Self-regulation and academic performance in early childhood :an East London study
- Authors: Martin, Glynnis Michelle
- Date: 2018
- Subjects: Self-control in children Early childhood education Child rearing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/10949 , vital:35969
- Description: Previous research studies have identified various factors as influential in whether one is successful in obtaining the education necessary for effective living within a given society. Early academic performance is consistently linked to later academic performance, which in turn, relates to physical, mental and even financial health outcomes in adulthood. The recognition that competence with the demands of learning and socialization can set up cycles of success or failure, lead to much research interest directed at the key role of self-regulation, as an executive function skill, in early academic performance. Despite this growing body of research, a comprehensive conceptual model for the predictive role and interaction between complex executive functions, socio-emotional competence, learning aptitudes and visuomotor skills, as predictors in early academic success, is still lacking. Knowledge of the integrated functioning of these predictors in the South African context is particularly scarce. This research was designed to address these knowledge gaps through an exploratory descriptive and causal-comparative study. Purposive, non-probability sampling was used to select a group of 183 Grade 1 learners from a low socio-economic area of East London in South Africa. Ages ranged from 6 to 8 years (M = 6.78, SD = 0.54), whilst 40% were female and 60% were male. Predictors of academic success were measured at the start of the first academic term, and a parent-report measure was used to measure socio-emotional competencies. Second term school report cards were used to measure mid-year academic achievement. Relationships between each predictor and their relationships to academic performance were explored through Pearson product-moment correlation coefficients. vii One-way Analysis of Variance with post-hoc Scheffé tests was used to explore differences between groups of Gender, Age, Home Language, Maternal Marital Status, Maternal Age and whether the grade was being Repeated or not. Two priori conceptual models of the relationships between the predictor variables and academic performance were estimated through Structural Equation Modeling. Results indicate various significant relationships between each predictor and specific aspects of academic performance. Visuomotor skills showed the strongest correlation to academic performance, followed by learning abilities and complex executive functions. Social-emotional competence was not practically significantly related to any of the factors and appeared to affect academic performance primarily through a significant relationship to complex executive functions. Interestingly, results indicate subtypes of visuomotor skills that are significantly correlated to the complex executive, as also highly correlated with academic performance. Precision tasks that were not related to complex executive function, was not significantly related to academic performance. Results furthermore identify the significant influence of caregiver factors on visuomotor skills and that of home language on learning abilities. Regression analysis results confirm a significant mediating effect of learning aptitudes in relation to the effects of complex executive function and visuomotor skills on academic performance. Model comparison supported this mediation-model as superior to a no-mediation model in predicting academic success in Grade 1. This study expands on the understanding of the role of the common executive function in relation to factors associated with crystallized intelligence, visuomotor skills and socio-emotional competencies in predicting early academic success. This study presents an innovative integrated mediation model of the relationships between the identified predictors in relation to academic success.
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- Date Issued: 2018
Spatial and seasonal variations of water quality determinants and pollutants as fitness-for-use and compliance assessments of the Mzimvubu catchment water resources for the proposed Mzimvubu Water Project, South Africa
- Authors: Mutingwende, Nhamo
- Date: 2018
- Subjects: Water quality -- South Africa Water quality management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9308 , vital:34320
- Description: The Department of Water Affairs as of late reported plans to build two substantial stockpiling dams in the Mzimvubu Catchment. The Mzimvubu stream basin is probably one of most prominent and undeveloped basin in South Africa. This is notwithstanding high yearly rainfall, high ecological status, high tourism potential, and appropriateness for afforestation, dryland/rainfed and water system agribusiness. Hence, the Department of Water Affairs researched the capability of building a multipurpose dam in the Mzimvubu catchment to catalyse financial and social improvement. The proposed dam will be based on the Tsitsa River. Often, scientific studies related to dam construction concentrate more on discovering the most, in fact, accessible place to construct it, than on the long haul socio-natural issues that come in its preparation. The water quality of the Tsitsa River, its tributaries and the underground drinking water sources within the Mzimvubu catchment are most likely to change once the dam wall is completed. Surface water resources are susceptible to chemical, physical, microbiological contamination and the so-called emerging pollutants either, through human or natural activities. A comprehensive baseline study on the water quality of the Mzimvubu water resources regarding traces of emerging pollutants and water quality determinants (physical, chemical and microbial) pre-dam construction is therefore essential. The objective of the water quality section of this study was to perform an in-depth analysis of water quality in the study area to form a baseline for future studies on how the built dam may affect these. The approach was to assess the spatial and seasonal variations of the pollutants (pharmaceuticals and pesticides) and water quality determinants for all water sources most likely to be affected by the development of the dam. The fitness-for-use and compliance assessments were conducted to assess if the current water resources are fit-for-use for various categories of use and if they comply