Investigating the consumer decision-making process and determinants of choice for prepaid services from mobile network service providers
- Authors: Ajayi, Ella
- Date: 2021-12
- Subjects: Mobile communication systems , Consumer behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53688 , vital:45713
- Description: The mobile telecommunications industry has been a fundamental and an important enabler in the advancement of the South African economy, with mobile network providers investing billions of rands in mobile infrastructure and facilitating a functional and progressive global marketplace (ICASA Annual Performance Plan, 2020/21). South Africa’s telecommunications system is one of the most sophisticated in the emerging markets, and according to Gillwald, Mothobi, and Rademan (2018, p.6), various indices including the ICT Development Index corroborate this view. The deployment of wireless communications networks in the country has had immeasurable social benefits for many consumers. The most rural areas of the country are now able to experience the convenience and ubiquity that comes with having access to mobile network technology. Though mobile network provision is making progress in terms of bridging the digital divide, inhibitors exist within the mobile competitive landscape that prevent consumers from exploring the full benefits of the advanced technologies at their disposal. According to Chinembiri (2020, p.6), mobile data costs remain high and out of reach for the average South African consumer, despite the recent requisite data price reduction by the dominant mobile network service providers. The prepaid segment is dominated by customers who either carry multiple SIM cards or switch between mobile network operators. The adoption by ICASA of the Mobile Number Portability (MNP), the process through which customers switch between mobile operators and keep their mobile number (Yadav, Dabhade, & Dabhade, 2013, p.1), resulted in significant reduction in switching costs thus perpetuating the migration of subscribers between mobile network providers. According to Olufemi and Strydom (2018, p. 52), the fiercest competition experienced by South African mobile providers is in the prepaid market. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Ajayi, Ella
- Date: 2021-12
- Subjects: Mobile communication systems , Consumer behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53688 , vital:45713
- Description: The mobile telecommunications industry has been a fundamental and an important enabler in the advancement of the South African economy, with mobile network providers investing billions of rands in mobile infrastructure and facilitating a functional and progressive global marketplace (ICASA Annual Performance Plan, 2020/21). South Africa’s telecommunications system is one of the most sophisticated in the emerging markets, and according to Gillwald, Mothobi, and Rademan (2018, p.6), various indices including the ICT Development Index corroborate this view. The deployment of wireless communications networks in the country has had immeasurable social benefits for many consumers. The most rural areas of the country are now able to experience the convenience and ubiquity that comes with having access to mobile network technology. Though mobile network provision is making progress in terms of bridging the digital divide, inhibitors exist within the mobile competitive landscape that prevent consumers from exploring the full benefits of the advanced technologies at their disposal. According to Chinembiri (2020, p.6), mobile data costs remain high and out of reach for the average South African consumer, despite the recent requisite data price reduction by the dominant mobile network service providers. The prepaid segment is dominated by customers who either carry multiple SIM cards or switch between mobile network operators. The adoption by ICASA of the Mobile Number Portability (MNP), the process through which customers switch between mobile operators and keep their mobile number (Yadav, Dabhade, & Dabhade, 2013, p.1), resulted in significant reduction in switching costs thus perpetuating the migration of subscribers between mobile network providers. According to Olufemi and Strydom (2018, p. 52), the fiercest competition experienced by South African mobile providers is in the prepaid market. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 2021
- Full Text:
- Date Issued: 2021-12
Study of the biotransformations and microbiological properties of cymbopogon citratus
- Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Authors: Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Date: 2015
- Subjects: Lemongras , Essences and essential oils
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19737 , vital:43197
