analysis enabled the tentative identification of compounds including phenolic glycosides, flavonoids, alkaloids, terpenoids saponins and sapogenins, many of which have been reported in literature to exert bioactivities relevant to the ones elucidated in the present study. Overall, H. argentea exhibited antidiabetic properties that may be mediated by its stimulation of glucose uptake in HepG2 and L6 cells; stimulation of proliferation in INS-1 cells; lack of stimulation of 3T3-L1 triglyceride accumulation and a tendency to reduce nitric oxide production in RAW macrophages. These activities suggest that H. argentea has promise for further investigations as an antidiabetic agent. On the contrary, D. thunbergii exhibited significant toxicity to HepG2 cells, INS-1 cells and RAW macrophages. Its cytotoxicity at the concentrations investigated in the present studies raises significant concerns about any potential antidiabetic applications for this plant.
- Full Text:
- Date Issued: 2017
Assessment of anti-urease and consequential inhibitory potential of South African honey extracts on the multiplication of drug-resistant, vacA and cagA positive helicobacter pylori strains under acidic conditions
- Authors: Dube, Callote
- Date: 2017
- Subjects: Helicobacter pylori Drug resistance in microorganisms Honey -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/7787 , vital:30764
- Description: Helicobacter pylori, a neutralophile chronically infects the gastric stomach of more than half of the world’s population. Infection with the organism is associated with acute or chronic duodenal/gastric ulcer disease, gastritis, gastric adenocarcinoma, mucosa-associated tissue lymphoma (MALT) and primary B-cell gastric lymphoma and has been grouped as a class one carcinogen by the World Health Organisation (WHO). Prevalence of this organism is very high in developing countries especially in Africa, including South Africa. H. pylori treatment using the common first and second line regimens, triple therapy with two antibiotics and a proton pump inhibitor (PPI) is showing inefficiency due to increasing drug resistance. However, newly developed treatment regimens seem to be more expensive and are accompanied by more side effects. Honey contains phytochemicals which are a wealthy source of biologically active compounds some of which have been put into good use in the pharmaceutical industry. Pathogenesis of H. pylori infection in the human stomach relies on several virulence factors which include the urease enzyme, cagA and vacA. The urease enzyme actively hydrolyses urea to produce ammonia an important by-product involved in pH regulation favouring the survival of the organism in the acidic human stomach. This study therefore focuses on screening for anti-urease solvent extracts of South African honey, and evaluate whether inhibition of urease offsets the growth of H. pylori under acidic conditions. Locally produced natural honeys; Bush honey, Raw honey, Gold Crest honey, Q Bee honey, Little Bee honey, Fleures honey-radurised, Siyakholwa pure honey and Manuka honey; an import from New Zealand were purchased and the method by Syazana et al. (2010) was used for the extraction of compounds in honey. A standard strain ATCC 43526 (American Type Culture Collection, Manassas, VA, USA) and 48 pure cultures obtained from clinical isolates cultured from gastric corpus biopsy specimen of patients with gastric morbidities who were ix visiting the endoscopy unit in Livingstone Hospital, Port Elizabeth between June 2008 to December 2008 were initially used as source of urease enzyme as per extraction method done by Amin et al. (2013), but with modifications. Prior to urease extraction, H. pylori strains were identified by biochemical tests (urease, catalase, oxidase, Gram stain), confirmed by PCR targeting the glmM gene (140 bp) and drug resistance profiling was done on all the 48 strains according to Seanego et al. (2012). The screening for anti-urease active compounds was done according to Kaltwasser et al. (1966), a method relying on the reduction of NADH in a coupled urease dehydrogenase (GDH) system. Acetohydroxamic acid was used as a standard inhibitor. Prevalence of cytotoxin-associated gene A (cagA) gene and vacuolating cytotoxin gene A (vacA) gene was determined among all 48 clinical samples. The standard strains of H. pylori, X47 (cagA positive), J99 (vacA s1m1) and Tx30a (s2m2) were used as positive controls. H. pylori’s growth was then monitored under acidic pH in a cocktail spiked with anti-urease compounds (test samples) and in a cocktail without anti-urease compounds (negative control). Acetohydroxamic acid was used as a standard urease inhibitor. H. pylori multiplication was monitored in Brain Heart Infusion Broth (BHIB) adjusted to pH of 2, 3, 4, 5, 6 and 7. The strain MP01 was used as a standard urease negative strain while X47 and J99 were used as positive standards for cagA and vacA s1m1 respectively. The compounds that had anti-urease activity and were successful towards suppressing the multiplication of H. pylori under acidic environment, all other factors optimised, were subjected to gas chromatograph mass spectrometry (GC-MS) and liquid chromatograph spectrometry (LCMS) to determine volatile compounds and drugs in honey extracts respectively. The findings of this study revealed that at a concentration of 50 mg/mL, urease inhibition by petroleum ether extracts of Gold Crest and Fleures honey, hexane extracts of Little Bee and Manuka honey, and chloroform extracts of Bush honey and Q Bee honey had a range above or equal to 50 percent and there was no significance difference in urease inhibition percentage (I percent) of urease from different sources including that extracted from drug resistant H. pylori (p >0.05). Virulence factors are important for the pathogenesis of H. pylori. All the 48 clinical isolates were glmM (140 bp) positive and cagA was detected in 97.9 percent of the test isolates. The vacA gene was detected in all isolates but with different subtypes. The vacA allelic combination s1m1 was detected in 75 percent of the test isolates and s1m2 allelic combination was detected in 16.7 percent of the test isolates while the combination s2m2 was detected in 8.3 percent of the test isolates. None of the test isolates possessed the allelic combination s2m1. When H. pylori multiplication was monitored under acidic conditions in the presence of anti-urease active compounds, it was revealed that anti-urease active compounds in honey are capable of inhibiting the normal multiplication of H. pylori strains that are cagA positive, vacA positive and drug resistant. The GC-MS analysis showed that Fleures honey (urease I percent = 67.8 – 68.5 percent) and Gold Crest honey (urease I percent = 50.9 percent – 53.3 percent), all petroleum ether extracts had 27 and 26 volatile compounds. The hexane extract of Manuka honey (urease I percent = 50.0 – 53.2) had 43 compounds detected. The chloroform extract of Q Bee (urease I percent = 64.2 – 66.2 percent) had 13 volatile compounds detected. All the volatile compounds considered as representative samples of GC-MS analysis had a spectral matching ≥ 90 percent with the NIST11 library. However, the majority of compounds that were detected by LC-MS in representative honey extracts include vardenafil, urapidil, hydrocortisone, e.t.c which are drugs commonly used in the treatment of different ailments or infections that affect human beings. In addition, two xi drugs, sulfaquinoxaline and hydroxyquinoline which are used in veterinary medicine and antiseptic, disinfectant and pesticide applications in agricultural activities were detected in Little Bee honey. We therefore conclude that inhibition of urease has a bactericidal effect on drug resistant, cagA positive and vacA positive H. pylori strains growing under acidic environment.
- Full Text:
- Date Issued: 2017
- Authors: Dube, Callote
- Date: 2017
- Subjects: Helicobacter pylori Drug resistance in microorganisms Honey -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/7787 , vital:30764
- Description: Helicobacter pylori, a neutralophile chronically infects the gastric stomach of more than half of the world’s population. Infection with the organism is associated with acute or chronic duodenal/gastric ulcer disease, gastritis, gastric adenocarcinoma, mucosa-associated tissue lymphoma (MALT) and primary B-cell gastric lymphoma and has been grouped as a class one carcinogen by the World Health Organisation (WHO). Prevalence of this organism is very high in developing countries especially in Africa, including South Africa. H. pylori treatment using the common first and second line regimens, triple therapy with two antibiotics and a proton pump inhibitor (PPI) is showing inefficiency due to increasing drug resistance. However, newly developed treatment regimens seem to be more expensive and are accompanied by more side effects. Honey contains phytochemicals which are a wealthy source of biologically active compounds some of which have been put into good use in the pharmaceutical industry. Pathogenesis of H. pylori infection in the human stomach relies on several virulence factors which include the urease enzyme, cagA and vacA. The urease enzyme actively hydrolyses urea to produce ammonia an important by-product involved in pH regulation favouring the survival of the organism in the acidic human stomach. This study therefore focuses on screening for anti-urease solvent extracts of South African honey, and evaluate whether inhibition of urease offsets the growth of H. pylori under acidic conditions. Locally produced natural honeys; Bush honey, Raw honey, Gold Crest honey, Q Bee honey, Little Bee honey, Fleures honey-radurised, Siyakholwa pure honey and Manuka honey; an import from New Zealand were purchased and the method by Syazana et al. (2010) was used for the extraction of compounds in honey. A standard strain ATCC 43526 (American Type Culture Collection, Manassas, VA, USA) and 48 pure cultures obtained from clinical isolates cultured from gastric corpus biopsy specimen of patients with gastric morbidities who were ix visiting the endoscopy unit in Livingstone Hospital, Port Elizabeth between June 2008 to December 2008 were initially used as source of urease enzyme as per extraction method done by Amin et al. (2013), but with modifications. Prior to urease extraction, H. pylori strains were identified by biochemical tests (urease, catalase, oxidase, Gram stain), confirmed by PCR targeting the glmM gene (140 bp) and drug resistance profiling was done on all the 48 strains according to Seanego et al. (2012). The screening for anti-urease active compounds was done according to Kaltwasser et al. (1966), a method relying on the reduction of NADH in a coupled urease dehydrogenase (GDH) system. Acetohydroxamic acid was used as a standard inhibitor. Prevalence of cytotoxin-associated gene A (cagA) gene and vacuolating cytotoxin gene A (vacA) gene was determined among all 48 clinical samples. The standard strains of H. pylori, X47 (cagA positive), J99 (vacA s1m1) and Tx30a (s2m2) were used as positive controls. H. pylori’s growth was then monitored under acidic pH in a cocktail spiked with anti-urease compounds (test samples) and in a cocktail without anti-urease compounds (negative control). Acetohydroxamic acid was used as a standard urease inhibitor. H. pylori multiplication was monitored in Brain Heart Infusion Broth (BHIB) adjusted to pH of 2, 3, 4, 5, 6 and 7. The strain MP01 was used as a standard urease negative strain while X47 and J99 were used as positive standards for cagA and vacA s1m1 respectively. The compounds that had anti-urease activity and were successful towards suppressing the multiplication of H. pylori under acidic environment, all other factors optimised, were subjected to gas chromatograph mass spectrometry (GC-MS) and liquid chromatograph spectrometry (LCMS) to determine volatile compounds and drugs in honey extracts respectively. The findings of this study revealed that at a concentration of 50 mg/mL, urease inhibition by petroleum ether extracts of Gold Crest and Fleures honey, hexane extracts of Little Bee and Manuka honey, and chloroform extracts of Bush honey and Q Bee honey had a range above or equal to 50 percent and there was no significance difference in urease inhibition percentage (I percent) of urease from different sources including that extracted from drug resistant H. pylori (p >0.05). Virulence factors are important for the pathogenesis of H. pylori. All the 48 clinical isolates were glmM (140 bp) positive and cagA was detected in 97.9 percent of the test isolates. The vacA gene was detected in all isolates but with different subtypes. The vacA allelic combination s1m1 was detected in 75 percent of the test isolates and s1m2 allelic combination was detected in 16.7 percent of the test isolates while the combination s2m2 was detected in 8.3 percent of the test isolates. None of the test isolates possessed the allelic combination s2m1. When H. pylori multiplication was monitored under acidic conditions in the presence of anti-urease active compounds, it was revealed that anti-urease active compounds in honey are capable of inhibiting the normal multiplication of H. pylori strains that are cagA positive, vacA positive and drug resistant. The GC-MS analysis showed that Fleures honey (urease I percent = 67.8 – 68.5 percent) and Gold Crest honey (urease I percent = 50.9 percent – 53.3 percent), all petroleum ether extracts had 27 and 26 volatile compounds. The hexane extract of Manuka honey (urease I percent = 50.0 – 53.2) had 43 compounds detected. The chloroform extract of Q Bee (urease I percent = 64.2 – 66.2 percent) had 13 volatile compounds detected. All the volatile compounds considered as representative samples of GC-MS analysis had a spectral matching ≥ 90 percent with the NIST11 library. However, the majority of compounds that were detected by LC-MS in representative honey extracts include vardenafil, urapidil, hydrocortisone, e.t.c which are drugs commonly used in the treatment of different ailments or infections that affect human beings. In addition, two xi drugs, sulfaquinoxaline and hydroxyquinoline which are used in veterinary medicine and antiseptic, disinfectant and pesticide applications in agricultural activities were detected in Little Bee honey. We therefore conclude that inhibition of urease has a bactericidal effect on drug resistant, cagA positive and vacA positive H. pylori strains growing under acidic environment.