with various water quality standards and guidelines as determined by the Department of Water Affairs and Forestry. Department of Water Affairs and Forestry is the overseer of South Africa's water assets, and its central goal is to keep up the fitness-for-use of water on a sustained basis. Water samples (500ml) were collected from sixteen (16) sample points, ranging from the proposed mouth of the dam to the N2 bridge point of the Tsitsa River. Points were selected where the Tsitsa River was accessible using the dam project development roads or where tributaries to the Tsitsa River were accessible using dam development roads. Taps/groundwater sources were sampled from the five selected villages. Monthly samples were collected upstream and downstream of the proposed dam wall, from June 2015 to April 2017.Seventeen (17) water quality indices were therefore analysed at sixteen sampling sites, over a two year period. The AB SCIEX TripleTOF™5600 LC/MS/MS was used to screen for pharmaceutical and pesticide pollutants. All the water quality indices were analysed using the AL400 Aqua lytic photometer, and the microbial analysis was done using the Rand Water Method Number 1.2.2.09.1 for enumerating the amount of E. coli and coliforms in the water samples (Rand Water, 2010f). The South African Water Quality Guidelines, Volumes 1 to 7 (DWS, 1996a-g) were used to assess the fitness-for-use of the water sources. To confirm the compliance of the water resources to various standards and guidelines, the water quality data were assessed against international and national guidelines and standards i.e. the WHO guideline, South African water quality guidelines (domestic, irrigation, livestock and watering, aquaculture, and aquatic ecosystems), and the SANS: 241 (2015) standard for drinking water. Non-parametric statistics were utilised to ascertain the changeability, which is a measure of how water quality may vary after some time. With non-parametric insights, the interquartile extent, which lies between the 25th and the 75th percentile, was utilised to depict inconstancy. The median value (50th percentile) was used as an indication of the central tendency or average. The 90th percentile was included as it can be used to assess the frequency of excursions into higher and possibly unacceptable water quality conditions. 3D Sigma plot was used to graphical present the spatial and seasonal variations of water quality indices and emerging pollutants against their concentrations. Fundamental statistical properties and correlations of water quality variables from the Tsitsa River, Tsitsa River tributaries and the drinking water sources were examined using SAS descriptive statistics. The water quality was determined to be of relatively sound quality, based on the comparison with guidelines and standards for the various intended uses, even though some of the water quality determinants were non-compliant and were “unacceptable” regarding fitness for purpose. The water quality of the Ntabalenga dam would most probably be affected by natural influences (for example rainfall, weathering and geological composition) and anthropogenic factors through non-point source pollution from agriculture activities, human settlements (pit latrines and open defecation) as well as industrial activities in the Maclear and Tsolo towns (wastewater treatments plants effluent, hospital effluent). The Tsitsa River had the highest number of non-compliances, especially to the World Health Organisation and Department of Water and Sanitation aquaculture guidelines. Therefore, the Tsitsa River’s water quality would be a significant factor that could compromise the water quality of the water collected in the dam. The human settlement conditions and agricultural inputs seem to be the factors contributing most to contamination of the surface water of the catchment area. The lack of sanitation systems and facilities means that community members have to use the bush and rivers for ablutions, thus contributing to microbial contamination of the environment. The direct application of manure and fertilisers on the fields by farmers further exacerbates microbial contamination and high nutrient inputs into the environment as observed in elevated microbial and phosphate contaminants during the study period. The data obtained from the analysis of pesticides and pharmaceuticals confirmed the contamination of the drinking water sources, the Tsitsa River and its tributaries with pesticides and pharmaceuticals through non-point source pollution. The origins of these pharmaceutical contaminants were identified as the pit latrines, open defecation and wastewater treatment plant effluent, while agricultural application of pesticides was identified as the source of pesticides in surface waters. If not monitored closely, the presence of these emerging pollutants will negatively affect the quality of the dam water both at spatial and temporal scales once the dam wall is completed. Pit latrines and wastewater treatment plants are a significant source of non-point source pollution. The results of this study will add to the ongoing efforts on water quality remediation by recording the spatial and seasonal variations in water quality across various water sources within the study area. The study also provides a baseline for future water quality fitness-for-use and compliance assessments. By these findings and conclusions, it is recommended that a long-term continuous monitoring programme be implemented, especially in areas where increased agricultural activities have been observed. Monitoring should be implemented for the Tsitsa River, its tributaries, and selected drinking water sources which showed the highest number of non-compliances and microbial contamination. All anthropogenic activities in the catchment areas of these sources, both upstream and downstream of the proposed dam wall, must be monitored and strictly managed to prevent and mitigate their possible impacts. Specific emphasis should be placed on agricultural development, which should be controlled to ensure sustainable livestock and cropping practises. Sanitation facilities, systems and community programmes should be put in place to minimise microbial contamination. It would be beneficial for the Department of Water and Sanitation office responsible for the Mzimvubu water resources to establish a central database for all information concerning the water quality of their water resources including the findings in this report. The database must be freely accessible to the residents of the Mzimvubu catchment.
