Effect of increasing fossil shell flour levels on digestive and metabolic utilization, health, body weight change and wool production, and quality in Dohne-Merino wethers
- Authors: Ikusika, Olusegun Oyebade
- Date: 2020
- Subjects: Merino sheep Sheep -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/18465 , vital:42542
- Description: The study's broad objective was to assess growth performance, blood and parasitic profiles, wool parameters, methane emission, and nutritional status of Dohne-Merino wethers fed diets supplemented with varying levels of fossil shell flour. Twenty-four Dohne-Merino wethers, averagely weighing 20.0±1.50 kg, were divided into four groups and used in this study. The effects of varying inclusion levels of fossil shell flour (FSF) (0, 2, 4, and 6 %) on feed intake, water intake, nutrient digestibility, N-retention, hematobiochemical and parasitic profiles, body condition scores, feed preference, wool parameters and methane output were determined. The influence of FSF's varying inclusion levels on fermentation parameters, in vitro true digestibility, and relative feed values were also determined. Wethers fed with 4% FSF inclusion level diet showed the highest (P<0.05) values for dry matter intake, average daily weight gain, N retention, (Nitrogen retention) and apparent digestibility of crude protein (CP), Ether Extract (EE) and Ash 6 % (P < 0.05). The urinary N and fecal N were lowest in wethers fed 4% FSF inclusion level and highest in those fed on diets without FSF (P < 0.05). Water intake was highest in wethers fed 0% FSF diet, followed by those fed on 4% and lowest in 6% FSF (P< 0.05). There was a significant increase in white blood cell counts in wethers fed on a diet with 4% and 6% FSF inclusion levels from day 10 to 100 compared to wethers fed on a diet with 0% and 2% FSF (P <0.05). Red blood cell counts also increased significantly in wethers fed on a diet containing 4% FSF, but a slight increase in wethers with 6 % FSF diet, throughout the experimental period (P < 0.05). Blood urea was highest in wethers fed 0% FSF inclusion level and lowest in 6% at day 30 to day 100. Wethers on 4% FSF diet showed an increase in blood urea from day 30 to day 100 (P < 0.05) while wethers on 0% and 2% remained unchanged (P<0.05) during this period and not different (P > 0.05) from wethers on 4% FSF as well. The total protein concentration, albumin, total bilirubin, Na, K, glucose, cholesterol, and liver enzymes were normal for wethers. However, serum creatinine level was lower in wethers fed on 4% FSF than those on 0% FSF (P < 0.01). Haemonchus and Coccidian fecal egg counts were low in wethers fed diets with 2%, 4%, and 6 % FSF (P < 0.01) compared 11 with wethers fed with 0% FSF inclusion level during the same period. The body condition score of wethers fed on diets with 2%, 4%, and 6% FSF inclusion levels were higher than those on 0% (P < 0.05). Wool yield, staple length, the coefficient variation of the fibre diameter, and fibre of wethers fed on diets with FSF were higher than those without FSF (P < 0.05). The fibre diameter of the wethers fed on FSF supplemented diets was the same as those on 0 % FSF (P > 0.05). The wethers spent more time on FSF supplemented diets and consumed more feed compared to that without FSF supplemented (P < 0.05). The levels of FSF inclusion in the diet affected the enteric methane output (ppm-m), where 4 % FSF had the highest enteric methane output while wethers on 2 % FSF had the lowest methane output (P < 0.05). Resting wethers produced more methane (g/day) than those feeding or standing (P < 0.05). Increasing levels of FSF did not affect ruminal temperature and pH. Ammonia-N increased with increasing FSF except in wethers fed on a diet with 4% FSF (P < 0.01). The total molar concentrations of the wethers' volatile fatty acids decreased with increasing FSF levels (P > 0.05). The acetic propionic ratio of the wethers also decreased except at a 4% inclusion level. The in vitro true digestibility dry matter (IVTDDM), in vitro true digestibility neutral detergent fibre (IVTDNDF), and in vitro true digestibility acid detergent fibre (IVTDADF) of the wethers decreased up to 4% FSF inclusion but tended to increase at 6% inclusion. This study's result as one of the pioneer studies in Dohne-Marino wethers showed that FSF treatment has the potential to improve the nutritional status of the animal and the animal performance and wool quality. Health-wise, FSF decrease nematode population and boost animal immunity as seen in RBC and WBC counts. It also can play a major role in protecting the environment, as seen in its reduction in feacal and urinary nitrogen, which is heavily involved in environmental pollution. Result also confirmed that the best period to target for methane mitigation in ruminants is the resting period. In conclusion, the inclusion of FSF in the diet of Dohne-Merino wethers has the potential to improve the overall performance, with a 4% FSF inclusion level having optimal productivity. However, future research is required to investigate FSF's effect on meat quality, rumen microbial community, in-vivo digestibility, and milk production.
- Full Text:
- Date Issued: 2020
- Authors: Ikusika, Olusegun Oyebade
- Date: 2020
- Subjects: Merino sheep Sheep -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/18465 , vital:42542
- Description: The study's broad objective was to assess growth performance, blood and parasitic profiles, wool parameters, methane emission, and nutritional status of Dohne-Merino wethers fed diets supplemented with varying levels of fossil shell flour. Twenty-four Dohne-Merino wethers, averagely weighing 20.0±1.50 kg, were divided into four groups and used in this study. The effects of varying inclusion levels of fossil shell flour (FSF) (0, 2, 4, and 6 %) on feed intake, water intake, nutrient digestibility, N-retention, hematobiochemical and parasitic profiles, body condition scores, feed preference, wool parameters and methane output were determined. The influence of FSF's varying inclusion levels on fermentation parameters, in vitro true digestibility, and relative feed values were also determined. Wethers fed with 4% FSF inclusion level diet showed the highest (P<0.05) values for dry matter intake, average daily weight gain, N retention, (Nitrogen retention) and apparent digestibility of crude protein (CP), Ether Extract (EE) and Ash 6 % (P < 0.05). The urinary N and fecal N were lowest in wethers fed 4% FSF inclusion level and highest in those fed on diets without FSF (P < 0.05). Water intake was highest in wethers fed 0% FSF diet, followed by those fed on 4% and lowest in 6% FSF (P< 0.05). There was a significant increase in white blood cell counts in wethers fed on a diet with 4% and 6% FSF inclusion levels from day 10 to 100 compared to wethers fed on a diet with 0% and 2% FSF (P <0.05). Red blood cell counts also increased significantly in wethers fed on a diet containing 4% FSF, but a slight increase in wethers with 6 % FSF diet, throughout the experimental period (P < 0.05). Blood urea was highest in wethers fed 0% FSF inclusion level and lowest in 6% at day 30 to day 100. Wethers on 4% FSF diet showed an increase in blood urea from day 30 to day 100 (P < 0.05) while wethers on 0% and 2% remained unchanged (P<0.05) during this period and not different (P > 0.05) from wethers on 4% FSF as well. The total protein concentration, albumin, total bilirubin, Na, K, glucose, cholesterol, and liver enzymes were normal for wethers. However, serum creatinine level was lower in wethers fed on 4% FSF than those on 0% FSF (P < 0.01). Haemonchus and Coccidian fecal egg counts were low in wethers fed diets with 2%, 4%, and 6 % FSF (P < 0.01) compared 11 with wethers fed with 0% FSF inclusion level during the same period. The body condition score of wethers fed on diets with 2%, 4%, and 6% FSF inclusion levels were higher than those on 0% (P < 0.05). Wool yield, staple length, the coefficient variation of the fibre diameter, and fibre of wethers fed on diets with FSF were higher than those without FSF (P < 0.05). The fibre diameter of the wethers fed on FSF supplemented diets was the same as those on 0 % FSF (P > 0.05). The wethers spent more time on FSF supplemented diets and consumed more feed compared to that without FSF supplemented (P < 0.05). The levels of FSF inclusion in the diet affected the enteric methane output (ppm-m), where 4 % FSF had the highest enteric methane output while wethers on 2 % FSF had the lowest methane output (P < 0.05). Resting wethers produced more methane (g/day) than those feeding or standing (P < 0.05). Increasing levels of FSF did not affect ruminal temperature and pH. Ammonia-N increased with increasing FSF except in wethers fed on a diet with 4% FSF (P < 0.01). The total molar concentrations of the wethers' volatile fatty acids decreased with increasing FSF levels (P > 0.05). The acetic propionic ratio of the wethers also decreased except at a 4% inclusion level. The in vitro true digestibility dry matter (IVTDDM), in vitro true digestibility neutral detergent fibre (IVTDNDF), and in vitro true digestibility acid detergent fibre (IVTDADF) of the wethers decreased up to 4% FSF inclusion but tended to increase at 6% inclusion. This study's result as one of the pioneer studies in Dohne-Marino wethers showed that FSF treatment has the potential to improve the nutritional status of the animal and the animal performance and wool quality. Health-wise, FSF decrease nematode population and boost animal immunity as seen in RBC and WBC counts. It also can play a major role in protecting the environment, as seen in its reduction in feacal and urinary nitrogen, which is heavily involved in environmental pollution. Result also confirmed that the best period to target for methane mitigation in ruminants is the resting period. In conclusion, the inclusion of FSF in the diet of Dohne-Merino wethers has the potential to improve the overall performance, with a 4% FSF inclusion level having optimal productivity. However, future research is required to investigate FSF's effect on meat quality, rumen microbial community, in-vivo digestibility, and milk production.
- Full Text:
- Date Issued: 2020
Individualism and collectivism as moderators of the relationship between achievement motivation and entrepreneurial interest among undergraduate students at Walter Sisulu University
- Authors: Magadlela, Asanda Sinazo
- Date: 2020
- Subjects: Individualism -- Psychological aspects Collectivism -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/18543 , vital:42607
- Description: The purpose of this study” is “to explore individualism and collectivism” “as moderators of the relationship between entrepreneurial” interest “and achievement motivation”among undergraduate students. The study is focused on analysing the relationship behind the variables and what drives the University students of Walter Sisulu University towards the business development of young people. “Researchers have traditionally associated individualism with high rates of firm creation, arguing that an orientation towards achievement and the pursuit of personal objectives” (dominant aspects of individualist cultures) “are determinants of entrepreneurial activity.” “The current analysis shows that a culture correlates to entrepreneurship”, “but cannot uphold the idea that higher levels of individualism mean higher rates of entrepreneurship.” “Many universities have introduced entrepreneurship education to promote the interest” of undergraduates in “becoming future entrepreneurs. Here, the researcher tries to retrieve the undergraduate’s interest and achievement motivation which influences them to entrepreneurial intentions. Based on” the “literature” review, it identifies various factors that are used in the predictions of entrepreneurial interest. “These factors were” adopted “to explore” student’s interests. “Survey questionnaires were distributed to” two campuses from the University of Walter Sisulu, namely; College street campus (East London) and the Potsdam campus which is the main campus of the University. “A total of” 154 “valid data” was “analysed using multiple regressions. The results show that entrepreneurial” interest “was predicted by achievement” motivation, individualism and collectivism.
- Full Text:
- Date Issued: 2020
- Authors: Magadlela, Asanda Sinazo
- Date: 2020
- Subjects: Individualism -- Psychological aspects Collectivism -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/18543 , vital:42607
- Description: The purpose of this study” is “to explore individualism and collectivism” “as moderators of the relationship between entrepreneurial” interest “and achievement motivation”among undergraduate students. The study is focused on analysing the relationship behind the variables and what drives the University students of Walter Sisulu University towards the business development of young people. “Researchers have traditionally associated individualism with high rates of firm creation, arguing that an orientation towards achievement and the pursuit of personal objectives” (dominant aspects of individualist cultures) “are determinants of entrepreneurial activity.” “The current analysis shows that a culture correlates to entrepreneurship”, “but cannot uphold the idea that higher levels of individualism mean higher rates of entrepreneurship.” “Many universities have introduced entrepreneurship education to promote the interest” of undergraduates in “becoming future entrepreneurs. Here, the researcher tries to retrieve the undergraduate’s interest and achievement motivation which influences them to entrepreneurial intentions. Based on” the “literature” review, it identifies various factors that are used in the predictions of entrepreneurial interest. “These factors were” adopted “to explore” student’s interests. “Survey questionnaires were distributed to” two campuses from the University of Walter Sisulu, namely; College street campus (East London) and the Potsdam campus which is the main campus of the University. “A total of” 154 “valid data” was “analysed using multiple regressions. The results show that entrepreneurial” interest “was predicted by achievement” motivation, individualism and collectivism.
- Full Text:
- Date Issued: 2020
Information needs and information-seeking behaviour of practising medical doctors at Katutura and Windhoek central state hospitals in Namibia
- Authors: Matsveru, David
- Date: 2020
- Subjects: Information behavior Information resources
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17976 , vital:42000
- Description: This study investigated the information needs and information-seeking behaviour of practising medical doctors at Katutura and Windhoek Central hospitals in Namibia. Anchored on Wilson’s (1996) model of information-seeking behaviour, the purpose of the study was to establish the information required by practising medical doctors to carry out their work, how they seek information, the information sources and resources they use, and the factors that affect them as they do so. Understanding users’ information needs and the way information is disseminated in hospitals is necessary in developing an effective information provision system and ensuring the quality of information services in the hospitals. A mixed-methods research approach was used to meet the objectives of the study. Questionnaires were administered on 140 practising medical doctors at Katutura and Windhoek Central state hospitals, while fifteen doctors were interviewed telephonically, using a semi-structured interview guide. IBM SPSS (Version 25) was used to analyse quantitative data from the questionnaires, while content analysis was used to analyse qualitative data from the interviews. The findings of this research are that practising medical doctors need information mainly for improving clinical decision-making, keeping up-to-date, improving professional knowledge, and continuing education. The study also revealed that medical doctors use a variety of information sources and resources. However, the degree to which information sources are xiii used depends on the clinical context (outpatients, wards and casualty/emergency). Some contextual factors (organisational context, socio-cultural context, and information sources) can either support or hinder doctors in seeking the information they need. The patient is one of the primary information sources for medical doctors. However, language problems are a significant challenge in communicating with patients or patients’ relatives. Lack of patients’ understanding of medical terms and unavailability of properly run libraries in hospitals are some of the factors that affect doctors’ information-seeking behaviour. Participants recommended health education for patients, training of medical doctors on the use of the Internet and ICT, provision of properly run hospital libraries, and improved communication with other international hospitals as some of the ways to improve health information sources and services. Three related models were drawn from the study’s findings, based on Wilson’s (1996) model and literature, namely, the doctors’ decision-making model (DDmM), the clinical context information sources model (CCISM), and the model of information needs and information-seeking behaviour of medical doctors (MINISBMD). The thesis concludes with practical recommendations to enhance the provision of information at Katutura and Windhoek Central hospitals and suggestions for further research.