- Description: Variations in the essential oil yield, chemical composition and kinetics of chemical transformation, antibacterial, and antioxidant properties of the Cymbopogon citratus cultivated in Alice, Eastern Cape of South Africa, over a period of 12 months using the solvent-free microwave extraction and the modified forms of conventional hydrodistillation methods have been evaluated. The modified forms involve variation in the pH medium to effect extraction and to obtain the whole leaf extracts of Cymbopogon citratus (lemongrass). The GC-MS analyses of the essential oils revealed the presence of 10, 11, 13, and 9 principal compounds in the microwave, extraction, hydrodistillation (water-distilled), hydrodistillation (aciddistilled and hydrodistillation (base-distilled), respectively with citral being the prominent compound in all the various extraction methods, with the water-distilled method having the highest cumulative citral content under the period specified. Each of the components of the oils varied in quantity and quality of yield at different points of the year. Different extraction methods produce different compounds. Increase in the amount of citral content was observed during the maturation stage of Cymbopogon citratus in all the extraction methods. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration (MIC) values were determined on the oils and extracts of Cymbopogon citratus using agar dilution method. The essential oils obtained using all the methods of extraction showed activity against all the tested bacteria at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the acid-distilled varied between 1.25 and 5.0 mg mL-1, while those obtained by both water- and base-distilled showed equal activity on the microorganisms with the MIC ranging between 2.5 and 10 mg mL-1. The microwave extraction showed the least activity with the MIC of 10 mg mL-1. This however suggested that the oils obtained through acid-distillation showed the greatest activity than all other methods of extraction. Activity of the various extracts on bacteria showed that the ethanol extract had the highest activity on the tested organisms with MIC ranging between 0.625 and 1.25 mg mL-1. This was closely followed by the acid-extract (1.25 and 5.0 mg mL-1), methanol extract (1.25 and 10 mg mL-1), acetone extract (2.5 and 5.0 mg mL-1), and base extract (5.0 mg mL-1). Both cold water and hot water extracts showed the least activity of MIC, >10 mg mL-1. The antioxidant and free-radical scavenging activity of the obtained oils and extracts were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay, [(2,2ˊ-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS), nitric oxide and ferric reducing power assays. The oils and extracts showed DPPH radical scavenging ability, but not as high as the standard drugs. The base extract showed a higher reducing power than the standard drug, rutin. There were significant differences in the phytochemicals contents of the various leaf extracts. The acetone extract has the highest flavonol, proanthocyanidin, and alkaloid contents. The ethanol extract showed the highest amount of phenolic content with the acid extract, having the least. Thin layer chromatography (TLC) and column chromatography was employed to obtain different fractions of extracts using four eluent solvent systems of varying polarities: toluene, petroleum ether, hexane and ethyl acetate and sprayed with anisaldehyde. A single, visible spot of B-fraction was developed, collected and analyzed as 1-methyl-2,4,5- trinitroimidazole with renown valuable properties. , Thesis (PhD) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Date: 2015
- Subjects: Lemongras , Essences and essential oils
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19737 , vital:43197
- Description: Variations in the essential oil yield, chemical composition and kinetics of chemical transformation, antibacterial, and antioxidant properties of the Cymbopogon citratus cultivated in Alice, Eastern Cape of South Africa, over a period of 12 months using the solvent-free microwave extraction and the modified forms of conventional hydrodistillation methods have been evaluated. The modified forms involve variation in the pH medium to effect extraction and to obtain the whole leaf extracts of Cymbopogon citratus (lemongrass). The GC-MS analyses of the essential oils revealed the presence of 10, 11, 13, and 9 principal compounds in the microwave, extraction, hydrodistillation (water-distilled), hydrodistillation (aciddistilled and hydrodistillation (base-distilled), respectively with citral being the prominent compound in all the various extraction methods, with the water-distilled method having the highest cumulative citral content under the period specified. Each of the components of the oils varied in quantity and quality of yield at different points of the year. Different extraction methods produce different compounds. Increase in the amount of citral content was observed during the maturation stage of Cymbopogon citratus in all the extraction methods. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration (MIC) values were determined on the oils and extracts of Cymbopogon citratus using agar dilution method. The essential oils obtained using all the methods of extraction showed activity against all the tested bacteria at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the acid-distilled varied between 1.25 and 5.0 mg mL-1, while those obtained by both water- and base-distilled showed equal activity on the microorganisms with the MIC ranging between 2.5 and 10 mg mL-1. The microwave extraction showed the least activity with the MIC of 10 mg mL-1. This however suggested that the oils obtained through acid-distillation showed the greatest activity than all other methods of extraction. Activity of the various extracts on bacteria showed that the ethanol extract had the highest activity on the tested organisms with MIC ranging between 0.625 and 1.25 mg mL-1. This was closely followed