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- Date Issued: 2018
Strategies used by teachers to promote reading in grade 4 : a case of english first additional language learners
- Authors: Fesi, Liziwe
- Date: 2018
- Subjects: English language -- Study and teaching English language -- Rhetoric Reading -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9264 , vital:34316
- Description: The study examines strategies used by teachers to promote reading: A Case of English First Additional Language Learners. The study was located within the constructivism paradigm of reading and used a qualitative research approach that incorporated a case study research design in the collection, analysis and interpretation of the data. The data instruments used were interviews and observations. Data were analyzed using non-statistical procedures. The findings of the study revealed that reading problems are still eminent in Grade Four. It was found that the resources in schools inhibits the progress to promote reading. The educational system is underdeveloped and under resourced with respect to reading materials, and schools are in a bad state due to obsolete facilities. Inadequate infrastructure is also another challenge since most of the participants reported that classes are overcrowded; thus, limiting the space to interact with learners. It was found that primary schools have no libraries; as a result, it was difficult for the teachers to instill the culture of reading. Some participants revealed that technology can be useful to encourage reading, however, their schools have no computer centers and most teachers do not know how to use computers. It emerged from the findings that parents fail to involve themselves in their children’s education. In addition, it was found that poor socio-economic backgrounds affect many homes, and this has a negative impact on schools. Most South African parents are found to be unable to support their children at all. There are also challenges interconnected with the English First Additional Language learners, the eccentricities of the English language, the teacher training and continuing professional development of teachers, as it emerged from the findings of this study that most teachers do not understand the reading strategies, skills of teaching reading and learners lack vocabulary, hence their resistance to reading. A comprehensive model of strategies to improve reading in primary schools was developed by the researcher based on the findings of the study and an extensive literature review.
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- Date Issued: 2018
The effect of guided enquiry-based learning approach on electrical engineering students' recall ability, conceptual understanding, problem solving skills and critical thinking ability in power electronics course at a selected university in South Africa
- Authors: Kumar, Vinod
- Date: 2018
- Subjects: Power electronics Power electronics -- Problems, exercises -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8474 , vital:32836
- Description: Power Electronics (PE) forms the major part of the syllabus for the Industrial Electronics (INDE) course of the National Diploma (ND) programme in Electrical Engineering. This study investigated the effect of Guided Enquiry-Based Learning (GEBL), an Active Learning (AL) approach on Electrical Engineering students’ recall ability, conceptual understanding of PE, problem solving skills and critical thinking ability. The study was carried out at one of the campuses of a selected university in South Africa’s Eastern Cape Province in an attempt to check if GEBL would improve student performances in the above focused areas. The expected population for this research in 2017 was 21, similar to the numbers enrolled in 2016. However, in 2017 the enrollment dropped to 14 and this posed a limitation. Since cancelling the study due to the drop in enrollment would have caused the loss of a research report on PE students, it was decided to continue with it. This was especially so, since no other report on PE within South Africa could be located. The instruments were developed using inputs from subject experts to ensure content validity. Cronbach’s Alpha was used to test the reliability of the instrument. A pilot study was conducted during the previous year with the 2016 PE students and deficiencies in the instruments were rectified. Out of the 14 students in 2017, seven volunteered to be taught using the GEBL approach. All ethical considerations applicable to the study were adhered to. All students from the GEBL group signed the informed consent forms prior to the study. The study adopted a pragmatist paradigm and a mixed method approach. A quasi experimental non-equivalent group post-test only research design was used where both the experimental group and the control group were selected (without random assignment). The post-test only design was selected because of the time constraints with the semester courses. A student-centred GEBL approach was used as an intervention for the experimental group and a teacher-centred traditional approach was used for the control group. Students from both the GEBL and Traditionally Taught Groups (TTGs) were subjected to the same assessments. Quantitative data were collected from two formative assessments and one summative assessment and the qualitative data were collected by interviewing all students from the GEBL group. The collected data were statistically and thematically analysed to determine the extent to which the intervention affected the students’ recall ability, conceptual understanding of PE, problem solving skills and their critical thinking ability. The main conclusions were that when compared to the traditional approach, GEBL was significantly more effective in enhancing recall as well as understanding of PE concepts. However, significant differences were not evident in problem solving and critical thinking. The recommendations are that: students must be encouraged to be more active in the learning process; the shift of strategy from traditional to AL methods such as GEBL must be introduced gradually; and the benefits of GEBL and exposure to it must be popularised in order to develop positive attitudes to GEBL not only among students, but also teaching staff.