- Full Text:
- Date Issued: 2020
- Authors: Matsveru, David
- Date: 2020
- Subjects: Information behavior Information resources
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17976 , vital:42000
- Description: This study investigated the information needs and information-seeking behaviour of practising medical doctors at Katutura and Windhoek Central hospitals in Namibia. Anchored on Wilson’s (1996) model of information-seeking behaviour, the purpose of the study was to establish the information required by practising medical doctors to carry out their work, how they seek information, the information sources and resources they use, and the factors that affect them as they do so. Understanding users’ information needs and the way information is disseminated in hospitals is necessary in developing an effective information provision system and ensuring the quality of information services in the hospitals. A mixed-methods research approach was used to meet the objectives of the study. Questionnaires were administered on 140 practising medical doctors at Katutura and Windhoek Central state hospitals, while fifteen doctors were interviewed telephonically, using a semi-structured interview guide. IBM SPSS (Version 25) was used to analyse quantitative data from the questionnaires, while content analysis was used to analyse qualitative data from the interviews. The findings of this research are that practising medical doctors need information mainly for improving clinical decision-making, keeping up-to-date, improving professional knowledge, and continuing education. The study also revealed that medical doctors use a variety of information sources and resources. However, the degree to which information sources are xiii used depends on the clinical context (outpatients, wards and casualty/emergency). Some contextual factors (organisational context, socio-cultural context, and information sources) can either support or hinder doctors in seeking the information they need. The patient is one of the primary information sources for medical doctors. However, language problems are a significant challenge in communicating with patients or patients’ relatives. Lack of patients’ understanding of medical terms and unavailability of properly run libraries in hospitals are some of the factors that affect doctors’ information-seeking behaviour. Participants recommended health education for patients, training of medical doctors on the use of the Internet and ICT, provision of properly run hospital libraries, and improved communication with other international hospitals as some of the ways to improve health information sources and services. Three related models were drawn from the study’s findings, based on Wilson’s (1996) model and literature, namely, the doctors’ decision-making model (DDmM), the clinical context information sources model (CCISM), and the model of information needs and information-seeking behaviour of medical doctors (MINISBMD). The thesis concludes with practical recommendations to enhance the provision of information at Katutura and Windhoek Central hospitals and suggestions for further research.
- Full Text:
- Date Issued: 2020
A critical analysis of the influence of media reporting on xenophobic behaviours among students in selected South African universities
- Authors: Mgogo, Quatro
- Date: 2019
- Subjects: Reporters and reporting Xenophobia -- South Africa Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17495 , vital:41081
- Description: A number of theoretical and empirically proven studies have shown that the media exert varying degree of influence on audience members. The South African media framing and coverage of foreign nationals is a good example of this. Media critics and scholars hold that the way and manner foreign nationals are represented in South African media landscape contributes to the endemic xenophobic outbreaks in the country. (Endong, 2018; George & Aidoo, 2017). This study aims to critically analyse the influence of media reporting on xenophobic behaviours among students in selected South African universities. Part of its aim is to assert if there exist xenophobic behaviours among students learning in South African universities, which are influenced by the manner in which media reports have stigmatised foreign nationals. Therefore, this study looked at three South African universities, namely the University of Fort Hare, Alice campus, the University of KwaZulu Natal, Howard college campus and the University of Johannesburg, Soweto campus. Data for the study were collected using the qualitative methods, particularly the focus groups discussions and in-depth interviews. The findings of this study have revealed that xenophobic behaviours were evident among students, in lecture-rooms, as well as student residences. The participants also confirmed that the media’s focus and reliance on negative stereotypes and generalized information when representing foreign nationals were the main contributing factors to xenophobic behaviours, including its previous adopting of the words like Amakwerekwere, Aliens and Amagrigamba. In an attempt to discourage xenophobic behaviours, this study has therefore recommended peace journalism and Ubuntu journalism as alternative models for reporting xenophobic violence and conflict.
- Full Text:
- Date Issued: 2019
- Authors: Mgogo, Quatro
- Date: 2019
- Subjects: Reporters and reporting Xenophobia -- South Africa Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17495 , vital:41081
- Description: A number of theoretical and empirically proven studies have shown that the media exert varying degree of influence on audience members. The South African media framing and coverage of foreign nationals is a good example of this. Media critics and scholars hold that the way and manner foreign nationals are represented in South African media landscape contributes to the endemic xenophobic outbreaks in the country. (Endong, 2018; George & Aidoo, 2017). This study aims to critically analyse the influence of media reporting on xenophobic behaviours among students in selected South African universities. Part of its aim is to assert if there exist xenophobic behaviours among students learning in South African universities, which are influenced by the manner in which media reports have stigmatised foreign nationals. Therefore, this study looked at three South African universities, namely the University of Fort Hare, Alice campus, the University of KwaZulu Natal, Howard college campus and the University of Johannesburg, Soweto campus. Data for the study were collected using the qualitative methods, particularly the focus groups discussions and in-depth interviews. The findings of this study have revealed that xenophobic behaviours were evident among students, in lecture-rooms, as well as student residences. The participants also confirmed that the media’s focus and reliance on negative stereotypes and generalized information when representing foreign nationals were the main contributing factors to xenophobic behaviours, including its previous adopting of the words like Amakwerekwere, Aliens and Amagrigamba. In an attempt to discourage xenophobic behaviours, this study has therefore recommended peace journalism and Ubuntu journalism as alternative models for reporting xenophobic violence and conflict.
- Full Text:
- Date Issued: 2019
A critical assessment of the implementation of community development projects in mitigating youth unemployment: A case of Mashonaland West province Zimbabwe
- Authors: Mafa, Dennyford
- Date: 2019
- Subjects: Economic development projects -- Evaluation Poverty -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17473 , vital:41079
- Description: The aim of the study was to critically assess the implementation of community development projects in mitigating youth unemployment in Mashonaland province of Zimbabwe. The study used the mixed method which dwells beneath a social phenomenon in order to draw substantiated findings. Data was collected using three method and these include, individual face-to- face interviews, focus group discussion and questionnaire administered to youth, government officials and the local authorities. The study was underpinned by the asset based community development theory and sustainable livelihood approach. Findings highlighted that the participants and the respondents meet the characteristics and criterion for selected community development projects aimed at mitigating youth unemployment. The study revealed that there has been lack on youth involvement in the planning and initiation of the youth community development projects which aim to mitigate youth unemployment and poverty eradication. It has been found out that the implementation process of the youth community development projects was surrounded by lack of knowledge and lack of the involvement of the youths, which resulted in the failure of mitigating youth unemployment and eradication of poverty. Although accessibility (to youth) of these community development projects was for all the community youth who were unemployed, it emerged that the access was not as indicated due to factors like, lack of funding, partisan distribution of resources. The study also realized that due to lack of involvement and proper implementation, the youth community development projects were not sustainable, which was evidenced by the high rate of youth unemployment and poverty levels. Furthermore, the study revealed that effectiveness of youth community development projects in v alleviating youth unemployment in the province has also been marred with pitfalls. Thus, there has been an increase of youth unemployment and poverty. Last but not least, the findings of the study revealed that there were a couple of challenges, which are rooted in partnerships, lack of youth inclusion and involvement, as well lack of involvement of other stakeholders with expertise on implementation of youth community development projects to eradicate poverty and alleviate youth unemployment. Regardless of the brilliant ideas and strategic interventions, the government lacks the practicality of the implementation of these intervention strategies. The study found that interventions were there. However, intervention entails a process which has different facets and obligates the government to function systematically to avoid default in the process of service delivery. It is recommended amongst others that the government and various stakeholders should take cognizance and develop mechanisms and strategies for poverty alleviation, growth, development and employment creation for the youth.
- Full Text:
- Date Issued: 2019
- Authors: Mafa, Dennyford
- Date: 2019
- Subjects: Economic development projects -- Evaluation Poverty -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17473 , vital:41079
- Description: The aim of the study was to critically assess the implementation of community development projects in mitigating youth unemployment in Mashonaland province of Zimbabwe. The study used the mixed method which dwells beneath a social phenomenon in order to draw substantiated findings. Data was collected using three method and these include, individual face-to- face interviews, focus group discussion and questionnaire administered to youth, government officials and the local authorities. The study was underpinned by the asset based community development theory and sustainable livelihood approach. Findings highlighted that the participants and the respondents meet the characteristics and criterion for selected community development projects aimed at mitigating youth unemployment. The study revealed that there has been lack on youth involvement in the planning and initiation of the youth community development projects which aim to mitigate youth unemployment and poverty eradication. It has been found out that the implementation process of the youth community development projects was surrounded by lack of knowledge and lack of the involvement of the youths, which resulted in the failure of mitigating youth unemployment and eradication of poverty. Although accessibility (to youth) of these community development projects was for all the community youth who were unemployed, it emerged that the access was not as indicated due to factors like, lack of funding, partisan distribution of resources. The study also realized that due to lack of involvement and proper implementation, the youth community development projects were not sustainable, which was evidenced by the high rate of youth unemployment and poverty levels. Furthermore, the study revealed that effectiveness of youth community development projects in v alleviating youth unemployment in the province has also been marred with pitfalls. Thus, there has been an increase of youth unemployment and poverty. Last but not least, the findings of the study revealed that there were a couple of challenges, which are rooted in partnerships, lack of youth inclusion and involvement, as well lack of involvement of other stakeholders with expertise on implementation of youth community development projects to eradicate poverty and alleviate youth unemployment. Regardless of the brilliant ideas and strategic interventions, the government lacks the practicality of the implementation of these intervention strategies. The study found that interventions were there. However, intervention entails a process which has different facets and obligates the government to function systematically to avoid default in the process of service delivery. It is recommended amongst others that the government and various stakeholders should take cognizance and develop mechanisms and strategies for poverty alleviation, growth, development and employment creation for the youth.
- Full Text:
- Date Issued: 2019
Analyses of Retail and Transport Geography of Liquefied Petroleum Products in Ibadan metropolis, Nigeria
- Authors: Ajayi, Adeyinka Peter
- Date: 2019
- Subjects: Petroleum products
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19065 , vital:40090
- Description: This study analyzed the effects that spatial arrangement of petroleum products retail outlets and the supply chain management techniques employed for products distribution (for both intra city and intercity shipments) have on the retailing dynamism of petroleum products within built environment and peripherals of Ibadan metropolis over the years. Specifically, the study investigated the differentials in the spatial configurations of petroleum products retail outlets between the core and periurban zones of the metropolis. An attempt was made to determine the explanatory variables that influence the spatial distributional decisions of petroleum products retail outlets in the metropolis. The study equally examined how the supply chain management (SCM) techniques by the different categories of the retail outlet owners influence the efficient and cost effective distribution of petroleum products. Lastly an attempt was made to analyze the relationship between the socio-economic attributes of the haulers and the achievement of compliance to the HSE stipulations guiding the conveyance of petroleum products. The theoretical underpinnings for the research were a derivative of the amalgamation of normative and psychological theories from geography, psychology, SCM and retailing science. Specifically, Expectation Disconfirmation Theory (EDT), Distributive Justice, Central Place Theory (CPT) Theories of Urban Impact (TUI) and Theory of Constraint (ToC) were the theories utilized in the study. For the achievement of the first objective which was to investigate the possible differential in the compliance rate between spatial pattern of fuel retail outlets in the core and peripheral zones of Ibadan metropolis, the first hypothesis of the study (which examined if there was no significant difference in the rate of compliance to the planning authority stipulations guiding the location pattern of petroleum product retail outlets between those located in the built up and xxiv peripheral zones of the city), was tested through the use of buffering and proximity analyses in the ArcMap environment of ArcGIS 10.1, while inferential statistical tool of an independent-samples t-test was conducted to compare the rate of compliance to the stipulations guiding the locations of these outlets in both the core and the peripheral zones. The result from the GIS analysis indicated that 33 (15.56%) out of the 220 outlets in the core zone of the metropolis complied with the planning stipulations guiding the location of fuel retail outlets. For the peripheral zone, out of the 220 fuel retail outlets 24 (10.90%) complied with the stipulations. The result from the t- test which was employed to test the hypothesis indicated that no significant difference existed in the rate of compliance t (263) =-2.66, p = 0.08 between fuel retail outlets in the core zone (M=3.9, SD=1.4) and peripheral zone (M=4.5, SD=1.79). The alternate hypothesis which stated that ―no significant difference existed in the compliance rate between fuel retail outlets located in the two zones‖ is accepted. For the achievement of the second objective of the study which was to analyze the factors which determine the location of fuel retail outlets both in the core and peripheral zones of Ibadan metropolis. All the managers/owners of the 432 fuel retail outlets in the metropolis were sampled out of which 256 questionnaires were retrieved for the purpose of this analysis. The breakdown of the socio-economic characteristics of the sampled respondents showed that the gender distribution showed that 194 (75.78%) of the respondents were males, while 64 (24.22 %) were females. The average age of the sampled population was 33.70 years. The mixed method was employed for the achievement of the second objective of this study. Logistic Regression Model (LRM) was employed to test the hypothesis and the result revealed that the inclusion of the independent variables in the model increased the overall level of it accuracy. The overall significance revealed that the Model Chi- xxv Square, derived from the likelihood fitted is also accurate (X2 = 43.47, df=5, p>.05). The model chi-square value of 43.47 (approximately 44% ) was significant. Thus, the indication is that the model has a good fit in predicting the possibility of a fuel retail outlet being located in the core or peripheral zone of the metropolis as determined by the explanatory variables (the independent variables accounted for about 44% of possible factors which determined whether a fuel retail outlets is located either within the core or peripheral zones of the metropolis. The remaining 56% are factors not considered in the study). The result gotten from the in depth interview sessions corroborated the findings from the tested hypothesis. The third objective was to examine the effects which the supply chain technique employed (either vertically integrated model or third-party arrangement) has on the achievement of efficient and effective distribution of the products. In order to achieve this objective, all the 389 registered members of Petroleum Tanker Drivers (PTD) association who are members of the PTD in the metropolis were sampled, 265 (around 70%) of the distributed questionnaires were retrieved and used for the analysis. In depth interview sessions were also conducted with three different managers of the three major conglomerates in the downstream sector of the Nigerian petroleum sector. The result of one-way between subjects (ANOVA) which was conducted to compare differences in the management and performances of haulage services outsourced to the 3PLS and those run under VIM showed that there was a significant effect of ownership type on management performance (F (2,262) = 60.26, p<.05). The null hypothesis was therefore rejected while the alternate hypothesis was accepted. The findings from the interview sessions posted similar results. The fourth and final objective was to analyze the effect that the socio-economic attributes of the participants (haulers and managers of retail outlets) involved in the distribution of xxvi petroleum products has on the safe, efficient and cost-effective distribution of product and this was done through the use of descriptive statistics, inferential statistics and incisive analysis of the interview sessions. A total number of 265 (70%) out of the 389 registered members of Petroleum Tanker Driver Association (PTDA) participated in the study. Multiple regression analysis (MRA) was used to test this hypothesis. The result from the statistical analysis show that the use of stimulant, work condition, marital status and educational attainment/literacy level have joint influence on compliance (R2 = 0.31, F (4,260) = 29.72, p<.05). On the basis of the foregoing, the hypothesis is thus accepted. The result from the interview sessions confirmed the existence of strong relationship between the explanatory variables and the hypothetical dependant variable. The study recommended a review of the planning processes guiding the establishment of fuel retail outlets. The study also advocated that retailers should endeavour to have stronger control over the supply chain of their products this could done by investing more in VIM rather than outsourcing such functions to 3PLs. This will help in better business performances. Government agencies in charge of monitoring drug abuse among haulers are advised to be more proactive by the duo of prevention and punishment strategies. This should include advocacy campaign against drug abuse. Different ranges of punishments should also be meted out for individual haulers found culpable.