by the acid-extract (1.25 and 5.0 mg mL-1), methanol extract (1.25 and 10 mg mL-1), acetone extract (2.5 and 5.0 mg mL-1), and base extract (5.0 mg mL-1). Both cold water and hot water extracts showed the least activity of MIC, >10 mg mL-1. The antioxidant and free-radical scavenging activity of the obtained oils and extracts were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay, [(2,2ˊ-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS), nitric oxide and ferric reducing power assays. The oils and extracts showed DPPH radical scavenging ability, but not as high as the standard drugs. The base extract showed a higher reducing power than the standard drug, rutin. There were significant differences in the phytochemicals contents of the various leaf extracts. The acetone extract has the highest flavonol, proanthocyanidin, and alkaloid contents. The ethanol extract showed the highest amount of phenolic content with the acid extract, having the least. Thin layer chromatography (TLC) and column chromatography was employed to obtain different fractions of extracts using four eluent solvent systems of varying polarities: toluene, petroleum ether, hexane and ethyl acetate and sprayed with anisaldehyde. A single, visible spot of B-fraction was developed, collected and analyzed as 1-methyl-2,4,5- trinitroimidazole with renown valuable properties. , Thesis (PhD) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015
Examining learners' and teachers' perceptions of the relationship between school infrastructure and learners' performance in Fort Beaufort Education District, Eastern Cape Province, South Africa
- Ajibade, Benedicta Aremevbemi
- Authors: Ajibade, Benedicta Aremevbemi
- Date: 2012-12
- Subjects: School facilities , Education and state -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24695 , vital:63526
- Description: This study examined learners’ and teachers’ perceptions of the relationship between school infrastructure and learners’ performance in Fort Beaufort Education District, Eastern Cape. The study arose from a concern that, despite South African Government’s commitment to funding the renovation of some old and dilapidated school buildings and constructing new ones so that there would be an improvement in both teaching and learning in affected secondary schools. Regrettably, most school buildings remain in deplorable conditions. There has been poor learner performance at all levels of the secondary education system in some rural areas of the Eastern Cape Province. Learners’ performance in the Province’s high schools has been described as the worst in the country. From the literature, it appears that no thorough and conclusive studies looking into the issues relating to school buildings and learners’ performance as perceived by learners and teachers in South Africa have been conducted. Hence, the researcher was motivated to examine the relationship between school buildings and learners’ performance. The study was placed within the post-positivism paradigm and used a mixed method research design that incorporated concurrent procedures in the collection, analysis and interpretation of the data. Likert-scale questionnaires were used to collect quantitative data while qualitative data were collected through interviews and observations. A total of 240 learners completed the questionnaire. The researcher conducted 48 brief interviews (36 with teachers and 12 with school principals) from 12 selected secondary schools. Furthermore, the researcher made observations to assess the state of the buildings. At school level, the study revealed that most of the school buildings were in deplorable condition. The teaching and learning environment also compounded the problem of poor learners’ performance. Learners’ motivation/morale, health and safety were not guaranteed in most of the schools, and teachers’ expressed difficulty in performing their job effectively. Large classes, lack of teaching and learning resources, and limited infrastructure were some of the factors hindering teaching and learning at school level. Results obtained from the study showed that the principals and teachers perceived strong links between the condition of their school buildings and learners’ performance. About half of the learners perceived some link between the condition of their schools and their academic performance. The study observed that the majority of school buildings were old and in very bad conditions with few under renovation from the Correctional service department. The study also showed that most schools lack recreational facilities, do not have electricity, laboratories, library and water. Most of the educators are unhappy about their work environment and are not motivated. The study has put forth recommendations for educational planners and for policies regarding the funding norms. Furthermore, based on the findings of the study, there is need for collaborative effort among educational stakeholders to ensure adequate and appropriated delivery of school infrastructure specifically school building that will translate into improved teaching practice at school level and better learners’ performance. , Thesis (MEd) -- Faculty of Education, 2012
- Full Text:
- Date Issued: 2012-12
- Authors: Ajibade, Benedicta Aremevbemi
- Date: 2012-12
- Subjects: School facilities , Education and state -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24695 , vital:63526