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- Date Issued: 2018
The moderating role of occupational self-efficacy and organisational justice in the relationship between perceived job insecurity and counterproductive work behaviour among bank employees in Nigeria
- Authors: Oluwole, Olugbenga Joseph
- Date: 2018
- Subjects: Job security Self-efficacy Bank employees
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12665 , vital:39297
- Description: The unstable global economy and the drive by every organisation to remain in business and be competitive has led to many organisational downsizing, which in turn poses concerns towards identifying behaviours of the survivors’. These behaviours constitute the components of employees’ job performance which include task performance, organisational citizenship behaviour and counterproductive work behaviour (CWB). One of the major behavioural concerns facing organisations globally, in particular in Nigeria, is CWB, which previous studies identified as an attitudinal reaction of perceived job insecurity. Very few empirical studies in Nigeria have attempted to examine the relationship as well as the variables that can moderate the negative effect of job insecurity-CWB. This study, therefore, explores the moderating effects of occupational self-efficacy (OSE) and organisational justice on the job insecurity–CWB relationship among bank employees in Nigeria. Four theories provided the framework for the study, while a descriptive research design which utilized a cross-sectional survey was used. The multi-stage sampling procedure and purposive technique were employed to select the two participating banking organisations from the 22 licensed commercial banks in Nigeria. Using the convenience sampling technique, a total of 380 Nigerian bank employees who gave their personal consent participated through a structured questionnaire. The reliability coefficient of all the instruments are as follows: counterproductive work behaviour (α = .92), perceived job insecurity (α = .65), occupational self-efficacy (α = .82), organisational justice (α = .93) were used for data collection. The sample was taken from branches of the two selected banking organisations that cut across Lagos State, Nigeria, a cosmopolitan and Nigeria business hub. Six hypotheses were tested using descriptive statistics, zero-order correlation and hierarchical multiple regression at 0.05 level of significance. A significant positive relationship existed between: job insecurity and CWB (r = .14); job insecurity and sabotage (r = .23), job insecurity and withdrawal (r = .14) and job insecurity and abuse (r = .20) of sub-dimensions of CWB. Also, a significant relationship existed between OSE and CWB (r = .12); OSE and withdrawal (r = .27) and OSE and abuse (r = .12) of the sub-dimensions of CWB. And lastly, a significant positive relationship existed between organisational justice and CWB (r = .11); distributive justice and CWB (r = .13), procedural justice and CWB (r = .17); organisational justice and withdrawal (r = .35), and a negative relationship between organisational justice and production deviance (r = -.12) of the sub-dimensions of CWB. Also, a significant positive relationship existed on distributive justice and withdrawal behaviour (r = .22) and distributive justice and abuse (r = .12); procedural justice and sabotage (r = .17); procedural justice and withdrawal (r = .44); Interactional justice and withdrawal (r = .29) and a significant negative relationship existed on interactional justice and sabotage. Furthermore, there were significant moderator effects of OSE on job insecurity- CWB relationship (β = .11, p<.05); significant moderator effects of OSE on job insecurity-abuse behaviour (β = .13, p<.05) of sub-dimension of CWB. Also, there was significant moderator effects of organisational justice in job insecurity-CWB relationship (β = -.10, p<.05), interaction effect of procedural justice in job insecurity-withdrawal behaviour relationship (β = .24, p<.01) and interaction effect of interactional justice in job insecurity-abuse behaviour relationship (β = -.39, p<.001). And lastly, there was no significant joint moderator effects of OSE and organisational justice in job insecurity and CWB relationship (β = .00, ns), while there was significant moderator effect of joint OSE and organisational justice on job insecurity – sabotage relationshi0p (β = .17, p<.01) and job insecurity – withdrawal behaviour (β = .14, p<.01) The findings of this study pointed to the significance of employees’ cognitive sense as important and stable resources which organisational practitioners need to take into consideration during organisational change approach. Also, the banking organisation must clearly state the procedure and implementations of downsizing policies.