- Full Text:
- Date Issued: 2019
- Authors: Ajayi, Adeyinka Peter
- Date: 2019
- Subjects: Petroleum products
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19065 , vital:40090
- Description: This study analyzed the effects that spatial arrangement of petroleum products retail outlets and the supply chain management techniques employed for products distribution (for both intra city and intercity shipments) have on the retailing dynamism of petroleum products within built environment and peripherals of Ibadan metropolis over the years. Specifically, the study investigated the differentials in the spatial configurations of petroleum products retail outlets between the core and periurban zones of the metropolis. An attempt was made to determine the explanatory variables that influence the spatial distributional decisions of petroleum products retail outlets in the metropolis. The study equally examined how the supply chain management (SCM) techniques by the different categories of the retail outlet owners influence the efficient and cost effective distribution of petroleum products. Lastly an attempt was made to analyze the relationship between the socio-economic attributes of the haulers and the achievement of compliance to the HSE stipulations guiding the conveyance of petroleum products. The theoretical underpinnings for the research were a derivative of the amalgamation of normative and psychological theories from geography, psychology, SCM and retailing science. Specifically, Expectation Disconfirmation Theory (EDT), Distributive Justice, Central Place Theory (CPT) Theories of Urban Impact (TUI) and Theory of Constraint (ToC) were the theories utilized in the study. For the achievement of the first objective which was to investigate the possible differential in the compliance rate between spatial pattern of fuel retail outlets in the core and peripheral zones of Ibadan metropolis, the first hypothesis of the study (which examined if there was no significant difference in the rate of compliance to the planning authority stipulations guiding the location pattern of petroleum product retail outlets between those located in the built up and xxiv peripheral zones of the city), was tested through the use of buffering and proximity analyses in the ArcMap environment of ArcGIS 10.1, while inferential statistical tool of an independent-samples t-test was conducted to compare the rate of compliance to the stipulations guiding the locations of these outlets in both the core and the peripheral zones. The result from the GIS analysis indicated that 33 (15.56%) out of the 220 outlets in the core zone of the metropolis complied with the planning stipulations guiding the location of fuel retail outlets. For the peripheral zone, out of the 220 fuel retail outlets 24 (10.90%) complied with the stipulations. The result from the t- test which was employed to test the hypothesis indicated that no significant difference existed in the rate of compliance t (263) =-2.66, p = 0.08 between fuel retail outlets in the core zone (M=3.9, SD=1.4) and peripheral zone (M=4.5, SD=1.79). The alternate hypothesis which stated that ―no significant difference existed in the compliance rate between fuel retail outlets located in the two zones‖ is accepted. For the achievement of the second objective of the study which was to analyze the factors which determine the location of fuel retail outlets both in the core and peripheral zones of Ibadan metropolis. All the managers/owners of the 432 fuel retail outlets in the metropolis were sampled out of which 256 questionnaires were retrieved for the purpose of this analysis. The breakdown of the socio-economic characteristics of the sampled respondents showed that the gender distribution showed that 194 (75.78%) of the respondents were males, while 64 (24.22 %) were females. The average age of the sampled population was 33.70 years. The mixed method was employed for the achievement of the second objective of this study. Logistic Regression Model (LRM) was employed to test the hypothesis and the result revealed that the inclusion of the independent variables in the model increased the overall level of it accuracy. The overall significance revealed that the Model Chi- xxv Square, derived from the likelihood fitted is also accurate (X2 = 43.47, df=5, p>.05). The model chi-square value of 43.47 (approximately 44% ) was significant. Thus, the indication is that the model has a good fit in predicting the possibility of a fuel retail outlet being located in the core or peripheral zone of the metropolis as determined by the explanatory variables (the independent variables accounted for about 44% of possible factors which determined whether a fuel retail outlets is located either within the core or peripheral zones of the metropolis. The remaining 56% are factors not considered in the study). The result gotten from the in depth interview sessions corroborated the findings from the tested hypothesis. The third objective was to examine the effects which the supply chain technique employed (either vertically integrated model or third-party arrangement) has on the achievement of efficient and effective distribution of the products. In order to achieve this objective, all the 389 registered members of Petroleum Tanker Drivers (PTD) association who are members of the PTD in the metropolis were sampled, 265 (around 70%) of the distributed questionnaires were retrieved and used for the analysis. In depth interview sessions were also conducted with three different managers of the three major conglomerates in the downstream sector of the Nigerian petroleum sector. The result of one-way between subjects (ANOVA) which was conducted to compare differences in the management and performances of haulage services outsourced to the 3PLS and those run under VIM showed that there was a significant effect of ownership type on management performance (F (2,262) = 60.26, p<.05). The null hypothesis was therefore rejected while the alternate hypothesis was accepted. The findings from the interview sessions posted similar results. The fourth and final objective was to analyze the effect that the socio-economic attributes of the participants (haulers and managers of retail outlets) involved in the distribution of xxvi petroleum products has on the safe, efficient and cost-effective distribution of product and this was done through the use of descriptive statistics, inferential statistics and incisive analysis of the interview sessions. A total number of 265 (70%) out of the 389 registered members of Petroleum Tanker Driver Association (PTDA) participated in the study. Multiple regression analysis (MRA) was used to test this hypothesis. The result from the statistical analysis show that the use of stimulant, work condition, marital status and educational attainment/literacy level have joint influence on compliance (R2 = 0.31, F (4,260) = 29.72, p<.05). On the basis of the foregoing, the hypothesis is thus accepted. The result from the interview sessions confirmed the existence of strong relationship between the explanatory variables and the hypothetical dependant variable. The study recommended a review of the planning processes guiding the establishment of fuel retail outlets. The study also advocated that retailers should endeavour to have stronger control over the supply chain of their products this could done by investing more in VIM rather than outsourcing such functions to 3PLs. This will help in better business performances. Government agencies in charge of monitoring drug abuse among haulers are advised to be more proactive by the duo of prevention and punishment strategies. This should include advocacy campaign against drug abuse. Different ranges of punishments should also be meted out for individual haulers found culpable.
- Full Text:
- Date Issued: 2019
Application of some missing data techniques in estimating missing data in high blood pressure covariates
- Authors: Odeyemi, A. S
- Date: 2019
- Subjects: Missing observations (Statistics) Hypertension
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15189 , vital:40195
- Description: Cases recorded with high blood pressure are a major concern in both public and private hospitals. Adequate provision of health information of patients relating to high blood pressure in Eastern Cape Hospitals hinges so much on the outcome of statistical analysis results. The usual statistical methodologies become inadequate in handling statistical analysis of data collected due to incomplete patients’ information stored in the hospital database. From time to time, new methods are developed to address the problem of missing data. High blood pressure is linked to a lot of diseases such hypertension, cardiovascular disease, kidney disease and stroke. In this study, we developed a new method for addressing the problem of missing data in assessing model used for estimating missing values in terms of minimum errors(using RMSE, MAE, and SE) and goodness-of-fits(using 2 R and adjusted 2 R ) of this model and P-value. . The study compared six different methods: Original data (OD), Listwise deletion (LD), Mean imputations (MEI), Mean above (MA), and Mean above below(MAB) and two steps nearest neighbour (2-NN).The comparison was performed using original data set, and missing values at 5%, 10%, 20%, 30% were simulated on Framingham risk scores under MCAR and MAR simulation on BMI values given some assumptions. Five performance indicators were used to describe the model minimum errors and goodness of fit for all the methods. The results showed that the 2-NN is the best replacement method at lower levels (5% and10%) of missing values while MA and MEI performed best at higher levels(15% and 20%) of missing values. All comparison was based on estimates closest to those of the original data where no value was missing. MAR results showed that 2-NN performed better than LD,MA,MAB, and MEI at 5%,10%, and 20% levels of missing data in terms of absolute difference in p-value to original data.
- Full Text:
- Date Issued: 2019
- Authors: Odeyemi, A. S
- Date: 2019
- Subjects: Missing observations (Statistics) Hypertension
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15189 , vital:40195
- Description: Cases recorded with high blood pressure are a major concern in both public and private hospitals. Adequate provision of health information of patients relating to high blood pressure in Eastern Cape Hospitals hinges so much on the outcome of statistical analysis results. The usual statistical methodologies become inadequate in handling statistical analysis of data collected due to incomplete patients’ information stored in the hospital database. From time to time, new methods are developed to address the problem of missing data. High blood pressure is linked to a lot of diseases such hypertension, cardiovascular disease, kidney disease and stroke. In this study, we developed a new method for addressing the problem of missing data in assessing model used for estimating missing values in terms of minimum errors(using RMSE, MAE, and SE) and goodness-of-fits(using 2 R and adjusted 2 R ) of this model and P-value. . The study compared six different methods: Original data (OD), Listwise deletion (LD), Mean imputations (MEI), Mean above (MA), and Mean above below(MAB) and two steps nearest neighbour (2-NN).The comparison was performed using original data set, and missing values at 5%, 10%, 20%, 30% were simulated on Framingham risk scores under MCAR and MAR simulation on BMI values given some assumptions. Five performance indicators were used to describe the model minimum errors and goodness of fit for all the methods. The results showed that the 2-NN is the best replacement method at lower levels (5% and10%) of missing values while MA and MEI performed best at higher levels(15% and 20%) of missing values. All comparison was based on estimates closest to those of the original data where no value was missing. MAR results showed that 2-NN performed better than LD,MA,MAB, and MEI at 5%,10%, and 20% levels of missing data in terms of absolute difference in p-value to original data.
- Full Text:
- Date Issued: 2019
Challenges faced by grandparents in caring for their grandchildren in Mdlankomo location, Libode, Eastern Cape
- Authors: Soganga, Aseza
- Date: 2019
- Subjects: Grandparents as parents Grandchildren -- Care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/16188 , vital:40692
- Description: The study aimed to investigate the challenges that older grandparents face in caring for their grandchildren in Mdlankomo Location, Libode, Eastern Cape. The study intended to achieve three (3) objectives: (i) to establish factors that make caregiving of children by their grandparents challenging, (ii) to establish resources that grandparents need to care for their grandchildren and (iii) to establish the availability of resources required by the grandparents to care for their grandchildren and its possible gaps. The study utilized qualitative research approach, and date collection methods used were in-depth interviews, focus group discussion and key informant method. The number of participants was 34 in total consisting of 23 grandparents and 11 key informants. The findings of the study showed that death of children’s own parents; cultural expectations, youth unemployment, abdication of parental responsibilities, youth unemployment, and carelessness of biological parents were the major reasons for grandparents to care for their grandchildren. The study findings also revealed that grandparents in this caregiving experience both benefits and barriers. The findings further revealed that there are gaps in welfare services, medical services and education. Therefore, the researcher recommended that, those in power should be interested, eager and inquisitive enough about certain aspects that need attention in caregiving of children by their grandparents.
- Full Text:
- Date Issued: 2019
- Authors: Soganga, Aseza
- Date: 2019
- Subjects: Grandparents as parents Grandchildren -- Care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/16188 , vital:40692
- Description: The study aimed to investigate the challenges that older grandparents face in caring for their grandchildren in Mdlankomo Location, Libode, Eastern Cape. The study intended to achieve three (3) objectives: (i) to establish factors that make caregiving of children by their grandparents challenging, (ii) to establish resources that grandparents need to care for their grandchildren and (iii) to establish the availability of resources required by the grandparents to care for their grandchildren and its possible gaps. The study utilized qualitative research approach, and date collection methods used were in-depth interviews, focus group discussion and key informant method. The number of participants was 34 in total consisting of 23 grandparents and 11 key informants. The findings of the study showed that death of children’s own parents; cultural expectations, youth unemployment, abdication of parental responsibilities, youth unemployment, and carelessness of biological parents were the major reasons for grandparents to care for their grandchildren. The study findings also revealed that grandparents in this caregiving experience both benefits and barriers. The findings further revealed that there are gaps in welfare services, medical services and education. Therefore, the researcher recommended that, those in power should be interested, eager and inquisitive enough about certain aspects that need attention in caregiving of children by their grandparents.