- Description: This study examined learners’ and teachers’ perceptions of the relationship between school infrastructure and learners’ performance in Fort Beaufort Education District, Eastern Cape. The study arose from a concern that, despite South African Government’s commitment to funding the renovation of some old and dilapidated school buildings and constructing new ones so that there would be an improvement in both teaching and learning in affected secondary schools. Regrettably, most school buildings remain in deplorable conditions. There has been poor learner performance at all levels of the secondary education system in some rural areas of the Eastern Cape Province. Learners’ performance in the Province’s high schools has been described as the worst in the country. From the literature, it appears that no thorough and conclusive studies looking into the issues relating to school buildings and learners’ performance as perceived by learners and teachers in South Africa have been conducted. Hence, the researcher was motivated to examine the relationship between school buildings and learners’ performance. The study was placed within the post-positivism paradigm and used a mixed method research design that incorporated concurrent procedures in the collection, analysis and interpretation of the data. Likert-scale questionnaires were used to collect quantitative data while qualitative data were collected through interviews and observations. A total of 240 learners completed the questionnaire. The researcher conducted 48 brief interviews (36 with teachers and 12 with school principals) from 12 selected secondary schools. Furthermore, the researcher made observations to assess the state of the buildings. At school level, the study revealed that most of the school buildings were in deplorable condition. The teaching and learning environment also compounded the problem of poor learners’ performance. Learners’ motivation/morale, health and safety were not guaranteed in most of the schools, and teachers’ expressed difficulty in performing their job effectively. Large classes, lack of teaching and learning resources, and limited infrastructure were some of the factors hindering teaching and learning at school level. Results obtained from the study showed that the principals and teachers perceived strong links between the condition of their school buildings and learners’ performance. About half of the learners perceived some link between the condition of their schools and their academic performance. The study observed that the majority of school buildings were old and in very bad conditions with few under renovation from the Correctional service department. The study also showed that most schools lack recreational facilities, do not have electricity, laboratories, library and water. Most of the educators are unhappy about their work environment and are not motivated. The study has put forth recommendations for educational planners and for policies regarding the funding norms. Furthermore, based on the findings of the study, there is need for collaborative effort among educational stakeholders to ensure adequate and appropriated delivery of school infrastructure specifically school building that will translate into improved teaching practice at school level and better learners’ performance. , Thesis (MEd) -- Faculty of Education, 2012
- Full Text:
- Date Issued: 2012-12
The role of records management in the sustainability of small micro medium enterprises (SMMEs) in the Eastern Cape, South Africa: a study of Alice and Fort Beaufort
- Ajibade, Patrick https://orcid.org/0000-0002-8608-8378
- Authors: Ajibade, Patrick https://orcid.org/0000-0002-8608-8378
- Date: 2014
- Subjects: Knowledge management , Small business
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/25259 , vital:64122
- Description: The study sought to investigate the role of records management in the sustainability of the Small Micro, Medium enterprises (SMMEs) in the Eastern Cape Province of South Africa with focus on Alice and Fort Beaufort towns. The objectives of the study were to identify the types of records that are kept by SMMEs; evaluate the infrastructure for the SMMEs records management; determine the compliance of SMMEs with the existing RM legal and regulatory requirements; and identify the challenges related to SMMEs records practices. Twenty three (23) respondents from SMMEs were interviewed. Findings revealed all the respondents could not confirm adoption of any systemic way of records management to support business functions and operations. Majority of the SMMEs due to their inability to maintain records could not identify potential benefit of business RM with an exception of three SMMEs. The respondents were not aware of any compliance and regulatory framework most especially on business records management. The challenges facing SMMEs include; inability to capture/create maintain, preserve business records systematically in its lifecycle. The SMMEs lack needed training especially in records management to allow them the benefit of maintaining business records. It is recommended that SMMEs should acquire skill that would enable them manage their business records that may help improved decision making. There should be legislative and regulatory framework that ensures compliance. And assistance should be rendered to train SMMEs on basic RM skills that could improve their business operations. , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2014
