Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) population ecology in citrus orchards: the influence of orchard age
- Authors: Albertyn, Sonnica
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Population biology , Insect populations , Orchards , Insect nematodes , Entomopathogenic fungi
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62615 , vital:28213
- Description: Anecdotal reports in the South African citrus industry claim higher populations of false codling moth (FCM), Thaumatotibia (Cryptophlebia) leucotreta (Meyr) (Lepidoptera: Tortricidae), in orchards during the first three to five harvesting years of citrus planted in virgin soil, after which, FCM numbers seem to decrease and remain consistent. Various laboratory studies and field surveys were conducted to determine if, and why juvenile orchards (four to eight years old) experience higher FCM infestation than mature orchards (nine years and older). In laboratory trials, Washington Navel oranges and Nova Mandarins from juvenile trees were shown to be significantly more susceptible to FCM damage and significantly more attractive for oviposition in both choice and no-choice trials, than fruit from mature trees. Although fruit from juvenile Cambria Navel trees were significantly more attractive than mature orchards for oviposition, they were not more susceptible to FCM damage. In contrast, fruit from juvenile and mature Midnight Valencia orchards were equally attractive for oviposition, but fruit from juvenile trees were significantly more susceptible to FCM damage than fruit from mature trees. Artificial diets were augmented with powder from fruit from juvenile or mature Washington Navel orchards at 5%, 10%, 15% or 30%. Higher larval survival of 76%, 63%, 50% and 34%, respectively, was recorded on diets containing fruit powder from the juvenile trees than on diets containing fruit powder from the mature trees, at 69%, 57%, 44% and 27% larval survival, respectively. Bioassays were conducted to determine if differences in plant chemistry between fruit from juvenile and mature trees will have an impact on the susceptibility FCM to entomopathogenic nematodes (EPN), entomopathogenic fungi (EPF) and Cryptophlebia leucotreta granulovirus (CrleGV). No significant differences in the susceptibility of larvae reared on diets containing 15% fruit powder from juvenile and mature trees to EPN and EPF were recorded. Mortality of neonate larvae was significantly lower when placed on diets containing 15% fruit powder from mature trees (45% mortality) than diets containing 15% fruit powder from juvenile trees (61% mortality), after larvae ingested the lowest virus concentration tested, being 2 x104 OBs/ml. Data collected from field surveys showed significantly lower egg parasitism, virus infection of larvae and EPF occurrence in juvenile orchards than mature orchards. Egg parasitism was between 11% and 54% higher in mature orchards than juvenile orchards, with the exception of Mandarins during 2015, where egg parasitism was slightly higher in juvenile orchards, but not significantly so. A significantly higher proportion of larvae retrieved from mature orchards (7% of larvae) were infected with CrleGV than larvae retrieved from juvenile orchards (4% of larvae). A significantly higher occurrence of EPF was recorded in non-bearing and mature orchards, with 40% and 37% occurrence respectively, than in juvenile orchards, with 25% occurrence recorded. EPF occurrence in juvenile orchards increased significantly by 16% to 32% from the first to the third year of sampling. In contrast to results recorded in laboratory trials, similar or higher pest pressure in juvenile orchards than mature orchards did not always result in significantly higher levels of FCM damage under field conditions. FCM damage in juvenile orchards may have been lower than expected, as greater extremes of temperature and lower humidity were recorded in juvenile orchards, which would increase larval mortality. Results of this study showed that juvenile and mature orchards are significantly different and should be managed differently.
- Full Text:
- Date Issued: 2018
- Authors: Albertyn, Sonnica
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Population biology , Insect populations , Orchards , Insect nematodes , Entomopathogenic fungi
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62615 , vital:28213
- Description: Anecdotal reports in the South African citrus industry claim higher populations of false codling moth (FCM), Thaumatotibia (Cryptophlebia) leucotreta (Meyr) (Lepidoptera: Tortricidae), in orchards during the first three to five harvesting years of citrus planted in virgin soil, after which, FCM numbers seem to decrease and remain consistent. Various laboratory studies and field surveys were conducted to determine if, and why juvenile orchards (four to eight years old) experience higher FCM infestation than mature orchards (nine years and older). In laboratory trials, Washington Navel oranges and Nova Mandarins from juvenile trees were shown to be significantly more susceptible to FCM damage and significantly more attractive for oviposition in both choice and no-choice trials, than fruit from mature trees. Although fruit from juvenile Cambria Navel trees were significantly more attractive than mature orchards for oviposition, they were not more susceptible to FCM damage. In contrast, fruit from juvenile and mature Midnight Valencia orchards were equally attractive for oviposition, but fruit from juvenile trees were significantly more susceptible to FCM damage than fruit from mature trees. Artificial diets were augmented with powder from fruit from juvenile or mature Washington Navel orchards at 5%, 10%, 15% or 30%. Higher larval survival of 76%, 63%, 50% and 34%, respectively, was recorded on diets containing fruit powder from the juvenile trees than on diets containing fruit powder from the mature trees, at 69%, 57%, 44% and 27% larval survival, respectively. Bioassays were conducted to determine if differences in plant chemistry between fruit from juvenile and mature trees will have an impact on the susceptibility FCM to entomopathogenic nematodes (EPN), entomopathogenic fungi (EPF) and Cryptophlebia leucotreta granulovirus (CrleGV). No significant differences in the susceptibility of larvae reared on diets containing 15% fruit powder from juvenile and mature trees to EPN and EPF were recorded. Mortality of neonate larvae was significantly lower when placed on diets containing 15% fruit powder from mature trees (45% mortality) than diets containing 15% fruit powder from juvenile trees (61% mortality), after larvae ingested the lowest virus concentration tested, being 2 x104 OBs/ml. Data collected from field surveys showed significantly lower egg parasitism, virus infection of larvae and EPF occurrence in juvenile orchards than mature orchards. Egg parasitism was between 11% and 54% higher in mature orchards than juvenile orchards, with the exception of Mandarins during 2015, where egg parasitism was slightly higher in juvenile orchards, but not significantly so. A significantly higher proportion of larvae retrieved from mature orchards (7% of larvae) were infected with CrleGV than larvae retrieved from juvenile orchards (4% of larvae). A significantly higher occurrence of EPF was recorded in non-bearing and mature orchards, with 40% and 37% occurrence respectively, than in juvenile orchards, with 25% occurrence recorded. EPF occurrence in juvenile orchards increased significantly by 16% to 32% from the first to the third year of sampling. In contrast to results recorded in laboratory trials, similar or higher pest pressure in juvenile orchards than mature orchards did not always result in significantly higher levels of FCM damage under field conditions. FCM damage in juvenile orchards may have been lower than expected, as greater extremes of temperature and lower humidity were recorded in juvenile orchards, which would increase larval mortality. Results of this study showed that juvenile and mature orchards are significantly different and should be managed differently.
- Full Text:
- Date Issued: 2018
The adoption of green building in South Africa
- Authors: Simpeh, Eric Kwame
- Date: 2018
- Subjects: Ecological houses -- Design and construction -- South Africa , Sustainable buildings -- Design and construction -- South Africa Sustainable construction -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35653 , vital:33771
- Description: In South Africa there is pressure to deliver green building due to environmental issues such as climate changes, the energy crisis, as well as persistent water shortages. Although awareness and promotional effort have increased drastically concerning the adoption of green buildings, the South African design and construction industry is still lagging due to the conservativeness and slow rate of change in the construction industry. While enablers / facilitators have been recognised as opportunities to advance green building development, the South African built environment has not extensively explored the various possibilities to initiate enablers / facilitating conditions to enhance the adoption of green building. This study therefore investigates the critical factors impeding the adoption of green building and to explore the economic and non-economic facilitators / enablers regarded as the most important to stimulate stakeholders’ behavioural intentions to adopt green building. After an extensive review of literature with respect to barriers and factors that engender green building adoption, coupled with theoretical arguments relating change agents to construction innovation and sustainability theory, an exhaustive mixed-mode research approach was adopted. The sampling frame for the study was limited to four provinces, namely the Eastern Cape, Gauteng, Kwazulu–Natal, and Western Cape, given that 99% of the green building accredited professionals registered with the GBCSA are from these four provinces. The quantitative data was analysed using descriptive and inferential statistics, namely paired sample test, ANOVA test, Factor Analysis (FA), and logistic regression analysis (LRA). The qualitative data obtained across individual cases by means of a semi-structured interview was analysed using content analysis. In total, 106 professionals participated in the survey, and three respondents indicated their willingness and availability to be interviewed, hence three case studies were conducted. The results emanating from the study, inter-alia, indicate that the factors constraining the adoption of green building are categorised as: lack of information and incentives; inadequate skilled professionals; behavioural barriers; regulatory and steering factors, and the cost of green building. The results also indicate that green building consultants and environmental groups are classified as ‘innovators’, whilst architects are ‘early adopters’. However, government; municipalities, and general contractors are characterised as ‘late majority’. It was also evident from the empirical findings that the key attributes of adopters that encourage the adoption of green building were classified as: qualities of consultant team and contractor, and developers / clients’ experience. The perceived benefits of green buildings emanating from the findings were categorised as socio-economic, financial, and health and community benefits. The enablers that engender the adoption of green building were also categorised as: extended knowledge base and technical capacity; research and training of professionals; green lending incentives; progressive green building policy; economic incentives, and reward scheme and technical assistance. Two models have been developed using logistic regression model (LRM), model one (1) examined the predictable effect of economic and non-economic factors on the intention to adopt green building, whereas model two (2) examined the likelihood of the extent of green building adoption. The LRM results revealed five predictors and two control variables made a unique statistically significant contribution to model 1. The strongest predictor to enhance the intention to adopt green building was financial benefit (FB), recording an odds ratio of 9.1, which indicates that the likelihood to adopt is approximately 9.1 times more if financial benefits is evident. With respect to Model two (2), the LRM results showed that only two of the independent variables and three control variables contributed significantly to the model. The strongest predictor that determines the extent of adoption of green building was research and training of professionals (RTP), with odd ratio equal to 2.9. In effect, to engender the adoption of green building within the South African built environment, there is the need for an integrated and holistic approach forecasting on the importance of economic and non-economic enablers / facilitators in enhancing decision to adopt green building.
- Full Text:
- Date Issued: 2018
- Authors: Simpeh, Eric Kwame
- Date: 2018
- Subjects: Ecological houses -- Design and construction -- South Africa , Sustainable buildings -- Design and construction -- South Africa Sustainable construction -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35653 , vital:33771
- Description: In South Africa there is pressure to deliver green building due to environmental issues such as climate changes, the energy crisis, as well as persistent water shortages. Although awareness and promotional effort have increased drastically concerning the adoption of green buildings, the South African design and construction industry is still lagging due to the conservativeness and slow rate of change in the construction industry. While enablers / facilitators have been recognised as opportunities to advance green building development, the South African built environment has not extensively explored the various possibilities to initiate enablers / facilitating conditions to enhance the adoption of green building. This study therefore investigates the critical factors impeding the adoption of green building and to explore the economic and non-economic facilitators / enablers regarded as the most important to stimulate stakeholders’ behavioural intentions to adopt green building. After an extensive review of literature with respect to barriers and factors that engender green building adoption, coupled with theoretical arguments relating change agents to construction innovation and sustainability theory, an exhaustive mixed-mode research approach was adopted. The sampling frame for the study was limited to four provinces, namely the Eastern Cape, Gauteng, Kwazulu–Natal, and Western Cape, given that 99% of the green building accredited professionals registered with the GBCSA are from these four provinces. The quantitative data was analysed using descriptive and inferential statistics, namely paired sample test, ANOVA test, Factor Analysis (FA), and logistic regression analysis (LRA). The qualitative data obtained across individual cases by means of a semi-structured interview was analysed using content analysis. In total, 106 professionals participated in the survey, and three respondents indicated their willingness and availability to be interviewed, hence three case studies were conducted. The results emanating from the study, inter-alia, indicate that the factors constraining the adoption of green building are categorised as: lack of information and incentives; inadequate skilled professionals; behavioural barriers; regulatory and steering factors, and the cost of green building. The results also indicate that green building consultants and environmental groups are classified as ‘innovators’, whilst architects are ‘early adopters’. However, government; municipalities, and general contractors are characterised as ‘late majority’. It was also evident from the empirical findings that the key attributes of adopters that encourage the adoption of green building were classified as: qualities of consultant team and contractor, and developers / clients’ experience. The perceived benefits of green buildings emanating from the findings were categorised as socio-economic, financial, and health and community benefits. The enablers that engender the adoption of green building were also categorised as: extended knowledge base and technical capacity; research and training of professionals; green lending incentives; progressive green building policy; economic incentives, and reward scheme and technical assistance. Two models have been developed using logistic regression model (LRM), model one (1) examined the predictable effect of economic and non-economic factors on the intention to adopt green building, whereas model two (2) examined the likelihood of the extent of green building adoption. The LRM results revealed five predictors and two control variables made a unique statistically significant contribution to model 1. The strongest predictor to enhance the intention to adopt green building was financial benefit (FB), recording an odds ratio of 9.1, which indicates that the likelihood to adopt is approximately 9.1 times more if financial benefits is evident. With respect to Model two (2), the LRM results showed that only two of the independent variables and three control variables contributed significantly to the model. The strongest predictor that determines the extent of adoption of green building was research and training of professionals (RTP), with odd ratio equal to 2.9. In effect, to engender the adoption of green building within the South African built environment, there is the need for an integrated and holistic approach forecasting on the importance of economic and non-economic enablers / facilitators in enhancing decision to adopt green building.