- Full Text:
- Date Issued: 2019
Communication barriers within virtual communities in an ethnoreligious diverse society: a case study of Nigeria
- Authors: Ogunnubi ,Adeyemi
- Date: 2019
- Subjects: Communication
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15859 , vital:40533
- Description: The study explores the communication barriers that exist within virtual communities in an ethno-religious diverse society like Nigeria. Qualitative research approach was employed. Subsequently, data was collected using qualitative questionnaire that contained open ended questions and through participant observation (online ethnography). Purposive sampling was used to select participants through liaising with Facebook users, as one of the online virtual communities in Nigeria. Having monitored online discourse on Facebook for some months, this study purposively selected 300 active facebook users from various Nigerian cultural and ethnic backgrounds, but only 60 participants indicated their interest to participate. Also, out of the 60 participants who agreed to participate, only 30 participants (25 males and 5 females) fully participated to the final stage while the other 30 withdrew from the study. The participants were mainly adults between the age brackets of 20 and 59. Thematic Analysis was subsequently used to analyse the data by identifying main themes to provide detailed descriptions of the setting, participants as well as activities. The findings of this study revealed that majority of the participants agree that due to Facebook familiarity and Nigeria's religious colouration, there is a display of disrespect, insolence and deep arrogance to other interactants online. The study further identified and revealed other barriers such as differences in cultural backgrounds and opinions, lack of politeness, prejudging and filtering, name calling and insults. The study proposes that social media platforms as virtual communities should be regulated with full implementation of the law and its sustenance, regardless of individuals having power to make their own choices about the kind of languages they use within virtual communities and considering its effect on other online users. Vulgar languages, hate speeches, incitements, bullying and other offensive comments would hopefully be curbed to the barest minimum if this intervention could be implemented. The conclusion of the study was that Nigerians should be civil in responding to discourse in virtual communities as certain inflammatory, religious or utterances based on ethnicity due to an uninformed perspective usually display one's poor knowledge on issues of national interests
- Full Text:
- Date Issued: 2019
- Authors: Ogunnubi ,Adeyemi
- Date: 2019
- Subjects: Communication
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15859 , vital:40533
- Description: The study explores the communication barriers that exist within virtual communities in an ethno-religious diverse society like Nigeria. Qualitative research approach was employed. Subsequently, data was collected using qualitative questionnaire that contained open ended questions and through participant observation (online ethnography). Purposive sampling was used to select participants through liaising with Facebook users, as one of the online virtual communities in Nigeria. Having monitored online discourse on Facebook for some months, this study purposively selected 300 active facebook users from various Nigerian cultural and ethnic backgrounds, but only 60 participants indicated their interest to participate. Also, out of the 60 participants who agreed to participate, only 30 participants (25 males and 5 females) fully participated to the final stage while the other 30 withdrew from the study. The participants were mainly adults between the age brackets of 20 and 59. Thematic Analysis was subsequently used to analyse the data by identifying main themes to provide detailed descriptions of the setting, participants as well as activities. The findings of this study revealed that majority of the participants agree that due to Facebook familiarity and Nigeria's religious colouration, there is a display of disrespect, insolence and deep arrogance to other interactants online. The study further identified and revealed other barriers such as differences in cultural backgrounds and opinions, lack of politeness, prejudging and filtering, name calling and insults. The study proposes that social media platforms as virtual communities should be regulated with full implementation of the law and its sustenance, regardless of individuals having power to make their own choices about the kind of languages they use within virtual communities and considering its effect on other online users. Vulgar languages, hate speeches, incitements, bullying and other offensive comments would hopefully be curbed to the barest minimum if this intervention could be implemented. The conclusion of the study was that Nigerians should be civil in responding to discourse in virtual communities as certain inflammatory, religious or utterances based on ethnicity due to an uninformed perspective usually display one's poor knowledge on issues of national interests
- Full Text:
- Date Issued: 2019
Diversity, host plant range and ecology of Lepidoptera stem borers in South Africa
- Authors: Stemele, Mxolisi Arnold
- Date: 2019
- Subjects: Lepidoptera Host plants Stem borers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15409 , vital:40405
- Description: The biology and ecology of Lepidopteran pests stem borers has been extensively studied because of the economic importance of pest species such as Busseola fusca (Fuller) (Noctuidae), Sesamia calamistis (Hampson) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae), and Eldana saccharina (Walker) (Pyralidae). Knowledge relating to diversity, infestation dynamics, and host plant range is readily available. In natural vegetation, the variety of stem borers is higher than that found in agroecosystems. However, there is a paucity of South African studies that explain the observed differences in diversity between the two systems. Stem borers are also known to exhibit species-specific ecological requirements, which influence their distribution between African countries. South African biomes are classified based on vegetation structure and climate, which happens to be the most critical factors that affect the distribution of phytophagous insects. This makes biomes an excellent model to investigate diversity and distribution of stem borer species. In this study, we investigated diversity, distribution and species composition in four biomes. The results showed that diversity and distribution of the stem borers in natural vegetation was determined by host plant distribution. Stem borer diversity correlated with high diversity of host plants. Thirty-two stem borer species were collected from 27 host plants and another three from light traps. Widely distributed host plants supported a higher diversity of stem borers, which is consistent with the resource availability hypotheses. Non-metric dimensional scale unfolding revealed disparity in host plant preference and plant species composition between the various stem borer families (Kruskal’s Stress = 0.16). Tortricidae species and Sesamia typhae (Le rü) (Noctuidae) feed exclusively on hydrophytic Cyperaceae species. The majority of Noctuidae, Crambidae and Phycitidae species collected were oligophagous on terrestrial Poaceae, with a few polyphagous exceptions feeding on hydrophytic Cyperaceae and Typhaceae. Additionally, species composition of Poaceae host plants differed between 8 Crambidae and the Phycitidae species. Stem borer species composition between biomes revealed the presence of distinct host plants (2D stress = 0.09) and stem borer (2D stress = 0.13) communities. The stem borer abundance and diversity were strongly correlated (R2 = 0.64), but species diversity (R2 = - 0.95) and host plant diversity (R2 = - 0.85) were inversely correlated to altitude. Based on these results it was concluded that stem borer diversity and distribution in natural vegetation was influenced by host plant diversity and distribution as well as climate associated with altitudinal gradients. In the last two decades, four stem borer species previously known on wild host plants; Busseola segeta (Bowden), Busseola phaia (Bowden), Pirateolea piscator (Fletcher) and Conicofrontia sesamoides (Hampson) have invaded cultivated crops. These invasions remained undetected because of a shortage of surveys, habitat transformation and misidentifications. Misidentifications are common among stem borers due to the considerable resemblance between morphospecies. In this study, we assessed the capacity of the mitochondrial gene Cytochrome c oxidase (COI) to delineate closely related species to develop monitoring and early detection of invasive species and to assess migration patterns and gene flow between the populations. The results demonstrated that COI is an effective DNA marker for species delineation and assessment of intra- and interspecific genetic relationship. The K2P distances and phylogenetic tree defined boundaries between Noctuidae species with high resolution. No divergence distance was detected between intraspecific species, but for the congener species, divergence distance was 0.044%-0.111% with an average of 0.076%. The average interspecies K2P distance (0.57%) was 5-15 times higher than the congener species distances. Phylogenetic analysis revealed the presence of two clades. Busseola and Sesamia species were connected in a monophyletic clade with a strong (93%) bootstrap. The second monophyletic clade comprised of a cluster of Pirateolea, Acrapex and Conicofrontia species, and this was also supported with 9 a strong bootstrap (100%). The gene flow study revealed low levels of genetic differentiation between the populations of B. fusca collected from different maize producing areas in South Africa. This low genetic differentiation was consistent with high gene flow. The number of effective migrants between the populations was between 8 and 99 individuals per generation. These results indicate high connectivity between the populations.
- Full Text:
- Date Issued: 2019
- Authors: Stemele, Mxolisi Arnold
- Date: 2019
- Subjects: Lepidoptera Host plants Stem borers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15409 , vital:40405
- Description: The biology and ecology of Lepidopteran pests stem borers has been extensively studied because of the economic importance of pest species such as Busseola fusca (Fuller) (Noctuidae), Sesamia calamistis (Hampson) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae), and Eldana saccharina (Walker) (Pyralidae). Knowledge relating to diversity, infestation dynamics, and host plant range is readily available. In natural vegetation, the variety of stem borers is higher than that found in agroecosystems. However, there is a paucity of South African studies that explain the observed differences in diversity between the two systems. Stem borers are also known to exhibit species-specific ecological requirements, which influence their distribution between African countries. South African biomes are classified based on vegetation structure and climate, which happens to be the most critical factors that affect the distribution of phytophagous insects. This makes biomes an excellent model to investigate diversity and distribution of stem borer species. In this study, we investigated diversity, distribution and species composition in four biomes. The results showed that diversity and distribution of the stem borers in natural vegetation was determined by host plant distribution. Stem borer diversity correlated with high diversity of host plants. Thirty-two stem borer species were collected from 27 host plants and another three from light traps. Widely distributed host plants supported a higher diversity of stem borers, which is consistent with the resource availability hypotheses. Non-metric dimensional scale unfolding revealed disparity in host plant preference and plant species composition between the various stem borer families (Kruskal’s Stress = 0.16). Tortricidae species and Sesamia typhae (Le rü) (Noctuidae) feed exclusively on hydrophytic Cyperaceae species. The majority of Noctuidae, Crambidae and Phycitidae species collected were oligophagous on terrestrial Poaceae, with a few polyphagous exceptions feeding on hydrophytic Cyperaceae and Typhaceae. Additionally, species composition of Poaceae host plants differed between 8 Crambidae and the Phycitidae species. Stem borer species composition between biomes revealed the presence of distinct host plants (2D stress = 0.09) and stem borer (2D stress = 0.13) communities. The stem borer abundance and diversity were strongly correlated (R2 = 0.64), but species diversity (R2 = - 0.95) and host plant diversity (R2 = - 0.85) were inversely correlated to altitude. Based on these results it was concluded that stem borer diversity and distribution in natural vegetation was influenced by host plant diversity and distribution as well as climate associated with altitudinal gradients. In the last two decades, four stem borer species previously known on wild host plants; Busseola segeta (Bowden), Busseola phaia (Bowden), Pirateolea piscator (Fletcher) and Conicofrontia sesamoides (Hampson) have invaded cultivated crops. These invasions remained undetected because of a shortage of surveys, habitat transformation and misidentifications. Misidentifications are common among stem borers due to the considerable resemblance between morphospecies. In this study, we assessed the capacity of the mitochondrial gene Cytochrome c oxidase (COI) to delineate closely related species to develop monitoring and early detection of invasive species and to assess migration patterns and gene flow between the populations. The results demonstrated that COI is an effective DNA marker for species delineation and assessment of intra- and interspecific genetic relationship. The K2P distances and phylogenetic tree defined boundaries between Noctuidae species with high resolution. No divergence distance was detected between intraspecific species, but for the congener species, divergence distance was 0.044%-0.111% with an average of 0.076%. The average interspecies K2P distance (0.57%) was 5-15 times higher than the congener species distances. Phylogenetic analysis revealed the presence of two clades. Busseola and Sesamia species were connected in a monophyletic clade with a strong (93%) bootstrap. The second monophyletic clade comprised of a cluster of Pirateolea, Acrapex and Conicofrontia species, and this was also supported with 9 a strong bootstrap (100%). The gene flow study revealed low levels of genetic differentiation between the populations of B. fusca collected from different maize producing areas in South Africa. This low genetic differentiation was consistent with high gene flow. The number of effective migrants between the populations was between 8 and 99 individuals per generation. These results indicate high connectivity between the populations.
- Full Text:
- Date Issued: 2019
Effect of social capital and information acquisition on the adoption and benefits of conservation agriculture among cassava and maize smallholder farmers in South-West Nigeria
- Authors: Olawuyi, Seyi Olalekan
- Date: 2019
- Subjects: Agricultural conservation , Sustainable agriculture , Farms, Small
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15200 , vital:40200
- Description: Sustainable economic growth and development in developing economy like Nigeria is achievable through the agricultural sector and sub-sectors which are concentrated in rural areas. Rural areas represent a home to majority (about 75%) of the households practicing farming for family sustenance and/or to earn income from the sales of agricultural products (Oyakhilomen and Zibah, 2014). In addition to the persistent use of traditional farming practices, these rural farming households cultivate crops varieties that are low-yielding on small and scattered farmland holdings (smallholder farmers) (Oyakhilomen and Zibah, 2014). This act depletes the soil organic matter with devastating consequences on production output, income generation as well as the ecosystem. Similarly, non-access to agricultural credit and limited technical knowhow are parts of the challenges that are facing the development of farming activities in subSaharan Africa, including Nigeria (Kassie, Pender, Yesuf, Köhlin, Bluffstone and Mulugeta, 2008). These challenges call for holistic interventions such as conservative agricultural practices; which are sustainable, promote safe environment and ultimately increase production output.
- Full Text:
- Date Issued: 2019
- Authors: Olawuyi, Seyi Olalekan
- Date: 2019
- Subjects: Agricultural conservation , Sustainable agriculture , Farms, Small
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15200 , vital:40200
- Description: Sustainable economic growth and development in developing economy like Nigeria is achievable through the agricultural sector and sub-sectors which are concentrated in rural areas. Rural areas represent a home to majority (about 75%) of the households practicing farming for family sustenance and/or to earn income from the sales of agricultural products (Oyakhilomen and Zibah, 2014). In addition to the persistent use of traditional farming practices, these rural farming households cultivate crops varieties that are low-yielding on small and scattered farmland holdings (smallholder farmers) (Oyakhilomen and Zibah, 2014). This act depletes the soil organic matter with devastating consequences on production output, income generation as well as the ecosystem. Similarly, non-access to agricultural credit and limited technical knowhow are parts of the challenges that are facing the development of farming activities in subSaharan Africa, including Nigeria (Kassie, Pender, Yesuf, Köhlin, Bluffstone and Mulugeta, 2008). These challenges call for holistic interventions such as conservative agricultural practices; which are sustainable, promote safe environment and ultimately increase production output.
- Full Text:
- Date Issued: 2019
Effects of pre-slaughter stress, sex and breed on blood stress indicators, heat shock proteins, glycolytic potential and lamb quality
- Authors: Stempa, Thuthuzelwa
- Date: 2019
- Subjects: Animal welfare , Meat--Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15376 , vital:40402
- Description: The main objective of this study was to determine the effects of pre-slaughter stress (transportation distance and lairage duration), sex and breed on blood stress indicators, heat shock proteins, post-mortem muscle metabolites (glycogen, glucose, glucose-6-phosphate and lactate), glycolytic potential and meat quality attributes from lambs slaughtered at a commercial abattoir. The study was conducted in a high-throughput commercial abattoir in the Buffalo City local municipality of the Eastern Cape Province, South Africa. A total of a hundred eight-month old Dorper and Merino lambs, both male and female, were used in the study. Blood samples for the analysis of glucose and lactate levels were collected using 10.0 mL disposable Becton Dickinson vacutainer tubes treated with fluoride oxalate (grey top) whereas those for determination of cortisol and heat shock protein 70 (HSPA1A) levels were collected using plasma separating vacutainer tubes (SSTTMII, gold top), and those for analysis of creatine kinase and lactate dehydrogenase were collected using 10.0 ml vacutainer tubes treated with Ethylenediaminetetraacetic acid (EDTA). Meat samples (~50 g) for the measurement of post-mortem energy metabolites (glycogen, lactate glucose-6-phosphate and glucose content) were collected from the Muscularis longimissius thoracis et lumborum (LTL) of each carcass ~30 minutes after slaughter and immediately frozen in liquid nitrogen (-196 oC) to prevent further glycolysis. Cold carcass weight (CCW), warm carcass weight (WCW) and carcass fatness (CF) was measured. Meat pH and temperature were measured at iii 45 minutes (initial pH), 6 hours and 24 hours ultimate pH (pHu) post-mortem. Meat colour coordinates [lightness (L*), redness (a*), yellowness (b*), hue angle (H*), chroma (C*)] were also measured 24 hours after slaughter. Furthermore, thawing loss (TL%), cooking loss (CL%) and warner braztler shear force (WBSF) was measured in the LTL 7 days post slaughter. Breed had a significant effect on plasma HSPA1A, plasma lactate, WCW, CCW, L*, muscle glycogen and WBSF. Sex had a significant effect on plasma HSPA1A and pHu. Pearson‘s correlations showed that meat muscle glycogen was positively correlated to glycolytic potential (P<0.001; r=0.63) and initial pH (P<0.05, r=0.20). Muscle lactate was positively correlated to muscle glucose (P<0.01, r=0.30) and glycolytic potential (P<0.001, r=0.79). A positive correlation was shown between muscle glucose and glycolytic potential (P<0.05, r=0.23). The level of LDH was affected by the distance travelled by lambs prior to slaughter. Lairage duration did not affect the levels of CK and LDH. Principal Component Analysis showed a relationship between distance travelled and CK and LDH; and that CK and LDH also influenced the quality of meat from lambs. With respect to sex and breed, the results indicate that female and Dorper were more stressed than male and Merino respectively. Muscle glycolytic potential and post-mortem metabolites have an impact on the quality of meat produced and the Merino had higher muscle glycogen levels at slaughter; hence they produced better meat quality compared to the Dorper. Moreover, no associations were seen between pHu and blood stress indicators. These results indicate that blood stress indicators at exsanguination cannot be used as useful indicators of dark cutting condition in lamb. A relationship between pHu, muscle glycogen and glycolytic potential was established and thus meat pHu can be used as a reliable indicator of tenderness in lamb.