- Full Text:
- Date Issued: 2017
Characterisation of human pathogenic vibrios and methicillin-resistant staphylococcus aureus (MRSA) from wild and tank cultured dusky kob (agyrosomus japonicus) in the Eastern Cape Province, South Africa
- Authors: Justine, Fri
- Date: 2017
- Subjects: Marine microbiology Marine microbiology--South Africa--Eastern Cape Staphylococcus aureus infections--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/16047 , vital:40607
- Description: Introduction: Marine finfish including dusky kob (Agyrosomus japonicus), in addition to its high protein value, is bestowed with numerous health benefits including being heart friendly due to high proportion of omega 3 fatty acids. They are therefore used as powerful preventive measures against cardiovaslcular diseases. They are also important in neurological development during gestation and infancy, thus a regular recommendation by nutritionists. However, fish and its environment may be contaminated by bacteria pathogens. Human infections caused by members of the genus Vibrio, and Staphylococcus especially Methicillin-resistant S. aureus (MRSA) are of increased concern worldwide especially with increased Vibrio disease outbreaks and rapid spread of MRSA in the community. Methicillin-resistant Staphylococcus aureus is regarded as an emerging zoonotic agent, therefore marine fish may be considered as a reservoir for infection. The emergence of multi-drug resistant organisms in both farm animals and humans has also been a challenge that hurdles chemotherapy worldwide. Methods: We enumerated the bacteria flora of skin, gill and gut of marine dusky kob (Agyrosomus japonicus) raised in a recirculatory aquaculture system using metagenomic sequencing of the 16S rRNA. We further screened 120 dusky kob fishes (skin, gill and gut) and 80 water samples from two fish farms and Kariega estuary collected over a 10 month period for human pathogenic vibrios, and MRSA using standard procedures. Vibrio species were further subjected to species specific PCRs delineating them into V. cholerae, V. parahaemolyticus, V. vulnificus, and V. fluvialis. This was followed by elucidation of the genotypic virulence determinants. The Reverse Fragment Length Polymorphism (RFLP) of the cytotoxin hemolysin (vvhA) gene of V. vulnificus strains was carried out to determine the associated biotypes. A total of 277 Vibrio strains consisting of 126 V. fluvialis, 45 Vibrio vulnificus, 30 V. parahaemolyticus and 76 vibrios belonging to other species were subjected to susceptibility testing to 15 antibiotics by the disc diffusion method and resistant strains were further evaluated for their genotypic antimicrobial resistant determinants by polymerase chain reaction followed by plasmid profiling. For MRSA screening, we evaluated the reliability of cefoxitin disc diffusion, oxacillin screen agar and BrillianceTM MRSA 2 agar tests, in detecting methicillin resistance from fish (environmental) samples using PCR detection of the mecA as the gold standard. A total of 33 mecA positive S. aureus strains (MRSA) were subjected to PCR detection of enterotoxins (Staphylococcal enterotoxin A-E) and Panton Valentine Leucocidin (PVL) encoding genes. The SCCmec types were also investigated by multiplex PCR targeting genes encoding type I-V. The antibiogram profiles of MRSA strains to 12 antibiotics by the disc diffusion method and to vancomycin by broth micro dilution method were elucidated. Polymerase chain reaction was employed to evaluate the presence of antibiotic resistant genes. The nucleotide sequences of the rpoB gene were analysed to determine mutations that could lead to rifampicin resistance. Results: A broad diversity of pathogenic and non-pathogenic bacterial species of different taxonomic groups was observed with Proteobacteria revealed as the most common bacteria phyla. Fifty one families were identified with Enterobacteriaceae the most frequently detected in all the anatomical sites and the gut showing the highest species diversity. A total of 606 (60.23 percent ) presumptive Vibrio isolates were confirmed by PCR of which V. fluvialis was the most predominant, 193 (31.85 percent ). This was followed by Vibrio vulnificus 74 (12.21 percent ), and V. parahaemolyticus 33 (5.45 percent ). No V. cholerae strain was detected. Only one of the V. parahaemolyticus strains possessed the trh virulent gene with no tdh detected. Virulence factors of V. fluvialis detected were stn (13.5 percent ), hupO (10.4 percent ), and vfpA (1.0 percent ). V. vulnificus biotype 3, formerly restricted to Isreal was identified. Generally, resistance among Vibrio isolates varied considerably with highest resistances recorded to amoxicillin (76.2 percent ), ampicillin (67.5 percent ), erythromycin (38.3 percent ), and doxycycline (35.0 percent ) while higher susceptibilities were revealed by gentamicin (100 percent ), norfloxacin (97.8 percent ), florfenicol (90.3 percent ), tetracycline (87.7 percent ), and chloramphenicol (87.4 percent ). Multiple antibiotic resistance (MAR) (resistance to ≥ 2 classes of antibiotics) was 58.5 percent . The MAR index did not vary significantly between sites (P>0.05) and values of >0.20 were recorded in 40 percent (108/277) of all the isolates. The resistant genes ampC, blaOXA, tetA, tetM, dfr1, sul1, sul2, ermB, nptII and strA were detected in two or more Vibrio isolates while the SXT intergrase was detected only in one isolate. Seven of the 18 extreme drug resistant isolates possessed 1–3 plasmids of 1.5–10 kb range. A total of 321 presumptive Staphylococcus aureus isolates were recovered by culture out of which 202 (62.9 percent ) were identified as S. aureus by PCR. Of these, 33 (16.3 percent ) strains were mecA positive while the rest, 169 (83.7 percent ) were mecA negative. The sensitivity and specificity of MRSA detection by use of cefoxitin disc (30 μg) test was 93.9 percent and 91.7 percent , that for oxacillin screen agar test (6 μg/mL) was 81.8 percent and 92.3 percent while that of BrillianceTM MRSATM 2 agar was 87.9 percent and 94.1 percent respectively. Staphylococcal enterotoxin SEE was detected in 12.1 percent (4/33) of total strains followed by SEA 3.0 percent (1/33), and SEC 3.0 percent (1/33). SEB and SED were absent. Six of the isolates had the PVL gene, giving a prevalence of 18.2 percent . The most frequently detected SCCmec type was SCCmec type III (17/33; 51.5 percent ), closely followed by SCCmec subtype IVc (10/33; 30.3 percent ) and the least were SCCmec types I and II with only 3.0 percent (1/33) each. The rest four (4/33; 12.1 percent ) did not belong to any of the above types and were therefore considered to belong to other subtypes of SCCmec type IV not tested in the study. For antibiogram patterns, 12 (36.4 percent ) strains were resistant to doxycyline, 10 (30.3 percent ) to trimethroprim-sulfamethoxazole, 9 (27.3 percent ) to tetracycline and only 1 (3.0 percent ) strain was resistant to ciprofloxacin. Nineteen (57.6 percent ) of the MRSA strains had vancomycin MIC of ≤ 2 μg/mL, 4 (12.1 percent ) with MIC range of 4-8 μg/mL, and 10 (30.3 percent ) with values ≥ 16 μg/mL. Overall, 27 (91.percent) isolates showed simultaneous resistance to 3 or more antibiotics. The resistant genes tetM, tetA, ermB, BlaZ femA were detected in two or more strains resistant to various antimicrobials. Resistance to rifampicin was not caused by mutations in the rpoB gene. Conclusions: To the best of our knowledge, this study is the first study reporting a broad, and diverse bacteria flora of skin, gill, and gut of the South African dusky kob as well as the first study on human pathogenic vibrios, and MRSA from marine finfish especially those from recirculatory aquaculture systems. Also, our study revealed that Vibrio species with pathogenic potential are present in marine dusky kob and its environs. Dusky kob is contaminated with CA- MRSA and HA- MRSA that may cause difficult to treat infections with regular antibiotics. Some of the MRSA strains contained toxins that can cause food-borne gastroeneteritis. The present study revealed that MRSA and Vibrio species are potential reservoirs for antibiotic resistant genes, which could be disseminated to other bacterial species probably through plasmids, a public health risk.
- Full Text:
- Date Issued: 2017
- Authors: Justine, Fri
- Date: 2017
- Subjects: Marine microbiology Marine microbiology--South Africa--Eastern Cape Staphylococcus aureus infections--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/16047 , vital:40607
- Description: Introduction: Marine finfish including dusky kob (Agyrosomus japonicus), in addition to its high protein value, is bestowed with numerous health benefits including being heart friendly due to high proportion of omega 3 fatty acids. They are therefore used as powerful preventive measures against cardiovaslcular diseases. They are also important in neurological development during gestation and infancy, thus a regular recommendation by nutritionists. However, fish and its environment may be contaminated by bacteria pathogens. Human infections caused by members of the genus Vibrio, and Staphylococcus especially Methicillin-resistant S. aureus (MRSA) are of increased concern worldwide especially with increased Vibrio disease outbreaks and rapid spread of MRSA in the community. Methicillin-resistant Staphylococcus aureus is regarded as an emerging zoonotic agent, therefore marine fish may be considered as a reservoir for infection. The emergence of multi-drug resistant organisms in both farm animals and humans has also been a challenge that hurdles chemotherapy worldwide. Methods: We enumerated the bacteria flora of skin, gill and gut of marine dusky kob (Agyrosomus japonicus) raised in a recirculatory aquaculture system using metagenomic sequencing of the 16S rRNA. We further screened 120 dusky kob fishes (skin, gill and gut) and 80 water samples from two fish farms and Kariega estuary collected over a 10 month period for human pathogenic vibrios, and MRSA using standard procedures. Vibrio species were further subjected to species specific PCRs delineating them into V. cholerae, V. parahaemolyticus, V. vulnificus, and V. fluvialis. This was followed by elucidation of the genotypic virulence determinants. The Reverse Fragment Length Polymorphism (RFLP) of the cytotoxin hemolysin (vvhA) gene of V. vulnificus strains was carried out to determine the associated biotypes. A total of 277 Vibrio strains consisting of 126 V. fluvialis, 45 Vibrio vulnificus, 30 V. parahaemolyticus and 76 vibrios belonging to other species were subjected to susceptibility testing to 15 antibiotics by the disc diffusion method and resistant strains were further evaluated for their genotypic antimicrobial resistant determinants by polymerase chain reaction followed by plasmid profiling. For MRSA screening, we evaluated the reliability of cefoxitin disc diffusion, oxacillin screen agar and BrillianceTM MRSA 2 agar tests, in detecting methicillin resistance from fish (environmental) samples using PCR detection of the mecA as the gold standard. A total of 33 mecA positive S. aureus strains (MRSA) were subjected to PCR detection of enterotoxins (Staphylococcal enterotoxin A-E) and Panton Valentine Leucocidin (PVL) encoding genes. The SCCmec types were also investigated by multiplex PCR targeting genes encoding type I-V. The antibiogram profiles of MRSA strains to 12 antibiotics by the disc diffusion method and to vancomycin by broth micro dilution method were elucidated. Polymerase chain reaction was employed to evaluate the presence of antibiotic resistant genes. The nucleotide sequences of the rpoB gene were analysed to determine mutations that could lead to rifampicin resistance. Results: A broad diversity of pathogenic and non-pathogenic bacterial species of different taxonomic groups was observed with Proteobacteria revealed as the most common bacteria phyla. Fifty one families were identified with Enterobacteriaceae the most frequently detected in all the anatomical sites and the gut showing the highest species diversity. A total of 606 (60.23 percent ) presumptive Vibrio isolates were confirmed by PCR of which V. fluvialis was the most predominant, 193 (31.85 percent ). This was followed by Vibrio vulnificus 74 (12.21 percent ), and V. parahaemolyticus 33 (5.45 percent ). No V. cholerae strain was detected. Only one of the V. parahaemolyticus strains possessed the trh virulent gene with no tdh detected. Virulence factors of V. fluvialis detected were stn (13.5 percent ), hupO (10.4 percent ), and vfpA (1.0 percent ). V. vulnificus biotype 3, formerly restricted to Isreal was identified. Generally, resistance among Vibrio isolates varied considerably with highest resistances recorded to amoxicillin (76.2 percent ), ampicillin (67.5 percent ), erythromycin (38.3 percent ), and doxycycline (35.0 percent ) while higher susceptibilities were revealed by gentamicin (100 percent ), norfloxacin (97.8 percent ), florfenicol (90.3 percent ), tetracycline (87.7 percent ), and chloramphenicol (87.4 percent ). Multiple antibiotic resistance (MAR) (resistance to ≥ 2 classes of antibiotics) was 58.5 percent . The MAR index did not vary significantly between sites (P>0.05) and values of >0.20 were recorded in 40 percent (108/277) of all the isolates. The resistant genes ampC, blaOXA, tetA, tetM, dfr1, sul1, sul2, ermB, nptII and strA were detected in two or more Vibrio isolates while the SXT intergrase was detected only in one isolate. Seven of the 18 extreme drug resistant isolates possessed 1–3 plasmids of 1.5–10 kb range. A total of 321 presumptive Staphylococcus aureus isolates were recovered by culture out of which 202 (62.9 percent ) were identified as S. aureus by PCR. Of these, 33 (16.3 percent ) strains were mecA positive while the rest, 169 (83.7 percent ) were mecA negative. The sensitivity and specificity of MRSA detection by use of cefoxitin disc (30 μg) test was 93.9 percent and 91.7 percent , that for oxacillin screen agar test (6 μg/mL) was 81.8 percent and 92.3 percent while that of BrillianceTM MRSATM 2 agar was 87.9 percent and 94.1 percent respectively. Staphylococcal enterotoxin SEE was detected in 12.1 percent (4/33) of total strains followed by SEA 3.0 percent (1/33), and SEC 3.0 percent (1/33). SEB and SED were absent. Six of the isolates had the PVL gene, giving a prevalence of 18.2 percent . The most frequently detected SCCmec type was SCCmec type III (17/33; 51.5 percent ), closely followed by SCCmec subtype IVc (10/33; 30.3 percent ) and the least were SCCmec types I and II with only 3.0 percent (1/33) each. The rest four (4/33; 12.1 percent ) did not belong to any of the above types and were therefore considered to belong to other subtypes of SCCmec type IV not tested in the study. For antibiogram patterns, 12 (36.4 percent ) strains were resistant to doxycyline, 10 (30.3 percent ) to trimethroprim-sulfamethoxazole, 9 (27.3 percent ) to tetracycline and only 1 (3.0 percent ) strain was resistant to ciprofloxacin. Nineteen (57.6 percent ) of the MRSA strains had vancomycin MIC of ≤ 2 μg/mL, 4 (12.1 percent ) with MIC range of 4-8 μg/mL, and 10 (30.3 percent ) with values ≥ 16 μg/mL. Overall, 27 (91.percent) isolates showed simultaneous resistance to 3 or more antibiotics. The resistant genes tetM, tetA, ermB, BlaZ femA were detected in two or more strains resistant to various antimicrobials. Resistance to rifampicin was not caused by mutations in the rpoB gene. Conclusions: To the best of our knowledge, this study is the first study reporting a broad, and diverse bacteria flora of skin, gill, and gut of the South African dusky kob as well as the first study on human pathogenic vibrios, and MRSA from marine finfish especially those from recirculatory aquaculture systems. Also, our study revealed that Vibrio species with pathogenic potential are present in marine dusky kob and its environs. Dusky kob is contaminated with CA- MRSA and HA- MRSA that may cause difficult to treat infections with regular antibiotics. Some of the MRSA strains contained toxins that can cause food-borne gastroeneteritis. The present study revealed that MRSA and Vibrio species are potential reservoirs for antibiotic resistant genes, which could be disseminated to other bacterial species probably through plasmids, a public health risk.
- Full Text:
- Date Issued: 2017
Determinants of smallholder vegetable farmers' participation on post-harvest practices and market access : evidence from Mashonaland East Province of Zimbabwe
- Authors: Mukarumbwa, Peter
- Date: 2017
- Subjects: Farms, Small -- Zimbabwe Vegetables -- Zimbabwe -- Marketing Vegetable trade -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8703 , vital:33431
- Description: Smallholder vegetable production is very vital in enhancing livelihoods in Zimbabwe’s rural areas. Vegetable production generates household income and improves household food security. Despite this, smallholder vegetable farmers in Zimbabwe suffer huge post-harvest losses which reduce their profits and market competiveness. Post-harvest losses of vegetables are a major dilemma faced by smallholder farmers. They not only represent waste of scare resources such as farm inputs but they also entail wasted investment in terms of time, human effort and food. Furthermore, there are also a myriad of other challenges which constrain smallholder vegetable farmers in Zimbabwe from accessing lucrative markets. The broad objective of the study was to assess smallholder vegetable farmers` preferred post-harvest practices for value addition as well as factors that condition their selection choices, adoption and product market access. The study was conducted in four districts: Seke, Goromonzi, Murehwa and Mutoko, in the Mashonaland East Province of Zimbabwe. A multistage sampling procedure was adopted in the selection of villages and households. A total of 385 smallholder vegetable farmers were interviewed. The survey was undertaken from August–October 2016. Descriptive statistics were employed to analyse the socio-economic and demographic characteristics of households that were sampled in Mashonaland East Province. Age of household head, gender, educational level, household size, farming experience, main sources of income, land ownership, main vegetables produced and main causes of post-harvest losses were some of the statistics that were analysed. The average age of the farmers varied significantly across districts and it was generally high (average of 50 years). Moreover, the average household size was about six (6) individuals, which is an indication of high dependency ratio. The study also revealed the major causes of post-harvest losses across all vegetables predominantly cultivated in the study area were pests and diseases, followed by decay. Most of the underlying causes of huge post-harvest losses were within the control of the farmer. Therefore, the study recommends strategies from policymakers and Non-Governmental Organisations (NGOs) which enhance post-harvest management. These can result in substantial reduction in losses which can increase farmers’ income without necessarily expanding land under cultivation. The Poisson count regression model (PCRM) was used to analyse factors influencing number of post-harvest techniques adopted by smallholder vegetable farmers in the study area. The results of the PCRM revealed that the following variables were significant in influencing number of post-harvest practices adopted by smallholder vegetable growers: gender, education level, household size, age, farming experience, distance to market, market information, group membership, credit, and hired labour. The study recommends concerted efforts through public private partnerships (PPP) to provide active extension about post-harvest education. This will promote the adoption of simple, uncomplicated and innovative low-cost technologies for post-harvest management. The binary logit model was employed to analyse factors that influence smallholder vegetable farmers’ decisions to select a specific post-harvest practice for value addition. This was based on the three major post-harvest practices which were mainly being adopted by smallholder vegetable farmers’ in the study area which were drying, grading and washing. The results of the binary model showed that nine (9) variables were significant in influencing smallholder vegetable farmers’ decisions to select post-harvest practice for value addition. These were: gender, land size, distance to market, market information, family labour, training, target market, quantity produced and storage facilities. Policymakers and other stakeholders need to provide productive resources such as inputs to improve productivity and ultimately selection of basic post-harvest management techniques along the vegetable supply chain. The multinomial logit model was used in the study to analyse factors that influence market channel choice of smallholder vegetable farmers in the study area. The results from the multinomial logistic regression model revealed that distance to market, group membership, adding value, road infrastructure and quantity produced influenced participation in informal markets. On the other hand, gender, distance to market, market information, group membership, producer price, adding value, road infrastructure, quantity produced and market infrastructure influenced farmers’ participation in formal markets. Policies aimed at assisting resources for improved productivity of vegetables should be gender sensitive. Establishment of irrigation schemes as well as provision of credit for smallholder vegetable production are vital interventions. In the same way, crafting of appropriate policies and programmes which foster collective action amongst smallholder vegetable farmers are required. This will enable them to produce larger volumes as well as participate in more lucrative markets. Finally, smallholder vegetable farmers’ transaction costs can be reduced by investment in infrastructure such as roads.