- Full Text:
- Date Issued: 2014
- Authors: Ajibade, Patrick https://orcid.org/0000-0002-8608-8378
- Date: 2014
- Subjects: Knowledge management , Small business
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/25259 , vital:64122
- Description: The study sought to investigate the role of records management in the sustainability of the Small Micro, Medium enterprises (SMMEs) in the Eastern Cape Province of South Africa with focus on Alice and Fort Beaufort towns. The objectives of the study were to identify the types of records that are kept by SMMEs; evaluate the infrastructure for the SMMEs records management; determine the compliance of SMMEs with the existing RM legal and regulatory requirements; and identify the challenges related to SMMEs records practices. Twenty three (23) respondents from SMMEs were interviewed. Findings revealed all the respondents could not confirm adoption of any systemic way of records management to support business functions and operations. Majority of the SMMEs due to their inability to maintain records could not identify potential benefit of business RM with an exception of three SMMEs. The respondents were not aware of any compliance and regulatory framework most especially on business records management. The challenges facing SMMEs include; inability to capture/create maintain, preserve business records systematically in its lifecycle. The SMMEs lack needed training especially in records management to allow them the benefit of maintaining business records. It is recommended that SMMEs should acquire skill that would enable them manage their business records that may help improved decision making. There should be legislative and regulatory framework that ensures compliance. And assistance should be rendered to train SMMEs on basic RM skills that could improve their business operations. , Thesis (MLIS) -- Faculty of Social Sciences and Humanities, 2014
- Full Text:
- Date Issued: 2014
Orí (Head) as an xxpression of Yorùbá aesthetic philosophy:
- Ajíbóyè, Olusegun, Fọlárànmí, Stephen, Umoru-Ọkẹ, Nanashaitu
- Authors: Ajíbóyè, Olusegun , Fọlárànmí, Stephen , Umoru-Ọkẹ, Nanashaitu
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146145 , vital:38499 , DOI https://doi.org/10.2478/mjss-2018-0115
- Description: Aesthetics was never a subject or a separate philosophy in the traditional philosophies of black Africa. This is however not a justification to conclude that it is nonexistent. Indeed, aesthetics is a day to day affair among Africans. There are criteria for aesthetic judgment among African societies which vary from one society to the other. The Yorùbá of Southwestern Nigeria are not different. This study sets out to examine how the Yorùbá make their aesthetic judgments and demonstrate their aesthetic philosophy in decorating their orí, which means head among the Yorùbá. The head receives special aesthetic attention because of its spiritual and biological importance. It is an expression of the practicalities of Yorùbá aesthetic values. Literature and field work has been of paramount aid to this study. The study uses photographs, works of art and visual illustrations to show the various ways the head is adorned and cared for among the Yoruba. It relied on Yoruba art and language as a tool of investigating the concept of ori and aesthetics. Yorùbá aesthetic values are practically demonstrable and deeply located in the Yorùbá societal, moral and ethical idealisms. It concludes that the spiritual importance of orí or its aesthetics has a connection which has been demonstratively established by the Yorùbá as epressed in the images and illustrations used in this paper.
- Full Text:
- Date Issued: 2018
- Authors: Ajíbóyè, Olusegun , Fọlárànmí, Stephen , Umoru-Ọkẹ, Nanashaitu
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146145 , vital:38499 , DOI https://doi.org/10.2478/mjss-2018-0115
- Description: Aesthetics was never a subject or a separate philosophy in the traditional philosophies of black Africa. This is however not a justification to conclude that it is nonexistent. Indeed, aesthetics is a day to day affair among Africans. There are criteria for aesthetic judgment among African societies which vary from one society to the other. The Yorùbá of Southwestern Nigeria are not different. This study sets out to examine how the Yorùbá make their aesthetic judgments and demonstrate their aesthetic philosophy in decorating their orí, which means head among the Yorùbá. The head receives special aesthetic attention because of its spiritual and biological importance. It is an expression of the practicalities of Yorùbá aesthetic values. Literature and field work has been of paramount aid to this study. The study uses photographs, works of art and visual illustrations to show the various ways the head is adorned and cared for among the Yoruba. It relied on Yoruba art and language as a tool of investigating the concept of ori and aesthetics. Yorùbá aesthetic values are practically demonstrable and deeply located in the Yorùbá societal, moral and ethical idealisms. It concludes that the spiritual importance of orí or its aesthetics has a connection which has been demonstratively established by the Yorùbá as epressed in the images and illustrations used in this paper.