- Full Text:
- Date Issued: 2019
- Authors: Stempa, Thuthuzelwa
- Date: 2019
- Subjects: Animal welfare , Meat--Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15376 , vital:40402
- Description: The main objective of this study was to determine the effects of pre-slaughter stress (transportation distance and lairage duration), sex and breed on blood stress indicators, heat shock proteins, post-mortem muscle metabolites (glycogen, glucose, glucose-6-phosphate and lactate), glycolytic potential and meat quality attributes from lambs slaughtered at a commercial abattoir. The study was conducted in a high-throughput commercial abattoir in the Buffalo City local municipality of the Eastern Cape Province, South Africa. A total of a hundred eight-month old Dorper and Merino lambs, both male and female, were used in the study. Blood samples for the analysis of glucose and lactate levels were collected using 10.0 mL disposable Becton Dickinson vacutainer tubes treated with fluoride oxalate (grey top) whereas those for determination of cortisol and heat shock protein 70 (HSPA1A) levels were collected using plasma separating vacutainer tubes (SSTTMII, gold top), and those for analysis of creatine kinase and lactate dehydrogenase were collected using 10.0 ml vacutainer tubes treated with Ethylenediaminetetraacetic acid (EDTA). Meat samples (~50 g) for the measurement of post-mortem energy metabolites (glycogen, lactate glucose-6-phosphate and glucose content) were collected from the Muscularis longimissius thoracis et lumborum (LTL) of each carcass ~30 minutes after slaughter and immediately frozen in liquid nitrogen (-196 oC) to prevent further glycolysis. Cold carcass weight (CCW), warm carcass weight (WCW) and carcass fatness (CF) was measured. Meat pH and temperature were measured at iii 45 minutes (initial pH), 6 hours and 24 hours ultimate pH (pHu) post-mortem. Meat colour coordinates [lightness (L*), redness (a*), yellowness (b*), hue angle (H*), chroma (C*)] were also measured 24 hours after slaughter. Furthermore, thawing loss (TL%), cooking loss (CL%) and warner braztler shear force (WBSF) was measured in the LTL 7 days post slaughter. Breed had a significant effect on plasma HSPA1A, plasma lactate, WCW, CCW, L*, muscle glycogen and WBSF. Sex had a significant effect on plasma HSPA1A and pHu. Pearson‘s correlations showed that meat muscle glycogen was positively correlated to glycolytic potential (P<0.001; r=0.63) and initial pH (P<0.05, r=0.20). Muscle lactate was positively correlated to muscle glucose (P<0.01, r=0.30) and glycolytic potential (P<0.001, r=0.79). A positive correlation was shown between muscle glucose and glycolytic potential (P<0.05, r=0.23). The level of LDH was affected by the distance travelled by lambs prior to slaughter. Lairage duration did not affect the levels of CK and LDH. Principal Component Analysis showed a relationship between distance travelled and CK and LDH; and that CK and LDH also influenced the quality of meat from lambs. With respect to sex and breed, the results indicate that female and Dorper were more stressed than male and Merino respectively. Muscle glycolytic potential and post-mortem metabolites have an impact on the quality of meat produced and the Merino had higher muscle glycogen levels at slaughter; hence they produced better meat quality compared to the Dorper. Moreover, no associations were seen between pHu and blood stress indicators. These results indicate that blood stress indicators at exsanguination cannot be used as useful indicators of dark cutting condition in lamb. A relationship between pHu, muscle glycogen and glycolytic potential was established and thus meat pHu can be used as a reliable indicator of tenderness in lamb.
- Full Text:
- Date Issued: 2019
Electrical, photo-thermal and mechanical degradation analysis of degraded single junction amorphous silicon solar modules
- Osayemwenre, Gilbert Omorodion
- Authors: Osayemwenre, Gilbert Omorodion
- Date: 2019
- Subjects: Solar cells Amorphous semiconductors Silicon
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15211 , vital:40204
- Description: In this present era of sustainable energy development, photovoltaic modules which are based on amorphous silicon cells have immeasurable prospects of contributing meaningfully to the energy demand of the world at large. The global consciousness of environmental safety issues has birthed the rapid demand for the photovoltaic system. However, the production increase is mainly in bulk-type crystalline (c-Si) solar cells. Thus, to meet the high demand of the market, single junction amorphous silicon (a-Si:H) solar cells production must be encouraged through active research in that regard. This could also help to improve its efficiency and reliability. There has recently been a sharp decrease in the production cost of the bulk Si solar cell, but the a-Si:H solar cell still remains the most economically viable in comparison to the other PV technologies. Companies such as Sharp are currently developing large-scale a-Si:H solar modules that can produce an efficiency of 10.5% after the long-term degradation process. To date, a-Si:H is believed to be one of the most promising thin-film PV technologies (Saito et al., 1993; Hamakawa et al., 1994). The cost of a solar PV manufacturing fell by 6% in 2014 (Santa, 2014), this is in accordance with the 2008 cost production forecast; thus, the cost record stands at 0.20 per watt, as reported by the NPD Solar publisher. Amorphous silicon (a-Si) solar modules generate more kilowatt-hour (kWh) of electricity per kilowatt (kW) than crystalline silicon or other technologies of the same capacity of installation. Furthermore, a-Si:H modules have more functional hours per day. Single junction amorphous silicon (a-Si:H) modules can function beyond the peak sun hours, and they also have a better performance on a cloudy day. vii In other words, a 1kW PV system of a-Si:H is expected to generate more electricity per year in comparison to 1kW PV from other technologies, hence there is a low energy payback time. In this study, commercially available single junction amorphous silicon modules were bought from a local market and they were immediately deployed outdoors. The initial reading of the modules, which served as baseline reading, showed an average of 25% decrease in the modules performance, therefore, there is a need for a long term monitoring process to obtain the best and worst performing modules. Measuring the performance parameters of these PV modules under real sun light (IV) provides a better degradation assessment. This conventional assessment cannot provide an in-depth insight responsible for the variation and degradation of the performance parameters. More obscured parameters like recombination current and ideality factor were obtained from the dark IV measurements. However, this is still superficial in a way. The intrinsic parameters were obtained from scanning probe microscopy (SPM) and CV measurements. The study focuses on the degradation analysis of a-Si:H due to an increase in defect density. A rise in the defect concentration is a huge problem because it causes long-term solar cell degradation, which increases the recombination current and decreases the conversion efficiency. Furthermore, it decreases the photo-generating current and reduces the effective efficiency of the solar device. In other words, the electrical output decreases. This research investigates the reduction in a-Si:H modules’ maximum power, and correlates these with a hot spot formation. A PVPM IV tracer was used for the outdoor characterisation of the module’s temperature profile, while the IR camera was used to analyse the hot spot centre. A four probe IV/CV from NMU was used for the indoor assessment of smaller samples cleaved from both the affected and non-affected regions to characterise the electrical variations across the module viii samples. To be precise, in this study, a naturally degraded single junction amorphous silicon module was delaminated and its mechanical properties were analysed and correlated with the contact potential from a Kelvin probe force microscopy (KPFM).
- Full Text:
- Date Issued: 2019
- Authors: Osayemwenre, Gilbert Omorodion
- Date: 2019
- Subjects: Solar cells Amorphous semiconductors Silicon
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15211 , vital:40204
- Description: In this present era of sustainable energy development, photovoltaic modules which are based on amorphous silicon cells have immeasurable prospects of contributing meaningfully to the energy demand of the world at large. The global consciousness of environmental safety issues has birthed the rapid demand for the photovoltaic system. However, the production increase is mainly in bulk-type crystalline (c-Si) solar cells. Thus, to meet the high demand of the market, single junction amorphous silicon (a-Si:H) solar cells production must be encouraged through active research in that regard. This could also help to improve its efficiency and reliability. There has recently been a sharp decrease in the production cost of the bulk Si solar cell, but the a-Si:H solar cell still remains the most economically viable in comparison to the other PV technologies. Companies such as Sharp are currently developing large-scale a-Si:H solar modules that can produce an efficiency of 10.5% after the long-term degradation process. To date, a-Si:H is believed to be one of the most promising thin-film PV technologies (Saito et al., 1993; Hamakawa et al., 1994). The cost of a solar PV manufacturing fell by 6% in 2014 (Santa, 2014), this is in accordance with the 2008 cost production forecast; thus, the cost record stands at 0.20 per watt, as reported by the NPD Solar publisher. Amorphous silicon (a-Si) solar modules generate more kilowatt-hour (kWh) of electricity per kilowatt (kW) than crystalline silicon or other technologies of the same capacity of installation. Furthermore, a-Si:H modules have more functional hours per day. Single junction amorphous silicon (a-Si:H) modules can function beyond the peak sun hours, and they also have a better performance on a cloudy day. vii In other words, a 1kW PV system of a-Si:H is expected to generate more electricity per year in comparison to 1kW PV from other technologies, hence there is a low energy payback time. In this study, commercially available single junction amorphous silicon modules were bought from a local market and they were immediately deployed outdoors. The initial reading of the modules, which served as baseline reading, showed an average of 25% decrease in the modules performance, therefore, there is a need for a long term monitoring process to obtain the best and worst performing modules. Measuring the performance parameters of these PV modules under real sun light (IV) provides a better degradation assessment. This conventional assessment cannot provide an in-depth insight responsible for the variation and degradation of the performance parameters. More obscured parameters like recombination current and ideality factor were obtained from the dark IV measurements. However, this is still superficial in a way. The intrinsic parameters were obtained from scanning probe microscopy (SPM) and CV measurements. The study focuses on the degradation analysis of a-Si:H due to an increase in defect density. A rise in the defect concentration is a huge problem because it causes long-term solar cell degradation, which increases the recombination current and decreases the conversion efficiency. Furthermore, it decreases the photo-generating current and reduces the effective efficiency of the solar device. In other words, the electrical output decreases. This research investigates the reduction in a-Si:H modules’ maximum power, and correlates these with a hot spot formation. A PVPM IV tracer was used for the outdoor characterisation of the module’s temperature profile, while the IR camera was used to analyse the hot spot centre. A four probe IV/CV from NMU was used for the indoor assessment of smaller samples cleaved from both the affected and non-affected regions to characterise the electrical variations across the module viii samples. To be precise, in this study, a naturally degraded single junction amorphous silicon module was delaminated and its mechanical properties were analysed and correlated with the contact potential from a Kelvin probe force microscopy (KPFM).
- Full Text:
- Date Issued: 2019
Evaluation of pre-treatment methods on production of bioethanol from bagasse and sugarcane trash
- Authors: Dodo, Charlie Marembo
- Date: 2019
- Subjects: Lignocellulose
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15387 , vital:40403
- Description: A variety of methods have been researched on for bioethanol preparation from different feedstocks. Amongst the available feedstock, one such feedstock is the sugarcane plant. In most of the research on bioethanol preparation with sugarcane the sugary juice has been widely used, with the bagasse and trash having been discarded as waste. The “waste” bagasse and trash are usually removed and thrown away or burnt during harvesting or in sugar mills to supplement energy requirements. This research on lignocellulosic bagasse and trash was done so as not to discard them but to rather find ways in which to use this biomass constructively. Alternatives to burning that can potentially add value to this biomass need to be researched on by evaluating their hydrolysis content. The different lignocellulose pretreatment methods of concentrated and dilute acid pretreatment, with subsequent enzyme hydrolysis as well as alkali and oxidative alkali pretreatment with enzyme hydrolysis were experimented on the bagasse and trash for hydrolysis efficiency and effectiveness. There are two types of acid hydrolysis which were investigated on which are concentrated and dilute sulphuric acid pretreatments. Use of concentrated sulphuric acid yielded the highest amounts of reducing sugars but also resulted in the highest amounts of downstream process inhibitors formation. This resulted in the need for neutralisation steps which in turn increase the overall costs of using this method to obtain reducing sugars. It has however the advantage of occurring at a faster rate, within minutes or hours, than using biological enzymes which took days, up to 72 hours to obtain the highest reducing sugar amounts. Dilute sulphuric acid pretreatment offered the advantage of using fewer chemicals which are therefore less severe on equipment and result in fewer fermentation inhibitors being formed. Dilute sulphuric acid hydrolysis also takes a relatively shorter period than biological methods of pretreatment. A challenge of fermentation inhibitors formed during acid hydrolysis was countered by using the methods of overliming (calcium hydroxide) and comparing it to neutralization with sodium hydroxide. Alkali pretreatment with sodium hydroxide was researched on by applying different pretreatment concentrations during experiments on the lignocellulosic biomass. There was an increase in the available quantities of cellulose with a significant reduction in lignin with pretreatment. Alkali pretreatment proved effective in exposing the cellulose which made v more cellulose surface area available to cellulase enzymes for enzyme hydrolysis. The highest yield of reducing sugars was obtained from hydrolysates pretreated with 0.25 M sodium hydroxide for 60 min and a period of 72 h of enzyme hydrolysis. In general the longer the pretreatment time the more reducing sugars were produced from the enzyme hydrolysis. Alkali peroxide pretreatment also resulted in significant reductions in lignin quantities of lignocellulose material. In this method sodium hydroxide in combination with hydrogen peroxide were used in pretreating the biomass. Hydrolysates with even fewer fermentation inhibitors were produced as a result. The highest percentage concentration of cellulose of 63% (g/g) was achieved after pretreatment of bagasse with 5% alkali hydrogen peroxide and trash with 0,25M sodium hydroxide pretreatment. Pretreatment of biomass using alkali with subsequent enzymatic hydrolysis gave the highest yields of fermentable sugars of 38% (g/g) using 7% (v/v) alkali peroxide pre-treated trash than 36% (g/g) for 5% (v/v) with the least inhibitors. Reducing sugar yields of 25% (g/g) and 22% (g/g) were obtained after pretreatment with concentrated and dilute acid respectively. Neutralization of the acid hydrolysates was necessary to reduce inhibitors formed with neutralisation by sodium hydroxide resulting in low dilutions and loss of fermentable sugars as unlike in the case of overliming. Subsequent steps of fermenting the reducing sugars resulting from pretreatment into bioethanol were based on using the yeast Saccharomyces cerevisae. Pretreatment hydrolysates from alkali peroxide experiments produced higher bioethanol yields of 13.7 (g/l) after enzyme hydrolysates versus 6.9 (g/l) bioethanol from dilute acid hydrolyzates. A comparison of the effects of time showed there was more bioethanol yield of 13.7 (g/l) after 72 h of fermentation with the yeast versus 7.0 (g/l) bioethanol after pretreatment for 24 h. The only drawback is the longer fermentation period which thus reduces the process and so reduces the value of the increase in yield
- Full Text:
- Date Issued: 2019
- Authors: Dodo, Charlie Marembo
- Date: 2019
- Subjects: Lignocellulose
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15387 , vital:40403
- Description: A variety of methods have been researched on for bioethanol preparation from different feedstocks. Amongst the available feedstock, one such feedstock is the sugarcane plant. In most of the research on bioethanol preparation with sugarcane the sugary juice has been widely used, with the bagasse and trash having been discarded as waste. The “waste” bagasse and trash are usually removed and thrown away or burnt during harvesting or in sugar mills to supplement energy requirements. This research on lignocellulosic bagasse and trash was done so as not to discard them but to rather find ways in which to use this biomass constructively. Alternatives to burning that can potentially add value to this biomass need to be researched on by evaluating their hydrolysis content. The different lignocellulose pretreatment methods of concentrated and dilute acid pretreatment, with subsequent enzyme hydrolysis as well as alkali and oxidative alkali pretreatment with enzyme hydrolysis were experimented on the bagasse and trash for hydrolysis efficiency and effectiveness. There are two types of acid hydrolysis which were investigated on which are concentrated and dilute sulphuric acid pretreatments. Use of concentrated sulphuric acid yielded the highest amounts of reducing sugars but also resulted in the highest amounts of downstream process inhibitors formation. This resulted in the need for neutralisation steps which in turn increase the overall costs of using this method to obtain reducing sugars. It has however the advantage of occurring at a faster rate, within minutes or hours, than using biological enzymes which took days, up to 72 hours to obtain the highest reducing sugar amounts. Dilute sulphuric acid pretreatment offered the advantage of using fewer chemicals which are therefore less severe on equipment and result in fewer fermentation inhibitors being formed. Dilute sulphuric acid hydrolysis also takes a relatively shorter period than biological methods of pretreatment. A challenge of fermentation inhibitors formed during acid hydrolysis was countered by using the methods of overliming (calcium hydroxide) and comparing it to neutralization with sodium hydroxide. Alkali pretreatment with sodium hydroxide was researched on by applying different pretreatment concentrations during experiments on the lignocellulosic biomass. There was an increase in the available quantities of cellulose with a significant reduction in lignin with pretreatment. Alkali pretreatment proved effective in exposing the cellulose which made v more cellulose surface area available to cellulase enzymes for enzyme hydrolysis. The highest yield of reducing sugars was obtained from hydrolysates pretreated with 0.25 M sodium hydroxide for 60 min and a period of 72 h of enzyme hydrolysis. In general the longer the pretreatment time the more reducing sugars were produced from the enzyme hydrolysis. Alkali peroxide pretreatment also resulted in significant reductions in lignin quantities of lignocellulose material. In this method sodium hydroxide in combination with hydrogen peroxide were used in pretreating the biomass. Hydrolysates with even fewer fermentation inhibitors were produced as a result. The highest percentage concentration of cellulose of 63% (g/g) was achieved after pretreatment of bagasse with 5% alkali hydrogen peroxide and trash with 0,25M sodium hydroxide pretreatment. Pretreatment of biomass using alkali with subsequent enzymatic hydrolysis gave the highest yields of fermentable sugars of 38% (g/g) using 7% (v/v) alkali peroxide pre-treated trash than 36% (g/g) for 5% (v/v) with the least inhibitors. Reducing sugar yields of 25% (g/g) and 22% (g/g) were obtained after pretreatment with concentrated and dilute acid respectively. Neutralization of the acid hydrolysates was necessary to reduce inhibitors formed with neutralisation by sodium hydroxide resulting in low dilutions and loss of fermentable sugars as unlike in the case of overliming. Subsequent steps of fermenting the reducing sugars resulting from pretreatment into bioethanol were based on using the yeast Saccharomyces cerevisae. Pretreatment hydrolysates from alkali peroxide experiments produced higher bioethanol yields of 13.7 (g/l) after enzyme hydrolysates versus 6.9 (g/l) bioethanol from dilute acid hydrolyzates. A comparison of the effects of time showed there was more bioethanol yield of 13.7 (g/l) after 72 h of fermentation with the yeast versus 7.0 (g/l) bioethanol after pretreatment for 24 h. The only drawback is the longer fermentation period which thus reduces the process and so reduces the value of the increase in yield
- Full Text:
- Date Issued: 2019
Exploring the interplay of sociolinguistic factors in the teaching of esl at secondary school level in Zimbabwe
- Authors: Jhamba , Duren
- Date: 2019
- Subjects: Sociolinguistics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15770 , vital:40522
- Description: The researcher noted that earlier second language teaching models tended to treat language as an artefact to be scrutinised and adhered to with grammatical precision. This tended to reduce all language learning to the mere acquisition of grammatical skills. However, since all language behaviour is embedded in sociocultural and contextual frameworks, all teaching should provide cross-cultural awareness of that complexity as well as of the internal variation within language. Therefore, the research explored the interplay of sociolinguistic factors in the teaching of English in Zimbabwe. The Mixed Methods design; a combination of the descriptive survey and the case study was adopted. The questionnaire, interview, observation and document analysis methods were used to collect both qualitative and quantitative data to assess the role of sociolinguistic factors in second language teaching pedagogy. A combination of convenient sampling and stratified random sampling was used to come up with a sample representative of the school categories and the gender of teachers in the 38 secondary schools in Gweru District. The data for the research was collected from a random sample of 50 teachers. The data analysis supported the need for a reconceptualisation of ESL teaching in Zimbabwe. Notably, language teaching tended to be exam-centric, unimaginative and not well linked to the needs of the learners in the communicative environment outside the school. This confirmed the initial observation that the secondary school graduates generally lacked sociolinguistic competence skills. The teachers were, however generally not motivated to include culture and sociolinguistics in their teaching. The research therefore recommended a revisit of the 7 | Page allowance for the interplay of sociolinguistic factors at all the planning stages of the ESL curriculum; the status, corpus and acquisition stages.