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- Date Issued: 2018
The role of assisted reproduction technologies in improving cattle production under communal and emerging farming systems in Limpopo, Mpumalanga and KwaZulu-Natal, South Africa
- Authors: Mugwabana, Thinawanga Joseph
- Date: 2018
- Subjects: Beef cattle -- Breeding -- South Africa Beef cattle breeds -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9100 , vital:34262
- Description: The aim of the study was to determine the effect of assisted reproductive technologies (ARTs) in improving cattle production with the purpose of providing policy directives for the successful implementation of the ART project among communal and emerging livestock systems. The study was conducted under communal and emerging cattle farming systems in Limpopo, Mpumalanga and KwaZulu-Natal provinces. The selected districts in Limpopo were Vhembe, Capricorn, Mopani and Waterberg, in Mpumalanga were Gert Sibande and Ehlanzeni while in KwaZulu-Natal the selected districts were Zululand and Harry Gwala. A total of 282 cows were selected for the study, 38 percent in Limpopo, 32 percent in Mpumalanga and 30 percent in KwaZuluNatal. The cow parameters evaluated were breed type, parity, age, body condition score, frame size and lactation status. An ovsynch protocol which allows for fixed-time artificial insemination (FTAI) was used during the oestrous synchronisation process. A heat mount detector (Karma®) was used to detect oestrous synchronisation response. The dominant cattle breed types were the Bonsmara, Brahman and Nguni. All experimental cows that responded positively to oestrous synchronisation protocol and were inseminated with semen from a Nguni bull. Chi-Square Test of Independence were computed to determine the association among factors. Data was further modelled using the logistic regression model of SAS, establishing the probability of success. Districts, breed type, parity, age, and lactation status did not significantly influence (P > 0.05) conception rate following oestrous synchronisation and timed artificial insemination. However, conception rate was not independent (P < 0.05) of provinces, body condition score and body frame size. Cows in KwaZulu-Natal (66 percent) had significantly higher (P < 0.05) conception rates than those in Limpopo (44 percent) and Mpumalanga (60 percent). Cows of body condition score of ≥ 3.5 (72 percent) had a significantly higher (P < 0.05) conception rate than those of body condition score of ≤ 2.5 (66 percent) and 3 (48 percent). Large (82 percent) framed cows had a significantly higher (P < 0.05) conception rate than small (49 percent) and medium (55 percent) framed cows. Cows in Mpumalanga had more chances to conceive than those of Limpopo and KwaZulu-Natal with odds ratio of 0.605 and 0.863, respectively. Cows in KwaZulu-Natal were in much better body conditions than those from the other two provinces. Cows of body condition score of ≥ 3.5 had more chances to conceive than those of body condition score of ≤ 2.5 and 3 with odds ratio of 0.592 and 0.388, respectively, and the difference was significant (P < 0.05). The study recorded a 100 percent calf survival rate following synchronisation and timed artificial insemination. The breed type, parity, age frame size and lactation status did not significantly influence calving response following oestrous synchronisation and timed artificial insemination (P > 0.05). However, calving rate was not independent of provinces, districts and body condition score (P < 0.05). Calving rate in Mpumalanga (58 percent) and KwaZulu-Natal (54 percent) was significantly higher (P < 0.05) than that recorded in Limpopo Province (36 percent). Calving rate of Gert Sibande (61 percent) and Ehlanzeni (50 percent) districts in Mpumalanga and Zululand (50 percent) and Harry Gwala (61 percent) in KwaZulu-Natal was significantly higher (P < 0.05) than that of the Capricorn (32 percent), Mopani (23 percent and Waterberg (30 percent) in Limpopo Province with the exception of Vhembe (44 percent). Cows with body condition score of ≤ 2.5 (60 percent) had a significantly higher (P < 0.05) calving rate than those with a body condition score of 3 (43 percent). Cows in Mpumalanga had more chances to calve than those in Limpopo and KwaZulu-Natal with odds ratio of 0.076 and 