- Full Text:
- Date Issued: 2017
- Authors: Mukarumbwa, Peter
- Date: 2017
- Subjects: Farms, Small -- Zimbabwe Vegetables -- Zimbabwe -- Marketing Vegetable trade -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8703 , vital:33431
- Description: Smallholder vegetable production is very vital in enhancing livelihoods in Zimbabwe’s rural areas. Vegetable production generates household income and improves household food security. Despite this, smallholder vegetable farmers in Zimbabwe suffer huge post-harvest losses which reduce their profits and market competiveness. Post-harvest losses of vegetables are a major dilemma faced by smallholder farmers. They not only represent waste of scare resources such as farm inputs but they also entail wasted investment in terms of time, human effort and food. Furthermore, there are also a myriad of other challenges which constrain smallholder vegetable farmers in Zimbabwe from accessing lucrative markets. The broad objective of the study was to assess smallholder vegetable farmers` preferred post-harvest practices for value addition as well as factors that condition their selection choices, adoption and product market access. The study was conducted in four districts: Seke, Goromonzi, Murehwa and Mutoko, in the Mashonaland East Province of Zimbabwe. A multistage sampling procedure was adopted in the selection of villages and households. A total of 385 smallholder vegetable farmers were interviewed. The survey was undertaken from August–October 2016. Descriptive statistics were employed to analyse the socio-economic and demographic characteristics of households that were sampled in Mashonaland East Province. Age of household head, gender, educational level, household size, farming experience, main sources of income, land ownership, main vegetables produced and main causes of post-harvest losses were some of the statistics that were analysed. The average age of the farmers varied significantly across districts and it was generally high (average of 50 years). Moreover, the average household size was about six (6) individuals, which is an indication of high dependency ratio. The study also revealed the major causes of post-harvest losses across all vegetables predominantly cultivated in the study area were pests and diseases, followed by decay. Most of the underlying causes of huge post-harvest losses were within the control of the farmer. Therefore, the study recommends strategies from policymakers and Non-Governmental Organisations (NGOs) which enhance post-harvest management. These can result in substantial reduction in losses which can increase farmers’ income without necessarily expanding land under cultivation. The Poisson count regression model (PCRM) was used to analyse factors influencing number of post-harvest techniques adopted by smallholder vegetable farmers in the study area. The results of the PCRM revealed that the following variables were significant in influencing number of post-harvest practices adopted by smallholder vegetable growers: gender, education level, household size, age, farming experience, distance to market, market information, group membership, credit, and hired labour. The study recommends concerted efforts through public private partnerships (PPP) to provide active extension about post-harvest education. This will promote the adoption of simple, uncomplicated and innovative low-cost technologies for post-harvest management. The binary logit model was employed to analyse factors that influence smallholder vegetable farmers’ decisions to select a specific post-harvest practice for value addition. This was based on the three major post-harvest practices which were mainly being adopted by smallholder vegetable farmers’ in the study area which were drying, grading and washing. The results of the binary model showed that nine (9) variables were significant in influencing smallholder vegetable farmers’ decisions to select post-harvest practice for value addition. These were: gender, land size, distance to market, market information, family labour, training, target market, quantity produced and storage facilities. Policymakers and other stakeholders need to provide productive resources such as inputs to improve productivity and ultimately selection of basic post-harvest management techniques along the vegetable supply chain. The multinomial logit model was used in the study to analyse factors that influence market channel choice of smallholder vegetable farmers in the study area. The results from the multinomial logistic regression model revealed that distance to market, group membership, adding value, road infrastructure and quantity produced influenced participation in informal markets. On the other hand, gender, distance to market, market information, group membership, producer price, adding value, road infrastructure, quantity produced and market infrastructure influenced farmers’ participation in formal markets. Policies aimed at assisting resources for improved productivity of vegetables should be gender sensitive. Establishment of irrigation schemes as well as provision of credit for smallholder vegetable production are vital interventions. In the same way, crafting of appropriate policies and programmes which foster collective action amongst smallholder vegetable farmers are required. This will enable them to produce larger volumes as well as participate in more lucrative markets. Finally, smallholder vegetable farmers’ transaction costs can be reduced by investment in infrastructure such as roads.
- Full Text:
- Date Issued: 2017
Development of conservation strategies for Alepidea Amatymbica ECKL. & ZEYH. : a rare medicinal plant in the Eastern Cape, South Africa
- Mangoale, Ramatsobane Maureen
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017
Effects of Vigna unguiculata and Lablab purpureus on methanogenesis, haematological parameters and the quality of meat from Xhosa Lop Ear goats
- Authors: Washaya, Soul
- Date: 2017
- Subjects: Legumes Forage Forage plants
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/9996 , vital:35249
- Description: The objective of the current study was to evaluate the nutritive value of forage legumes Lablab purpureus (Lablab) and Vigna unguiculata (Cowpea) and their effects on intake, growth, blood parameters and meat quality in Xhosa goats. Forages were established at UFH research farm in the summer of the 2014 /15 growing season in blocks measuring 8m width x 16m long for each legume, replicated three times, making a total of four blocks, and eight treatment units for each legume. Samples were collected at three different stages of growth of preanthesis, anthesis and post anthesis for biomass yield determination. A homogenous sub-sample was then oven dried for 72 hours at 60 0C. After drying the forage samples were milled through a 1mm screen and a 20g sample from each stage of growth and forage sample was subjected to proximate analysis, in-vitro digestibility and anti-nutrient evaluation. The in-vitro digestibility experiment was done with rumen liquor of cattle and sheep collected from an abbatoir. Tannins, total phenolics and sapponins were the only anti-nutrients evaluated as they are perceived to influence methanogenesis in ruminat animals. At 50percent flowering, forage legumes were harvested for hay making which was then used in an in-vivo trial to evaluate the nutritive value of forages. This trial was conducted using eighteen one-year-old goats of average weight 14.2±0.24 kg over a period of sixty days. The results showed that biomass yield, which increased with stage of growth, was significantly higher (P < 0.05) for Lablab than Cowpea (7.968t/ha vs 7.105t/ha). Cowpea exhibited higher moisture content (7.72percent), Ash (13.11percent), acid detergent fibre (ADF) (38.42percent) and crude protein (CP) (20.23percent) than Lablab which had 7.50percent, 11.45 percent, 36.17percent and 19percent, respectively. Lablab forage had significantly higher (P < 0.05) fat content (2.41percent), neutral detergent fibre (NDF) (49.27percent) and hemicellulose (13.07percent) than Cowpea which had 2.1percent; 46.91percent and 8.48percent, respectively. The stage of growth significantly (P < 0.05) affected the mineral content of both forages. Lablab showed significantly higher (P < 0.05) values (1.22percent 0.55percent, 2.67percent) than Cowpea (1.00percent, 0.45percent, 2.30percent) for calcium (Ca), phosphorus (P), and potassium (K) respectively. Lablab forage had significantly higher (P < 0.05) tannin (3.345mgCAE/gDM), phenolic (13.47mgGAE/gDM) and saponin (0.75percent) content compared to Cowpea with values of 1.494mgCAEg/DM; 9.402mgGAE/gDM and vs 1.55percent respectively. The tannin content significantly influenced in-vitro digestibility and enteric methane production. The forage type, harvesting stage and inoculum source significantly (P < 0.05) affected the in-vitro digestibility of the forages. The in-vitro dry matter (IVDM) and in-vitro organic matter (IVOM) digestibility was significantly higher (P < 0.05) for Lablab (41.13percent; 39.63percent) than Cowpea (39.86percent; 19.44percent), respectively. Both forages recorded higher dry matter (DM) digestibility coefficients at anthesis stage of growth 61.58percent, and 51.5 percent for Lablab and Cowpea respectively. The IVOM digestibility increased with stage of harvest (23.7percent to 25.57percent) for Cowpea while Lablab showed a decrease (44.6 percent to 43.9percent) when cattle inoculum was used. The IVDM digestibility was higher (P < 0.05) for Lablab (50.5percent) when cattle inoculum was used while Cowpea was observed to have higher digestibility co-efficiencies (38.54percent) when sheep inoculum was used. Cowpea had lower (P < 0.05) IVOM digestibility than Lablab (19.44percent) vs. 39.6percent). Lablab exhibited higher (P < 0.05) metabolisable energy (ME) values than Cowpea (6.21 vs. 2.70 MJ/kgDM). In the feeding study, the total DM intake by goats for Lablab was higher (P < 0.05) compared to Cowpea (688.1 vs. 607.8 g/head/ day). There was a positive (P < 0.05) correlation between dry matter intake and average daily gain (r= 0.8513, and r=0.5279) for Cowpea and Lablab respectively. Lablab and Cowpea promoted growth of Xhosa goats at a rate of 35.0g/d; and 38.3g/d, respectively which was not significantly different (P > 0.05). However, this growth was associated with a significantly higher (P < 0.05) food conversion ratio (FCR) of 19.16 vs 18.11 for Cowpea and Lablab, respectively. The apparent DM, non structural carbohydrate (NSC) nutrient digestibilities were significantly different (P < 0.05) for Lablab and Cowpea. Furthermore sex of animal influenced significantly (P < 0.05) the DM, ADF, NSC and NDF digestibilities. Lablab and Cowpea did not influence (P > 0.05) individual VFA molar concentrations in both sexes. However, animals fed Lablab had significantly higher butyrate concentrations (P < 0.05). Lablab and Cowpea forages significantly lowered (P > 0.05) enteric methane production in goats compared to a concentrate diet, and this was related to animal activity. Animals produced significantly more (P < 0.05) methane gas when ruminating than feeding or just standing. The average methane produced each year was lower but not significant (P > 0.05) for animals fed Cowpea than Lablab (4.602kg CH4, vs. 4.719kg CH4) when expressed per year. Male animals produced more gas than females with values of 17.40L/day; 12.46 g/kg DMI and 0.126g/day vs. 15.47L/day, 12.28 g/kg DMI, and 0.0109g/day, respectively. Forage legumes had no significant effects (P > 0.05) on serum total proteins (TP), globulin, urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma- glutamyl transferase (GGT) concentrations, but serum concentration of albumin was influenced by the diets (P < 0.05). Sex of animals significantly influenced ALP concentration (P < 0.05) with male animals exhibiting higer ALP values than females. Measured over time, the plasma concentration of urea and ALP significantly increased (P < 0.05) while creatinine and cholesterol concentration decreased (P < 0.05). Although the overall serum concentration of urea, total proteins, globulin, creatinine, ALT, ALP and GGT remained unchanged among the treatments and between sexes; treatment by sex, treatment by day and sex by day interactions were significant (P < 0.05). The white blood cell (WBC), red blood cell (RBC), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), haemoglobin, haematocrite, platelet and mean platelet volume (MPV) levels were similar among treatments and between sexes (P > 0.05). The WBC decreased with time by 8.07 x10 9/l while mean crepuscular volume (MCV) increased by 11.83(fl) from day 15 to day 55. Treatment diets significantly (P < 0.05) influenced neutrophile (percent) content while sex influenced basophile (percent) content. There were no treatment or sex effects (P > 0.05) on lymphocytes (percent), monocytes (percent) and eosinophiles (percent). In the meat quality study, the dietary treatments and sex had a significant (P < 0.05) effect on dressing out percent (DPpercent), initial pH, redness (a*), yellowness (b*), Warner Blartze Shear force (WBS) , drip loss and cooking loss in the chevon from Xhosa goats. Compared with a commercial pellet diet, Lablab and Cowpea diets resulted in similar slaughter body weights (SBW), hot carcass weight (HCW) and cold dressed mass (CDM) of carcasses. However, female animals exhibited a significantly (P < 0.05) higher DPpercent than male animals (42.3percent vs. 38.9percent) for all treatments. The male animals exhibited significantly (P < 0.05) higher pH values one hour after slaughter than females (5.79 vs 5.67). Neverthreless the diet and gender did not significantly (P > 0.05) affect the ultimate pH (pHu). Meat samples from male animals had significantly (P < 0.05) higher redness values than females. Feeding cowpea significantly (P < 0.05) increased meat redness with the least drip loss of chevon. Female animals produced significantly (P < 0.05) tougher chevon compared to male animals; 4.16kg and 3.36kg for female and male, respectively. Lablab and Cowpea posses high CP levels and moderately lower NDF with high ADF values that influences dry matter intake (DMI), digestibility and growth of goats. These forage legumes meet animal requirements for fat, ADF, NDF, CP, Ca, Mn, zinc and Cu and their biomass yield is satisfactory.