- Full Text:
- Date Issued: 2019
- Authors: Jhamba , Duren
- Date: 2019
- Subjects: Sociolinguistics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15770 , vital:40522
- Description: The researcher noted that earlier second language teaching models tended to treat language as an artefact to be scrutinised and adhered to with grammatical precision. This tended to reduce all language learning to the mere acquisition of grammatical skills. However, since all language behaviour is embedded in sociocultural and contextual frameworks, all teaching should provide cross-cultural awareness of that complexity as well as of the internal variation within language. Therefore, the research explored the interplay of sociolinguistic factors in the teaching of English in Zimbabwe. The Mixed Methods design; a combination of the descriptive survey and the case study was adopted. The questionnaire, interview, observation and document analysis methods were used to collect both qualitative and quantitative data to assess the role of sociolinguistic factors in second language teaching pedagogy. A combination of convenient sampling and stratified random sampling was used to come up with a sample representative of the school categories and the gender of teachers in the 38 secondary schools in Gweru District. The data for the research was collected from a random sample of 50 teachers. The data analysis supported the need for a reconceptualisation of ESL teaching in Zimbabwe. Notably, language teaching tended to be exam-centric, unimaginative and not well linked to the needs of the learners in the communicative environment outside the school. This confirmed the initial observation that the secondary school graduates generally lacked sociolinguistic competence skills. The teachers were, however generally not motivated to include culture and sociolinguistics in their teaching. The research therefore recommended a revisit of the 7 | Page allowance for the interplay of sociolinguistic factors at all the planning stages of the ESL curriculum; the status, corpus and acquisition stages.
- Full Text:
- Date Issued: 2019
Genetic characteristics of Human Immunodeficiency Virus-1, and deter-minants of late presentation for care and Diabetes mellitus amongst newly diagnosed Human Immunodeficiency Virus positive patients in the Eastern Cape, South Africa.
- Authors: Sogbanmu, Olufunso Oladipo
- Date: 2019
- Subjects: HIV infections
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/${Handle} , vital:40495
- Description: Phylogenies may help to characterize transmission pairs, enhance contact tracing and outbreak investigations, track the origin and spread of epidemics over place and time, and to identify patterns of onward Human Immunodeficiency-Virus (HIV) transmission among risk groups. If the pattern and evolution of HIV drug resistance can be mapped, this may influence the development of guidelines in the clinical management of HIV especially with issues relating to prevalence of primary drug resistance and its impact on outcomes of present antiretroviral treatment (ART) regimen in use and the ability to trace and track the development of drug resistant strains. The roll-out of the test and treat Programme for newly diagnosed HIV infected pa-tient, seeks to identify HIV infected individuals early and to prevent morbidity and mortality associated with the late presentation for HIV care. The determination of the magnitude of ‘late presentation’ and or ‘presentation with advanced HIV disease’ can be used in very diverse settings and for many purposes. It provides a unified way to define the problem, thereby targeting appropriate interventions to prevent the detrimental outcomes associated with late presentation to care. The subtle relationship between HIV and diabetes mellitus (DM) may also help in formulating better preventive programs to aid the control of non-communicable diseases such as DM. This cross-sectional study includes a purposive selection of 335 HIV positive patients attending the voluntary counselling and Testing (VCT) and HIV Counselling and Testing (HCT) centres and outpatient departments at Cecilia Makiwane Hospital and the HCT sites at the Buffalo District municipality community health centres, Eastern Cape Province, South Africa. Late or delayed presentation of HIV infection was defined as CD4 cell count beneath 350 cells/μL and/or patients presenting with an AIDS-defining event at the first follow-up regardless of the CD4 cell count. Chapter 1 provides the general introduction had an overview of the introduction to the study, the statement of the research problem, hypothesis, the aim and the objectives. xx Chapter 2 looked in-depth at the HIV, case definition, the latest epidemiology of HIV, the HIV genome, the life cycle of HIV, its diagnosis, the classes of antiretroviral drugs, development of drug resistance. Chapter 3 highlighted the prevalence of Transmitted Drug Resistance (TDR) with focus on the protease gene. RNA was extracted from blood samples of 72 newly diagnosed HIV-1 patients attending some HIV testing and counselling clinics from August 2016 to July 2017. Protease fragments were amplified with specific primers by RT-PCR followed by nested PCR. The amplified products were sequenced using the ABI 360 sequencer, edited with Geneious version 9.1.5 and translated into amino acid with BioEdit software. Drug related resistance mutation (DRMs) analysis was performed on all the protease sequences in accordance with the 2009 WHO list of surveillance drug resistance mutations by submitting the edited sequences to Stanford HIV drug interpretation programme and the international AIDS society-USA guidelines for query of drug resistance associated mutations while phylogenetic analysis was performed using MEGA 6 to allocate all viral sequences into subtypes. In the study, a total of 52/72 (71.1%) reliable HIV-1 protease sequences were obtained in which subtyping and drug resistance mutations were performed. Two (3.8%) major Protease resistance associated mutation (V82A/L and L90M) were observed while another polymorphism like L10F, T74S, Q58E, L10I/V and M46V were also identified. Phylogenetic analyses delineated all the sequences as HIV-1 subtype C. Chapter 4 describes the prevalence and the determinants of late presentation amongst newly diagnosed HIV positive individuals in the Eastern Cape. It indicates the extent of the prevalence of patients presenting to care and at what HIV stage they were assessing health care services since the inception of the ‘test and treat’ strategy. It is a cross-sectional study where a total of 335 newly diagnosed patients were recruited consecutively be-tween August 2016 and July 2017. Late presenter for HIV care was defined in accordance with the European Late Presenter Consensus working group as a patient who reports for care when the CD4 count is below 350 cells/μL and/or when there is an established Aids- xxi defining clinical condition, irrespective of CD4 count. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of late HIV diagnosis. The study showed that 60% of patients were late presenters, with 35% presenting with advanced disease. The major determinants identified were being male and low level of education. This led to recommendations directed at ensuring programmes that targets men in identifying their HIV status and assess care at early stage to prevents the morbidity and mortality associated with delayed presentation. Also, it was recommended that effort should be made to improve access to education and also include HIV related topics into the educational curriculum. Chapter 5 aimed to describe the prevalence and determinants of DM amongst newly diagnosed HIV positive individuals. This is a cross-sectional study which recruited 335 patients between August 2016 and September 2017. Definition for diabetes mellitus was made based on the SEDMSA 2015 guideline of HBA1C of above 6.5%. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of abnormal glycated haemoglobin. Findings showed the prevalence of DM at about 6% amongst newly diagnosed HIV positive individuals. This is similar to findings in other study within the country, but a bit lower than what was obtained in the developed countries. The role of older age (above 40 years) as predisposing factor to development of diabetes in newly diagnosed HIV positive individual was well noted and taken. This ensures that screening for DM should be targeted at elderly HIV positive individuals. The grey area of the appropriate mode of diagnostic test to use to diagnose HIV is still debatable, however, a combination of HBA1c and fasting blood sugar (FBS) may improve the diagnosis of DM in this population group. In chapter 6, the general conclusions, recommendations and future perspectives of the study are reflected.
- Full Text:
- Date Issued: 2019
- Authors: Sogbanmu, Olufunso Oladipo
- Date: 2019
- Subjects: HIV infections
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/${Handle} , vital:40495
- Description: Phylogenies may help to characterize transmission pairs, enhance contact tracing and outbreak investigations, track the origin and spread of epidemics over place and time, and to identify patterns of onward Human Immunodeficiency-Virus (HIV) transmission among risk groups. If the pattern and evolution of HIV drug resistance can be mapped, this may influence the development of guidelines in the clinical management of HIV especially with issues relating to prevalence of primary drug resistance and its impact on outcomes of present antiretroviral treatment (ART) regimen in use and the ability to trace and track the development of drug resistant strains. The roll-out of the test and treat Programme for newly diagnosed HIV infected pa-tient, seeks to identify HIV infected individuals early and to prevent morbidity and mortality associated with the late presentation for HIV care. The determination of the magnitude of ‘late presentation’ and or ‘presentation with advanced HIV disease’ can be used in very diverse settings and for many purposes. It provides a unified way to define the problem, thereby targeting appropriate interventions to prevent the detrimental outcomes associated with late presentation to care. The subtle relationship between HIV and diabetes mellitus (DM) may also help in formulating better preventive programs to aid the control of non-communicable diseases such as DM. This cross-sectional study includes a purposive selection of 335 HIV positive patients attending the voluntary counselling and Testing (VCT) and HIV Counselling and Testing (HCT) centres and outpatient departments at Cecilia Makiwane Hospital and the HCT sites at the Buffalo District municipality community health centres, Eastern Cape Province, South Africa. Late or delayed presentation of HIV infection was defined as CD4 cell count beneath 350 cells/μL and/or patients presenting with an AIDS-defining event at the first follow-up regardless of the CD4 cell count. Chapter 1 provides the general introduction had an overview of the introduction to the study, the statement of the research problem, hypothesis, the aim and the objectives. xx Chapter 2 looked in-depth at the HIV, case definition, the latest epidemiology of HIV, the HIV genome, the life cycle of HIV, its diagnosis, the classes of antiretroviral drugs, development of drug resistance. Chapter 3 highlighted the prevalence of Transmitted Drug Resistance (TDR) with focus on the protease gene. RNA was extracted from blood samples of 72 newly diagnosed HIV-1 patients attending some HIV testing and counselling clinics from August 2016 to July 2017. Protease fragments were amplified with specific primers by RT-PCR followed by nested PCR. The amplified products were sequenced using the ABI 360 sequencer, edited with Geneious version 9.1.5 and translated into amino acid with BioEdit software. Drug related resistance mutation (DRMs) analysis was performed on all the protease sequences in accordance with the 2009 WHO list of surveillance drug resistance mutations by submitting the edited sequences to Stanford HIV drug interpretation programme and the international AIDS society-USA guidelines for query of drug resistance associated mutations while phylogenetic analysis was performed using MEGA 6 to allocate all viral sequences into subtypes. In the study, a total of 52/72 (71.1%) reliable HIV-1 protease sequences were obtained in which subtyping and drug resistance mutations were performed. Two (3.8%) major Protease resistance associated mutation (V82A/L and L90M) were observed while another polymorphism like L10F, T74S, Q58E, L10I/V and M46V were also identified. Phylogenetic analyses delineated all the sequences as HIV-1 subtype C. Chapter 4 describes the prevalence and the determinants of late presentation amongst newly diagnosed HIV positive individuals in the Eastern Cape. It indicates the extent of the prevalence of patients presenting to care and at what HIV stage they were assessing health care services since the inception of the ‘test and treat’ strategy. It is a cross-sectional study where a total of 335 newly diagnosed patients were recruited consecutively be-tween August 2016 and July 2017. Late presenter for HIV care was defined in accordance with the European Late Presenter Consensus working group as a patient who reports for care when the CD4 count is below 350 cells/μL and/or when there is an established Aids- xxi defining clinical condition, irrespective of CD4 count. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of late HIV diagnosis. The study showed that 60% of patients were late presenters, with 35% presenting with advanced disease. The major determinants identified were being male and low level of education. This led to recommendations directed at ensuring programmes that targets men in identifying their HIV status and assess care at early stage to prevents the morbidity and mortality associated with delayed presentation. Also, it was recommended that effort should be made to improve access to education and also include HIV related topics into the educational curriculum. Chapter 5 aimed to describe the prevalence and determinants of DM amongst newly diagnosed HIV positive individuals. This is a cross-sectional study which recruited 335 patients between August 2016 and September 2017. Definition for diabetes mellitus was made based on the SEDMSA 2015 guideline of HBA1C of above 6.5%. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of abnormal glycated haemoglobin. Findings showed the prevalence of DM at about 6% amongst newly diagnosed HIV positive individuals. This is similar to findings in other study within the country, but a bit lower than what was obtained in the developed countries. The role of older age (above 40 years) as predisposing factor to development of diabetes in newly diagnosed HIV positive individual was well noted and taken. This ensures that screening for DM should be targeted at elderly HIV positive individuals. The grey area of the appropriate mode of diagnostic test to use to diagnose HIV is still debatable, however, a combination of HBA1c and fasting blood sugar (FBS) may improve the diagnosis of DM in this population group. In chapter 6, the general conclusions, recommendations and future perspectives of the study are reflected.