- Full Text:
- Date Issued: 2018
The classification of fuzzy groups of finite cyclic groups Zpn Zqm Zr and Zp1 Zp2 Zpn for distinct prime numbers p; q; r; p1; p2; ; pn and n;m 2 Z+
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
The construction of household livelihood strategies in urban areas: the case of Budiriro, Harare, Zimbabwe
- Authors: Chevo, Tafadzwa
- Date: 2018
- Subjects: Income -- Zimbabwe -- Harare , Cost and standard of living -- Zimbabwe -- Harare , Quality of life -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Agricultural wages -- Zimbabwe -- Harare , Households -- Economic aspects -- Zimbabwe -- Harare , Macrosociology , Zimbabwe -- Social conditions -- 1980- , Zimbabwe -- Economic conditions -- 1980- , Livelihoods Framework
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63043 , vital:28357
- Description: The main objective of this thesis is to understand and explain the ongoing construction of livelihood activities by urban households in the low-income high-density area of Budiriro, Harare, Zimbabwe in a context characterised by systemic crisis and a general decline of the national economy. The study utilised a mixed methods research approach, which combined both qualitative and quantitative research, including a survey, life histories and focus group discussions. The thesis discusses a diverse range of livelihood activities of Budiriro households, such as formal employment, informal trading and agricultural activities, and the ways in which households seeks to diversify their livelihood portfolio. It does this by way of also examining the contemporary and historical factors influencing the livelihood activities pursued by these households, along with the shocks and disturbances encountered and experienced by households in trying to construct viable livelihoods. The thesis makes useful contributions to the existing literature on livelihoods studies. Firstly, the thesis disaggregates the households by showing the existence of three wealth categories in Budiriro and the varying livelihood strategies of households in different wealth categories. Secondly, the study highlights the significance of intra-household dynamics in Budiriro for livelihoods as well as of inter-household kinship networks, which transcend the urban space and entail multi-spatial livelihoods. Thirdly, the thesis examines livelihoods over time, such that it goes beyond a strictly synchronic examination, therefore providing a diachronic analysis of diverse and complicated livelihood pathways. Finally, the Livelihoods Framework is located within broader macro-sociological theorising including the work of Pierre Bourdieu. In this respect, important insights arise about livelihood choices and practices in the light of ongoing debates within sociology about human agency.
- Full Text:
- Date Issued: 2018
- Authors: Chevo, Tafadzwa
- Date: 2018
- Subjects: Income -- Zimbabwe -- Harare , Cost and standard of living -- Zimbabwe -- Harare , Quality of life -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Agricultural wages -- Zimbabwe -- Harare , Households -- Economic aspects -- Zimbabwe -- Harare , Macrosociology , Zimbabwe -- Social conditions -- 1980- , Zimbabwe -- Economic conditions -- 1980- , Livelihoods Framework
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63043 , vital:28357
- Description: The main objective of this thesis is to understand and explain the ongoing construction of livelihood activities by urban households in the low-income high-density area of Budiriro, Harare, Zimbabwe in a context characterised by systemic crisis and a general decline of the national economy. The study utilised a mixed methods research approach, which combined both qualitative and quantitative research, including a survey, life histories and focus group discussions. The thesis discusses a diverse range of livelihood activities of Budiriro households, such as formal employment, informal trading and agricultural activities, and the ways in which households seeks to diversify their livelihood portfolio. It does this by way of also examining the contemporary and historical factors influencing the livelihood activities pursued by these households, along with the shocks and disturbances encountered and experienced by households in trying to construct viable livelihoods. The thesis makes useful contributions to the existing literature on livelihoods studies. Firstly, the thesis disaggregates the households by showing the existence of three wealth categories in Budiriro and the varying livelihood strategies of households in different wealth categories. Secondly, the study highlights the significance of intra-household dynamics in Budiriro for livelihoods as well as of inter-household kinship networks, which transcend the urban space and entail multi-spatial livelihoods. Thirdly, the thesis examines livelihoods over time, such that it goes beyond a strictly synchronic examination, therefore providing a diachronic analysis of diverse and complicated livelihood pathways. Finally, the Livelihoods Framework is located within broader macro-sociological theorising including the work of Pierre Bourdieu. In this respect, important insights arise about livelihood choices and practices in the light of ongoing debates within sociology about human agency.
- Full Text:
- Date Issued: 2018
The current utility of oligonucleotide aptamers in targeting the MUC1 mucin tumour marker
- Authors: Flanagan, Shane Patrick
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62969 , vital:28348
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: Flanagan, Shane Patrick
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62969 , vital:28348
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
The customary law practice of ukuthwala – an antithesis in the South African constitutional order
- Jokani, Mkhuseli Christopher
- Authors: Jokani, Mkhuseli Christopher
- Date: 2018
- Subjects: Customary law -- South Africa , Culture -- Legal status, laws, etc -- South Africa Forced marriage -- Legal status, laws, etc -- South Africa Teenage marriage -- South Africa -- Eastern Cape Xhosa (African people) -- Law and legislation -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/22474 , vital:29973
- Description: The concept of ukuthwala is an age-old customary marriage practice prevalent amongst the Nguni speaking tribes of South Africa. It is a practice whereby, preliminary to a customary marriage, a young man, by force, takes a girl to his home. The SABC and E-tv evening television news coverage of 15th March 2009 reported the prevalence of forced and child marriages of young girls with elderly men in the East Pondoland of the Eastern Cape. The question arose as to whether the custom of ukuthwala could be justified as a legitimate cultural practice in the context of a modern constitutional democracy because some view it as an outdated customary practice that targets girl children, while others view it as a legitimate cultural practice. Since ukuthwala cannot be treated as a unitary phenomenon, variants of the practice must be distinguished. The thesis reveals that there are three variants of ukuthwala, which are ukuthwala ngemvumelwano, ukuthwala kobolawu and ukuthwala okungenamvumelwano. The thesis concludes by drawing a distinction between ukuthwala, forced marriage and child marriage. It proposes that ukuthwala in its traditional form is not synonymous with forced marriage and child marriage. The thesis poses the following main legal questions, namely: does the South African criminal jurisprudence criminalise ukuthwala, and if so, on what charges are perpetrators tried; and how is the inherent conflict between the customary law practice of ukuthwala and the Bill of Rights enshrined in the Constitution, resolved? The thesis responds to these questions as follows. Firstly, it is suggested that ukuthwala in itself is not a formally defined crime, but a customary law practice resorted to by the prospective suitor to force the parents of the young woman into marriage negotiations. However, in recent times the practice has been abused and distorted which borders on the commission of a criminal offence and the violation of the young woman’s human rights. The criminal offences that are committed because of the distorted form of ukuthwala are both in terms of the common and statutory laws of South Africa. The thesis suggests that those found guilty of committing a crime under the pretext of customary law practice of ukuthwala should be punished. South Africa has a number of statutory as well as common law provisions, which can be used to prosecute those found to have committed offences. South Africa does not need to outlaw and criminalise ukuthwala in its entirety but does need to distinguish between the distorted and the traditional forms of ukuthwala. The thesis responds to the second main question as follows. Firstly, the violation of the young woman’s human rights brings to the fore a conflict between the customary law practice of ukuthwala and the Bill of Rights enshrined in the Constitution. The thesis makes a distinction between the three variants of ukuthwala customary practices and concludes that ukuthwala ngemvumelwano is the most acceptable form because it takes place when there is mutual consent between parties. It further proposes that the positive elements within the customary law practice of ukuthwala must be developed and promoted provided that they are consistent with the provisions of the Constitution. However, the negative elements that conflict with provisions of the Constitution should be done away with. The thesis suggests that the latter approach is important to addressing the conflict between ukuthwala customary practice and the Bill of Rights. The thesis concludes by suggesting that the distorted form of subjecting young women and girl children into forced marriages under the pretext of the customary law practice of ukuthwala are unconstitutional and cannot be justified in terms of sections 30 and 31 of the Constitution. Therefore, ukuthwala customary law practice is not free from criticism if one considers the two variants of ukuthwala where there has been no consent from one of the parties concerned. A comparative analysis is undertaken with selected Southern African Development Community countries to establish similarities in practices related to ukuthwala and how the consequent contradictions between customary law and common law have been dealt with. The thesis concludes that ukuthwala is a unique South African customary practice that is different from other customary practices in some selected jurisdictions. Therefore, the comparative analysis has helped in identifying how poverty perpetuates the different but related, customary law practices across the selected jurisdictions. Therefore, in order for Mother Africa to adequately respond to the harmful traditional practices there is a need to address the socio-economic issues particularly in the rural parts of Africa. The harmful traditional practices seem to be more common in the rural parts of the selected jurisdictions rather than in urban and semi-urban areas. The lesson learnt is that social development should have a particular bias towards the rural areas of Africa. The findings, amongst others, are that ukuthwala in its traditional form is a legitimate customary law practice which was often resorted to when obstacles arose in order to force the parents of the young woman to negotiate marriage. Ukuthwala is not synonymous with forced and early marriages. The thesis recommends that South Africa does not need to outlaw ukuthwala despite the fact that it has now been abused and distorted. It is argued that there are sufficient statutory and common laws to respond to the scourge of distorted versions of ukuthwala in South Africa. The thesis recommends that South Africa with its plural legal system should highlight the supremacy of the Constitution aligned with international human rights standards to avoid conflict in legal interpretation and implementation. It is hoped that this will assist in the implementation of the positive aspects of African customary law within the legal system and will remove the negative elements that infringe on the rights of women and children. It is recommended that it would be useful to pursue non-legislative measures to deal comprehensively with the causes of ukuthwala and its consequences by investing in education, training and awareness raising campaigns among sectors of society, most importantly rural people. Education, when employed, should not be an event but a process that will start at school level and extend to post-university. The emphasis should be on the inclusion of gender studies from early grades to undo the mentality of male superiority and entrench an equality attitude between boys and girls from a very early age. The reason for this suggestion is that attitudes manifested in our society always portray girls and women as being weak and therefore not equal to boys and men. It is important to ensure that role-players in the fight against gender-based violence are adequately trained to equip them to handle these cases properly. These role-players include South African Police Service members, National Prosecuting Authority, Judiciary and Non-Governmental Organisations to mitigate secondary victimisation of victims of these distorted cultural practices.