- Full Text:
- Date Issued: 2017
- Authors: Washaya, Soul
- Date: 2017
- Subjects: Legumes Forage Forage plants
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/9996 , vital:35249
- Description: The objective of the current study was to evaluate the nutritive value of forage legumes Lablab purpureus (Lablab) and Vigna unguiculata (Cowpea) and their effects on intake, growth, blood parameters and meat quality in Xhosa goats. Forages were established at UFH research farm in the summer of the 2014 /15 growing season in blocks measuring 8m width x 16m long for each legume, replicated three times, making a total of four blocks, and eight treatment units for each legume. Samples were collected at three different stages of growth of preanthesis, anthesis and post anthesis for biomass yield determination. A homogenous sub-sample was then oven dried for 72 hours at 60 0C. After drying the forage samples were milled through a 1mm screen and a 20g sample from each stage of growth and forage sample was subjected to proximate analysis, in-vitro digestibility and anti-nutrient evaluation. The in-vitro digestibility experiment was done with rumen liquor of cattle and sheep collected from an abbatoir. Tannins, total phenolics and sapponins were the only anti-nutrients evaluated as they are perceived to influence methanogenesis in ruminat animals. At 50percent flowering, forage legumes were harvested for hay making which was then used in an in-vivo trial to evaluate the nutritive value of forages. This trial was conducted using eighteen one-year-old goats of average weight 14.2±0.24 kg over a period of sixty days. The results showed that biomass yield, which increased with stage of growth, was significantly higher (P < 0.05) for Lablab than Cowpea (7.968t/ha vs 7.105t/ha). Cowpea exhibited higher moisture content (7.72percent), Ash (13.11percent), acid detergent fibre (ADF) (38.42percent) and crude protein (CP) (20.23percent) than Lablab which had 7.50percent, 11.45 percent, 36.17percent and 19percent, respectively. Lablab forage had significantly higher (P < 0.05) fat content (2.41percent), neutral detergent fibre (NDF) (49.27percent) and hemicellulose (13.07percent) than Cowpea which had 2.1percent; 46.91percent and 8.48percent, respectively. The stage of growth significantly (P < 0.05) affected the mineral content of both forages. Lablab showed significantly higher (P < 0.05) values (1.22percent 0.55percent, 2.67percent) than Cowpea (1.00percent, 0.45percent, 2.30percent) for calcium (Ca), phosphorus (P), and potassium (K) respectively. Lablab forage had significantly higher (P < 0.05) tannin (3.345mgCAE/gDM), phenolic (13.47mgGAE/gDM) and saponin (0.75percent) content compared to Cowpea with values of 1.494mgCAEg/DM; 9.402mgGAE/gDM and vs 1.55percent respectively. The tannin content significantly influenced in-vitro digestibility and enteric methane production. The forage type, harvesting stage and inoculum source significantly (P < 0.05) affected the in-vitro digestibility of the forages. The in-vitro dry matter (IVDM) and in-vitro organic matter (IVOM) digestibility was significantly higher (P < 0.05) for Lablab (41.13percent; 39.63percent) than Cowpea (39.86percent; 19.44percent), respectively. Both forages recorded higher dry matter (DM) digestibility coefficients at anthesis stage of growth 61.58percent, and 51.5 percent for Lablab and Cowpea respectively. The IVOM digestibility increased with stage of harvest (23.7percent to 25.57percent) for Cowpea while Lablab showed a decrease (44.6 percent to 43.9percent) when cattle inoculum was used. The IVDM digestibility was higher (P < 0.05) for Lablab (50.5percent) when cattle inoculum was used while Cowpea was observed to have higher digestibility co-efficiencies (38.54percent) when sheep inoculum was used. Cowpea had lower (P < 0.05) IVOM digestibility than Lablab (19.44percent) vs. 39.6percent). Lablab exhibited higher (P < 0.05) metabolisable energy (ME) values than Cowpea (6.21 vs. 2.70 MJ/kgDM). In the feeding study, the total DM intake by goats for Lablab was higher (P < 0.05) compared to Cowpea (688.1 vs. 607.8 g/head/ day). There was a positive (P < 0.05) correlation between dry matter intake and average daily gain (r= 0.8513, and r=0.5279) for Cowpea and Lablab respectively. Lablab and Cowpea promoted growth of Xhosa goats at a rate of 35.0g/d; and 38.3g/d, respectively which was not significantly different (P > 0.05). However, this growth was associated with a significantly higher (P < 0.05) food conversion ratio (FCR) of 19.16 vs 18.11 for Cowpea and Lablab, respectively. The apparent DM, non structural carbohydrate (NSC) nutrient digestibilities were significantly different (P < 0.05) for Lablab and Cowpea. Furthermore sex of animal influenced significantly (P < 0.05) the DM, ADF, NSC and NDF digestibilities. Lablab and Cowpea did not influence (P > 0.05) individual VFA molar concentrations in both sexes. However, animals fed Lablab had significantly higher butyrate concentrations (P < 0.05). Lablab and Cowpea forages significantly lowered (P > 0.05) enteric methane production in goats compared to a concentrate diet, and this was related to animal activity. Animals produced significantly more (P < 0.05) methane gas when ruminating than feeding or just standing. The average methane produced each year was lower but not significant (P > 0.05) for animals fed Cowpea than Lablab (4.602kg CH4, vs. 4.719kg CH4) when expressed per year. Male animals produced more gas than females with values of 17.40L/day; 12.46 g/kg DMI and 0.126g/day vs. 15.47L/day, 12.28 g/kg DMI, and 0.0109g/day, respectively. Forage legumes had no significant effects (P > 0.05) on serum total proteins (TP), globulin, urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma- glutamyl transferase (GGT) concentrations, but serum concentration of albumin was influenced by the diets (P < 0.05). Sex of animals significantly influenced ALP concentration (P < 0.05) with male animals exhibiting higer ALP values than females. Measured over time, the plasma concentration of urea and ALP significantly increased (P < 0.05) while creatinine and cholesterol concentration decreased (P < 0.05). Although the overall serum concentration of urea, total proteins, globulin, creatinine, ALT, ALP and GGT remained unchanged among the treatments and between sexes; treatment by sex, treatment by day and sex by day interactions were significant (P < 0.05). The white blood cell (WBC), red blood cell (RBC), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), haemoglobin, haematocrite, platelet and mean platelet volume (MPV) levels were similar among treatments and between sexes (P > 0.05). The WBC decreased with time by 8.07 x10 9/l while mean crepuscular volume (MCV) increased by 11.83(fl) from day 15 to day 55. Treatment diets significantly (P < 0.05) influenced neutrophile (percent) content while sex influenced basophile (percent) content. There were no treatment or sex effects (P > 0.05) on lymphocytes (percent), monocytes (percent) and eosinophiles (percent). In the meat quality study, the dietary treatments and sex had a significant (P < 0.05) effect on dressing out percent (DPpercent), initial pH, redness (a*), yellowness (b*), Warner Blartze Shear force (WBS) , drip loss and cooking loss in the chevon from Xhosa goats. Compared with a commercial pellet diet, Lablab and Cowpea diets resulted in similar slaughter body weights (SBW), hot carcass weight (HCW) and cold dressed mass (CDM) of carcasses. However, female animals exhibited a significantly (P < 0.05) higher DPpercent than male animals (42.3percent vs. 38.9percent) for all treatments. The male animals exhibited significantly (P < 0.05) higher pH values one hour after slaughter than females (5.79 vs 5.67). Neverthreless the diet and gender did not significantly (P > 0.05) affect the ultimate pH (pHu). Meat samples from male animals had significantly (P < 0.05) higher redness values than females. Feeding cowpea significantly (P < 0.05) increased meat redness with the least drip loss of chevon. Female animals produced significantly (P < 0.05) tougher chevon compared to male animals; 4.16kg and 3.36kg for female and male, respectively. Lablab and Cowpea posses high CP levels and moderately lower NDF with high ADF values that influences dry matter intake (DMI), digestibility and growth of goats. These forage legumes meet animal requirements for fat, ADF, NDF, CP, Ca, Mn, zinc and Cu and their biomass yield is satisfactory.
- Full Text:
- Date Issued: 2017
Enhancing productivity and market participation for poverty reduction and shared prosperity in South Africa
- Authors: Avuletey, Richard
- Date: 2017
- Subjects: Poverty -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13978 , vital:39736
- Description: There have been several attempts by the South Africa government to improve the agricultural productivity on smallholder farms since the end of apartheid. In spite of the government support, agricultural productivity has stagnated for several years across the Eastern Cape rural communities including Mthatha and Qamata. The aim of this study was to understand the roles played by irrigation adoption and market participation in addressing poverty reduction and shared prosperity levels of smallholder farmers in Eastern Cape of South Africa. Data were collected using purposive and random sampling approach through the use of the snowball method. To collect data, a questionnaire was designed and administered through face-to-face interviews. Overall, 200 farmers were interviewed both at Mthatha and Qamata irrigation scheme to represent the farmers in the area. The collected data were analysed using both parametric and non-parametric methods. The non-parametric methods used include descriptive analysis, estimation of gross margins as a proxy for profitability. The Stochastic Frontier Analysis (SFA), Binomial Logistic Regression (BLR), Ordinary Least Squares (OLS), tobit censored regression and propensity score matching (PSM) were the parametric methods used in the study. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (Cobb-douglas). Stochastic Production Frontier (SPF) technique was used to determine the technical efficiency of individual farmers and to identify the major factors that influence technical efficiency. Binomial logistic regression was used to determine factors affecting irrigation adoption and market participation among smallholder farmers. OLS was used to estimate the impact of institutional characteristics, socio-economic and agronomic factors on smallholder farmers’ level of market participation for selected crop enterprises. Lastly, tobit regression and propensity score matching (PSM) analyses were used to estimate the impact of irrigation technology adoption on poverty reduction in the province. The results of the descriptive statistics of the overall sample revealed an average age of 61 years, and mean household size of 4.6 persons with majority of the household head having at least obtained some primary school education (59.5percent). Most of the household heads interviewed were men (68.5percent). Most farmers are single (65percent) with regard to their marital status. Farming is viewed as major source of livelihood for smallholders with an average income of R12523.37 for overall sample and income of R15559.80 and R5795.59 per crop season, respectively, for irrigators and non irrigators. Smallholder irrigators generated a higher gross margin of R7585.26, R21966.89 and R6266.07 from maize, cabbage and potato enterprises, respectively, compared to their non irrigator counterparts in maize (R131.39), cabbage (R10938.04) and potato (R3433.31) enterprises. The results of the frontier profit model revealed mean profit efficiency of 90percent, 99.99percent and 99.99percent, respectively, for maize, cabbage and potato.The binary logistic regression model for irrigation adoption indicated that years in school, cooperative membership, off-farm income, credit access and distance to market significantly explain smallholder farmers’ irrigation adoption decision. On the other hand, age of household head, market support, farm size, livestock income and distance to market were the key variables that accounted for smallholder farmers’ market participation adoption behaviour. The findings from the stochastic production frontier (SPF) indicate that smallholder farmers are technically efficient in maize and cabbage enterprises both at 99.99percent. Lastly, the findings from the Tobit regression and propensity score matching are consistent across the two methods, suggesting that being a member of irrigation adoption has a positive significant impact on income of smallholder farmers. Irrigation and market participation appear to have a significant and positive impact on smallholder poverty reduction (measured by crop income) for those farmers engaged in them. The findings from this study provide useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of irrigation technology and market participation.
- Full Text:
- Date Issued: 2017
- Authors: Avuletey, Richard
- Date: 2017
- Subjects: Poverty -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13978 , vital:39736
- Description: There have been several attempts by the South Africa government to improve the agricultural productivity on smallholder farms since the end of apartheid. In spite of the government support, agricultural productivity has stagnated for several years across the Eastern Cape rural communities including Mthatha and Qamata. The aim of this study was to understand the roles played by irrigation adoption and market participation in addressing poverty reduction and shared prosperity levels of smallholder farmers in Eastern Cape of South Africa. Data were collected using purposive and random sampling approach through the use of the snowball method. To collect data, a questionnaire was designed and administered through face-to-face interviews. Overall, 200 farmers were interviewed both at Mthatha and Qamata irrigation scheme to represent the farmers in the area. The collected data were analysed using both parametric and non-parametric methods. The non-parametric methods used include descriptive analysis, estimation of gross margins as a proxy for profitability. The Stochastic Frontier Analysis (SFA), Binomial Logistic Regression (BLR), Ordinary Least Squares (OLS), tobit censored regression and propensity score matching (PSM) were the parametric methods used in the study. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (Cobb-douglas). Stochastic Production Frontier (SPF) technique was used to determine the technical efficiency of individual farmers and to identify the major factors that influence technical efficiency. Binomial logistic regression was used to determine factors affecting irrigation adoption and market participation among smallholder farmers. OLS was used to estimate the impact of institutional characteristics, socio-economic and agronomic factors on smallholder farmers’ level of market participation for selected crop enterprises. Lastly, tobit regression and propensity score matching (PSM) analyses were used to estimate the impact of irrigation technology adoption on poverty reduction in the province. The results of the descriptive statistics of the overall sample revealed an average age of 61 years, and mean household size of 4.6 persons with majority of the household head having at least obtained some primary school education (59.5percent). Most of the household heads interviewed were men (68.5percent). Most farmers are single (65percent) with regard to their marital status. Farming is viewed as major source of livelihood for smallholders with an average income of R12523.37 for overall sample and income of R15559.80 and R5795.59 per crop season, respectively, for irrigators and non irrigators. Smallholder irrigators generated a higher gross margin of R7585.26, R21966.89 and R6266.07 from maize, cabbage and potato enterprises, respectively, compared to their non irrigator counterparts in maize (R131.39), cabbage (R10938.04) and potato (R3433.31) enterprises. The results of the frontier profit model revealed mean profit efficiency of 90percent, 99.99percent and 99.99percent, respectively, for maize, cabbage and potato.The binary logistic regression model for irrigation adoption indicated that years in school, cooperative membership, off-farm income, credit access and distance to market significantly explain smallholder farmers’ irrigation adoption decision. On the other hand, age of household head, market support, farm size, livestock income and distance to market were the key variables that accounted for smallholder farmers’ market participation adoption behaviour. The findings from the stochastic production frontier (SPF) indicate that smallholder farmers are technically efficient in maize and cabbage enterprises both at 99.99percent. Lastly, the findings from the Tobit regression and propensity score matching are consistent across the two methods, suggesting that being a member of irrigation adoption has a positive significant impact on income of smallholder farmers. Irrigation and market participation appear to have a significant and positive impact on smallholder poverty reduction (measured by crop income) for those farmers engaged in them. The findings from this study provide useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of irrigation technology and market participation.
- Full Text:
- Date Issued: 2017
Factor analysis for dtetermination of metabolic syndrome components of anthropometric data from Kinshasa hiterland of the Democractic Republic of Congo
- Authors: Nasila, John Sungwacha
- Date: 2017
- Subjects: Factor analysis Multivariate analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14032 , vital:39799
- Description: Factor analysis is a multivariate statistical approach commonly used in psychology, education, and more recently in the health-related professions. This thesis will attempt to provide novice and experienced researchers an application of two factor analysis methods which are; exploratory factor analysis (EFA) and Confirmatory Factor Analysis (CFA) to medical data. As Biostatistics knowledge continues to grow, it is timely that this thesis contributes immensely; firstly to the discipline of Biostatistics and secondly to Medicine both nationally and internationally. Factor analysis is an important tool that can be used in the development, refinement, and evaluation of tests, scales, and measures that can be used in education and in health-related professions such as medicine. This thesis is focused on applying Factor Analysis on medical data, specifically on data obtained from patients that suffer from Metabolic Syndrome and patients who don’t suffer from Metabolic Syndrome. Metabolic Syndrome (MS) is a constellation of components (factors) such as obesity, lipid-lipoprotein (fats) disorders, increase in glucose (sugar), hypertension (blood pressure), and inflammation/ hypercoagulability (clotting). MS and other risk factors; (smoking, physical inactivity, excessive alcohol intake, and inappropriate diet) determine high morbidity and mortality for the cardiovascular disease (CVD=heart attack, brain attack, peripheral vascular disease) or cardio-metabolic risk (CMR=type 2 diabetes, kidney disease, retinopathy). Obesity, CVD, and CMR are emerging as epidemic conditions worldwide. However, Africa is not paying priority to early detection, treatment, prevention and control of atherosclerotic diseases (MS, CMR) from valid and reliable data. The aim of this thesis was to examine anthropometry, glucose and blood pressure (non-lipid components of MS) as most valid, reliable, less time-consuming, less complex and less expensive procedure of identifying people at high risks of CVD and CMR. A further contribution of this thesis was its understanding of the economic implications of the burden of Metabolic Syndrome. Other burden factors have been identified and also discussed. The study has revealed that the presence of metabolic syndrome has contributed to an enormous economic burden by about 20percent of the total economic loss experienced by many countries. The prevalence has risen recently and elevated patients’ use of more health care resources, and face higher morbidity and mortality, resulting in an enormous economic burden. Some studies have shown healthcare costs to be as much as 20percent higher than those accrued by patients without the risk factors. Patients with the Metabolic Syndrome have been shown to have greater drug expenditures, more frequent hospitalizations, and higher utilization of outpatient and physician services. When considered alone, the individual risk factor components account for a substantial economic burden to patients, health plans, and society as a whole. Overall, this has had serious economic impacts on many countries. The diagnosis of Metabolic Syndrome as a condition may encourage appropriate management and thus help prevent disease progression and reduce the considerable economic impact. This study was a cross-sectional, comparative, and correlational survey conducted between January and April 2005, in Kinshasa Hinterland, DRC. Participants were black Bantu Africans. In this study, the researcher attempted to determine latent factors that could explain the variability in a large set of data collected on many individuals of mixed health statuses. The original population consisted of 9770 people of whom, only 977 (10percent) participated. Factor analysis and interpretation of the results were based on anthropometric parameters (body mass index or BMI and waist circumference or WC), blood pressure (BP), lipid (triglycerides)-lipoprotein (HDL-C) and glucose with different numbers and cutoffs of components of Metabolic Syndrome. A number of different statistical procedural methods have been employed to clearly scrutinize and bring out the information which is concealed in a variety of variables observed/collected on many human participants. A large portion of these approaches was based on multivariate statistical methods. The approach, in this case, was the application of Principal Component Analysis (PCA); a multivariate statistical approach used under Factor Analysis to reduce many variables into a few latent variables which are seen as capable of explaining the variability. The approach was effected under both conditions of presence and absence of metabolic risk. Other data settings were: within males, within females, in the rural and in urban communities.