0.537, respectively. Additionally, quantitative data was collected through in-depth interviews using a semi-structured questionnaire. Data collected was managed and coded into themes using the Nvivo Version 11 software programme. Themes and issues that emerged were analysed and interpreted using critical social thinking and systems thinking. The results of the study revealed many factors that could compromise the implementation and adoption of ARTs in the study areas. The general feeling amongst cattle farmers interviewed was that government should address these challenges. A shortage of bulls was the main cause of the low cattle reproduction rate. The Nguni breed type cattle was perceived as the ideal cattle breed for rural areas by respondents. Oestrous synchronisation and artificial insemination can be applied under communal and emerging farming systems with success. From the study results, breeding with small framed animals such as the Nguni type breed under communal and emerging farming systems makes a lot of sense because the breed is known for its low feed maintenance requirement. Furthermore, cattle stakeholders should co-operate and work together to address many of the constraints facing cattle productivity and the implementation and adoption of ARTs in rural areas.
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- Date Issued: 2018
The role of the church in social development : the case of selected churches in Nairobi, Kenya
- Authors: Mutunga, Daniel Kioko
- Date: 2018
- Subjects: Perception Social action Community development
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12599 , vital:39291
- Description: The church as a unique society was founded by Jesus Christ who also set a pattern for its operations. Primary to the core responsibilities of the church, according to Scripture, is to reconcile creation to the Creator by transforming society to regain its lost nature. The Christian Church in Kenya was established by missionaries from different parts of the world about three centuries ago. It has since grown and spread to almost all the parts of the country, but all the major denominations have vibrant congregations in Nairobi. A quick categorisation of the church in Kenya would be into the Mainline and the Pentecostal churches. This study set out to investigate the perception the church in Nairobi holds on in its involvement in social action, whether the church thinks social action is part of its ministry, and what kind of engagements in social action the church in Nairobi is currently having. The study employed a qualitative approach and an exploratory design. Using the questionnaire and interview methods, data was collected from thirty two (32) church leaders (including pastors) sampled to be representative of the Mainline and the Pentecostal groups of churches. The data was transcribed, coded, categorised and interpreted following the themes which emerged in relation to the study objectives and the nature of the responses. The results of the study show that the church holds different perceptions on its responsibility and involvement with regard to social action. The findings show two extremes: those who see social action as core to the mission of the church and those who think social action is the responsibility of the government or of non-governmental agencies. Generally most churches do not plan or budget for social actions. The few that are engaged in in it the budgets are far too low compared to the other church activities and the plans are unstructured and sporadic Active engagement in social action by the church in Nairobi is therefore, by and large, unplanned and episodic. However, the few who are already engaged in social action have witnessed great success in community transformation. The study concludes that the church has not fully understood its ministry and this could be the reason why social action is not part of its agenda. This further explains the sporadic and truncated nature of social action in the church in Nairobi. The study recommends a review of the curriculum in seminaries and the retraining of practising pastors to embrace holistic ministry. This will address the current misconceptions, address the current dichotomy of sacred-secular in church ministry, and hence increase organised participation of the church in social action.