- Full Text:
- Date Issued: 2018
- Authors: Jokani, Mkhuseli Christopher
- Date: 2018
- Subjects: Customary law -- South Africa , Culture -- Legal status, laws, etc -- South Africa Forced marriage -- Legal status, laws, etc -- South Africa Teenage marriage -- South Africa -- Eastern Cape Xhosa (African people) -- Law and legislation -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/22474 , vital:29973
- Description: The concept of ukuthwala is an age-old customary marriage practice prevalent amongst the Nguni speaking tribes of South Africa. It is a practice whereby, preliminary to a customary marriage, a young man, by force, takes a girl to his home. The SABC and E-tv evening television news coverage of 15th March 2009 reported the prevalence of forced and child marriages of young girls with elderly men in the East Pondoland of the Eastern Cape. The question arose as to whether the custom of ukuthwala could be justified as a legitimate cultural practice in the context of a modern constitutional democracy because some view it as an outdated customary practice that targets girl children, while others view it as a legitimate cultural practice. Since ukuthwala cannot be treated as a unitary phenomenon, variants of the practice must be distinguished. The thesis reveals that there are three variants of ukuthwala, which are ukuthwala ngemvumelwano, ukuthwala kobolawu and ukuthwala okungenamvumelwano. The thesis concludes by drawing a distinction between ukuthwala, forced marriage and child marriage. It proposes that ukuthwala in its traditional form is not synonymous with forced marriage and child marriage. The thesis poses the following main legal questions, namely: does the South African criminal jurisprudence criminalise ukuthwala, and if so, on what charges are perpetrators tried; and how is the inherent conflict between the customary law practice of ukuthwala and the Bill of Rights enshrined in the Constitution, resolved? The thesis responds to these questions as follows. Firstly, it is suggested that ukuthwala in itself is not a formally defined crime, but a customary law practice resorted to by the prospective suitor to force the parents of the young woman into marriage negotiations. However, in recent times the practice has been abused and distorted which borders on the commission of a criminal offence and the violation of the young woman’s human rights. The criminal offences that are committed because of the distorted form of ukuthwala are both in terms of the common and statutory laws of South Africa. The thesis suggests that those found guilty of committing a crime under the pretext of customary law practice of ukuthwala should be punished. South Africa has a number of statutory as well as common law provisions, which can be used to prosecute those found to have committed offences. South Africa does not need to outlaw and criminalise ukuthwala in its entirety but does need to distinguish between the distorted and the traditional forms of ukuthwala. The thesis responds to the second main question as follows. Firstly, the violation of the young woman’s human rights brings to the fore a conflict between the customary law practice of ukuthwala and the Bill of Rights enshrined in the Constitution. The thesis makes a distinction between the three variants of ukuthwala customary practices and concludes that ukuthwala ngemvumelwano is the most acceptable form because it takes place when there is mutual consent between parties. It further proposes that the positive elements within the customary law practice of ukuthwala must be developed and promoted provided that they are consistent with the provisions of the Constitution. However, the negative elements that conflict with provisions of the Constitution should be done away with. The thesis suggests that the latter approach is important to addressing the conflict between ukuthwala customary practice and the Bill of Rights. The thesis concludes by suggesting that the distorted form of subjecting young women and girl children into forced marriages under the pretext of the customary law practice of ukuthwala are unconstitutional and cannot be justified in terms of sections 30 and 31 of the Constitution. Therefore, ukuthwala customary law practice is not free from criticism if one considers the two variants of ukuthwala where there has been no consent from one of the parties concerned. A comparative analysis is undertaken with selected Southern African Development Community countries to establish similarities in practices related to ukuthwala and how the consequent contradictions between customary law and common law have been dealt with. The thesis concludes that ukuthwala is a unique South African customary practice that is different from other customary practices in some selected jurisdictions. Therefore, the comparative analysis has helped in identifying how poverty perpetuates the different but related, customary law practices across the selected jurisdictions. Therefore, in order for Mother Africa to adequately respond to the harmful traditional practices there is a need to address the socio-economic issues particularly in the rural parts of Africa. The harmful traditional practices seem to be more common in the rural parts of the selected jurisdictions rather than in urban and semi-urban areas. The lesson learnt is that social development should have a particular bias towards the rural areas of Africa. The findings, amongst others, are that ukuthwala in its traditional form is a legitimate customary law practice which was often resorted to when obstacles arose in order to force the parents of the young woman to negotiate marriage. Ukuthwala is not synonymous with forced and early marriages. The thesis recommends that South Africa does not need to outlaw ukuthwala despite the fact that it has now been abused and distorted. It is argued that there are sufficient statutory and common laws to respond to the scourge of distorted versions of ukuthwala in South Africa. The thesis recommends that South Africa with its plural legal system should highlight the supremacy of the Constitution aligned with international human rights standards to avoid conflict in legal interpretation and implementation. It is hoped that this will assist in the implementation of the positive aspects of African customary law within the legal system and will remove the negative elements that infringe on the rights of women and children. It is recommended that it would be useful to pursue non-legislative measures to deal comprehensively with the causes of ukuthwala and its consequences by investing in education, training and awareness raising campaigns among sectors of society, most importantly rural people. Education, when employed, should not be an event but a process that will start at school level and extend to post-university. The emphasis should be on the inclusion of gender studies from early grades to undo the mentality of male superiority and entrench an equality attitude between boys and girls from a very early age. The reason for this suggestion is that attitudes manifested in our society always portray girls and women as being weak and therefore not equal to boys and men. It is important to ensure that role-players in the fight against gender-based violence are adequately trained to equip them to handle these cases properly. These role-players include South African Police Service members, National Prosecuting Authority, Judiciary and Non-Governmental Organisations to mitigate secondary victimisation of victims of these distorted cultural practices.
- Full Text:
- Date Issued: 2018
The development of an optimised decision based methodology for the replacement timing of frontline equipment utilised within the quarrying industry
- Authors: Basson, Kenneth Mervyn
- Date: 2018
- Subjects: Decision making , Industrial equipment Industrial equipment -- Maintenance and repair
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/23647 , vital:30592
- Description: At present, frontline equipment employed at B&E International, and operating within the quarrying sector is typically replaced as soon as the operating expenses are deemed to be excessive. From a capital budgeting perspective, the trigger for signalling the replacement of equipment occurs when prescribed operating cost performance metrics are violated. In some instances, a further consideration for motivating the replacement of equipment is when the perception arises that the nonavailability of the equipment employed, results in financial losses being incurred by a company. It can therefore be argued that the current equipment replacement timing methodological approach adopted at B&E International is suboptimal in nature. The situation is further aggravated by the fact that in many instances, escalation of commitment manifests itself whereby unnecessary capital is repeatedly invested in order to extend the life of an asset resulting in a situation occurring whereby the required level of investment return is not achieved. In the event of these situations arising, the decision to replace an asset is prolonged as a result of the suboptimal investment decisions being made. The primary focus of this study is to provide a methodological equipment replacement framework that is based upon sound capital budgeting fundamentals. A comprehensive literature review of capital budgeting approaches that specifically focus on the optimal replacement timing of frontline quarrying equipment, did not yield any relevant studies that have been undertaken in this regard. This study did however investigate contemporary equipment replacement approaches based upon a capital budgeting paradigm and highlighted their respective limitations. Convincing evidence obtained, indicated that the most widely accepted method of identifying the optimal replacement timing of equipment occurs when the economic life of the asset is attained. This in itself would therefore infer that a cost minimisation approach is the most pervasive methodological approach adopted in order to identify the optimal replacement timing of equipment. When considering capital investment based decisions, it was found that the discounted cash flow based methodologies are the most widely used and accepted approach applied in the mining industry. Notwithstanding this, one major caveat manifests itself in that when considering the optimal replacement timing of front line equipment within the quarrying industry, the inclusion of uncertainty, flexibility and the associated financial risks was not evident. In order to model these effects, a probabilistic Net Present Value (NPV) approach was adopted and the required Discounted Cash Flow (DCF) models were constructed. Given the uncertainty of the expected cumulative R&M profiles for the asset classes constituting this study, an extensive statistical analysis was carried out in order to establish the required predictive Repair and Maintenance (R&M) models required for the DCF analysis by means of regression analysis. Further regression analyses were conducted in order to model the overall availability and utilisation metrics for the respective asset classes included in this study. The consequence of incurring downtime was investigated and the resultant DCF analysis yielded a significant impact on the Free Cash Flow (FCF) generated by the respective assets. The magnitude of the incurred consequential financial losses incurred as a result of the respective downtime was found to be significant when considering frontline equipment. In order to model the effect of, and the extent to which, the respective independent variables influence the static NPV outcome, a sensitivity analysis was performed. From this, the influence of the independent variables constituting the NPV model employed in this study, were observed. A Real Options Analysis (ROA) approach was initially employed in order to model the effects of FCF uncertainty and the results of carrying out this analysis indicated a minimal influence on the static NPV model referred to earlier. It was therefore concluded that from an equipment replacement timing perspective, the ROA approach did not provide a robust and accurate representation of the probabilistic NPV outcomes anticipated. In order to address these perceived shortcomings, an Monte Carlo Simulation (MCS) model was constructed and the requisite probability distribution functions representing the most influential independent variables determined from the sensitivity analysis were identified and subsequently analysed. The results of the MCS analysis yielded the expected NPV outcomes that were found to be far more conservative compared to the static NPV outcomes referred to previously. Furthermore, the concluding findings of this study indicate that in order to estimate the optimal time to dispose of an asset, a static NPV analysis must first be modelled and thereafter a probabilistic NPV analysis. The respective uncertainty aspects over the lifespan of the assets should be identified to be incorporated into the MCS model. This methodological approach therefore opposes the use of a strictly deterministic based approach and rather predicates the use of a probabilistic NPV based framework. This study further concluded that traditional DCF approaches fail to consider management flexibility in terms of adapting to uncertainty and to also reduce the possibility of “escalation of commitment” occurring as a result of sub-optimal equipment replacement timing decisions by management. The use and acceptance of the traditional DCF approaches are acknowledged, but in order to develop an equipment replacement methodological approach that considers uncertainty and risk on the one hand and also allows for the incorporation of real data over the assets lifetime on the other, the use of an MCS probabilistic NPV based model was found to be the optimal approach to be adopted. The result of updating the static NPV model with updated data as soon as it is obtained enables one to generate accurate probabilistic distribution functions required for the subsequent MCS analysis. By adopting this approach the study has concluded that one can obtain realistic and accurate NPV forecasts from the anticipated FCF estimates. The principal conclusion obtained from this study is that the optimal time in which to replace front line assets employed at B&E International is when the probabilistic net earnings profile, viz., NPV of the equipment is maximized.
- Full Text:
- Date Issued: 2018
- Authors: Basson, Kenneth Mervyn
- Date: 2018
- Subjects: Decision making , Industrial equipment Industrial equipment -- Maintenance and repair
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/23647 , vital:30592
- Description: At present, frontline equipment employed at B&E International, and operating within the quarrying sector is typically replaced as soon as the operating expenses are deemed to be excessive. From a capital budgeting perspective, the trigger for signalling the replacement of equipment occurs when prescribed operating cost performance metrics are violated. In some instances, a further consideration for motivating the replacement of equipment is when the perception arises that the nonavailability of the equipment employed, results in financial losses being incurred by a company. It can therefore be argued that the current equipment replacement timing methodological approach adopted at B&E International is suboptimal in nature. The situation is further aggravated by the fact that in many instances, escalation of commitment manifests itself whereby unnecessary capital is repeatedly invested in order to extend the life of an asset resulting in a situation occurring whereby the required level of investment return is not achieved. In the event of these situations arising, the decision to replace an asset is prolonged as a result of the suboptimal investment decisions being made. The primary focus of this study is to provide a methodological equipment replacement framework that is based upon sound capital budgeting fundamentals. A comprehensive literature review of capital budgeting approaches that specifically focus on the optimal replacement timing of frontline quarrying equipment, did not yield any relevant studies that have been undertaken in this regard. This study did however investigate contemporary equipment replacement approaches based upon a capital budgeting paradigm and highlighted their respective limitations. Convincing evidence obtained, indicated that the most widely accepted method of identifying the optimal replacement timing of equipment occurs when the economic life of the asset is attained. This in itself would therefore infer that a cost minimisation approach is the most pervasive methodological approach adopted in order to identify the optimal replacement timing of equipment. When considering capital investment based decisions, it was found that the discounted cash flow based methodologies are the most widely used and accepted approach applied in the mining industry. Notwithstanding this, one major caveat manifests itself in that when considering the optimal replacement timing of front line equipment within the quarrying industry, the inclusion of uncertainty, flexibility and the associated financial risks was not evident. In order to model these effects, a probabilistic Net Present Value (NPV) approach was adopted and the required Discounted Cash Flow (DCF) models were constructed. Given the uncertainty of the expected cumulative R&M profiles for the asset classes constituting this study, an extensive statistical analysis was carried out in order to establish the required predictive Repair and Maintenance (R&M) models required for the DCF analysis by means of regression analysis. Further regression analyses were conducted in order to model the overall availability and utilisation metrics for the respective asset classes included in this study. The consequence of incurring downtime was investigated and the resultant DCF analysis yielded a significant impact on the Free Cash Flow (FCF) generated by the respective assets. The magnitude of the incurred consequential financial losses incurred as a result of the respective downtime was found to be significant when considering frontline equipment. In order to model the effect of, and the extent to which, the respective independent variables influence the static NPV outcome, a sensitivity analysis was performed. From this, the influence of the independent variables constituting the NPV model employed in this study, were observed. A Real Options Analysis (ROA) approach was initially employed in order to model the effects of FCF uncertainty and the results of carrying out this analysis indicated a minimal influence on the static NPV model referred to earlier. It was therefore concluded that from an equipment replacement timing perspective, the ROA approach did not provide a robust and accurate representation of the probabilistic NPV outcomes anticipated. In order to address these perceived shortcomings, an Monte Carlo Simulation (MCS) model was constructed and the requisite probability distribution functions representing the most influential independent variables determined from the sensitivity analysis were identified and subsequently analysed. The results of the MCS analysis yielded the expected NPV outcomes that were found to be far more conservative compared to the static NPV outcomes referred to previously. Furthermore, the concluding findings of this study indicate that in order to estimate the optimal time to dispose of an asset, a static NPV analysis must first be modelled and thereafter a probabilistic NPV analysis. The respective uncertainty aspects over the lifespan of the assets should be identified to be incorporated into the MCS model. This methodological approach therefore opposes the use of a strictly deterministic based approach and rather predicates the use of a probabilistic NPV based framework. This study further concluded that traditional DCF approaches fail to consider management flexibility in terms of adapting to uncertainty and to also reduce the possibility of “escalation of commitment” occurring as a result of sub-optimal equipment replacement timing decisions by management. The use and acceptance of the traditional DCF approaches are acknowledged, but in order to develop an equipment replacement methodological approach that considers uncertainty and risk on the one hand and also allows for the incorporation of real data over the assets lifetime on the other, the use of an MCS probabilistic NPV based model was found to be the optimal approach to be adopted. The result of updating the static NPV model with updated data as soon as it is obtained enables one to generate accurate probabilistic distribution functions required for the subsequent MCS analysis. By adopting this approach the study has concluded that one can obtain realistic and accurate NPV forecasts from the anticipated FCF estimates. The principal conclusion obtained from this study is that the optimal time in which to replace front line assets employed at B&E International is when the probabilistic net earnings profile, viz., NPV of the equipment is maximized.