- Full Text:
- Date Issued: 2017
- Authors: Nasila, John Sungwacha
- Date: 2017
- Subjects: Factor analysis Multivariate analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14032 , vital:39799
- Description: Factor analysis is a multivariate statistical approach commonly used in psychology, education, and more recently in the health-related professions. This thesis will attempt to provide novice and experienced researchers an application of two factor analysis methods which are; exploratory factor analysis (EFA) and Confirmatory Factor Analysis (CFA) to medical data. As Biostatistics knowledge continues to grow, it is timely that this thesis contributes immensely; firstly to the discipline of Biostatistics and secondly to Medicine both nationally and internationally. Factor analysis is an important tool that can be used in the development, refinement, and evaluation of tests, scales, and measures that can be used in education and in health-related professions such as medicine. This thesis is focused on applying Factor Analysis on medical data, specifically on data obtained from patients that suffer from Metabolic Syndrome and patients who don’t suffer from Metabolic Syndrome. Metabolic Syndrome (MS) is a constellation of components (factors) such as obesity, lipid-lipoprotein (fats) disorders, increase in glucose (sugar), hypertension (blood pressure), and inflammation/ hypercoagulability (clotting). MS and other risk factors; (smoking, physical inactivity, excessive alcohol intake, and inappropriate diet) determine high morbidity and mortality for the cardiovascular disease (CVD=heart attack, brain attack, peripheral vascular disease) or cardio-metabolic risk (CMR=type 2 diabetes, kidney disease, retinopathy). Obesity, CVD, and CMR are emerging as epidemic conditions worldwide. However, Africa is not paying priority to early detection, treatment, prevention and control of atherosclerotic diseases (MS, CMR) from valid and reliable data. The aim of this thesis was to examine anthropometry, glucose and blood pressure (non-lipid components of MS) as most valid, reliable, less time-consuming, less complex and less expensive procedure of identifying people at high risks of CVD and CMR. A further contribution of this thesis was its understanding of the economic implications of the burden of Metabolic Syndrome. Other burden factors have been identified and also discussed. The study has revealed that the presence of metabolic syndrome has contributed to an enormous economic burden by about 20percent of the total economic loss experienced by many countries. The prevalence has risen recently and elevated patients’ use of more health care resources, and face higher morbidity and mortality, resulting in an enormous economic burden. Some studies have shown healthcare costs to be as much as 20percent higher than those accrued by patients without the risk factors. Patients with the Metabolic Syndrome have been shown to have greater drug expenditures, more frequent hospitalizations, and higher utilization of outpatient and physician services. When considered alone, the individual risk factor components account for a substantial economic burden to patients, health plans, and society as a whole. Overall, this has had serious economic impacts on many countries. The diagnosis of Metabolic Syndrome as a condition may encourage appropriate management and thus help prevent disease progression and reduce the considerable economic impact. This study was a cross-sectional, comparative, and correlational survey conducted between January and April 2005, in Kinshasa Hinterland, DRC. Participants were black Bantu Africans. In this study, the researcher attempted to determine latent factors that could explain the variability in a large set of data collected on many individuals of mixed health statuses. The original population consisted of 9770 people of whom, only 977 (10percent) participated. Factor analysis and interpretation of the results were based on anthropometric parameters (body mass index or BMI and waist circumference or WC), blood pressure (BP), lipid (triglycerides)-lipoprotein (HDL-C) and glucose with different numbers and cutoffs of components of Metabolic Syndrome. A number of different statistical procedural methods have been employed to clearly scrutinize and bring out the information which is concealed in a variety of variables observed/collected on many human participants. A large portion of these approaches was based on multivariate statistical methods. The approach, in this case, was the application of Principal Component Analysis (PCA); a multivariate statistical approach used under Factor Analysis to reduce many variables into a few latent variables which are seen as capable of explaining the variability. The approach was effected under both conditions of presence and absence of metabolic risk. Other data settings were: within males, within females, in the rural and in urban communities.
- Full Text:
- Date Issued: 2017
Genetically modified (GM) maize cultivation by smallholders in the Eastern Cape Province of South Africa: Effects on target and non-target organisms and adoption challenges
- Authors: Kotey, Daniel Ashie
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Genetically modified foods -- South Africa -- Eastern Cape Corn -- Biotechnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5161 , vital:29092
- Description: The use of genetically modified (GM) maize technology is subject to compliance with stewardship requirements and the adoption of specific management practices that promote the long-term effectiveness and environmental sustainability of the technology. For smallholders to comply with these requirements and adopt the desired management practices to ultimately benefit from the technology, they require information that creates awareness of the value of these requirements. To determine what information farmers receive about GM maize and how this information is disseminated to farmers, face to face interviews were conducted with 81 extension personnel and 210 smallhoder GM maize farmers in the Eastern Cape Province of South Africa. The effect of Bt maize introduction and management practices in smallholder maize agroecosystems in the Eastern Cape on Bt maize target [Busseola fusca (Fuller) (Lepidoptera: Noctuidae)] and non-target insect pests [Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)] and a snail species, [Cornu aspersum (Müller) (Gastropoda: Helicidae)] was determined through laboratory, field and cage experiments. The effect of smallhoder farmers‟ GM maize cultivation practices on the profitability of GM maize technology was also determined through on-farm trials in different localities of the Eastern Cape identified as hot-spots for stem borer and weed infestation. Results of surveys indicated that extension personnel had a low level of awareness of GM maize technology stewardship requirements. GM maize technology was also largely disseminated to smallholder farmers through non-participatory approaches and print media sourced from GM seed companies. Although farmers had a high level of contact with extension services, they lacked access to information about GM maize technology. Smallholder farmers‟ level of awareness about GM maize and compliance with the requirement for the planting of non-Bt maize refuge areas adjacent to Bt maize was also very low. While Bt maize event (MON810) commonly cultivated by smallholder farmers in the Eastern Cape Province had a variable effect on A. segetum under laboratory conditions, it had no effect on the incidence of plants damaged by A. segetum and C. aspersum under field conditions. The incidence of H. armigera damage on Bt maize plants was however significantly affected by Bt maize. Populations of B. fusca collected from smallholder maize fields in the province were observed to be still highly susceptible to Bt maize. Results of on-farm evaluation of the profitability of GM maize revealed that stem borer pressure, growing conditions, input supplies and market access affect the productivity and profitability of GM maize cultivation. Challenges within the extension and advisory services of the Eastern Cape which can militate against smallholder farmers‟ ability to benefit from GM maize technology and sustain the long-term efficacy of the technology were identified during this study. Given these challenges and the fact that the cultivation of GM maize may not be profitable under typical smallholder maize cultivation conditions and management practices, dissemination approaches that provide farmers the opportunity to evaluate GM maize technology alongside alternate technologies under their conditions, may prove beneficial.
- Full Text:
- Date Issued: 2017
- Authors: Kotey, Daniel Ashie
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Genetically modified foods -- South Africa -- Eastern Cape Corn -- Biotechnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5161 , vital:29092
- Description: The use of genetically modified (GM) maize technology is subject to compliance with stewardship requirements and the adoption of specific management practices that promote the long-term effectiveness and environmental sustainability of the technology. For smallholders to comply with these requirements and adopt the desired management practices to ultimately benefit from the technology, they require information that creates awareness of the value of these requirements. To determine what information farmers receive about GM maize and how this information is disseminated to farmers, face to face interviews were conducted with 81 extension personnel and 210 smallhoder GM maize farmers in the Eastern Cape Province of South Africa. The effect of Bt maize introduction and management practices in smallholder maize agroecosystems in the Eastern Cape on Bt maize target [Busseola fusca (Fuller) (Lepidoptera: Noctuidae)] and non-target insect pests [Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)] and a snail species, [Cornu aspersum (Müller) (Gastropoda: Helicidae)] was determined through laboratory, field and cage experiments. The effect of smallhoder farmers‟ GM maize cultivation practices on the profitability of GM maize technology was also determined through on-farm trials in different localities of the Eastern Cape identified as hot-spots for stem borer and weed infestation. Results of surveys indicated that extension personnel had a low level of awareness of GM maize technology stewardship requirements. GM maize technology was also largely disseminated to smallholder farmers through non-participatory approaches and print media sourced from GM seed companies. Although farmers had a high level of contact with extension services, they lacked access to information about GM maize technology. Smallholder farmers‟ level of awareness about GM maize and compliance with the requirement for the planting of non-Bt maize refuge areas adjacent to Bt maize was also very low. While Bt maize event (MON810) commonly cultivated by smallholder farmers in the Eastern Cape Province had a variable effect on A. segetum under laboratory conditions, it had no effect on the incidence of plants damaged by A. segetum and C. aspersum under field conditions. The incidence of H. armigera damage on Bt maize plants was however significantly affected by Bt maize. Populations of B. fusca collected from smallholder maize fields in the province were observed to be still highly susceptible to Bt maize. Results of on-farm evaluation of the profitability of GM maize revealed that stem borer pressure, growing conditions, input supplies and market access affect the productivity and profitability of GM maize cultivation. Challenges within the extension and advisory services of the Eastern Cape which can militate against smallholder farmers‟ ability to benefit from GM maize technology and sustain the long-term efficacy of the technology were identified during this study. Given these challenges and the fact that the cultivation of GM maize may not be profitable under typical smallholder maize cultivation conditions and management practices, dissemination approaches that provide farmers the opportunity to evaluate GM maize technology alongside alternate technologies under their conditions, may prove beneficial.
- Full Text:
- Date Issued: 2017
Impact of formulated soil types on growth performance, phytochemical constituents and pharmacological properties of solanum nigurm L. : a wild vegetable in the Eastern Cape Province, South Africa
- Authors: Ogundola, Adijat Funke
- Date: 2017
- Subjects: Solanum Materia medica, Vegetable Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8758 , vital:33519
- Description: Solanum nigrum L. is a wild vegetable that is highly recognised for its high nutiritional and therapeutical purposes. However, proper identification of the plant is essential not only to plant scientists but to a wide range of users. Therefore, the plant’s roots, stems and leaves cultivated on different soil types were viewed under the Scanning Electron Microscope while the leaves were further viewed under the Light Microscope. significant increase was observed in densities of stomata, guard and subsidiary cells of leaves of S. nigrum grown on silty clay loam soil. The SEM analysis revealed abundant glandular and non-glandular trichromes on both surfaces of the leaves. The glandular trichome is known to be responsible for the storage of bioactive compounds for which this plant is well known. Cultivation was embarked upon, for the availability of the plant at all times. However, propagation was by seed alone, therefore, quality seed is necessary for cultivation. Study was carried out on seeds extracted from plants growing in the wild in Alice for the seed viability, germination and seedling emergence when subjected to different soil texture types and sowing depths. The seeds were 98.3 percent viable. Highest germination (94.66 percent) was recorded in sand paper scarification, 15, 20 and 25ºC. Continuous darkness and temperatures lower than 5ºC and higher than 35ºCwere detrimental to the seeds. Silty clay loam soil and a depth of 2 cm had the highest seedling emergence 90 percent and recommended as the ideal condition for seedlings emergence. The growth, yield and physiological response of S. nigrum to sandy clay loam, silty clay loam, clay loam, loam soils and control soil (sandy loam) were investigated in the glasshouse in two separate trials. The ANOVA analysed data results indicated that plant samples on silty clay loam significantly increased in height, stem girth, plant root, leaf area, number of leaves, number of branches, number of flowers, number of fruit bunch per plant dry weight, as well as weight of fruit bunch. However, plant samples grown on clay loam and loam soils recorded increased chlorophyll and produced dark green leaves. It is conceivable that silty clay loam soils have a strong ability to support the physiological growth and the yield of S. nigrum. These soils are therefore recommended for the cultivation of this plant. S. nigrum cultivated on these soils was evaluated for proximate compositions, anti-nutrients, vitamins A, C and E and mineral compositions using standard analytical methods. Using the translocation factor, the minerals’ toxicity accumulation levels in the plant were also determined. Accumulation of proximate parameters in the first and second trials are: ash (11.25-12.25 percent and 11.14- 11.54 percent), crude fibre (19.24-19.95 percent and 18.71-19.35 percent), protein (36.72-38.98 percent and 34.47-37.00 percent), phytate (0.84-1.17 and 0.88-1.15 mg/ml), saponnin (94.10-97.00 and 94.17-97.00 percent) and alkaloids (43.03-45.76 and 42.08- 44.10 percent) respectively. Vitamin A ranged between 117 and 137 mg/kg and betweens 108 and 128 mg/kg, vitamin C between 100 and 118 mg/kg and between 96 and 108 mg/kg and vitamin E between 250 and 269 mg/kg and between 227 and 261 mg/kg in the first and second trials respectively. The quantities of macro and micro-nutrients recorded in S. nigrum showed that this plant is a reservoir of nutrients. Plants cultivated on clay loam, silty clay loam and loam soils accumulated elevated nutritients compositions. Investigation was made on the ability of S. nigrum cultivated on different soil texture types to synthesise phytochemicals such as phenol, flavonoid, alkaloid proanthocyanidins, tannins, saponins and antioxidant. Highest concentrations of phenolics (73.87 mg/g), flavonoids (58.41 mg/g), proanthocyanidins (875.74 mg/g), tannins (49.32 mg/g), saponins (875.74 mg/g) and alkaloid (47.50 mg/g) contents were recorded in plant sample cultivated on silty clay loam soil. Also, highest radical scavenging power using DPPH (0.0102 mg/g), ABTS (0.1062 mg/g) and FRAP (0.8395 mg/g) were recorded in plant samples grown on silty clay loam and the next high values were recorded in plant samples grown on clay loam soil. It is showed in this study that silty clay loam soil and clay loam soils are the best soil types for cultivation of S. nigrum for increased antioxidant properties/ oxygen radical scavenging activities. Investigation was made on chemical compositions and antioxidant properties of essential oil extracts of S. nigrum shoot and root cultivated on different soil textures. The Gas Chromatography-Mass Spectrometry (GC-MS) profiling revealed variations in the quality index (QI) and number of chemical constituents of the oil of S. nigrum cultivated on different soil texture types. Geraniol and citronellol were two principal components of high quality common to oil from shoots and roots fromplants cultivated on all soil types. Results of DPPH and ABTS assays of the shoot oil showed that S. nigrum cultivated on clay loam soil had the highest antioxidant power. The presence of citronellol and geraniol among the major compounds is an indicaton of the plant’s role in defensive mechanisms. The work indicated that soil texture has effect on the quality, quantity and chemical compounds synthesised in the shoots and roots of S. nigrum. Antibacterial activities and the efficacy of S. nigrum cultivated on different soil types were carried out on reference strains of 4 gram-positive and 4 gram-negative bacteria. Toxicity evaluation of the plant’s acetone extract and water extract were also assessed on lethality of brine shrimp eggs. Plant water and acetone extracts exhibited strong antibacterial activity against Pseudomona aeruginosa, acetone extracts against Bacillus cereus, Listeria and Escherichia coli. Significantly (p< 0.05) low concentration (0.25 mg/mL) of acetone extracts from plant shoot cultivated on silty clay loam and clay loam soils inhibited B. cereus and P. aeruginosa. Antimicrobial activities of extracts of plant cultivated on clay loam appeared to be more superior to extracs from plants grown on other soil types. Toxicity of the plant extracts (water and acetone) was concentration and time dependent. The LD50 values for all plant extracts were greater than 1000 mg/mL which showed they are non-toxic.