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- Date Issued: 2018
Towards a framework to enhance entry-level national diploma students' learning of computer programming - effects of guided inquiry learning
- Authors: Lukose, Jose
- Date: 2018
- Subjects: Computer programming -- Study and teaching Computer science -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9522 , vital:34362
- Description: Research reports using global data show that the failure rates in introductory programming courses average about 32 percent. This study assessed the effect of elements of Guided Inquiry Learning (GIL) on enhancing academic performance of first year students in Introduction to Computer Programming course. As learners from schools join the university and enrol for different courses, they find the sudden transformation quite challenging. This makes it more challenging for first year university students, especially in difficult courses such as Introduction to Programming. As times change with advances in technology, the traditional ways of presenting information during teaching–learning interface may not address students’ needs. Lecturers and university stakeholders make efforts to address these challenges by proposing innovative teaching ways. One of the common approaches that have been used profitably in other science and engineering programmes is GIL. It is a form of inductive collaborative learning approach where students are presented with a challenge which challenges them to accomplish the desired learning outcomes in the process of responding to the posed challenge. The strategies in GIL include, among others, learning teams who participate in intra- and inter-learner interactions besides lecturer-learner interactions, linking theory and practical information cementing skills and problem solving strategies, scaffolding information, blended learning by integrating both traditional and technology-assisted learning, inquiry activities such as initiating investigations, gathering data, and critiquing evidence to come up with evidence-based solutions. The objective was to apply GIL to this module and observe if there were gains in students’ academic performance. This study was located in the pragmatic paradigm using action research design and a mixed method approach. The sample consisted offirst year students enrolled for Introduction to programming which was a year-long course (two semesters) at a South African university. The population consisted of the only 49 students who were registered for the module under focus. A group of 20 students were considered for the whole year in the GIL experiment. Although it would students were considered for the whole year in the GIL experiment. Although it would students were considered for the whole year in the GIL experiment. Although it would have been ideal to have experimental and control groups with same number of students, that was not possible in this study, because only 20 out of the 49 who were willing to be included in the experimental group. The present researcher employed willing to be included in the experimental group. The present researcher employed three of these GIL strategies in teaching the module Introduction to Programming to the experimental group while another colleague continued with traditional teaching in the control group. Care was taken to limit the insider outsider conflict. Both groups were assessed by the same assessment tools at the same times. Results from these assessments together with focus group interviews provided the core data for this study. Both quantitative and qualitative analyses were carried out on the data, statistical analysis (mainly, chi-Square and t-test) for the former and thematic analysis for the latter. Results indicated gains in the experimental group such as enhanced motivation, interaction, intra-group social cohesion, creativity and provided students the confidence to share knowledge and skills with their peers and keep everyone focused on the course contents. These gains are reflected in higher year marks and pass rates than those in the control group as the analysed data indicate. A study that will pilot the GIL framework in several universities with different teaching modes and large classes are recommended.
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- Date Issued: 2018
Water resources management and its impact on small scale farming :the case of Lesotho
- Authors: Malinga, Wayne
- Date: 2018
- Subjects: Water resources development -- Lesotho Water-supply -- Lesotho Farms, Small -- Lesotho
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9089 , vital:34256
- Description: This study is premised on the assumption that empowering the small-scale farmers in securing property rights and enforcement of these rights are the prime movers of agricultural development. Logically, it follows that by empowering small-scale farmers and giving them access to resources such as credits, subsidies and extension services the state can play a mediating role in transforming the agricultural land scape in Lesotho. Unless farmers are empowered the water resources in Lesotho will continue to serve the interest of the rent-seeking elite. Given the nature of the issues under investigation, the mixed research methodology (the use of both qualitative and quantitative methods) was used as a method of inquiry in order to get a deeper understanding of the phenomenon of water resources management and its subsequent impact on small scale farming in the rural areas of Lesotho. Both methods played a complimentary role by capitalising on both their strengths and weaknesses so as to provide various dynamics and linkages between the two variables of water resources management and small scale farming. The material condition of small scale farmers is intrinsically associated with the active state mediation in agriculture. Yet, the adopted Integrated Water Resources Management (IWRM) approach is still to materialise. This thesis, thus, argues that there is a need for a more holistic integrated water resources management framework that is livelihoods based and re-emphasises the need for conserving the ecosystem. Therefore, implementing a more holistic integrated water resources management approach is critical and vital in improving agricultural production and subsequently the livelihoods of small scale farmers and households. Although this thesis used Lesotho as the case study, it is hoped that the findings may provide tentative answers for other Sub-Saharan countries on how to properly and efficiently manage water resources so as to boost agricultural production amongst small scale farmers in order to improve human conditions and promote sustainable development in the rural areas.
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- Date Issued: 2018
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.
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- 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
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.
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- 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.
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- 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.
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- 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
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- 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.
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- 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.
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- 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.
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- Date Issued: 2019
Electrical, photo-thermal and mechanical degradation analysis of degraded single junction amorphous silicon solar modules
- 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).
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- 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
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- Date Issued: 2019