- Full Text:
- Date Issued: 2018
The ecological risk of acid mine drainage in a salinising landscape
- Authors: Vellemu, Emmanuel Captain
- Date: 2018
- Subjects: Acid mine drainage Environmental aspects South Africa Mpumalanga , Salinization South Africa Mpumalanga , Water salinization South Africa Mpumalanga , Water quality South Africa Mpumalanga , Aquatic animals Effect of water quality on South Africa Mpumalanga , Freshwater ecology South Africa Mpumalanga
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60563 , vital:27797
- Description: Acid mine drainage (AMD) and increasing salinity of freshwater ecosystems pose serious threats to water quality in water-stressed South Africa. These threats are exacerbated by mining activities, mainly gold and coal from both active and abandoned mines that continue to release acidic water that is rich in toxic metals and high sulphate concentrations. Therefore, the overarching hypothesis for this study was that “the combination of AMD and sulphate salts confers high ecological risk to the aquatic biota”. The study employed both laboratory and field investigations to test this hypothesis and provide appropriate tools to protect freshwater ecosystems from increasing anthropogenic impacts. Firstly, a laboratory investigation was carried out to develop risk-based water quality guidelines (WQGs) for sulphates and treated AMD (TAMD) using the species sensitivity distributions (SSDs) technique. Five South African freshwater species belonging to five different taxonomic groupings, including Adenophlebia auriculata (insect), Burnupia stenochorias (mollusc), Caridina nilotica (crustacea), Pseudokirchneriella subcapitata (algae) and Oreochromis mossambicus (fish) were exposed to varying concentrations of sodium sulphate (Na2SO4), magnesium sulphate (MgSO4) and calcium sulphate (CaSO4), as well as TAMD in separate ecotoxicological experiments, applying short-term (96 h) non-renewal and long-term (240 h) renewal exposure test methods. Secondly, a novel trait-based approach (TBA) was also used to predict the vulnerability of taxa to treated acid mine drainage (TAMD). The TBA used a combination of carefully selected traits of organisms that are mechanistically linked to TAMD for their potential vulnerability predictions. Leptoceridae (caddisflies) and Leptophlebiidae (mayflies) were selected taxa for evaluation of the trait-based vulnerability predictions to TAMD for laboratory toxicity exposures. This was followed by a field investigation to assess macroinvertebrates assemblage responses, abundance and richness to a TAMD-impacted stream using the South African Scoring System version 5 (SASS5) protocol. Outcomes form the above three sources were combined in a multi-criteria analysis (MCA) to develop an appropriate water quality management strategy in a form of a trait-based decision-making support tool. Results of the risk-based WQGs revealed that Na2SO4 was the most toxic of the tested salts. A concentration of 0.020 g/L Na2SO4, 0.055 g/L CaSO4, and 0.108 g/L MgSO4 or a combined sulphate salts limit of 0.067 g/L were derived as long-term WQGs to protect over 95% of the population species in a natural environment considered as relatively pristine. This means that the generic 0.25 g/L sulphate compliance limit for South African freshwater systems is under-protective. Burnupia stenochorias was the most sensitive to AMD after long-term exposures, and it was adjudged as a good indicator of AMD along with P. subcapitata. Long-term scenario-specific WQG for AMD for the protection of over 95% of the population species was derived as 0.014%. Results of the TBA revealed that the relative abundance and diversity of taxa at a site that received direct impact from TAMD generally corresponded to trait-based predictions. The site that received direct TAMD was largely dominated by members of the Corixidae and Naucoridae families. However, Leptoceridae was more vulnerable to TAMD than Leptophlebidae contrary to predictions. Its assemblage did not match the predictions although Leptophlebiidae corresponded to predictions in terms of its assemblage and diversity. As water quality improved further downstream of the TAMD source, macroinvertebrates assemblage and diversity also improved as predicted. However, it is important to note that other equally important traits that were not studied might influence the response of organisms during toxicity test exposures. The MCA findings suggest that the trait-based decision-making support tool is a useful management strategy for the predicting vulnerability of taxa aquatic stressors including AMD and increasing salinity. Overall, the outcome of this study suggests that AMD poses an ecological risk to aquatic biota, but this becomes riskier in the presence of excess sulphate salts. Albeit, the WQGs for sulphate salts and AMD as well as the developed trait-based decision support tool all contribute novel sound scientific knowledge basis for managing the AMD and increasing salinity in freshwater ecosystems. The study recommends incorporating different life stages of indigenous species tested to determine if their sensitivity to AMD and sulphate would correspond to current findings because early life stages could be more sensitive to aquatic stressors than juveniles or adults. This is important for the derivation of strong and relevant WQGs. The TBA requires further refinement for its incorporation in ecotoxicology on a wide scale.
- Full Text:
- Date Issued: 2018
- Authors: Vellemu, Emmanuel Captain
- Date: 2018
- Subjects: Acid mine drainage Environmental aspects South Africa Mpumalanga , Salinization South Africa Mpumalanga , Water salinization South Africa Mpumalanga , Water quality South Africa Mpumalanga , Aquatic animals Effect of water quality on South Africa Mpumalanga , Freshwater ecology South Africa Mpumalanga
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60563 , vital:27797
- Description: Acid mine drainage (AMD) and increasing salinity of freshwater ecosystems pose serious threats to water quality in water-stressed South Africa. These threats are exacerbated by mining activities, mainly gold and coal from both active and abandoned mines that continue to release acidic water that is rich in toxic metals and high sulphate concentrations. Therefore, the overarching hypothesis for this study was that “the combination of AMD and sulphate salts confers high ecological risk to the aquatic biota”. The study employed both laboratory and field investigations to test this hypothesis and provide appropriate tools to protect freshwater ecosystems from increasing anthropogenic impacts. Firstly, a laboratory investigation was carried out to develop risk-based water quality guidelines (WQGs) for sulphates and treated AMD (TAMD) using the species sensitivity distributions (SSDs) technique. Five South African freshwater species belonging to five different taxonomic groupings, including Adenophlebia auriculata (insect), Burnupia stenochorias (mollusc), Caridina nilotica (crustacea), Pseudokirchneriella subcapitata (algae) and Oreochromis mossambicus (fish) were exposed to varying concentrations of sodium sulphate (Na2SO4), magnesium sulphate (MgSO4) and calcium sulphate (CaSO4), as well as TAMD in separate ecotoxicological experiments, applying short-term (96 h) non-renewal and long-term (240 h) renewal exposure test methods. Secondly, a novel trait-based approach (TBA) was also used to predict the vulnerability of taxa to treated acid mine drainage (TAMD). The TBA used a combination of carefully selected traits of organisms that are mechanistically linked to TAMD for their potential vulnerability predictions. Leptoceridae (caddisflies) and Leptophlebiidae (mayflies) were selected taxa for evaluation of the trait-based vulnerability predictions to TAMD for laboratory toxicity exposures. This was followed by a field investigation to assess macroinvertebrates assemblage responses, abundance and richness to a TAMD-impacted stream using the South African Scoring System version 5 (SASS5) protocol. Outcomes form the above three sources were combined in a multi-criteria analysis (MCA) to develop an appropriate water quality management strategy in a form of a trait-based decision-making support tool. Results of the risk-based WQGs revealed that Na2SO4 was the most toxic of the tested salts. A concentration of 0.020 g/L Na2SO4, 0.055 g/L CaSO4, and 0.108 g/L MgSO4 or a combined sulphate salts limit of 0.067 g/L were derived as long-term WQGs to protect over 95% of the population species in a natural environment considered as relatively pristine. This means that the generic 0.25 g/L sulphate compliance limit for South African freshwater systems is under-protective. Burnupia stenochorias was the most sensitive to AMD after long-term exposures, and it was adjudged as a good indicator of AMD along with P. subcapitata. Long-term scenario-specific WQG for AMD for the protection of over 95% of the population species was derived as 0.014%. Results of the TBA revealed that the relative abundance and diversity of taxa at a site that received direct impact from TAMD generally corresponded to trait-based predictions. The site that received direct TAMD was largely dominated by members of the Corixidae and Naucoridae families. However, Leptoceridae was more vulnerable to TAMD than Leptophlebidae contrary to predictions. Its assemblage did not match the predictions although Leptophlebiidae corresponded to predictions in terms of its assemblage and diversity. As water quality improved further downstream of the TAMD source, macroinvertebrates assemblage and diversity also improved as predicted. However, it is important to note that other equally important traits that were not studied might influence the response of organisms during toxicity test exposures. The MCA findings suggest that the trait-based decision-making support tool is a useful management strategy for the predicting vulnerability of taxa aquatic stressors including AMD and increasing salinity. Overall, the outcome of this study suggests that AMD poses an ecological risk to aquatic biota, but this becomes riskier in the presence of excess sulphate salts. Albeit, the WQGs for sulphate salts and AMD as well as the developed trait-based decision support tool all contribute novel sound scientific knowledge basis for managing the AMD and increasing salinity in freshwater ecosystems. The study recommends incorporating different life stages of indigenous species tested to determine if their sensitivity to AMD and sulphate would correspond to current findings because early life stages could be more sensitive to aquatic stressors than juveniles or adults. This is important for the derivation of strong and relevant WQGs. The TBA requires further refinement for its incorporation in ecotoxicology on a wide scale.
- Full Text:
- Date Issued: 2018
The economic and ecological trade-offs of wetland conversion for development projects: the case of the Kampala–Mukono corridor
- Authors: Wasswa, Hannington
- Date: 2018
- Subjects: Wetland ecology -- Uganda -- Kampala , Wetlands -- Uganda -- Kampala Wetland management -- Uganda -- Kampala Hydrogeology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36409 , vital:33939
- Description: Wetland diminution for development projects (DPs) in the Kampala–Mukono Corridor (KMC) continues to pose threats to the socio-economic and ecological benefits of wetlands because decision-makers and wetland users at various levels often have insufficient knowledge of these benefits. This situation has resulted in unsustainable development decisions that accord little weight to wetlands and have allocated many of them to DPs. In order to inform decision making for optimal development in the KMC, the present study analysed the spatial and temporal wetland loss to DPs, estimated the economic value of the KMC wetlands, and assessed the environmental consequences of wetland conversion for DPs. Sets of ortho-rectified and cloud-free multi-temporal Landsat MSS (1974) and Landsat TM/ETM+ images (30m) for 1986, 2006, and 2013 were analysed in a spatial and temporal framework. The 79m Landsat image (MSS) of 1974 was resampled and later filtered with subsequent 30m images using a majority filter method. An unsupervised classification approach was employed to characterize the wetlands and associated DPs. The classified DPs and wetland cover types were validated by reference to topographical maps (sheets) of 1974 at a scale of 1:50,000 obtained from Uganda Lands and Surveys, apriori knowledge and Google earth images corresponding to the same spatial and temporal frames. The IDRISI Selva-based Markov Chain model was employed to model future wetland loss to DPs. The Total Economic Valuation Approach (TEV) was employed to quantify selected use values of wetland economic benefits using the market price, replacement cost and contingent valuation techniques. The ecological implications of wetland loss focused on soil organic carbon (SOC) and hydrological impacts in the KMC wetlands. The estimated SOC was assessed with climatic data in order to infer the implication of SOC loss for local climate variability. The manual wet chemistry/oxidation method by Walkley-Black (1934) was adopted to estimate SOC in various wetland cover types. Hydrological impact assessments focused on water quality analysis in various wetland cover types, with major parameters being total nitrogen (TN), total phosphorous (TP) total dissolved solids – (TDS) and total suspended sediments (TSS). Hydrologic flow data parameters across the different wetland cover types in the KMC focused on water level, speed, stream width, and bed load. Results from analysis of the spatial-temporal wetland change revealed that by 2013 the KMC wetlands had lost almost half (47%) of their 1974 areal coverage, with 56% of this loss resulting from conversion to DPs. It is projected that 26% of the KMC wetlands will be lost to more DPs by 2040. Wetland loss is attributed to intensified economic activity and preference of Kampala as an industrial zone, weakness in the previous spatial planning of Kampala, and the general lack of information flow to various institutions involved in the establishment of DPs. The KMC wetlands provide a flow of economic benefits at a minimum approximated value of US$ 3,418 / ha / per year. It is revealed that a great deal of these economic benefits (88%) accrues to the local subsistence level in the form of livelihood products, incomes, and employment benefits. The 56% wetlands loss to DPs in the KMC by 2013 brings the minimum economic value lost to US$ 19,311,700 in the sampled wetlands, and projections of future wetland loss put the minimum economic loss at US$ 48,368,118 by 2040. Continuous degradation of these wetlands means serious economic costs to the government and local communities, as reflected in high replacement expenditures for wetland services, foregone incomes, subsistence livelihood support and alternative employment. The highest carbon (C) sinks were identified in forest swamps, palms, thickets and wetlands converted to agriculture, which accounted for 25% of the KMC wetlands by 2013, while the lowest total soil organic carbon (TSOC) range occurred in converted wetland cover types (converted wetlands to industrial and settlements) that occupied 47% of the study area. A general decrease in SOC sequestration from 1974 to 2013 across the KMC wetlands is identified, with the lowest C pool registered in 2013. The dwindling SOC banks are considered to be partly responsible for varying climate and related feedbacks on wetland benefits in the KMC. The hydrologic impacts of wetland loss are felt mainly in converted wetland cover types, in the form of compromised water quality, with increased nutrient pollution and TSS. These all create negative impacts on wetland hydrological services, particularly filtration, flood attenuation, recharge and discharge benefits, all of which have profound effects on biodiversity. There is an urgent need to reduce the scale of wetland diminution in the KMC. This will be achieved if mitigation and conservation measures are undertaken. Mitigation measures should include a revision of development plans, user sensitization on wetland economic values and enforcement of regulatory mechanisms. Conservation strategies should involve the use of economic incentives and disincentives which include: a revision of historic property rights to regulate wetland use, performance bonds or subsidies for environmentally friendly activities and taxes, fees or fines for unacceptable levels of degradation and tradable permits that utilise the concept of ‘wetland banks’ to ensure no further loss of the KMC wetlands to DPs. Future research should focus on modelling the response of wetland ecosystems to multiple threats and management interventions, and on a feasibility study of wetland restoration options and the implications for local people’s livelihoods in the KMC.