- Full Text:
- Date Issued: 2017
- Authors: Ogundola, Adijat Funke
- Date: 2017
- Subjects: Solanum Materia medica, Vegetable Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8758 , vital:33519
- Description: Solanum nigrum L. is a wild vegetable that is highly recognised for its high nutiritional and therapeutical purposes. However, proper identification of the plant is essential not only to plant scientists but to a wide range of users. Therefore, the plant’s roots, stems and leaves cultivated on different soil types were viewed under the Scanning Electron Microscope while the leaves were further viewed under the Light Microscope. significant increase was observed in densities of stomata, guard and subsidiary cells of leaves of S. nigrum grown on silty clay loam soil. The SEM analysis revealed abundant glandular and non-glandular trichromes on both surfaces of the leaves. The glandular trichome is known to be responsible for the storage of bioactive compounds for which this plant is well known. Cultivation was embarked upon, for the availability of the plant at all times. However, propagation was by seed alone, therefore, quality seed is necessary for cultivation. Study was carried out on seeds extracted from plants growing in the wild in Alice for the seed viability, germination and seedling emergence when subjected to different soil texture types and sowing depths. The seeds were 98.3 percent viable. Highest germination (94.66 percent) was recorded in sand paper scarification, 15, 20 and 25ºC. Continuous darkness and temperatures lower than 5ºC and higher than 35ºCwere detrimental to the seeds. Silty clay loam soil and a depth of 2 cm had the highest seedling emergence 90 percent and recommended as the ideal condition for seedlings emergence. The growth, yield and physiological response of S. nigrum to sandy clay loam, silty clay loam, clay loam, loam soils and control soil (sandy loam) were investigated in the glasshouse in two separate trials. The ANOVA analysed data results indicated that plant samples on silty clay loam significantly increased in height, stem girth, plant root, leaf area, number of leaves, number of branches, number of flowers, number of fruit bunch per plant dry weight, as well as weight of fruit bunch. However, plant samples grown on clay loam and loam soils recorded increased chlorophyll and produced dark green leaves. It is conceivable that silty clay loam soils have a strong ability to support the physiological growth and the yield of S. nigrum. These soils are therefore recommended for the cultivation of this plant. S. nigrum cultivated on these soils was evaluated for proximate compositions, anti-nutrients, vitamins A, C and E and mineral compositions using standard analytical methods. Using the translocation factor, the minerals’ toxicity accumulation levels in the plant were also determined. Accumulation of proximate parameters in the first and second trials are: ash (11.25-12.25 percent and 11.14- 11.54 percent), crude fibre (19.24-19.95 percent and 18.71-19.35 percent), protein (36.72-38.98 percent and 34.47-37.00 percent), phytate (0.84-1.17 and 0.88-1.15 mg/ml), saponnin (94.10-97.00 and 94.17-97.00 percent) and alkaloids (43.03-45.76 and 42.08- 44.10 percent) respectively. Vitamin A ranged between 117 and 137 mg/kg and betweens 108 and 128 mg/kg, vitamin C between 100 and 118 mg/kg and between 96 and 108 mg/kg and vitamin E between 250 and 269 mg/kg and between 227 and 261 mg/kg in the first and second trials respectively. The quantities of macro and micro-nutrients recorded in S. nigrum showed that this plant is a reservoir of nutrients. Plants cultivated on clay loam, silty clay loam and loam soils accumulated elevated nutritients compositions. Investigation was made on the ability of S. nigrum cultivated on different soil texture types to synthesise phytochemicals such as phenol, flavonoid, alkaloid proanthocyanidins, tannins, saponins and antioxidant. Highest concentrations of phenolics (73.87 mg/g), flavonoids (58.41 mg/g), proanthocyanidins (875.74 mg/g), tannins (49.32 mg/g), saponins (875.74 mg/g) and alkaloid (47.50 mg/g) contents were recorded in plant sample cultivated on silty clay loam soil. Also, highest radical scavenging power using DPPH (0.0102 mg/g), ABTS (0.1062 mg/g) and FRAP (0.8395 mg/g) were recorded in plant samples grown on silty clay loam and the next high values were recorded in plant samples grown on clay loam soil. It is showed in this study that silty clay loam soil and clay loam soils are the best soil types for cultivation of S. nigrum for increased antioxidant properties/ oxygen radical scavenging activities. Investigation was made on chemical compositions and antioxidant properties of essential oil extracts of S. nigrum shoot and root cultivated on different soil textures. The Gas Chromatography-Mass Spectrometry (GC-MS) profiling revealed variations in the quality index (QI) and number of chemical constituents of the oil of S. nigrum cultivated on different soil texture types. Geraniol and citronellol were two principal components of high quality common to oil from shoots and roots fromplants cultivated on all soil types. Results of DPPH and ABTS assays of the shoot oil showed that S. nigrum cultivated on clay loam soil had the highest antioxidant power. The presence of citronellol and geraniol among the major compounds is an indicaton of the plant’s role in defensive mechanisms. The work indicated that soil texture has effect on the quality, quantity and chemical compounds synthesised in the shoots and roots of S. nigrum. Antibacterial activities and the efficacy of S. nigrum cultivated on different soil types were carried out on reference strains of 4 gram-positive and 4 gram-negative bacteria. Toxicity evaluation of the plant’s acetone extract and water extract were also assessed on lethality of brine shrimp eggs. Plant water and acetone extracts exhibited strong antibacterial activity against Pseudomona aeruginosa, acetone extracts against Bacillus cereus, Listeria and Escherichia coli. Significantly (p< 0.05) low concentration (0.25 mg/mL) of acetone extracts from plant shoot cultivated on silty clay loam and clay loam soils inhibited B. cereus and P. aeruginosa. Antimicrobial activities of extracts of plant cultivated on clay loam appeared to be more superior to extracs from plants grown on other soil types. Toxicity of the plant extracts (water and acetone) was concentration and time dependent. The LD50 values for all plant extracts were greater than 1000 mg/mL which showed they are non-toxic.
- Full Text:
- Date Issued: 2017
Market participation and value chain integration among smallholder homestead and irrigated crop farmers in the Eastern Cape province of South Africa
- Authors: Mdoda, Lelethu
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15023 , vital:40152
- Description: The irrigation schemes had been established over the years and now are operational but there is no marked improvement in the living conditions of the rural farmers and households. Smallholder farmers still face numerous constraints in market participation that hinder smallholder farmers, irrigators and homestead growth which have been attributed to lack of access to markets and technical expertise. Despite the government efforts, smallholder farmers effectively functioning in the agro-food chains, high-valued markets and commercial agricultural markets are rare; this indicates that the objective to allow smallholder farmers to advance their livelihood through participating in commercial agro-food chains has not yet been met. Farmers in the Eastern Cape produce many crops which they mainly sell in informal local markets; there is minimal number of smallholder farmers supplying their produce to the formal markets. Irrigation development is very crucial to the development of the agricultural sector as it ensures improvement in yields and reduces rural poverty through creating rural employment, enhance smallholder farmers’ market participation and enhance market access policies by smallholder farmers as means to achieve the Sustainable Development Goals The study was conducted in the Eastern Cape Province and employed survey data obtained from 200 smallholder irrigated crop farmers and homestead gardeners. A multistage stratified sampling procedure was used in which the first stage involved selecting the study areas. This was followed by the selection of the district and then the respondents. The farmers were selected from three District Municipalities which have operational irrigation schemes, namely OR Tambo, Amathole and Chris Hani District Municipalities in the province. STATA and SPSS were used to analyze the data. The Heckman model was applied to examine factors influencing farmers’ decision to participate in market among crop producing farmers in the province. In the first stage Heckman analysis, the decision as to whether or not to participate (which is a binary choice situation) is used to undertake the maximum likelihood estimation (MLE). In the second stage, the conditional quantity sold (continuous variable) is assumed to follow a truncated normal regression model, whereby the MLE is estimated by fitting a truncated normal regression of quantity sold. Gross Margin and Net Farm Income were used to measure farm profit as well as multiple regression analysis to estimate determinants of profitability in the study area. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (translog). he descriptive statistics employed include means, percentages and frequencies mostly of the socio-economic characteristics of farmers in the study area. The results show that males were dominant with the representation of 61.7percent. The majority of farmers were aged and the mean age was 60 years, indicating that farmers in the province are old which has implication for productivity and market participation. High level of illiteracy is shown in the data and mean household size of 5 persons with the household head having at least obtained some primary school education.The irrigated crop farmers and homesteads were found to have farm size under 4 ha. About 86.5percent were full time farmers and Farming is their major source of livelihood. Smallholder irrigators and homestead gardeners derive their income from social grants and remittances. This thesis found out that majority of the farmers do not participate in markets. In this instance, farming becomes a scapegoat for failure to enter alternative labour markets. The average annual on-farm production income from smallholder irrigators was R7 860.27 and homestead gardeners was R5 915.50. The empirical results from probit model suggest that age of the farmer, level of education of the farmer, household size, farm organization, access to extension, distance to markets, occupation and farm experience were some of the key determinants that had significant and positive effects on farmers’ decision to participate in markets while access to credit, transport to the markets and farm size were some of the key determinants that had significant and negative effect on farmers’ decision to participate in markets. The volume of crops sold to the market is determined by gender, age, years spent in school, distance to the market, farm experience, household size, access to extension, membership in farm organization and non-farm income.
- Full Text:
- Date Issued: 2017
- Authors: Mdoda, Lelethu
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15023 , vital:40152
- Description: The irrigation schemes had been established over the years and now are operational but there is no marked improvement in the living conditions of the rural farmers and households. Smallholder farmers still face numerous constraints in market participation that hinder smallholder farmers, irrigators and homestead growth which have been attributed to lack of access to markets and technical expertise. Despite the government efforts, smallholder farmers effectively functioning in the agro-food chains, high-valued markets and commercial agricultural markets are rare; this indicates that the objective to allow smallholder farmers to advance their livelihood through participating in commercial agro-food chains has not yet been met. Farmers in the Eastern Cape produce many crops which they mainly sell in informal local markets; there is minimal number of smallholder farmers supplying their produce to the formal markets. Irrigation development is very crucial to the development of the agricultural sector as it ensures improvement in yields and reduces rural poverty through creating rural employment, enhance smallholder farmers’ market participation and enhance market access policies by smallholder farmers as means to achieve the Sustainable Development Goals The study was conducted in the Eastern Cape Province and employed survey data obtained from 200 smallholder irrigated crop farmers and homestead gardeners. A multistage stratified sampling procedure was used in which the first stage involved selecting the study areas. This was followed by the selection of the district and then the respondents. The farmers were selected from three District Municipalities which have operational irrigation schemes, namely OR Tambo, Amathole and Chris Hani District Municipalities in the province. STATA and SPSS were used to analyze the data. The Heckman model was applied to examine factors influencing farmers’ decision to participate in market among crop producing farmers in the province. In the first stage Heckman analysis, the decision as to whether or not to participate (which is a binary choice situation) is used to undertake the maximum likelihood estimation (MLE). In the second stage, the conditional quantity sold (continuous variable) is assumed to follow a truncated normal regression model, whereby the MLE is estimated by fitting a truncated normal regression of quantity sold. Gross Margin and Net Farm Income were used to measure farm profit as well as multiple regression analysis to estimate determinants of profitability in the study area. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (translog). he descriptive statistics employed include means, percentages and frequencies mostly of the socio-economic characteristics of farmers in the study area. The results show that males were dominant with the representation of 61.7percent. The majority of farmers were aged and the mean age was 60 years, indicating that farmers in the province are old which has implication for productivity and market participation. High level of illiteracy is shown in the data and mean household size of 5 persons with the household head having at least obtained some primary school education.The irrigated crop farmers and homesteads were found to have farm size under 4 ha. About 86.5percent were full time farmers and Farming is their major source of livelihood. Smallholder irrigators and homestead gardeners derive their income from social grants and remittances. This thesis found out that majority of the farmers do not participate in markets. In this instance, farming becomes a scapegoat for failure to enter alternative labour markets. The average annual on-farm production income from smallholder irrigators was R7 860.27 and homestead gardeners was R5 915.50. The empirical results from probit model suggest that age of the farmer, level of education of the farmer, household size, farm organization, access to extension, distance to markets, occupation and farm experience were some of the key determinants that had significant and positive effects on farmers’ decision to participate in markets while access to credit, transport to the markets and farm size were some of the key determinants that had significant and negative effect on farmers’ decision to participate in markets. The volume of crops sold to the market is determined by gender, age, years spent in school, distance to the market, farm experience, household size, access to extension, membership in farm organization and non-farm income.
- Full Text:
- Date Issued: 2017
Performance of magnetic nanocomposites for the removal of some selected contaminants from aqueous solution
- Authors: Ojemaye, Mike Onyewelehi
- Date: 2017
- Subjects: Nanocomposites (Materials)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8746 , vital:33508
- Description: In this thesis, the performances of magnetic nanoparticles based materials were assessed for the removal or reduction of heavy metals in aqueous solutions. The successful synthesis of a novel adsorbent, azomethine functionalized magnetic nanoparticles (MNP-Maph) by covalent bonding between the amine group (-NH2) of amine functionalized magnetic nanoparticles (MNP-NH2) and carboxylic group (-COOH) of 4-{[(E)-phenylmethylidene]amino}benzoic acid (Maph-COOH) was achieved. This adsorbent was examined for the removal of di and trivalent ions (Cu2+, Zn2+, As3+, Pb2+ and Hg2+) from aqueous solutions. Also, magnetic photocatalyst with silica interlayer (NiFe2O4-SiO2-TiO2) was synthesized and employed for the reduction of Cr(VI) in aqueous solution. The photocatalytic reduction efficiency of this material was compared with that of magnetic titanium dioxide (NiFe2O4-TiO2) photocatalyst and titanium dioxide (TiO2) to ascertain the material with the best photocatalytic efficiency and ease of separation. All synthesized materials were characterized by using XRD, FT-IR, TEM, SEM, TGA and VSM before application. For the adsorption processes, the effects of pH, contact time, adsorbent dose and temperature were examined to ascertain the experimental condition necessary for the optimal removal of metal ions from solution. The data obtained from all experiments were fitted into four kinetic models; pseudo-first order, pseudo-second order, elovich and intra particle diffusion models to determine the mechanism involved in the adsorption of these di and trivalent ions while two isotherm models were employed in the adorption processes; these include: Langmuir and Freudlich models. Also, for the photocatalytic experiment, the effects of pH, contact time and photocatalyst dose were investigated to determine the experimental conditions necessary for the optimal reduction of Cr(VI) in aqueous solution. MNP-Maph showed excellent removal capacities of 34.08, 35.83, 50.08, 58.24 and 59.24 mg g-1 for Cu2+, Zn2+, As3+, Pb2+ and Hg2+ respectively compared to data previously reported in literature. This is as a result of the high affinity of azomethine group towards metal ions which tremendously enhanced removal of metal ions by adsorption. The incorporation of azomethine to magnetic nanoparticles improved the affinity towards metal ions removal forming strong electrostatic interaction between the adsorbent active sites and adsorbates. Also, the utilization of NiFe2O4-SiO2-TiO4, NiFe2O4-TiO2 and TiO2 for the reduction of Cr(VI) in aqueous solution showed a good photocatalytic performance with NiFe2O4-SiO2-TiO2 showing to be better in terms of both photocatalytic reduction and magnetic separation. TiO2 was observed to have 96.7percent reduction efficiency within 240 min while NiFe2O4-SiO2-TiO2 has 96.5percent reduction efficiency within 300 min and NiFe2O4-TiO2 gave 60percent reduction efficiency within 300 min of UV irradiation. This magnetic photocatalyst composite (NiFe2O4-SiO2-TiO2) gives the advantage of avoiding the problem of separation often encountered with most photocatalyst materials including TiO2 by allowing separation with the aid of a magnetic field. The adsorption processes were all described by pseudo-second order and Langmuir isotherm models while the photocatalytic process was described by Langmuir-Hinshelwood (L-H) kinetic model. Furthermore, thermodynamic experiment studied for the adsorption processes showed that all metal ion adsorption except Hg2+ by MNP-Maph were endothermic in nature, rapid and spontaneous indicating the feasibility of the sorbent material for the removal of metal ions from aqueous solutions. Also, regenerability study conducted to determine the reusability of sorbent material after seven cycles showed the potential to reuse sorbent material seven times or more. The reusability of the sorbent material was observed to show a percentage of an average of 78percent using 50:50 mixture of 0.1 mol dm-3 HNO3 and HCl for all adsorption processes. For the photocatalytic experiment, regenerability using 0.1 mol dm-3 for 1 h was observed to be very impressive after 3 runs for all synthesized photocatalytic materials. This thereby implies that the removal of metal ions by these materials will not in any way introduce secondary pollutants into the environment. Rather, it will avert the production of secondary pollutants. Also, the use of simple conventional chemicals for the regeneration of synthesized materials showed that regeneration in this study is cost effective as regeneration has been known to cost about three quarter of the total operation and maintenance of an adsorption or photocatalytic process. Application of MNP-Maph to real wastewater sampled from five different wastewater treatment plants in Eastern Cape Province for the removal of Cu2+, Zn2+ and As3+ showed that removal efficiencies of approximately 80 percent were achieved for all three metal ions upon adsorption by MNP-Maph. These therefore show that the introduction of metal loving ligand such as Maph-COOH improved the efficiency of MNP towards the removal of heavy metal ions from aqueous solution. Also, silica positively influenced the performance of magnetic titanium dioxide towards Cr(VI) reduction and separation from aqueous solution. This study therefore showed that these materials should be considered for future applications in the area of water/wastewater decontamination.