- Full Text:
- Date Issued: 2019
Genetic diversity, resistance profile of hiv and risk assessment of mother-to-child transmission in pregnant women on antiretroviral therapy in the Eastern Cape, South Africa
- Authors: Adeniyi, Oladele Vincent
- Date: 2019
- Subjects: Antiretroviral agents , HIV infections -- Treatment -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15120 , vital:40183
- Description: Despite the initiation of life-long ART in HIV-infected pregnant women, the rate and determinants of infant HIV transmission are not known, especially in the poor resource settings of the Eastern Cape, South Africa. Maternal anti-retroviral therapy (ART) is crucial for elimination of mother-to-child transmission (MTCT) of HIV. However, the inevitable risks of emergence of HIV drug resistance poses significant threat to achieving this goal of HIV-free generation and keeping mothers alive. Also, it is unclear if women with high viral load at delivery have acquired clinically relevant mutations, which could confer resistance to the ART, thus, further increasing the risks of motherto-child transmission of HIV-drug resistance strains. In addition to the gaps identified in the prevention of mother-to-child transmission (PMTCT) context, the understanding of regional epidemics is crucial to the broader epidemiological profiling of HIV infections in the country. Despite the rapid influx of foreign nationals to South African and Eastern Cape Province, there has not been any molecular epidemiological studies profiling the HIV diversity in the Eastern Cape.
- Full Text:
- Date Issued: 2019
- Authors: Adeniyi, Oladele Vincent
- Date: 2019
- Subjects: Antiretroviral agents , HIV infections -- Treatment -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15120 , vital:40183
- Description: Despite the initiation of life-long ART in HIV-infected pregnant women, the rate and determinants of infant HIV transmission are not known, especially in the poor resource settings of the Eastern Cape, South Africa. Maternal anti-retroviral therapy (ART) is crucial for elimination of mother-to-child transmission (MTCT) of HIV. However, the inevitable risks of emergence of HIV drug resistance poses significant threat to achieving this goal of HIV-free generation and keeping mothers alive. Also, it is unclear if women with high viral load at delivery have acquired clinically relevant mutations, which could confer resistance to the ART, thus, further increasing the risks of motherto-child transmission of HIV-drug resistance strains. In addition to the gaps identified in the prevention of mother-to-child transmission (PMTCT) context, the understanding of regional epidemics is crucial to the broader epidemiological profiling of HIV infections in the country. Despite the rapid influx of foreign nationals to South African and Eastern Cape Province, there has not been any molecular epidemiological studies profiling the HIV diversity in the Eastern Cape.
- Full Text:
- Date Issued: 2019
Ict literacy skills and demographic factors as determinants of electronic resources use among the undergraduate students in the selected universities the Eastern Cape, South Africa
- Olatoye , Oluwayemi IbukunOluwa
- Authors: Olatoye , Oluwayemi IbukunOluwa
- Date: 2019
- Subjects: Electronic information resources
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/16176 , vital:40675
- Description: In today’s world, information is the foundation on which every strata in society is built and established. As we are in the jet age, the use of Information Communications Technology (ICT) is sine-qua-non to academic development. It is equally important to acquire skills and build capacity in ICT applications, as well as reflect on the demographic factors that determine the utilization of electronic resources among the undergraduate respondents. ICT has also evolutionalized professionalism in librarianship by providing delivery of appropriate, suitable and value-added information services in digital format. This research, therefore, investigated undergraduate students’ ICT literacy skills and demographic factors as determinants of electronic resources use, with selected tertiary institutions of learning in Eastern Cape South Africa as a case study. The study was premised on the Diffusion of Innovation Theory (DOI), Technology Acceptance Model (TAM) and the Theory of Reasoned Action (TRA) with the aim of appraising undergraduate students’ ICT literacy skills and demographic factors as causative elements of e-resources utilization in designated Eastern Cape universities in South Africa, as well as to unravel the impact of the theories on the adoption of technology and the perceived utilization of the electronic resources. The application of DOI, TAM and TRA theories for this study exemplifies the acceptance and usage of technological innovations by envisioned users in ICT literacy skill and electronic resources research, and these theories formed the theoretical basis to strengthen the study. The specific x objectives of the study are: To ascertain how undergraduate students in selected Higher Education Institutions (HEIs) in the Eastern Cape access e-resources; to determine the level of influence of ICT literacy skills on the use of electronic resources by Undergraduate students in the selected universities; to determine the regularity levels of use and problems encountered in the use of electronic resources by Undergraduate students in the selected universities; to ascertain the contributions of demographic factors on the use of electronic resources by Undergraduate students in the selected universities; and to determine the attitudes and perceptions of undergraduate students towards the use of eresources. The approach of the study was in threefold; one, general discussion regarding ICT literacy skills of the respondents and secondly the demographic factors that determine electronic resources use of undergraduate students in the University of Fort Hare and Rhodes University. Finally, ICT literacy skills and demographic factors were investigated with the applicability of TAM, DOI and TRA theories Specifically, under these theories (TAM, TRA and DOI), TAM and TRA models were used to explain behavioural intention and to envisage user acceptance of technology usage (electronic resources), and to elucidate the correlation between the respondent’s (undergraduate students) perceptions, attitudes, beliefs and ultimately system utilization. DOI was conceptualized in this study as a valued tool for appraising the effect of demographic factors on the utilization of electronic resources among the undergraduate students in their academic pursuit. The major findings of the study specifies that ICT literacy skills and demographic factors determine the use of electronic resources. Hence, it is reasoned in the thesis that ICT xi literacy and demographic factors affects the frequency of electronic resources with those, for instance, who have obtained high ICT literacy skill levels when compared to others who are yet to develop their ICT literacy skills. Further, it has been disclosed elsewhere in the study that in terms of age, the younger undergraduate students (from 21 to 30 years) utilize electronic resources more regularly than their older colleagues (those who are 30 years of age and above).The study was approached with the adoption of the mixed-method research technique. The administration of a total of 377 copies of the questionnaire to undergraduate respondents in the aforementioned HEIs, (out of which 266 copies were returned), was conducted with in-depth interview conversations comprising of ten participants, with six respondents selected in the University of Fort Hare and four respondents from Rhodes University. Data acquired from the study were processed and analyzed with the aid of Statistical Package for Social Science (SPSS) for the quantitative data. In the light of the theoretical frameworks of the study, research results established that the ICT experience of the undergraduate respondents greatly influences their proficiency levels. This hypothesized assertion was subjected to statistical validity test through regression analysis. The result depicts that the p-value is 0.49 (which means that p≤ 0.05), and interprets to mean that the hypothesis is accepted. Also, the findings of this study depicts that the utilization of electronic resources by the respondents is mostly for entertainment purposes (such as viewing online videos, listening to sport commentaries, music and video downloads, e-mail communications, chatting with other people) had the highest rankings from the component matrix analysis which were greater than 0.5. From the forgoing, this is interpreted to mean that the respondents possess excellent proficiency in ICT literacy skills as well as in the use of Microsoft packages. xii Also, in the course of the in-depth research interview, it was discovered that most of the interviewees have excellent proficiency in ICT literacy skills. Generally, gender is an essential element that determines accessibility and e-resource utilization of respondents to electronic resources through the home and from other sources. Furthermore, it was discovered that that language is not a determinant regarding respondents’ accessibility and e-resource utilization from other sources of access to respondents. The analysis of this study revealed that more males, who are within the active e-resource using age bracket of 21 to 30 years old access and utilize electronic resources through the residences than their female counterparts. This age bracket is followed in terms of access and use of e-resources through residences by the respondents that are 20 years and below. A chi-square test of independence was also performed to survey the level of correlation between age and access to E-resources. A small p-value (typically ≤ 0.05) indicates strong evidence against the null hypothesis, so you reject the null hypothesis. A large p-value (> 0.05) shows weak evidence against the null hypothesis, so you reject the null hypothesis i.e. X2 (3, N=53) = 7.82. The Pearson chi-square (p-value) generated was .294, which is construed to mean that it is insignificant. Therefore, the explanation is that age has no influence on access of respondents to electronic resources through cybercafé. In order to make ICT literacy skills more beneficial to the undergraduate students in the selected HEIs, recommendations were made in this study. Firstly, there is a need for mass enlightenment campaigns on the use and benefits of E-resources among undergraduate respondents, the building of capacity of the undergraduate students in the use of electronic resources ICT literacy skill development programmes, need for intervention programmes focusing on the application xiii of some E-resources and software where the students are ranked low. Further, it is recommended that female students need to be encouraged to use E-resources. Also, delivery and empowering of Wi-Fi services, as well as the provision of CD- ROM databases should be considered.
- Full Text:
- Date Issued: 2019
- Authors: Olatoye , Oluwayemi IbukunOluwa
- Date: 2019
- Subjects: Electronic information resources
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/16176 , vital:40675
- Description: In today’s world, information is the foundation on which every strata in society is built and established. As we are in the jet age, the use of Information Communications Technology (ICT) is sine-qua-non to academic development. It is equally important to acquire skills and build capacity in ICT applications, as well as reflect on the demographic factors that determine the utilization of electronic resources among the undergraduate respondents. ICT has also evolutionalized professionalism in librarianship by providing delivery of appropriate, suitable and value-added information services in digital format. This research, therefore, investigated undergraduate students’ ICT literacy skills and demographic factors as determinants of electronic resources use, with selected tertiary institutions of learning in Eastern Cape South Africa as a case study. The study was premised on the Diffusion of Innovation Theory (DOI), Technology Acceptance Model (TAM) and the Theory of Reasoned Action (TRA) with the aim of appraising undergraduate students’ ICT literacy skills and demographic factors as causative elements of e-resources utilization in designated Eastern Cape universities in South Africa, as well as to unravel the impact of the theories on the adoption of technology and the perceived utilization of the electronic resources. The application of DOI, TAM and TRA theories for this study exemplifies the acceptance and usage of technological innovations by envisioned users in ICT literacy skill and electronic resources research, and these theories formed the theoretical basis to strengthen the study. The specific x objectives of the study are: To ascertain how undergraduate students in selected Higher Education Institutions (HEIs) in the Eastern Cape access e-resources; to determine the level of influence of ICT literacy skills on the use of electronic resources by Undergraduate students in the selected universities; to determine the regularity levels of use and problems encountered in the use of electronic resources by Undergraduate students in the selected universities; to ascertain the contributions of demographic factors on the use of electronic resources by Undergraduate students in the selected universities; and to determine the attitudes and perceptions of undergraduate students towards the use of eresources. The approach of the study was in threefold; one, general discussion regarding ICT literacy skills of the respondents and secondly the demographic factors that determine electronic resources use of undergraduate students in the University of Fort Hare and Rhodes University. Finally, ICT literacy skills and demographic factors were investigated with the applicability of TAM, DOI and TRA theories Specifically, under these theories (TAM, TRA and DOI), TAM and TRA models were used to explain behavioural intention and to envisage user acceptance of technology usage (electronic resources), and to elucidate the correlation between the respondent’s (undergraduate students) perceptions, attitudes, beliefs and ultimately system utilization. DOI was conceptualized in this study as a valued tool for appraising the effect of demographic factors on the utilization of electronic resources among the undergraduate students in their academic pursuit. The major findings of the study specifies that ICT literacy skills and demographic factors determine the use of electronic resources. Hence, it is reasoned in the thesis that ICT xi literacy and demographic factors affects the frequency of electronic resources with those, for instance, who have obtained high ICT literacy skill levels when compared to others who are yet to develop their ICT literacy skills. Further, it has been disclosed elsewhere in the study that in terms of age, the younger undergraduate students (from 21 to 30 years) utilize electronic resources more regularly than their older colleagues (those who are 30 years of age and above).The study was approached with the adoption of the mixed-method research technique. The administration of a total of 377 copies of the questionnaire to undergraduate respondents in the aforementioned HEIs, (out of which 266 copies were returned), was conducted with in-depth interview conversations comprising of ten participants, with six respondents selected in the University of Fort Hare and four respondents from Rhodes University. Data acquired from the study were processed and analyzed with the aid of Statistical Package for Social Science (SPSS) for the quantitative data. In the light of the theoretical frameworks of the study, research results established that the ICT experience of the undergraduate respondents greatly influences their proficiency levels. This hypothesized assertion was subjected to statistical validity test through regression analysis. The result depicts that the p-value is 0.49 (which means that p≤ 0.05), and interprets to mean that the hypothesis is accepted. Also, the findings of this study depicts that the utilization of electronic resources by the respondents is mostly for entertainment purposes (such as viewing online videos, listening to sport commentaries, music and video downloads, e-mail communications, chatting with other people) had the highest rankings from the component matrix analysis which were greater than 0.5. From the forgoing, this is interpreted to mean that the respondents possess excellent proficiency in ICT literacy skills as well as in the use of Microsoft packages. xii Also, in the course of the in-depth research interview, it was discovered that most of the interviewees have excellent proficiency in ICT literacy skills. Generally, gender is an essential element that determines accessibility and e-resource utilization of respondents to electronic resources through the home and from other sources. Furthermore, it was discovered that that language is not a determinant regarding respondents’ accessibility and e-resource utilization from other sources of access to respondents. The analysis of this study revealed that more males, who are within the active e-resource using age bracket of 21 to 30 years old access and utilize electronic resources through the residences than their female counterparts. This age bracket is followed in terms of access and use of e-resources through residences by the respondents that are 20 years and below. A chi-square test of independence was also performed to survey the level of correlation between age and access to E-resources. A small p-value (typically ≤ 0.05) indicates strong evidence against the null hypothesis, so you reject the null hypothesis. A large p-value (> 0.05) shows weak evidence against the null hypothesis, so you reject the null hypothesis i.e. X2 (3, N=53) = 7.82. The Pearson chi-square (p-value) generated was .294, which is construed to mean that it is insignificant. Therefore, the explanation is that age has no influence on access of respondents to electronic resources through cybercafé. In order to make ICT literacy skills more beneficial to the undergraduate students in the selected HEIs, recommendations were made in this study. Firstly, there is a need for mass enlightenment campaigns on the use and benefits of E-resources among undergraduate respondents, the building of capacity of the undergraduate students in the use of electronic resources ICT literacy skill development programmes, need for intervention programmes focusing on the application xiii of some E-resources and software where the students are ranked low. Further, it is recommended that female students need to be encouraged to use E-resources. Also, delivery and empowering of Wi-Fi services, as well as the provision of CD- ROM databases should be considered.