- Full Text:
- Date Issued: 2018
- Authors: Wasswa, Hannington
- Date: 2018
- Subjects: Wetland ecology -- Uganda -- Kampala , Wetlands -- Uganda -- Kampala Wetland management -- Uganda -- Kampala Hydrogeology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36409 , vital:33939
- Description: Wetland diminution for development projects (DPs) in the Kampala–Mukono Corridor (KMC) continues to pose threats to the socio-economic and ecological benefits of wetlands because decision-makers and wetland users at various levels often have insufficient knowledge of these benefits. This situation has resulted in unsustainable development decisions that accord little weight to wetlands and have allocated many of them to DPs. In order to inform decision making for optimal development in the KMC, the present study analysed the spatial and temporal wetland loss to DPs, estimated the economic value of the KMC wetlands, and assessed the environmental consequences of wetland conversion for DPs. Sets of ortho-rectified and cloud-free multi-temporal Landsat MSS (1974) and Landsat TM/ETM+ images (30m) for 1986, 2006, and 2013 were analysed in a spatial and temporal framework. The 79m Landsat image (MSS) of 1974 was resampled and later filtered with subsequent 30m images using a majority filter method. An unsupervised classification approach was employed to characterize the wetlands and associated DPs. The classified DPs and wetland cover types were validated by reference to topographical maps (sheets) of 1974 at a scale of 1:50,000 obtained from Uganda Lands and Surveys, apriori knowledge and Google earth images corresponding to the same spatial and temporal frames. The IDRISI Selva-based Markov Chain model was employed to model future wetland loss to DPs. The Total Economic Valuation Approach (TEV) was employed to quantify selected use values of wetland economic benefits using the market price, replacement cost and contingent valuation techniques. The ecological implications of wetland loss focused on soil organic carbon (SOC) and hydrological impacts in the KMC wetlands. The estimated SOC was assessed with climatic data in order to infer the implication of SOC loss for local climate variability. The manual wet chemistry/oxidation method by Walkley-Black (1934) was adopted to estimate SOC in various wetland cover types. Hydrological impact assessments focused on water quality analysis in various wetland cover types, with major parameters being total nitrogen (TN), total phosphorous (TP) total dissolved solids – (TDS) and total suspended sediments (TSS). Hydrologic flow data parameters across the different wetland cover types in the KMC focused on water level, speed, stream width, and bed load. Results from analysis of the spatial-temporal wetland change revealed that by 2013 the KMC wetlands had lost almost half (47%) of their 1974 areal coverage, with 56% of this loss resulting from conversion to DPs. It is projected that 26% of the KMC wetlands will be lost to more DPs by 2040. Wetland loss is attributed to intensified economic activity and preference of Kampala as an industrial zone, weakness in the previous spatial planning of Kampala, and the general lack of information flow to various institutions involved in the establishment of DPs. The KMC wetlands provide a flow of economic benefits at a minimum approximated value of US$ 3,418 / ha / per year. It is revealed that a great deal of these economic benefits (88%) accrues to the local subsistence level in the form of livelihood products, incomes, and employment benefits. The 56% wetlands loss to DPs in the KMC by 2013 brings the minimum economic value lost to US$ 19,311,700 in the sampled wetlands, and projections of future wetland loss put the minimum economic loss at US$ 48,368,118 by 2040. Continuous degradation of these wetlands means serious economic costs to the government and local communities, as reflected in high replacement expenditures for wetland services, foregone incomes, subsistence livelihood support and alternative employment. The highest carbon (C) sinks were identified in forest swamps, palms, thickets and wetlands converted to agriculture, which accounted for 25% of the KMC wetlands by 2013, while the lowest total soil organic carbon (TSOC) range occurred in converted wetland cover types (converted wetlands to industrial and settlements) that occupied 47% of the study area. A general decrease in SOC sequestration from 1974 to 2013 across the KMC wetlands is identified, with the lowest C pool registered in 2013. The dwindling SOC banks are considered to be partly responsible for varying climate and related feedbacks on wetland benefits in the KMC. The hydrologic impacts of wetland loss are felt mainly in converted wetland cover types, in the form of compromised water quality, with increased nutrient pollution and TSS. These all create negative impacts on wetland hydrological services, particularly filtration, flood attenuation, recharge and discharge benefits, all of which have profound effects on biodiversity. There is an urgent need to reduce the scale of wetland diminution in the KMC. This will be achieved if mitigation and conservation measures are undertaken. Mitigation measures should include a revision of development plans, user sensitization on wetland economic values and enforcement of regulatory mechanisms. Conservation strategies should involve the use of economic incentives and disincentives which include: a revision of historic property rights to regulate wetland use, performance bonds or subsidies for environmentally friendly activities and taxes, fees or fines for unacceptable levels of degradation and tradable permits that utilise the concept of ‘wetland banks’ to ensure no further loss of the KMC wetlands to DPs. Future research should focus on modelling the response of wetland ecosystems to multiple threats and management interventions, and on a feasibility study of wetland restoration options and the implications for local people’s livelihoods in the KMC.
- Full Text:
- 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.
- Full Text:
- Date Issued: 2018
- 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.
- Full Text:
- Date Issued: 2018
The effect of replacing antibiotic growth promoters with moringa oleifera leaf powder on growth performance, carcass characteristics, immune organ indices, gut microflora, physicochemical and sensory quality of broiler meat
- Nantapo, Carlos Wyson Tawanda
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2018
- Subjects: Moringa oleifera Meat--Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/17749 , vital:41197
- Description: The objective of the study was to determine the effect of feeding graded levels of Moringa oleifera leaf meal powder (MOLP) on growth performance, carcass characteristics, economic analysis, health status, physicochemical, sensory properties, mineral composition and retention values of meat. A total of 1600 Comb-500 day-old unsexed chicks were allotted to 4 dietary treatment groups, with 4 replicate pens of 100 birds each in a completely randomised design. The dietary treatments were basal diets supplemented with different levels of MOLP as follows; Treatment 1/ control: Basal diet with antibiotic Zinc bacitracin and coccidiostatic Maxiban and no MOLP (0MOLP); Treatment 2: Basal diet included 1percent MOLP (1MOLP); Treatment 3: Basal diet included 3.0 percent MOLP (3MOLP); Treatment 4: Basal diet included 5 percent MOLP (5MOLP). Birds fed basal diets plus 5percent MOLP at starter phase achieved the least FCR 1.53 (P < 0.037), whilst consuming significantly less feed ADFI 47.4 g (P < 0.05). For the entire feeding period, birds fed 5 percent MOLP achieved a favourable FCR of 1.80 among all treatment groups (P < 0.001), but achieved the lowest final live weight (1416 g), carcass weights (1044g) (P < 0.05). Birds fed 0 percent MOLP recorded highest final weight, carcass weight (1339) and the best dressing percentages (76.8percent) (P < 0.05). Abdominal fat levels were reduced by elevating MOLP in diets (P < 0.05). Improvements in proportions of giblets, gizzard, liver and intestine were observed with increase in dietary MOLP. Feed costs increased, while gross and net returns and economic efficiency decreased as dietary MOLP increased. Organ indices of spleen, Bursa of Fabricius and liver were significantly increased by 5percent MOLP in the diet (P < 0.05). Macroscopic lesions scores (P < 0.05) were significantly higher in duodenum, jejunum and ileum of birds in the 1MOLP treatment group on d 28 and d 35. Control and 5MOLP groups recorded the least bloody excreta scores among all treatment groups (P < 0.05). Highest total aerobic bacteria (TAB), E. coli, C. perfringens counts and the lowest lactobacillus spp counts were observed in all intestinal segments in birds in the 1MOLP treatment group. Lower E. coli and C. perfringens but higher lactobacillus spp counts were observed in control and 5MOLP groups (P < 0.05) in the duodenum and jejunum. Increasing MOLP levels in diets led to lower pH and pHu in both breast and leg muscles (P < 0.05). pH was consistently lower in leg muscles than in breast cuts in all treatments and a large decline in post-mortem pH was observed in all muscles of birds in control group. A dietary increase in MOLP level led to a significant increase in L* and b* (P < 0.05) negative correlation between pH and L* (r = -0.463) (P < 0.05) and a weak but significant (P < 0.001) correlation (r = 0.176) between pH and drip loss. Herb flavour (P = 0.0029), appearance (P = 0.0156), aroma (P = 0.0011), colour (P = 0.0375), taste (P = 0.0032) and overall acceptability (P = 0.0192) were improved by grilling, microwave cooking and pan-frying in olive oil. These changes were more pronounced in breast muscle, thus following the trend; microwave > pan-frying in olive oil > grilled samples > boiling for best cooked product based on overall acceptability. Grilling and frying heart muscles resulted in the highest Ca (45.9 mg/kg) and Mg (98.9 mg/kg), whereas boiling led to the lowest Ca (41.1 mg/kg) and Mg (91.4 mg/kg) concentration. The highest concentrations of Fe and Zn these minerals were recorded in grilled (32.7 mg/kg) and fried samples (75.2 mg/kg). Zinc and Fe concentration observed in liver and heart muscles were higher than those found in breast and leg muscle. In conclusion, the results confirm the potential of MOLP for use as an alternative to antibiotics in maintaining broiler health, reducing mortalities and improving carcass characteristics and some meat quality traits.
- Full Text:
- Date Issued: 2018
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2018
- Subjects: Moringa oleifera Meat--Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/17749 , vital:41197
- Description: The objective of the study was to determine the effect of feeding graded levels of Moringa oleifera leaf meal powder (MOLP) on growth performance, carcass characteristics, economic analysis, health status, physicochemical, sensory properties, mineral composition and retention values of meat. A total of 1600 Comb-500 day-old unsexed chicks were allotted to 4 dietary treatment groups, with 4 replicate pens of 100 birds each in a completely randomised design. The dietary treatments were basal diets supplemented with different levels of MOLP as follows; Treatment 1/ control: Basal diet with antibiotic Zinc bacitracin and coccidiostatic Maxiban and no MOLP (0MOLP); Treatment 2: Basal diet included 1percent MOLP (1MOLP); Treatment 3: Basal diet included 3.0 percent MOLP (3MOLP); Treatment 4: Basal diet included 5 percent MOLP (5MOLP). Birds fed basal diets plus 5percent MOLP at starter phase achieved the least FCR 1.53 (P < 0.037), whilst consuming significantly less feed ADFI 47.4 g (P < 0.05). For the entire feeding period, birds fed 5 percent MOLP achieved a favourable FCR of 1.80 among all treatment groups (P < 0.001), but achieved the lowest final live weight (1416 g), carcass weights (1044g) (P < 0.05). Birds fed 0 percent MOLP recorded highest final weight, carcass weight (1339) and the best dressing percentages (76.8percent) (P < 0.05). Abdominal fat levels were reduced by elevating MOLP in diets (P < 0.05). Improvements in proportions of giblets, gizzard, liver and intestine were observed with increase in dietary MOLP. Feed costs increased, while gross and net returns and economic efficiency decreased as dietary MOLP increased. Organ indices of spleen, Bursa of Fabricius and liver were significantly increased by 5percent MOLP in the diet (P < 0.05). Macroscopic lesions scores (P < 0.05) were significantly higher in duodenum, jejunum and ileum of birds in the 1MOLP treatment group on d 28 and d 35. Control and 5MOLP groups recorded the least bloody excreta scores among all treatment groups (P < 0.05). Highest total aerobic bacteria (TAB), E. coli, C. perfringens counts and the lowest lactobacillus spp counts were observed in all intestinal segments in birds in the 1MOLP treatment group. Lower E. coli and C. perfringens but higher lactobacillus spp counts were observed in control and 5MOLP groups (P < 0.05) in the duodenum and jejunum. Increasing MOLP levels in diets led to lower pH and pHu in both breast and leg muscles (P < 0.05). pH was consistently lower in leg muscles than in breast cuts in all treatments and a large decline in post-mortem pH was observed in all muscles of birds in control group. A dietary increase in MOLP level led to a significant increase in L* and b* (P < 0.05) negative correlation between pH and L* (r = -0.463) (P < 0.05) and a weak but significant (P < 0.001) correlation (r = 0.176) between pH and drip loss. Herb flavour (P = 0.0029), appearance (P = 0.0156), aroma (P = 0.0011), colour (P = 0.0375), taste (P = 0.0032) and overall acceptability (P = 0.0192) were improved by grilling, microwave cooking and pan-frying in olive oil. These changes were more pronounced in breast muscle, thus following the trend; microwave > pan-frying in olive oil > grilled samples > boiling for best cooked product based on overall acceptability. Grilling and frying heart muscles resulted in the highest Ca (45.9 mg/kg) and Mg (98.9 mg/kg), whereas boiling led to the lowest Ca (41.1 mg/kg) and Mg (91.4 mg/kg) concentration. The highest concentrations of Fe and Zn these minerals were recorded in grilled (32.7 mg/kg) and fried samples (75.2 mg/kg). Zinc and Fe concentration observed in liver and heart muscles were higher than those found in breast and leg muscle. In conclusion, the results confirm the potential of MOLP for use as an alternative to antibiotics in maintaining broiler health, reducing mortalities and improving carcass characteristics and some meat quality traits.