- Full Text:
- Date Issued: 2017
- Authors: Ojemaye, Mike Onyewelehi
- Date: 2017
- Subjects: Nanocomposites (Materials)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8746 , vital:33508
- Description: In this thesis, the performances of magnetic nanoparticles based materials were assessed for the removal or reduction of heavy metals in aqueous solutions. The successful synthesis of a novel adsorbent, azomethine functionalized magnetic nanoparticles (MNP-Maph) by covalent bonding between the amine group (-NH2) of amine functionalized magnetic nanoparticles (MNP-NH2) and carboxylic group (-COOH) of 4-{[(E)-phenylmethylidene]amino}benzoic acid (Maph-COOH) was achieved. This adsorbent was examined for the removal of di and trivalent ions (Cu2+, Zn2+, As3+, Pb2+ and Hg2+) from aqueous solutions. Also, magnetic photocatalyst with silica interlayer (NiFe2O4-SiO2-TiO2) was synthesized and employed for the reduction of Cr(VI) in aqueous solution. The photocatalytic reduction efficiency of this material was compared with that of magnetic titanium dioxide (NiFe2O4-TiO2) photocatalyst and titanium dioxide (TiO2) to ascertain the material with the best photocatalytic efficiency and ease of separation. All synthesized materials were characterized by using XRD, FT-IR, TEM, SEM, TGA and VSM before application. For the adsorption processes, the effects of pH, contact time, adsorbent dose and temperature were examined to ascertain the experimental condition necessary for the optimal removal of metal ions from solution. The data obtained from all experiments were fitted into four kinetic models; pseudo-first order, pseudo-second order, elovich and intra particle diffusion models to determine the mechanism involved in the adsorption of these di and trivalent ions while two isotherm models were employed in the adorption processes; these include: Langmuir and Freudlich models. Also, for the photocatalytic experiment, the effects of pH, contact time and photocatalyst dose were investigated to determine the experimental conditions necessary for the optimal reduction of Cr(VI) in aqueous solution. MNP-Maph showed excellent removal capacities of 34.08, 35.83, 50.08, 58.24 and 59.24 mg g-1 for Cu2+, Zn2+, As3+, Pb2+ and Hg2+ respectively compared to data previously reported in literature. This is as a result of the high affinity of azomethine group towards metal ions which tremendously enhanced removal of metal ions by adsorption. The incorporation of azomethine to magnetic nanoparticles improved the affinity towards metal ions removal forming strong electrostatic interaction between the adsorbent active sites and adsorbates. Also, the utilization of NiFe2O4-SiO2-TiO4, NiFe2O4-TiO2 and TiO2 for the reduction of Cr(VI) in aqueous solution showed a good photocatalytic performance with NiFe2O4-SiO2-TiO2 showing to be better in terms of both photocatalytic reduction and magnetic separation. TiO2 was observed to have 96.7percent reduction efficiency within 240 min while NiFe2O4-SiO2-TiO2 has 96.5percent reduction efficiency within 300 min and NiFe2O4-TiO2 gave 60percent reduction efficiency within 300 min of UV irradiation. This magnetic photocatalyst composite (NiFe2O4-SiO2-TiO2) gives the advantage of avoiding the problem of separation often encountered with most photocatalyst materials including TiO2 by allowing separation with the aid of a magnetic field. The adsorption processes were all described by pseudo-second order and Langmuir isotherm models while the photocatalytic process was described by Langmuir-Hinshelwood (L-H) kinetic model. Furthermore, thermodynamic experiment studied for the adsorption processes showed that all metal ion adsorption except Hg2+ by MNP-Maph were endothermic in nature, rapid and spontaneous indicating the feasibility of the sorbent material for the removal of metal ions from aqueous solutions. Also, regenerability study conducted to determine the reusability of sorbent material after seven cycles showed the potential to reuse sorbent material seven times or more. The reusability of the sorbent material was observed to show a percentage of an average of 78percent using 50:50 mixture of 0.1 mol dm-3 HNO3 and HCl for all adsorption processes. For the photocatalytic experiment, regenerability using 0.1 mol dm-3 for 1 h was observed to be very impressive after 3 runs for all synthesized photocatalytic materials. This thereby implies that the removal of metal ions by these materials will not in any way introduce secondary pollutants into the environment. Rather, it will avert the production of secondary pollutants. Also, the use of simple conventional chemicals for the regeneration of synthesized materials showed that regeneration in this study is cost effective as regeneration has been known to cost about three quarter of the total operation and maintenance of an adsorption or photocatalytic process. Application of MNP-Maph to real wastewater sampled from five different wastewater treatment plants in Eastern Cape Province for the removal of Cu2+, Zn2+ and As3+ showed that removal efficiencies of approximately 80 percent were achieved for all three metal ions upon adsorption by MNP-Maph. These therefore show that the introduction of metal loving ligand such as Maph-COOH improved the efficiency of MNP towards the removal of heavy metal ions from aqueous solution. Also, silica positively influenced the performance of magnetic titanium dioxide towards Cr(VI) reduction and separation from aqueous solution. This study therefore showed that these materials should be considered for future applications in the area of water/wastewater decontamination.
- Full Text:
- Date Issued: 2017
Pharmacological evaluation of phragmanthera capitata (sprengel) balle, loranthaceae :a parasiticmistletoe growing on rubber trees
- Ohikhena, Franklin Uangbaoje
- Authors: Ohikhena, Franklin Uangbaoje
- Date: 2017
- Subjects: Hevea Hevea -- Diseases and pests Rubber
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8899 , vital:33937
- Description: Rubber tree (Hevea brasiliensis Muell.) is the world’s major source of natural rubber and a major non-oil, agricultural export commodity in the producing countries in Africa. However, it is highly susceptible to specific mistletoes of the Loranthaceae family. Phragmanthera capitate (Sprengel) Balle is the major mistletoe parasitizing the rubber tree plantations in Africa and hence, alongside with other mistletoes, has attracted indiscriminate destruction from plantation owners. Indiscriminate destruction of plants could be as a result of ignorance of the importance or benefit(s) of the plants and this could lead to their extinction if not checked. Hence, there is the need for scientific documentation of plants and their uses because, from the pharmacological perception, the destruction of a plant could result in the permanent loss of a potential drug. Therefore, this study was aimed at documenting and evaluating the pharmacological potentials of P. capitata collected from rubber tree. Fresh leaves were gently rinsed with water and dried. Dried leaves were pulverised and kept at 4oC when not in use. Pulverised leaves were extracted with acetone, methanol, ethanol and water and concentrated to give the respective solvent crude extracts used in most of the assays. From the extraction, Methanol had the highest yield of 21.5percent, water had 10.8percent and acetone was 6.87percent while ethanol had the lowest yield of 4.3percent. Standard spectrophotometry assays on the extracts were used to quantify some major phytochemicals of pharmacological interest and also to determine the antioxidant potentials of the sample. The result revealed high amounts of phenols (175.53 ± 0.32 mg GAE/g to 218.62 ± 3.38 mg GAE/g), flavonoids (197.06 ± 3.80 mg QE/mg to 679.82 ± 6.26 mg QE/g) and proanthocyanidins (128.83 ± 1.69 mg CE/g to 645.68 ± 6.35 mg CE/g) with the acetone extract having the highest amount of the phytochemicals while the aqueous extract had the least. The results of the antioxidant assays revealed that the sample had high radical scavenging potentials with comparable inhibitory concentrations to standard antioxidant drugs. The proximate and mineral analysis on the pulverised sample showed that it is rich in carbohydrate with a composition of 57.73 ± 0.33 g/100 g. Protein, fat and fibre compositions were 12.50 ± 0.50 g/100 g, 3.34 ± 0.18 g/100 g and 11.66 ± 0.54 g/100g. The total energy composition was 310.97 ± 2.30 Kcal/100 g. The mineral composition revealed high potassium level of 1047.83 ± 34 mg/100g. Calcium (6.22.58 ± 0.01 mg/100g), magnesium (361.15 ± 0.01 mg/100 g) and phosphorous (115.40 ± 0.01 mg/100 g) were also present in appreciable amounts. The toxicity of the four extracts was assayed using brine shrimp. The LC50 in all the solvent extracts was greater than 1 mg/mL which according to Meyer’s index and other indexes signify “no toxicity” for crude plant extracts. Antimicrobial activity of the extracts was done using the minimal inhibitory concentration (MIC) assay against 10 bacteria (Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Streptococcus pyogenes, Vibrio cholera, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli) and 4 fungi (Trichophyton mucoides, Trichophyton tonsurans, Candida albicans and Aspergillus niger) of human pathogenic strains. The MIC of the antibacterial assay ranged from 1.25 mg/mL to 5 mg/mL for the organic extracts while no activity was observed in the aqueous extract at the highest concentration tested. However, the aqueous extract had a great inhibitory activity on all four of the tested fungi with a MIC of ≤ 0.3125 mg/mL to 1.25 mg/mL while only two fungi (Trichophyton Tonsurans and Aspergillus niger) were susceptible to the organic extracts. The MIC of the TB causative pathogen, Mycobacterium tuberculosis (H37Rv) strain ranged from 25 μg/mL (acetone and aqueous extracts) to 50 μg/mL in the ethanol extract while it was > 50 μg/mL (highest concentration tested) in the methanol extract. This study revealed that the sample has the potential in phytotherapy against oxidative stresses (inflammations) caused by free radicals. It could also be a useful herb in combating diseases caused by pathogenic organisms. The high anti-Mycobacterium tuberculosis activity observed in this study suggests it could be a plant with high promise in the fight against tuberculosis. The toxicity evaluation signifies it is safe for further plant-based pharmaceutical explorations. This study also validated some reported ethnopharmacological uses of this plant and call for its protection from indiscriminate destruction in rubber plantations and other crop gardens/plantations in the world.
- Full Text:
- Date Issued: 2017
- Authors: Ohikhena, Franklin Uangbaoje
- Date: 2017
- Subjects: Hevea Hevea -- Diseases and pests Rubber
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8899 , vital:33937
- Description: Rubber tree (Hevea brasiliensis Muell.) is the world’s major source of natural rubber and a major non-oil, agricultural export commodity in the producing countries in Africa. However, it is highly susceptible to specific mistletoes of the Loranthaceae family. Phragmanthera capitate (Sprengel) Balle is the major mistletoe parasitizing the rubber tree plantations in Africa and hence, alongside with other mistletoes, has attracted indiscriminate destruction from plantation owners. Indiscriminate destruction of plants could be as a result of ignorance of the importance or benefit(s) of the plants and this could lead to their extinction if not checked. Hence, there is the need for scientific documentation of plants and their uses because, from the pharmacological perception, the destruction of a plant could result in the permanent loss of a potential drug. Therefore, this study was aimed at documenting and evaluating the pharmacological potentials of P. capitata collected from rubber tree. Fresh leaves were gently rinsed with water and dried. Dried leaves were pulverised and kept at 4oC when not in use. Pulverised leaves were extracted with acetone, methanol, ethanol and water and concentrated to give the respective solvent crude extracts used in most of the assays. From the extraction, Methanol had the highest yield of 21.5percent, water had 10.8percent and acetone was 6.87percent while ethanol had the lowest yield of 4.3percent. Standard spectrophotometry assays on the extracts were used to quantify some major phytochemicals of pharmacological interest and also to determine the antioxidant potentials of the sample. The result revealed high amounts of phenols (175.53 ± 0.32 mg GAE/g to 218.62 ± 3.38 mg GAE/g), flavonoids (197.06 ± 3.80 mg QE/mg to 679.82 ± 6.26 mg QE/g) and proanthocyanidins (128.83 ± 1.69 mg CE/g to 645.68 ± 6.35 mg CE/g) with the acetone extract having the highest amount of the phytochemicals while the aqueous extract had the least. The results of the antioxidant assays revealed that the sample had high radical scavenging potentials with comparable inhibitory concentrations to standard antioxidant drugs. The proximate and mineral analysis on the pulverised sample showed that it is rich in carbohydrate with a composition of 57.73 ± 0.33 g/100 g. Protein, fat and fibre compositions were 12.50 ± 0.50 g/100 g, 3.34 ± 0.18 g/100 g and 11.66 ± 0.54 g/100g. The total energy composition was 310.97 ± 2.30 Kcal/100 g. The mineral composition revealed high potassium level of 1047.83 ± 34 mg/100g. Calcium (6.22.58 ± 0.01 mg/100g), magnesium (361.15 ± 0.01 mg/100 g) and phosphorous (115.40 ± 0.01 mg/100 g) were also present in appreciable amounts. The toxicity of the four extracts was assayed using brine shrimp. The LC50 in all the solvent extracts was greater than 1 mg/mL which according to Meyer’s index and other indexes signify “no toxicity” for crude plant extracts. Antimicrobial activity of the extracts was done using the minimal inhibitory concentration (MIC) assay against 10 bacteria (Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Streptococcus pyogenes, Vibrio cholera, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli) and 4 fungi (Trichophyton mucoides, Trichophyton tonsurans, Candida albicans and Aspergillus niger) of human pathogenic strains. The MIC of the antibacterial assay ranged from 1.25 mg/mL to 5 mg/mL for the organic extracts while no activity was observed in the aqueous extract at the highest concentration tested. However, the aqueous extract had a great inhibitory activity on all four of the tested fungi with a MIC of ≤ 0.3125 mg/mL to 1.25 mg/mL while only two fungi (Trichophyton Tonsurans and Aspergillus niger) were susceptible to the organic extracts. The MIC of the TB causative pathogen, Mycobacterium tuberculosis (H37Rv) strain ranged from 25 μg/mL (acetone and aqueous extracts) to 50 μg/mL in the ethanol extract while it was > 50 μg/mL (highest concentration tested) in the methanol extract. This study revealed that the sample has the potential in phytotherapy against oxidative stresses (inflammations) caused by free radicals. It could also be a useful herb in combating diseases caused by pathogenic organisms. The high anti-Mycobacterium tuberculosis activity observed in this study suggests it could be a plant with high promise in the fight against tuberculosis. The toxicity evaluation signifies it is safe for further plant-based pharmaceutical explorations. This study also validated some reported ethnopharmacological uses of this plant and call for its protection from indiscriminate destruction in rubber plantations and other crop gardens/plantations in the world.