- Full Text:
- Date Issued: 2019
Impact of adoption of drought tolerant maize varieties on yield in the face of climate change: A case of Salima, Chikwawa and Karonga districts, Malawi
- Rukasha, Conscience Tanyaradzwa
- Authors: Rukasha, Conscience Tanyaradzwa
- Date: 2019
- Subjects: Climatic changes Food security Dry farming
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15628 , vital:40491
- Description: Drought is a huge limiting factor in maize production, mainly in the rain-fed agriculture of subSaharan Africa. In response to this threat, drought-tolerant (DT) maize varieties have been developed with an aim to ensure maize productivity under drought conditions. This study assessed the impact of smallholder farmers’ adoption of DT maize varieties on maize productivity. The first step into understanding the impact of adoption of these varieties on smallholder farmers’ productivity was to first identify the varieties that they were growing. To achieve this, data was collected through the means of a household survey of 600 farmers from Karonga, Chikwawa and Salima districts in Malawi. The major findings drawn were that though most of the farmers have adopted the use of hybrids, as they are fairly common among the varieties that are being grown, most of these hybrids were not drought tolerant varieties. Previous studies had concluded that most of the farmers in Malawi were still growing local varieties. Results from this study showed a major increase in the use of hybrids with SC403 being the most grown variety. The second step in the analysis of the impact of DT maize adoption was to analyse the level and intensity of adoption of these varieties among the smallholder farmers. This was done using a Double Hurdle Model. The results from the double hurdle showed that only 23% of the sampled farmers were growing one or more DT varieties on their plots. Generally, farmers’ decision to use improved agricultural technologies and the intensity of the use in a given period of time are hypothesized to be influenced by a combined effect of various factors such as household characteristics, socioeconomic and physical environments in which farmers operate. The results in this study have shown that the geographical location of farmers plays a significant role in the decision to adopt as well as off-farm income and input subsidies. In terms of intensity, the results revealed that the farmers allocated an average of 0.46 ha of their land under maize cultivation to DT varieties. The results also showed that the intensity of adoption was influenced by gender, household size, whether or not the farmer is recycling the seed and soil fertility. The next step in the study was analysing the impact that intra-seasonal weather variability had on maize productivity. This was done by using daily weather variables for the whole growing season so as to take into account evaporation, rain gaps and other intra seasonal weather limitations. The Just and Pope Production Function was used to analyse the impact of intra-seasonal weather vi variability on productivity. The results suggest that the amount and distribution of rainfall have a strong impact on the development of the maize crop and consequently the quantity harvested. From the results, there was evidence of high variability in rainfall characteristics in terms of the intraseasonal distribution which in turn translated into high variability in maize quantity harvested by the smallholder farmers in Malawi. Lastly, the Endogenous Switching Regression Model was used to analyse the impact of adoption of DT varieties on yield. The results showed that the adoption of DT varieties increases productivity. The use of counterfactual data from the Endogenous Switching Regression (ESR) allowed for an in-depth analysis of the productive implications. The results from the ESR model showed that the farm households that did not adopt, had they adopted, they would have increased their productivity. Furthermore, the results indicated that the use of DT maize varieties successfully delivered relatively less reliance on the total and net rainfall, that is, adopters managed to support their productivity in the face of changing climate while the non-adopters were adversely affected by an increase in temperature and decrease in total rainfall. Adoption of DT varieties increased output among smallholder farmers by 441.33 kg which translates to a 41% increase. Conclusively, the results from this study showed that smallholder farmers are adopting new and improved hybrids and improved OPVs and moving away from the use of local varieties. However the new varieties they are currently using are mostly not DT varieties. This is an interesting finding because the farmers when asked about their preferred traits in maize seed mentioned drought tolerance, therefore the low level of adoption points to numerous factors. These factors include lack of awareness of these varieties among smallholder farmers and unavailability of seed. The results also showed that the level of adoption was low among the farmers. With respect to productivity, this study has shown that adoption of DT varieties by smallholder farmers will increase their yield in the face of climate change
- Full Text:
- Date Issued: 2019
- Authors: Rukasha, Conscience Tanyaradzwa
- Date: 2019
- Subjects: Climatic changes Food security Dry farming
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15628 , vital:40491
- Description: Drought is a huge limiting factor in maize production, mainly in the rain-fed agriculture of subSaharan Africa. In response to this threat, drought-tolerant (DT) maize varieties have been developed with an aim to ensure maize productivity under drought conditions. This study assessed the impact of smallholder farmers’ adoption of DT maize varieties on maize productivity. The first step into understanding the impact of adoption of these varieties on smallholder farmers’ productivity was to first identify the varieties that they were growing. To achieve this, data was collected through the means of a household survey of 600 farmers from Karonga, Chikwawa and Salima districts in Malawi. The major findings drawn were that though most of the farmers have adopted the use of hybrids, as they are fairly common among the varieties that are being grown, most of these hybrids were not drought tolerant varieties. Previous studies had concluded that most of the farmers in Malawi were still growing local varieties. Results from this study showed a major increase in the use of hybrids with SC403 being the most grown variety. The second step in the analysis of the impact of DT maize adoption was to analyse the level and intensity of adoption of these varieties among the smallholder farmers. This was done using a Double Hurdle Model. The results from the double hurdle showed that only 23% of the sampled farmers were growing one or more DT varieties on their plots. Generally, farmers’ decision to use improved agricultural technologies and the intensity of the use in a given period of time are hypothesized to be influenced by a combined effect of various factors such as household characteristics, socioeconomic and physical environments in which farmers operate. The results in this study have shown that the geographical location of farmers plays a significant role in the decision to adopt as well as off-farm income and input subsidies. In terms of intensity, the results revealed that the farmers allocated an average of 0.46 ha of their land under maize cultivation to DT varieties. The results also showed that the intensity of adoption was influenced by gender, household size, whether or not the farmer is recycling the seed and soil fertility. The next step in the study was analysing the impact that intra-seasonal weather variability had on maize productivity. This was done by using daily weather variables for the whole growing season so as to take into account evaporation, rain gaps and other intra seasonal weather limitations. The Just and Pope Production Function was used to analyse the impact of intra-seasonal weather vi variability on productivity. The results suggest that the amount and distribution of rainfall have a strong impact on the development of the maize crop and consequently the quantity harvested. From the results, there was evidence of high variability in rainfall characteristics in terms of the intraseasonal distribution which in turn translated into high variability in maize quantity harvested by the smallholder farmers in Malawi. Lastly, the Endogenous Switching Regression Model was used to analyse the impact of adoption of DT varieties on yield. The results showed that the adoption of DT varieties increases productivity. The use of counterfactual data from the Endogenous Switching Regression (ESR) allowed for an in-depth analysis of the productive implications. The results from the ESR model showed that the farm households that did not adopt, had they adopted, they would have increased their productivity. Furthermore, the results indicated that the use of DT maize varieties successfully delivered relatively less reliance on the total and net rainfall, that is, adopters managed to support their productivity in the face of changing climate while the non-adopters were adversely affected by an increase in temperature and decrease in total rainfall. Adoption of DT varieties increased output among smallholder farmers by 441.33 kg which translates to a 41% increase. Conclusively, the results from this study showed that smallholder farmers are adopting new and improved hybrids and improved OPVs and moving away from the use of local varieties. However the new varieties they are currently using are mostly not DT varieties. This is an interesting finding because the farmers when asked about their preferred traits in maize seed mentioned drought tolerance, therefore the low level of adoption points to numerous factors. These factors include lack of awareness of these varieties among smallholder farmers and unavailability of seed. The results also showed that the level of adoption was low among the farmers. With respect to productivity, this study has shown that adoption of DT varieties by smallholder farmers will increase their yield in the face of climate change
- Full Text:
- Date Issued: 2019
Incidence of cholera-causing and non cholera-causing pathogenic vibrio species in the river-k and two of its feeder wastewater treatment plants in the Raymond Mhlaba municipality, Eastern Cape province of South Africa
- Authors: Gcilitshana, Onele
- Date: 2019
- Subjects: Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15145 , vital:40190
- Description: Despite technological advances in water treatment and improved sanitation in many developing countries, acute microbial diseases still thrive and continue to distress millions of people. This is due to the high number of rural dwellers that still source water for drinking and other domestic uses from contaminated rivers. In South Africa, there have been reports on waterborne disease outbreaks, and specifically in the area understudy, two records of diarrhoeal outbreaks associated with consumption of river water were reported within the last decade. All those outbreaks and previous reports on isolation of other pathogenic bacteria within the area necessitated the conduction of this study in order to identify the potential causes of the cholera-associate diarrheal outbreaks previously reported in the area and nationally. This study was designed to assess the incidence of cholera-causing and non-cholera causing pathogens in final effluents and surface waters of the Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa. RiverK which serves as a major resource for domestic activities, agricultural practices as well as an abstraction point for a potable water treatment plant was used for this study. River-K freshwater and final effluents of its two feeder wastewater treatment plants were sampled monthly, over a twelve-month period (December 2016–November 2017). For purposes of confidentiality, the names of the wastewater treatment plants and river involved are coded in this report. A total of 108 water samples were assessed for the physicochemical parameters that influence the presence of Vibrio pathogens. For bacteriology, the membrane filtration method followed by polymerase chain reaction (PCR) was adopted to assess the incidence of cholera-causing and non-choleracausing Vibrio pathogens, as well as their virulence-associated genes from the two wastewater treatment plants and their receiving waterbody (River-K). Antibiotic susceptibility profiles of identified Vibrio species were determined using the disc diffusion method against a panel of xvi sixteen antibiotics commonly used as antimicrobial drugs of Vibrio infections. Multiple antibiotics resistance index (MARI) and phenotypes (MARP) were measured, and the existence of antibiotic resistance genes was evaluated by PCR using specific primer sets. Most of the physicochemical parameters measured (pH, TDS, temperature, salinity and DO) complied with the recommended standards for drinking water, while some fell short of the recommended limits (EC, turbidity, TSS, free chlorine). From the presumptive Vibrio isolates, 64.3% (476/740) were confirmed by PCR, with their Vibrio densities across all sampling points ranging between 0 and 2.7 × 104 CFU/100 mL, with high counts recorded in summer, hence their positive significant correlation (P< 0.01) with temperature. From the confirmed Vibrio isolates, only V. cholerae (53/476), V. mimicus (21/476) and V. parahaemolyticus (5/476) were detected. For virulence-associated genes, virulence genes homologous to V. cholerae virulence determinants, namely ompU (35%), TCP (14%), ACE (11%), ctx (7%) and HylA (4.5%) were widespread (independently) amongst the V. cholerae and V. mimicus species, while V. parahemolyticus isolates (100%) produced only the ToxR gene. Antibiogram profiling found resistance against some antibiotics such as Nalidixic acid (65%), Polymyxin B (43.8%) etc. The MAR indices ranged between 0 and 0.67 with 41.3% of the isolates recording MAR index values above 0.2. The results presented high degrees of MARPs ranging from four to eleven antimicrobials. For resistance gene detection, the SXT element was detected in 66% of the isolates, while cat1 (93%) was the most predominant, followed by aac (68%), ant (61%), with bla-V (7.1%) as the least detected gene. Findings from this study suggest that the wastewater effluents from the two wastewater treatment plants are potential sources of pathogenic Vibrio species and River-K contains a high quantity of pathogenic Vibrio species with fluctuating seasonal variations that reaffirm temperature as a strong reason for their abundance. The antibiotic-resistant Vibrio species isolated here carry a pool of virulence-associated genes and xvii antibiotic resistance genes, presenting a health threat to the communities that use it directly for domestic and irrigation purposes. In conclusion, some surface waters in the Eastern Cape Province, South Africa are widely contaminated with cholera-causing and non-cholera causing Vibrio pathogens; furthermore, some wastewater treatment plants are ineffective in adequately removing microbial contaminants and have become sources of pathogenic bacteria to their receiving waterbodie
- Full Text:
- Date Issued: 2019
- Authors: Gcilitshana, Onele
- Date: 2019
- Subjects: Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15145 , vital:40190
- Description: Despite technological advances in water treatment and improved sanitation in many developing countries, acute microbial diseases still thrive and continue to distress millions of people. This is due to the high number of rural dwellers that still source water for drinking and other domestic uses from contaminated rivers. In South Africa, there have been reports on waterborne disease outbreaks, and specifically in the area understudy, two records of diarrhoeal outbreaks associated with consumption of river water were reported within the last decade. All those outbreaks and previous reports on isolation of other pathogenic bacteria within the area necessitated the conduction of this study in order to identify the potential causes of the cholera-associate diarrheal outbreaks previously reported in the area and nationally. This study was designed to assess the incidence of cholera-causing and non-cholera causing pathogens in final effluents and surface waters of the Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa. RiverK which serves as a major resource for domestic activities, agricultural practices as well as an abstraction point for a potable water treatment plant was used for this study. River-K freshwater and final effluents of its two feeder wastewater treatment plants were sampled monthly, over a twelve-month period (December 2016–November 2017). For purposes of confidentiality, the names of the wastewater treatment plants and river involved are coded in this report. A total of 108 water samples were assessed for the physicochemical parameters that influence the presence of Vibrio pathogens. For bacteriology, the membrane filtration method followed by polymerase chain reaction (PCR) was adopted to assess the incidence of cholera-causing and non-choleracausing Vibrio pathogens, as well as their virulence-associated genes from the two wastewater treatment plants and their receiving waterbody (River-K). Antibiotic susceptibility profiles of identified Vibrio species were determined using the disc diffusion method against a panel of xvi sixteen antibiotics commonly used as antimicrobial drugs of Vibrio infections. Multiple antibiotics resistance index (MARI) and phenotypes (MARP) were measured, and the existence of antibiotic resistance genes was evaluated by PCR using specific primer sets. Most of the physicochemical parameters measured (pH, TDS, temperature, salinity and DO) complied with the recommended standards for drinking water, while some fell short of the recommended limits (EC, turbidity, TSS, free chlorine). From the presumptive Vibrio isolates, 64.3% (476/740) were confirmed by PCR, with their Vibrio densities across all sampling points ranging between 0 and 2.7 × 104 CFU/100 mL, with high counts recorded in summer, hence their positive significant correlation (P< 0.01) with temperature. From the confirmed Vibrio isolates, only V. cholerae (53/476), V. mimicus (21/476) and V. parahaemolyticus (5/476) were detected. For virulence-associated genes, virulence genes homologous to V. cholerae virulence determinants, namely ompU (35%), TCP (14%), ACE (11%), ctx (7%) and HylA (4.5%) were widespread (independently) amongst the V. cholerae and V. mimicus species, while V. parahemolyticus isolates (100%) produced only the ToxR gene. Antibiogram profiling found resistance against some antibiotics such as Nalidixic acid (65%), Polymyxin B (43.8%) etc. The MAR indices ranged between 0 and 0.67 with 41.3% of the isolates recording MAR index values above 0.2. The results presented high degrees of MARPs ranging from four to eleven antimicrobials. For resistance gene detection, the SXT element was detected in 66% of the isolates, while cat1 (93%) was the most predominant, followed by aac (68%), ant (61%), with bla-V (7.1%) as the least detected gene. Findings from this study suggest that the wastewater effluents from the two wastewater treatment plants are potential sources of pathogenic Vibrio species and River-K contains a high quantity of pathogenic Vibrio species with fluctuating seasonal variations that reaffirm temperature as a strong reason for their abundance. The antibiotic-resistant Vibrio species isolated here carry a pool of virulence-associated genes and xvii antibiotic resistance genes, presenting a health threat to the communities that use it directly for domestic and irrigation purposes. In conclusion, some surface waters in the Eastern Cape Province, South Africa are widely contaminated with cholera-causing and non-cholera causing Vibrio pathogens; furthermore, some wastewater treatment plants are ineffective in adequately removing microbial contaminants and have become sources of pathogenic bacteria to their receiving waterbodie
- Full Text:
- Date Issued: 2019