- Full Text:
- Date Issued: 2018
The effects of collective bargaining on wages at University of Fort Hare 2007-2016
- Authors: Olusola, Olasupo
- Date: 2018
- Subjects: Wages Collective bargaining -- South Africa Labor unions -- South Africa
- Language: English
- Type: Thesis , Doctoral , Public Administration
- Identifier: http://hdl.handle.net/10353/9962 , vital:35208
- Description: Collective bargaining is essential in labour relations because of its significant role on wages thereby structuring cordial labour-management relations. The essence of labour unions in South African higher education institutions such as National Education, Health and Allied Workers’ Union (NEHAWU) with specific reference to University of Fort Hare, is to ensure the good wages and conditions of service for their members through the instrumentality of collective bargaining between the Union and University management. The end result which is the bargaining agreement may improve on staff pay and encourage more cordial labour-management relations in South African higher institutions and specifically at University of Fort Hare which is the case study. This study was motivated by claims and evidences which show that University of Fort Hare’s staff is the least paid in South African higher education sector over the years due to unsustainability status of the University in the time past. Both the organized labour union and management at the University of Fort Hare entered into agreement that led to sacrificial forfeiture of salary increase by staff over the period of unsustainability of the University to avoid it from being closed down. This state has made the staff to suffer so many imbalances in their wages compared to what is obtainable in other universities in South Africa. This lingering situation has compelled NEHAWU to consistently engage the University management in bargaining in a bid to improve the wages of their members. The study made use of mixed research method which reveals that collective bargaining has effects on wages at University of Fort Hare. 307 participating staff were randomly selected from the following ÜFH Campuses; Bisho, Alice and East London.The questionnaire measured the effects of collective bargaining on wages at the University. In-depth Interviews were conducted among the staff at UFH. It involves the University management, NEHAWU officialsand top officers from the University Human Resources Department. Statistical Package for Social Science (SPSS) was utilized to analyze data collected. Descriptive and inferential statistics was used to interpret the data. Tables and graphs; confidence interval and p-value was utilized to demonstrate the characteristics of information collected from the participants. The research questions were tested by Pearson correlation and T. Test. The reliability of different instruments that were used in this study was tested by Cronbach alpha coefficients and also computed to determine the validity of question. The study concludes that there is a significant relationship between collective bargaining and wages at UFH. Recommendations were made in favour of transparency, time bound bargaining, mutual trust, proper communication and accountability among the negotiating parties at UFH for more successful bargaining that will further improve on staff pay at the University.
- Full Text:
- Date Issued: 2018
- Authors: Olusola, Olasupo
- Date: 2018
- Subjects: Wages Collective bargaining -- South Africa Labor unions -- South Africa
- Language: English
- Type: Thesis , Doctoral , Public Administration
- Identifier: http://hdl.handle.net/10353/9962 , vital:35208
- Description: Collective bargaining is essential in labour relations because of its significant role on wages thereby structuring cordial labour-management relations. The essence of labour unions in South African higher education institutions such as National Education, Health and Allied Workers’ Union (NEHAWU) with specific reference to University of Fort Hare, is to ensure the good wages and conditions of service for their members through the instrumentality of collective bargaining between the Union and University management. The end result which is the bargaining agreement may improve on staff pay and encourage more cordial labour-management relations in South African higher institutions and specifically at University of Fort Hare which is the case study. This study was motivated by claims and evidences which show that University of Fort Hare’s staff is the least paid in South African higher education sector over the years due to unsustainability status of the University in the time past. Both the organized labour union and management at the University of Fort Hare entered into agreement that led to sacrificial forfeiture of salary increase by staff over the period of unsustainability of the University to avoid it from being closed down. This state has made the staff to suffer so many imbalances in their wages compared to what is obtainable in other universities in South Africa. This lingering situation has compelled NEHAWU to consistently engage the University management in bargaining in a bid to improve the wages of their members. The study made use of mixed research method which reveals that collective bargaining has effects on wages at University of Fort Hare. 307 participating staff were randomly selected from the following ÜFH Campuses; Bisho, Alice and East London.The questionnaire measured the effects of collective bargaining on wages at the University. In-depth Interviews were conducted among the staff at UFH. It involves the University management, NEHAWU officialsand top officers from the University Human Resources Department. Statistical Package for Social Science (SPSS) was utilized to analyze data collected. Descriptive and inferential statistics was used to interpret the data. Tables and graphs; confidence interval and p-value was utilized to demonstrate the characteristics of information collected from the participants. The research questions were tested by Pearson correlation and T. Test. The reliability of different instruments that were used in this study was tested by Cronbach alpha coefficients and also computed to determine the validity of question. The study concludes that there is a significant relationship between collective bargaining and wages at UFH. Recommendations were made in favour of transparency, time bound bargaining, mutual trust, proper communication and accountability among the negotiating parties at UFH for more successful bargaining that will further improve on staff pay at the University.
- Full Text:
- Date Issued: 2018
The effects of environmental variability on the physiology and ecology of Cape stumpnose Rhabdosargus holubi (Steindachner, 1881) (Sparidae)
- Authors: Kisten, Yanasivan
- Date: 2018
- Subjects: Freshwater fishes -- South Africa , Fishes -- Ecology Freshwater fishes -- Ecology Estuarine ecology -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31424 , vital:31374
- Description: Estuaries are important nursery areas for early stages of marine estuarine-dependent fishes, such as the sparid Rhabdosargus holubi. Estuaries provide food, shelter from predators and optimal habitats and environmental conditions for growth and development. However, estuaries are environmentally dynamic and resident organisms must be able to adapt to rapid changes. Such changes are potentially further exacerbated anthropogenically by water and land use practices such as freshwater abstraction, impoundment, pollution and anthropogenically driven climatic change. An effective approach to better understanding the current and future impacts of these kinds of changes, is by assessing the environmental adaptability of organisms, especially to extreme conditions such as droughts and resulting water shortages, which are prevalent in some parts of southern Africa. This thesis examines the effect of various environmental changes such as salinity, turbidity and temperature on the ecology and physiology of a South African common endemic fish species, the Cape stumpnose, R. holubi. Previous work on the species have investigated short term impacts on physiology while this study investigates medium to short term impacts. The specie’s wide distribution in South Africa and tolerance enabled a range of environmental, ecological and physiological relationships to be tested in the context of a changing world. These included: 1) determining the relationship between environmental variability and the distribution and abundance of R. holubi larvae in 25 estuaries along the temperate coast of South Africa; 2) determining the relationship between environmental variability and the movement of larvae and juveniles within two permanently open estuaries; 3) determining the impact of shock and acclimatization on R. holubi salinity tolerance ranges under hypersaline conditions; 4) II determining the impact of hypersalinity on the potential long term impacts growth and skeletal deformities of juvenile R. holubi in aquaria. The findings of these studies suggest that larval occurrence and density within estuaries is a function of salinity and turbidity, by proxy indicating a preference for high freshwater inflow especially in estuary types such as permanently open estuaries. The movement of larvae and juveniles within these estuaries is also mediated by salinity, turbidity and temperature, indicating the importance of seasonality along with environmental conditions and potential olfactory recruitment cues driven by freshwater flow. Tolerance experiments showed that slower acclimation to higher salinities can expand the previously reported tolerance range indicating the potential for adaptation. Physiological experiments showed negative impacts on respiration at salinities exceeding 45, indicating potential long-term physiological effects in hypersaline conditions. Further, living at high salinities for extended periods may have potentially negative effects on long term physiology, particularly growth and skeletal development. The overall results indicate that low salinity (5–18), high turbidity (20–30 NTU) and high temperature (5–22°C) are integral to the distribution and abundance of the species in permanently open estuaries. This conforms to the general rule that estuarine-associated marine fish have higher growth rates in salinities of 12-19. However, juveniles are also adapted to survive at higher salinities for long periods (2 months in the current thesis). This explains why R. holubi is one of the few species in the estuarine fish community that may persist during droughts. The predicted future changes in coastal temperatures and rainfall by climate change investigators, are likely to result in range shifts and changes in recruitment times of estuarine fish communities. The current work addresses novel aspects of the ecology and physiology of R. holubi and indicates that this species will play an increasingly important role within the estuaries of South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Kisten, Yanasivan
- Date: 2018
- Subjects: Freshwater fishes -- South Africa , Fishes -- Ecology Freshwater fishes -- Ecology Estuarine ecology -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31424 , vital:31374
- Description: Estuaries are important nursery areas for early stages of marine estuarine-dependent fishes, such as the sparid Rhabdosargus holubi. Estuaries provide food, shelter from predators and optimal habitats and environmental conditions for growth and development. However, estuaries are environmentally dynamic and resident organisms must be able to adapt to rapid changes. Such changes are potentially further exacerbated anthropogenically by water and land use practices such as freshwater abstraction, impoundment, pollution and anthropogenically driven climatic change. An effective approach to better understanding the current and future impacts of these kinds of changes, is by assessing the environmental adaptability of organisms, especially to extreme conditions such as droughts and resulting water shortages, which are prevalent in some parts of southern Africa. This thesis examines the effect of various environmental changes such as salinity, turbidity and temperature on the ecology and physiology of a South African common endemic fish species, the Cape stumpnose, R. holubi. Previous work on the species have investigated short term impacts on physiology while this study investigates medium to short term impacts. The specie’s wide distribution in South Africa and tolerance enabled a range of environmental, ecological and physiological relationships to be tested in the context of a changing world. These included: 1) determining the relationship between environmental variability and the distribution and abundance of R. holubi larvae in 25 estuaries along the temperate coast of South Africa; 2) determining the relationship between environmental variability and the movement of larvae and juveniles within two permanently open estuaries; 3) determining the impact of shock and acclimatization on R. holubi salinity tolerance ranges under hypersaline conditions; 4) II determining the impact of hypersalinity on the potential long term impacts growth and skeletal deformities of juvenile R. holubi in aquaria. The findings of these studies suggest that larval occurrence and density within estuaries is a function of salinity and turbidity, by proxy indicating a preference for high freshwater inflow especially in estuary types such as permanently open estuaries. The movement of larvae and juveniles within these estuaries is also mediated by salinity, turbidity and temperature, indicating the importance of seasonality along with environmental conditions and potential olfactory recruitment cues driven by freshwater flow. Tolerance experiments showed that slower acclimation to higher salinities can expand the previously reported tolerance range indicating the potential for adaptation. Physiological experiments showed negative impacts on respiration at salinities exceeding 45, indicating potential long-term physiological effects in hypersaline conditions. Further, living at high salinities for extended periods may have potentially negative effects on long term physiology, particularly growth and skeletal development. The overall results indicate that low salinity (5–18), high turbidity (20–30 NTU) and high temperature (5–22°C) are integral to the distribution and abundance of the species in permanently open estuaries. This conforms to the general rule that estuarine-associated marine fish have higher growth rates in salinities of 12-19. However, juveniles are also adapted to survive at higher salinities for long periods (2 months in the current thesis). This explains why R. holubi is one of the few species in the estuarine fish community that may persist during droughts. The predicted future changes in coastal temperatures and rainfall by climate change investigators, are likely to result in range shifts and changes in recruitment times of estuarine fish communities. The current work addresses novel aspects of the ecology and physiology of R. holubi and indicates that this species will play an increasingly important role within the estuaries of South Africa.