- Full Text:
- Date Issued: 2017
Pharmacological investigations of Kedrostis africana (L.) Cogn. and Vernonia mespilifolia Less. used in folk medicine in the Eastern Cape, South Africa
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
- Full Text:
- Date Issued: 2017
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
- Full Text:
- Date Issued: 2017
Poverty, Food insecurity and livelihood diversification among households in Eastern Cape province, South Africa
- Authors: Megbowon, Ebenezer Toyin
- Date: 2017
- Subjects: Food supply -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13086 , vital:39464
- Description: Livelihood diversification have been thought to be a rural issue where agriculture is the main source of income, however in an era of dwindling global and national economic situations, livelihood diversification have been seen to be prominent among urban dwellers as well although literatures have focused more on rural households. There is also a growing evidence in literature showing that livelihood diversification is indispensable for improving household welfare. This study adopts the sustainable livelihood framework to investigate the pattern and determinants of livelihood diversification (number of income sources) and the welfare (poverty and food insecurity) effect of livelihood diversification on household in the Eastern Cape Province of South Africa. Indicators of poverty and food security were computed using Multidimensional Poverty Index (MPI) and FANTA’s Household Dietary Diversity Scores (HDDS). The study relied on data obtained from the Nation-wide annual General household Survey carried out in 2014 having 3033 households sampled from the Eastern Cape Province of South Africa. Data were analyzed using descriptive statistics, Poisson regression, Tobit regression and logistic regression models. The result of the Multidimensional Poverty Index headcount revealed that while majority (71.28 percent) of the households are not multidimensionaly poor, 20.51 percent, 6.89 percent and 1.32 percent are vulnerable to multidimensional poverty, multidimensionaly poor and severely multidimensionaly poor respectively. The study also revealed that while there is a significant differences between multidimensional poverty status in the both rural and urban area, there is no much differences when considering the gender of the household head. This indicates that poverty is still a rural phenomenon in the Province. Furthermore, the largest contributor (dimension and indicators) to household multidimensional poverty in the Province is standard of living dimension and specific indicator are the fuels use for cooking, water and space heating, toilet system, dwelling and asset accumulation are the most areas of highest deprivation. The household dietary diversity score show that household have a diverse diet with a mean score of 6.9; however the diversity is skewed toward food groups that do not give expected nutritional diets for a healthy and an economically active life. In General pulse diet and vegetables (spinach and wild green leaves) are least consumed in the province. Consumption of fruit is shown to be less consumed in the rural area as compared to the urban area. Descriptive analysis of livelihood diversification among households in the province revealed that majority of households are not diversified. Poisson regression estimate produced a good fit shown by the statistical insignificance of the deviance good of fit (p=1.09). Age of household head, population group of the head, education attainment of the head, engagement in agriculture, recipient of remittance and number of economic active member of the household) were found to be statistically significant (p<0.01) and were found to influence the probability of a household diversifying their livelihood base in the study area. The result of the Tobit regression on effect of livelihood diversification and other household socio-economic characteristics on household poverty suggest livelihood diversification has no statistically significant effect on the probability of being poor in the study area. Other variables found to influence poverty are, household head’s gender (male), age, education, employment status, access to electricity, engagement in agriculture, salary earning, economic active size of household and asset score) were found to be significantly (p<0.01) to influencing multidimensional poverty of the poor households. The result of the logistic regression indicates that livelihood diversification has no significant effect on the probability of a household being poor. Gender of head, age of household head, education attainment of the head, access to electricity, engagement in agriculture, recipients of pension, number of economic active and living in urban area were also found to be statistically significant in influencing household food insecurity in the province. The findings illustrates that livelihood diversification may not be relevant for household welfare in the case of South Africa. However promoting livelihood diversification remain imperative for household welfare in the South Africa in the long-run. It further illustrate that gender of head, education, access to electricity, home agriculture are imperative for the improvement of household welfare. Hence the study recommends policy relating to conditional granting of cash grant support, intensification of rural development programmes, education affordable and accessible at all level and support home stead or subsistence agriculture.
- Full Text:
- Date Issued: 2017
- Authors: Megbowon, Ebenezer Toyin
- Date: 2017
- Subjects: Food supply -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13086 , vital:39464
- Description: Livelihood diversification have been thought to be a rural issue where agriculture is the main source of income, however in an era of dwindling global and national economic situations, livelihood diversification have been seen to be prominent among urban dwellers as well although literatures have focused more on rural households. There is also a growing evidence in literature showing that livelihood diversification is indispensable for improving household welfare. This study adopts the sustainable livelihood framework to investigate the pattern and determinants of livelihood diversification (number of income sources) and the welfare (poverty and food insecurity) effect of livelihood diversification on household in the Eastern Cape Province of South Africa. Indicators of poverty and food security were computed using Multidimensional Poverty Index (MPI) and FANTA’s Household Dietary Diversity Scores (HDDS). The study relied on data obtained from the Nation-wide annual General household Survey carried out in 2014 having 3033 households sampled from the Eastern Cape Province of South Africa. Data were analyzed using descriptive statistics, Poisson regression, Tobit regression and logistic regression models. The result of the Multidimensional Poverty Index headcount revealed that while majority (71.28 percent) of the households are not multidimensionaly poor, 20.51 percent, 6.89 percent and 1.32 percent are vulnerable to multidimensional poverty, multidimensionaly poor and severely multidimensionaly poor respectively. The study also revealed that while there is a significant differences between multidimensional poverty status in the both rural and urban area, there is no much differences when considering the gender of the household head. This indicates that poverty is still a rural phenomenon in the Province. Furthermore, the largest contributor (dimension and indicators) to household multidimensional poverty in the Province is standard of living dimension and specific indicator are the fuels use for cooking, water and space heating, toilet system, dwelling and asset accumulation are the most areas of highest deprivation. The household dietary diversity score show that household have a diverse diet with a mean score of 6.9; however the diversity is skewed toward food groups that do not give expected nutritional diets for a healthy and an economically active life. In General pulse diet and vegetables (spinach and wild green leaves) are least consumed in the province. Consumption of fruit is shown to be less consumed in the rural area as compared to the urban area. Descriptive analysis of livelihood diversification among households in the province revealed that majority of households are not diversified. Poisson regression estimate produced a good fit shown by the statistical insignificance of the deviance good of fit (p=1.09). Age of household head, population group of the head, education attainment of the head, engagement in agriculture, recipient of remittance and number of economic active member of the household) were found to be statistically significant (p<0.01) and were found to influence the probability of a household diversifying their livelihood base in the study area. The result of the Tobit regression on effect of livelihood diversification and other household socio-economic characteristics on household poverty suggest livelihood diversification has no statistically significant effect on the probability of being poor in the study area. Other variables found to influence poverty are, household head’s gender (male), age, education, employment status, access to electricity, engagement in agriculture, salary earning, economic active size of household and asset score) were found to be significantly (p<0.01) to influencing multidimensional poverty of the poor households. The result of the logistic regression indicates that livelihood diversification has no significant effect on the probability of a household being poor. Gender of head, age of household head, education attainment of the head, access to electricity, engagement in agriculture, recipients of pension, number of economic active and living in urban area were also found to be statistically significant in influencing household food insecurity in the province. The findings illustrates that livelihood diversification may not be relevant for household welfare in the case of South Africa. However promoting livelihood diversification remain imperative for household welfare in the South Africa in the long-run. It further illustrate that gender of head, education, access to electricity, home agriculture are imperative for the improvement of household welfare. Hence the study recommends policy relating to conditional granting of cash grant support, intensification of rural development programmes, education affordable and accessible at all level and support home stead or subsistence agriculture.
- Full Text:
- Date Issued: 2017
Production systems, profitability and participation in the mainstream markets by smallholder broiler chicken farmers of Maseru district in Lesotho
- Mphahama, Litsoanelo Evodiah
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
- Full Text:
- Date Issued: 2017
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
- Full Text:
- Date Issued: 2017
Removal rate of endocrine disruptors (phthalates and phenolic compounds) in effluents of selected wastewater treatment plants operated under different treatment technologies in the Eastern Cape, South Africa
- Authors: Salaudeen, Taofeek Gbenga
- Date: 2017
- Subjects: Water -- Purification Phenols
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8552 , vital:33113
- Description: The presence of phthalate esters (PAEs) and certain phenolic compounds widely known as endocrine disruptors in environmental waters such as treated wastewaters constitutes health hazard to human and aquatic lives. Unfortunately, wastewater treatment plants (WWTPs) only partially remove these synthetic chemical compounds from wastewater. In order to forestall the health challenge faced by rural dwellers, which rely on surface water for their daily needs, the present study embarked on investigating these endocrine disruptors in Municipal wastewater in the Amathole and Buffalo Districts in the Eastern Cape, South Africa and their removal rate by different WWTP technologies. One WWTP each from Adelaide, Alice, Bedford, Berlin and Seymour, using activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were randomly selected. Some physicochemical parameters of these wastewaters were determined on-site using standard methods and the extraction method for endocrine disrupting chemicals (EDCs) in water was validated using solid phase extraction (SPE). Extracts were analysed using gas chromatography-mass spectrometer (GC-MS). Nine phenolic compounds; phenol (PH), 2-chlorophenol (2-CP), 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), 4-chloro-3-methylphenol (4-C-3MP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP) and six priority PAEs namely; dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were the investigated EDCs. PAEs were extracted from dried sludge samples in an ultrasonic bath using dichloromethane. Some physicochemical parameters of the wastewater assessed revealed that treatment processes of AS, TF, and OP reduced turbidity, total suspended solids (TSS), total dissolved solids (TDS), and electrical conductivity (EC) while dissolved oxygen (DO) was increased. There was no significant influence on temperature and pH across the sampling points. Except for turbidity, the quality of effluent released mostly falls within South Africa standard limits for domestic and recreational water. The nine phenolic compounds were detected across the sampling points for all the WWTPs at different frequencies. The prominent phenolic compounds were 2-NP, 4-C-3MP, PCP, and 2,4-DMP with concentrations ranging from 3.3 (2,4-DMP) – 83.0 μgL-1 (4-C-3MP) in the influents. However, their concentrations in the effluents and receiving water bodies were below tolerable limits of 5 μgL-1 set by the US Environmental Protection Agency (USEPA) and the European Union (EU) for domestic use. The removal capacities of the WWTPs varied between 33 and 96 percent. The six PAEs were detected in all water samples from all the WWTPs. DBP was the most abundant compound in all the sampling points and sometimes DEHP in some receiving waters. The maximum detection for DBP in influent, effluent, downstream and sludge were 2,488 μgL-1 (Alice), 26.47 μgL-1 (Adelaide), 115.3 μgL-1 (Seymour) and 1,249 μg/g dw (Alice), respectively. DEHP was the highest detected PAE in the upstream 17.53 μgL-1 (Seymour). There was a notable reduction of all PAEs in the final effluent with a removal efficiency which varied as much as 61.9 – 99.5 percent except for AS in Seymour which operated a single tank system (27.3 - 93.7 percent). Removal mechanisms continued more on adsorption on settling particles and sludge than biodegradation as this study found a high positive correlation between TSS, turbidity and PAEs removal. The concentrations of PAEs detected in the receiving waters were above 1.3 and 3μgL-1 limit standard set by the EU and USEPA, respectively for DEHP in surface water. Similarly, the average concentrations of DBP, BBP, DEHP and DOP which vary as much as 25.97 (BBP) – 1249 μg/g d.w (DBP) in sludge samples were above EU legislation of 100 μg/g d.w. for agricultural use. AS technology, showed a better performance in the removal of PAEs (77 – 99 percent), followed by TF (76 – 98 percent) and OP (61 – 98 percent). In conclusion, the PAE concentration in the WWTP effluents impacted negatively on the receiving water bodies and sewage sludge unlike the phenolic compounds that were notably reduced below the acceptable limits. Perhaps, due to the meagre amounts of the phenolic compounds that was detected entering the WWTPs. In order to avert the potential health risk to aquatic organisms’ and rural dwellers, it is exigent that constituted authorities gather more information on micro-pollutants in the environment as a basis for regulations on the use of these dangerous chemicals in industries.
- Full Text:
- Date Issued: 2017
- Authors: Salaudeen, Taofeek Gbenga
- Date: 2017
- Subjects: Water -- Purification Phenols
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8552 , vital:33113
- Description: The presence of phthalate esters (PAEs) and certain phenolic compounds widely known as endocrine disruptors in environmental waters such as treated wastewaters constitutes health hazard to human and aquatic lives. Unfortunately, wastewater treatment plants (WWTPs) only partially remove these synthetic chemical compounds from wastewater. In order to forestall the health challenge faced by rural dwellers, which rely on surface water for their daily needs, the present study embarked on investigating these endocrine disruptors in Municipal wastewater in the Amathole and Buffalo Districts in the Eastern Cape, South Africa and their removal rate by different WWTP technologies. One WWTP each from Adelaide, Alice, Bedford, Berlin and Seymour, using activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were randomly selected. Some physicochemical parameters of these wastewaters were determined on-site using standard methods and the extraction method for endocrine disrupting chemicals (EDCs) in water was validated using solid phase extraction (SPE). Extracts were analysed using gas chromatography-mass spectrometer (GC-MS). Nine phenolic compounds; phenol (PH), 2-chlorophenol (2-CP), 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), 4-chloro-3-methylphenol (4-C-3MP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP) and six priority PAEs namely; dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were the investigated EDCs. PAEs were extracted from dried sludge samples in an ultrasonic bath using dichloromethane. Some physicochemical parameters of the wastewater assessed revealed that treatment processes of AS, TF, and OP reduced turbidity, total suspended solids (TSS), total dissolved solids (TDS), and electrical conductivity (EC) while dissolved oxygen (DO) was increased. There was no significant influence on temperature and pH across the sampling points. Except for turbidity, the quality of effluent released mostly falls within South Africa standard limits for domestic and recreational water. The nine phenolic compounds were detected across the sampling points for all the WWTPs at different frequencies. The prominent phenolic compounds were 2-NP, 4-C-3MP, PCP, and 2,4-DMP with concentrations ranging from 3.3 (2,4-DMP) – 83.0 μgL-1 (4-C-3MP) in the influents. However, their concentrations in the effluents and receiving water bodies were below tolerable limits of 5 μgL-1 set by the US Environmental Protection Agency (USEPA) and the European Union (EU) for domestic use. The removal capacities of the WWTPs varied between 33 and 96 percent. The six PAEs were detected in all water samples from all the WWTPs. DBP was the most abundant compound in all the sampling points and sometimes DEHP in some receiving waters. The maximum detection for DBP in influent, effluent, downstream and sludge were 2,488 μgL-1 (Alice), 26.47 μgL-1 (Adelaide), 115.3 μgL-1 (Seymour) and 1,249 μg/g dw (Alice), respectively. DEHP was the highest detected PAE in the upstream 17.53 μgL-1 (Seymour). There was a notable reduction of all PAEs in the final effluent with a removal efficiency which varied as much as 61.9 – 99.5 percent except for AS in Seymour which operated a single tank system (27.3 - 93.7 percent). Removal mechanisms continued more on adsorption on settling particles and sludge than biodegradation as this study found a high positive correlation between TSS, turbidity and PAEs removal. The concentrations of PAEs detected in the receiving waters were above 1.3 and 3μgL-1 limit standard set by the EU and USEPA, respectively for DEHP in surface water. Similarly, the average concentrations of DBP, BBP, DEHP and DOP which vary as much as 25.97 (BBP) – 1249 μg/g d.w (DBP) in sludge samples were above EU legislation of 100 μg/g d.w. for agricultural use. AS technology, showed a better performance in the removal of PAEs (77 – 99 percent), followed by TF (76 – 98 percent) and OP (61 – 98 percent). In conclusion, the PAE concentration in the WWTP effluents impacted negatively on the receiving water bodies and sewage sludge unlike the phenolic compounds that were notably reduced below the acceptable limits. Perhaps, due to the meagre amounts of the phenolic compounds that was detected entering the WWTPs. In order to avert the potential health risk to aquatic organisms’ and rural dwellers, it is exigent that constituted authorities gather more information on micro-pollutants in the environment as a basis for regulations on the use of these dangerous chemicals in industries.
- Full Text:
- Date Issued: 2017