- Full Text:
- Date Issued: 2018
The effects of frost on Albany subtropical thicket and nama-karoo shrubland in South Africa
- Authors: Duker, Robert
- Date: 2018
- Subjects: Shrubland ecology , Desert ecology -- South Africa Ecological surveys -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29951 , vital:30799
- Description: Numerous treeless shrublands exist in areas where climates should support tree growth. In South Africa, the predominantly lowland Albany Subtropical Thicket (thicket), and the predominantly upland Nama-Karoo semi-desert shrubland share a boundary that is often abrupt and analogous to a forest-shrubland alpine ‘treeline’. This boundary exists across similar climatic and edaphic conditions, and field observations and leaf-level experiments suggest that certain thicket component species have lower levels of frost tolerance than the Nama-Karoo shrubs. The hypothesis is that the occurrence of sub-zero temperatures and frost dictates the position of this boundary at both the local landscape and broader regional levels. I test this hypothesis by quantifying leaf-level and whole-plant freezing tolerance of thicket and Nama-Karoo shrubland species, in relation to their local- and regional-scale distribution, and by modelling the occurrence of frost in the mountainous areas of the coastal lowlands relation to 1) naturally occurring boundaries between these two vegetation types, and 2) levels of aboveground net primary productivity (NPP) of Portulacaria afra Jacq. (spekboom) cuttings (planted with the aim of restoring livestock-degraded thicket). I found that the observed and modelled occurrence of frost in the local landscape has significant negative influences on the photosynthetic health, survival and growth rates of thicket component species, and that leaf-level freezing tolerance of evergreen thicket and Nama-Karoo shrubland species is strongly related to their broader regional-scale distributional thresholds. These results support the hypothesis that the occurrence of sub-zero temperatures and frost play a major role in determining the local- and regional-scale distribution of thicket and Nama-Karoo shrubland species, via their reliance on frost-defined refugia at a variety of different scales, and that the once-widespread and regionally dominant thicket vegetation contracted into small climatic refugia during the Last Glacial Maximum (LGM). These results also have major implications for landscape- and regional-level planning of livestock-degraded thicket restoration efforts that use planting of spekboom as an ecosystem engineer, and for predicting boundary shifts under the predicted future warming of global climates.
- Full Text:
- Date Issued: 2018
- Authors: Duker, Robert
- Date: 2018
- Subjects: Shrubland ecology , Desert ecology -- South Africa Ecological surveys -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29951 , vital:30799
- Description: Numerous treeless shrublands exist in areas where climates should support tree growth. In South Africa, the predominantly lowland Albany Subtropical Thicket (thicket), and the predominantly upland Nama-Karoo semi-desert shrubland share a boundary that is often abrupt and analogous to a forest-shrubland alpine ‘treeline’. This boundary exists across similar climatic and edaphic conditions, and field observations and leaf-level experiments suggest that certain thicket component species have lower levels of frost tolerance than the Nama-Karoo shrubs. The hypothesis is that the occurrence of sub-zero temperatures and frost dictates the position of this boundary at both the local landscape and broader regional levels. I test this hypothesis by quantifying leaf-level and whole-plant freezing tolerance of thicket and Nama-Karoo shrubland species, in relation to their local- and regional-scale distribution, and by modelling the occurrence of frost in the mountainous areas of the coastal lowlands relation to 1) naturally occurring boundaries between these two vegetation types, and 2) levels of aboveground net primary productivity (NPP) of Portulacaria afra Jacq. (spekboom) cuttings (planted with the aim of restoring livestock-degraded thicket). I found that the observed and modelled occurrence of frost in the local landscape has significant negative influences on the photosynthetic health, survival and growth rates of thicket component species, and that leaf-level freezing tolerance of evergreen thicket and Nama-Karoo shrubland species is strongly related to their broader regional-scale distributional thresholds. These results support the hypothesis that the occurrence of sub-zero temperatures and frost play a major role in determining the local- and regional-scale distribution of thicket and Nama-Karoo shrubland species, via their reliance on frost-defined refugia at a variety of different scales, and that the once-widespread and regionally dominant thicket vegetation contracted into small climatic refugia during the Last Glacial Maximum (LGM). These results also have major implications for landscape- and regional-level planning of livestock-degraded thicket restoration efforts that use planting of spekboom as an ecosystem engineer, and for predicting boundary shifts under the predicted future warming of global climates.
- Full Text:
- Date Issued: 2018
The efficacy of multi-track diplomacy in resolving intrastate and internationalised conflicts in Africa: the case of the 2007/2008 post-election violence in Kenya
- Authors: Natolooka, Kepha
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63546 , vital:28434
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Natolooka, Kepha
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63546 , vital:28434
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
The environmental imagination in Arthur Nortje’s poetry
- Authors: Kaze, Douglas Eric
- Date: 2018
- Subjects: Nortje, Arthur, 1942-1970 -- Criticism and interpretation , Ecology in literature , Race awareness in literature , South African poetry (English) -- History and criticism , Nature in literature , Transversal postcolonial environmental criticism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58024 , vital:27033
- Description: This thesis seeks to contribute to the conversations in the humanities about the treatment of the physical environment in the context of a global ecological fragility and increased scholarly interest in the poetry of Arthur Nortje, a South African poet who wrote in the 1960s. While previous studies on Nortje concentrate on the political, psychic and technical aspects of his poetry, this study particularly explores the representations of the environment in Nortje’s poetic imagination. Writing in the dark period of apartheid in South Africa’s history, Nortje’s poetry articulates a strong interest in the physical environment against the backdrop of official racialization of space and his personal nomadic life and exile. The poetry abounds with constant intersections of nature and culture (industrialism, urbanity and the quotidian), a sense of place and a deep sense of dislocation. The poems, therefore, present a platform from which to reevaluate conventional ecocritical ideas about nature, place-attachment and environmental consciousness. Drawing mainly on Felix Guattari’s ideas of three ecologies and transversality along with other theories, I conduct the study through what I call a transversal postcolonial environmental criticism, which considers the ecological value of the kind of assemblages that Nortje’s works represent. The first chapter focuses on conceptualizing a postcolonial approach to the environment based on Guattari’s concept of transversality to lay the theoretical foundation for the whole work. The second chapter analyses Nortje’s poetic imagination of place and displacement through his treatment of the private-public tension and the motif of exile. While the third chapter examines Nortje’s depiction of nature as both an everyday and urban phenomenon, the fourth chapter turns to his direct treatment of environmental crises handled through his imagination of the Canadian urban spaces, exile memory of apartheid geography, war and ecocide and the human body as a subject of environmental degradation. The fifth chapter, which is the conclusion, takes a brief look at the implication of Nortje’s complex treatment of the environment on postcolonial environmentalism.
- Full Text:
- Date Issued: 2018
- Authors: Kaze, Douglas Eric
- Date: 2018
- Subjects: Nortje, Arthur, 1942-1970 -- Criticism and interpretation , Ecology in literature , Race awareness in literature , South African poetry (English) -- History and criticism , Nature in literature , Transversal postcolonial environmental criticism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58024 , vital:27033
- Description: This thesis seeks to contribute to the conversations in the humanities about the treatment of the physical environment in the context of a global ecological fragility and increased scholarly interest in the poetry of Arthur Nortje, a South African poet who wrote in the 1960s. While previous studies on Nortje concentrate on the political, psychic and technical aspects of his poetry, this study particularly explores the representations of the environment in Nortje’s poetic imagination. Writing in the dark period of apartheid in South Africa’s history, Nortje’s poetry articulates a strong interest in the physical environment against the backdrop of official racialization of space and his personal nomadic life and exile. The poetry abounds with constant intersections of nature and culture (industrialism, urbanity and the quotidian), a sense of place and a deep sense of dislocation. The poems, therefore, present a platform from which to reevaluate conventional ecocritical ideas about nature, place-attachment and environmental consciousness. Drawing mainly on Felix Guattari’s ideas of three ecologies and transversality along with other theories, I conduct the study through what I call a transversal postcolonial environmental criticism, which considers the ecological value of the kind of assemblages that Nortje’s works represent. The first chapter focuses on conceptualizing a postcolonial approach to the environment based on Guattari’s concept of transversality to lay the theoretical foundation for the whole work. The second chapter analyses Nortje’s poetic imagination of place and displacement through his treatment of the private-public tension and the motif of exile. While the third chapter examines Nortje’s depiction of nature as both an everyday and urban phenomenon, the fourth chapter turns to his direct treatment of environmental crises handled through his imagination of the Canadian urban spaces, exile memory of apartheid geography, war and ecocide and the human body as a subject of environmental degradation. The fifth chapter, which is the conclusion, takes a brief look at the implication of Nortje’s complex treatment of the environment on postcolonial environmentalism.
- Full Text:
- Date Issued: 2018
The extraction, quantification and application of high-value biological compounds from olive oil processing waste
- Authors: Postma-Botha, Marthie
- Date: 2018
- Subjects: Organic compounds , Biochemistry , Biomass energy , Olive oil industry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34383 , vital:33371
- Description: Olive oil processing waste (pomace) as a by-product of the olive oil industry is regarded as a rich source of high-value biological compounds exhibiting antioxidant potential. The objective of the present work was to obtain a concentrated extract of high-value biological antioxidants from the pomace. The effect of extraction conditions on the concentration of the bioactive compounds in the extracts was investigated. The simultaneous recovery of both hydrophilic and lipophilic high-value biological compounds exhibiting antioxidant potential was achieved through a one-step extraction method under reduced pressure using a non-toxic solvent blend. A multilevel experimental design was implemented with the aim of optimising the recovery of selected compounds, namely, hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene from olive pomace by using solvent blends of n-heptane, d-limonene, ethanol and water. The factors considered were: extraction time, percentage composition of solvent blends and extraction temperature. The results suggested that a good recovery of the hydrophilic polyphenolic compounds, namely, hydroxytyrosol, tyrosol and oleuropein, as well as the lipophilic compounds, α-tocopherol and squalene may be achieved at a solvent temperature of 60°C at 400 mbar with a solvent blend of 30% n-heptane, 50% ethanol and 20% water and an extraction time of two hours. It was found that freeze-drying the pomace before extraction minimised production of artefacts, avoided degradation of biophenols, ensured long term stability of a reproducible sample and achieved better recovery of important hydrophilic and lipophilic bioactive compounds. Since the bioactive compounds are temperature sensitive, the extraction was performed under reduced pressure in order to reduce solvent reflux temperature and to improve extraction efficiency. The quantitative and qualitative determinations of the aforementioned high-value compounds were performed by high-performance liquid chromatography (HPLC), which revealed that the hydrophilic polyphenolic as well as the lipophilic α-tocopherol and squalene were present. In this study hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene were extracted from the pomace of two olive cultivars (Frantoio and Coratina). A comparison among the two cultivars showed quantitative differences between the two cultivars in all five high-value biological compounds and in the antioxidant capacity of the extracts evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical. Coratina cultivar was found to have a significantly higher antioxidant capacity than Frantoio due to the much greater oleuropein content in the Coratina compared to the Frantoio although Frantoio had a significantly greater amount of hydroxytyrosol. The stability of olive waste extracts stored at four temperatures was also investigated and the results show that increased temperatures caused greater extent of degradation of both the hydrophilic polyphenolic and lipophilic compounds. The proposed optimum storage condition for the olive pomace extracts was found to be at 5°C in the absence of light. The extracts were incorporated into two cosmetic formulations and were found, from a stability study, to be stable at room temperature and optimally stable at 5°C in the absence of light.
- Full Text:
- Date Issued: 2018
- Authors: Postma-Botha, Marthie
- Date: 2018
- Subjects: Organic compounds , Biochemistry , Biomass energy , Olive oil industry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34383 , vital:33371
- Description: Olive oil processing waste (pomace) as a by-product of the olive oil industry is regarded as a rich source of high-value biological compounds exhibiting antioxidant potential. The objective of the present work was to obtain a concentrated extract of high-value biological antioxidants from the pomace. The effect of extraction conditions on the concentration of the bioactive compounds in the extracts was investigated. The simultaneous recovery of both hydrophilic and lipophilic high-value biological compounds exhibiting antioxidant potential was achieved through a one-step extraction method under reduced pressure using a non-toxic solvent blend. A multilevel experimental design was implemented with the aim of optimising the recovery of selected compounds, namely, hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene from olive pomace by using solvent blends of n-heptane, d-limonene, ethanol and water. The factors considered were: extraction time, percentage composition of solvent blends and extraction temperature. The results suggested that a good recovery of the hydrophilic polyphenolic compounds, namely, hydroxytyrosol, tyrosol and oleuropein, as well as the lipophilic compounds, α-tocopherol and squalene may be achieved at a solvent temperature of 60°C at 400 mbar with a solvent blend of 30% n-heptane, 50% ethanol and 20% water and an extraction time of two hours. It was found that freeze-drying the pomace before extraction minimised production of artefacts, avoided degradation of biophenols, ensured long term stability of a reproducible sample and achieved better recovery of important hydrophilic and lipophilic bioactive compounds. Since the bioactive compounds are temperature sensitive, the extraction was performed under reduced pressure in order to reduce solvent reflux temperature and to improve extraction efficiency. The quantitative and qualitative determinations of the aforementioned high-value compounds were performed by high-performance liquid chromatography (HPLC), which revealed that the hydrophilic polyphenolic as well as the lipophilic α-tocopherol and squalene were present. In this study hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene were extracted from the pomace of two olive cultivars (Frantoio and Coratina). A comparison among the two cultivars showed quantitative differences between the two cultivars in all five high-value biological compounds and in the antioxidant capacity of the extracts evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical. Coratina cultivar was found to have a significantly higher antioxidant capacity than Frantoio due to the much greater oleuropein content in the Coratina compared to the Frantoio although Frantoio had a significantly greater amount of hydroxytyrosol. The stability of olive waste extracts stored at four temperatures was also investigated and the results show that increased temperatures caused greater extent of degradation of both the hydrophilic polyphenolic and lipophilic compounds. The proposed optimum storage condition for the olive pomace extracts was found to be at 5°C in the absence of light. The extracts were incorporated into two cosmetic formulations and were found, from a stability study, to be stable at room temperature and optimally stable at 5°C in the absence of light.
- Full Text:
- Date Issued: 2018
The FAST fabric objective measurement properties of commercial worsted apparel fabrics available in South Africa
- Authors: Das, Sweta
- Date: 2018
- Subjects: Textile fabrics -- Testing , Textile fabrics -- Measurement , Textile fibers -- Testing , Textile design
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/17814 , vital:28458
- Description: In the last few decades, there has been a shift globally towards the objective measurement of these textile fibre, yarn and fabric properties which determine processing performance and product quality. This shift is also very apparent in the objective measurement of fabric properties, particularly those relating to handle and making-up into a garment. This study was motivated by the fact that the adoption of fabric objective measurement (FOM), specifically the FAST system, will benefit the South African worsted apparel sector, as it has done in various other countries which produce high quality worsted apparel fabrics and garments. FAST is robust and portable, yet inexpensive. The main objective of the study was to develop a FAST referencing system which can be used for benchmarking by the local apparel industry and, as a basis for encouraging and persuading the industry to adopt this system of fabric quality measurement and assurance and thereby improve their product quality and international competitiveness. To achieve the main objective, involved sourcing and FAST testing a representative cross-section of commercial worsted apparel fabrics with the emphasis on wool and wool blends from the local fabric and clothing manufacturing industry, and determining how the various FAST properties were affected by factors such as fabric weave, fibre blend and weight, since this could impact on the specific nature and validity of the referencing system. A total of some 394 worsted type commercial fabrics, mainly in wool and wool blends, were sourced from, and with the inputs of, local apparel fabric and clothing manufacturers so as to ensure the local fabric and garment representative of the sample population and after which the fabrics were tested on the FAST system. ANOVA (regression analysis) was carried out on each of the FAST parameters in order to determine whether fabric weight, weave, thickness and fibre composition (pure wool and wool blends) had a statistically significant effect on them, since this is an important aspect which needs to be clarified prior to the development of a envisaged meaningful FAST system.
- Full Text:
- Date Issued: 2018
- Authors: Das, Sweta
- Date: 2018
- Subjects: Textile fabrics -- Testing , Textile fabrics -- Measurement , Textile fibers -- Testing , Textile design
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/17814 , vital:28458
- Description: In the last few decades, there has been a shift globally towards the objective measurement of these textile fibre, yarn and fabric properties which determine processing performance and product quality. This shift is also very apparent in the objective measurement of fabric properties, particularly those relating to handle and making-up into a garment. This study was motivated by the fact that the adoption of fabric objective measurement (FOM), specifically the FAST system, will benefit the South African worsted apparel sector, as it has done in various other countries which produce high quality worsted apparel fabrics and garments. FAST is robust and portable, yet inexpensive. The main objective of the study was to develop a FAST referencing system which can be used for benchmarking by the local apparel industry and, as a basis for encouraging and persuading the industry to adopt this system of fabric quality measurement and assurance and thereby improve their product quality and international competitiveness. To achieve the main objective, involved sourcing and FAST testing a representative cross-section of commercial worsted apparel fabrics with the emphasis on wool and wool blends from the local fabric and clothing manufacturing industry, and determining how the various FAST properties were affected by factors such as fabric weave, fibre blend and weight, since this could impact on the specific nature and validity of the referencing system. A total of some 394 worsted type commercial fabrics, mainly in wool and wool blends, were sourced from, and with the inputs of, local apparel fabric and clothing manufacturers so as to ensure the local fabric and garment representative of the sample population and after which the fabrics were tested on the FAST system. ANOVA (regression analysis) was carried out on each of the FAST parameters in order to determine whether fabric weight, weave, thickness and fibre composition (pure wool and wool blends) had a statistically significant effect on them, since this is an important aspect which needs to be clarified prior to the development of a envisaged meaningful FAST system.
- Full Text:
- Date Issued: 2018
The history and historiography of the Amamfengu of the Eastern Cape, 1820-1900
- Maxengana, Nomalungisa Sylvia
- Authors: Maxengana, Nomalungisa Sylvia
- Date: 2018
- Subjects: Fingo (African people) -- History Eastern Cape (South Africa) -- History
- Language: English
- Type: Thesis , Doctoral , PhD (History)
- Identifier: http://hdl.handle.net/10353/17872 , vital:41624
- Description: The name '' amaMfengu '' refers not to any specific African people, but is an umbrella term used up to the present day as a collective designation for amaHlubi, amaBhele, amaZizi and other chiefdoms and individuals who fled KwaZulu-Natal in the time of King Tshaka (1818 - 1828) and found refuge in the lands of the Xhosa King Hintsa. Despite their diverse origins, the shared historical experience of the various Mfengu groups provided them with a common identity and a common destiny. Their dire situation as refugees inclined them to mission Christianity which led, in turn, to alliance with the British Empire followed ultimately by rejection from the racist settler regime of the Cape Colony. All these traumatic events took place within a period of eighty years, and it is these eighty years which will be the focus of this dissertation
- Full Text:
- Date Issued: 2018
- Authors: Maxengana, Nomalungisa Sylvia
- Date: 2018
- Subjects: Fingo (African people) -- History Eastern Cape (South Africa) -- History
- Language: English
- Type: Thesis , Doctoral , PhD (History)
- Identifier: http://hdl.handle.net/10353/17872 , vital:41624
- Description: The name '' amaMfengu '' refers not to any specific African people, but is an umbrella term used up to the present day as a collective designation for amaHlubi, amaBhele, amaZizi and other chiefdoms and individuals who fled KwaZulu-Natal in the time of King Tshaka (1818 - 1828) and found refuge in the lands of the Xhosa King Hintsa. Despite their diverse origins, the shared historical experience of the various Mfengu groups provided them with a common identity and a common destiny. Their dire situation as refugees inclined them to mission Christianity which led, in turn, to alliance with the British Empire followed ultimately by rejection from the racist settler regime of the Cape Colony. All these traumatic events took place within a period of eighty years, and it is these eighty years which will be the focus of this dissertation
- Full Text:
- Date Issued: 2018
The impact of cultural attrition on youth behaviour: the case of ulwaluko and Intonjane cultural practices in Mthatha and Mount Frere, Eastern Cape, South Africa
- Authors: Nomngcoyiya, Thanduxolo
- Date: 2018
- Subjects: Afrocentrism , Female circumcision -- South Africa -- Eastern Cape , Initiation rites -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5576 , vital:29346
- Description: This study explored the impact of cultural attrition on youth behaviour: A case of ulwaluko and intonjane cultural practices in Mthatha and Mount Frere areas, Eastern Cape, South Africa. The study endeavoured to achieve the following specific objectives: (i) to respectively examine youth perceptions of ulwaluko and intonjane cultural practices and their impact towards their behaviour; (ii) to establish different stakeholders’ perceptions on the link between current youth behaviours and attrition of ulwaluko and intonjane cultural practices; (iii) to explore the extent to which cultural attrition has impacted upon the cultural goal posts of both ulwaluko and intonjane practices; and (iv) to establish the effectiveness of policy environment designed to uphold cultural preservation, integrity, growth and development. The study was premised on theoretical lenses of anomie theory, socio-cultural theory, cultural imperialism theory, and cultural feminism theory. Methodologically, the study used both qualitative and quantitative paradigm and was thus guided by mixed research design which was case study and mini survey. The data was collected through in-depth one-on-one interviews, focus group discussions and key informants i n t h e qualitative aspect of the study. In addition, the quantitative data was gathered through distribution of questionnaires. The study used both non-probability and probability methods sample selection, specifically purposive sampling (for qualitative data) and cluster random sampling (for quantitative) techniques were used. Using these techniques, forty-two (42) participants were selected for qualitative interviews, and comprised of eighteen (18) young men and women of both gender divides. Moreover, nine (9) key informants were included in the qualitative data collection. Therefore, the total number of both participants and respondents was 105. Data was analysed qualitatively through thematic analysis, while descriptive statistics was used to analyse quantitative data through the use of SPSS software versions 24. The study revealed the following: a state of cultural crossroad for both intonjane and ulwaluko rites; cultural attrition is indeed a reality; culture incapable of holding their goal posts; modern era a huge driver to cultural attrition; unfriendly policies on cultures a driver to cultural attrition; human rights’ wave and advocacy aiding cultural attrition; political infiltration of cultures; human rights’ wave and advocacy aiding cultural attrition; and community forums as avenues of disseminating the benefits of cultural practices. Based on the evidence gathered in this study, the following recommendations are made: purposive use of mass media to promote indigenous cultures; community awareness in promoting and maintaining cultures; formulating cultural policies that embed stakeholders’ self-determination, and youth ownership and participation in cultural preservation. The study concludes that cultural practices such as ulwaluko and intonjane play a pivotal role in shaping young people’s behaviours and moral conducts. However, modernity forces and various omissions by stakeholders of these cultural practices have contributed to their attrition.
- Full Text:
- Date Issued: 2018
- Authors: Nomngcoyiya, Thanduxolo
- Date: 2018
- Subjects: Afrocentrism , Female circumcision -- South Africa -- Eastern Cape , Initiation rites -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5576 , vital:29346
- Description: This study explored the impact of cultural attrition on youth behaviour: A case of ulwaluko and intonjane cultural practices in Mthatha and Mount Frere areas, Eastern Cape, South Africa. The study endeavoured to achieve the following specific objectives: (i) to respectively examine youth perceptions of ulwaluko and intonjane cultural practices and their impact towards their behaviour; (ii) to establish different stakeholders’ perceptions on the link between current youth behaviours and attrition of ulwaluko and intonjane cultural practices; (iii) to explore the extent to which cultural attrition has impacted upon the cultural goal posts of both ulwaluko and intonjane practices; and (iv) to establish the effectiveness of policy environment designed to uphold cultural preservation, integrity, growth and development. The study was premised on theoretical lenses of anomie theory, socio-cultural theory, cultural imperialism theory, and cultural feminism theory. Methodologically, the study used both qualitative and quantitative paradigm and was thus guided by mixed research design which was case study and mini survey. The data was collected through in-depth one-on-one interviews, focus group discussions and key informants i n t h e qualitative aspect of the study. In addition, the quantitative data was gathered through distribution of questionnaires. The study used both non-probability and probability methods sample selection, specifically purposive sampling (for qualitative data) and cluster random sampling (for quantitative) techniques were used. Using these techniques, forty-two (42) participants were selected for qualitative interviews, and comprised of eighteen (18) young men and women of both gender divides. Moreover, nine (9) key informants were included in the qualitative data collection. Therefore, the total number of both participants and respondents was 105. Data was analysed qualitatively through thematic analysis, while descriptive statistics was used to analyse quantitative data through the use of SPSS software versions 24. The study revealed the following: a state of cultural crossroad for both intonjane and ulwaluko rites; cultural attrition is indeed a reality; culture incapable of holding their goal posts; modern era a huge driver to cultural attrition; unfriendly policies on cultures a driver to cultural attrition; human rights’ wave and advocacy aiding cultural attrition; political infiltration of cultures; human rights’ wave and advocacy aiding cultural attrition; and community forums as avenues of disseminating the benefits of cultural practices. Based on the evidence gathered in this study, the following recommendations are made: purposive use of mass media to promote indigenous cultures; community awareness in promoting and maintaining cultures; formulating cultural policies that embed stakeholders’ self-determination, and youth ownership and participation in cultural preservation. The study concludes that cultural practices such as ulwaluko and intonjane play a pivotal role in shaping young people’s behaviours and moral conducts. However, modernity forces and various omissions by stakeholders of these cultural practices have contributed to their attrition.
- Full Text:
- Date Issued: 2018