- Full Text:
- Date Issued: 2018
Taxonomic and trait-based responses of the orders Ephemeroptera, Plecoptera, Odonata, And Trichoptera (EPOT) to sediment stress in the Tsitsa River and its tributaries, Eastern Cape, South Africa
- Akamagwuna, Frank Chukwuzuoke
- Authors: Akamagwuna, Frank Chukwuzuoke
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/68082 , vital:29196
- Description: Increased urbanization and industrialisation due to human population growth and associated high demand for food have led to widespread disturbances of freshwater ecosystems and associated resources. A widely recognised consequence of these disturbances is the excessive delivery of sediments into the freshwater ecosystems, which severely affects the functioning and integrity of these systems.. The major water quality impairment in the Tsitsa River and its tributaries, situated in the Mzimvubu catchment in the Eastern Cape Province of South Africa, is known to be excessive sediment input. In this study, the application of macroinvertebrates taxonomic-based and trait-based approaches was used to assess the responses and vulnerability of Ephemeroptera, Plecoptera, Odonata and Trichoptera (EPOT) species to settled and suspended sediments stress in eight selected sampling sites in the Tsitsa River and its tributaries. The eight selected sites were Site 1 (Tsitsa upstream), Site 2 (Tsitsa downstream), Site 3 (Qurana tributary), Site 4 (Pot River upstream), Site 5 (Pot River downstream), Site 6 (Little Pot River), Site 7 (Millstream upstream) and Site 8 (Millstream downstream). The methods used in this study involved the analysis of water physico-chemical variables as well as sediment characteristics, derivation of five EPOT metrics, EPOT species-level taxonomic analysis, individual EPOT trait analysis and the development of a novel trait-based approach using a combination of traits. The sampling of EPOT taxa was done using the SASS5 protocols. Identification of EPOT was done to genus/species level and all data were subjected to relevant statistical analysis. The results of ecological categories derived for the physico-chemical variables generally indicated the ecological categories A and B, which was indicative of good water quality conditions. The result of sediment particle analysis revealed four distinct site groups: site group 1 (Tsitsa River upstream and Qurana tributary), site group 2 (Tsitsa River downstream and Millstream upstream), site group 3 (Pot River, both upstream and downstream, and Millstream downstream) and site group 4 (Little Pot River). The species-level taxonomic analysis of EPOT revealed that site group 1 was the most sediment-influenced sites whereas site group 4 was the least sediment-influenced. Species such as Paragopmhus sp., Aeshna sp. and Baetis sp. were considered sediment-tolerant with strong positive association with site group 1. The novel trait-based approach developed in this study proved useful in predicting the responses of EPOT species to sediment stress, and further discriminated between the study sites. The approach was used to group EPOT species into four vulnerability classes. The result showed that filter feeding EPOT species that have filamentous gills, preferring stone biotopes and feeding on detritus (FPOM) were mostly classified as highly vulnerable to sediment stress and indicated no significant association with the highly sediment-influenced site group 1. The TBA largely corresponded well to the predictions made with the relative abundance of the vulnerable class decreasing in the sediment-influenced sites compared to the tolerant and highly tolerant classes. Overall, the study revealed the importance of the complementary use of taxonomic and trait-based approaches to biomonitoring.
- Full Text:
- Date Issued: 2019
- Authors: Akamagwuna, Frank Chukwuzuoke
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/68082 , vital:29196
- Description: Increased urbanization and industrialisation due to human population growth and associated high demand for food have led to widespread disturbances of freshwater ecosystems and associated resources. A widely recognised consequence of these disturbances is the excessive delivery of sediments into the freshwater ecosystems, which severely affects the functioning and integrity of these systems.. The major water quality impairment in the Tsitsa River and its tributaries, situated in the Mzimvubu catchment in the Eastern Cape Province of South Africa, is known to be excessive sediment input. In this study, the application of macroinvertebrates taxonomic-based and trait-based approaches was used to assess the responses and vulnerability of Ephemeroptera, Plecoptera, Odonata and Trichoptera (EPOT) species to settled and suspended sediments stress in eight selected sampling sites in the Tsitsa River and its tributaries. The eight selected sites were Site 1 (Tsitsa upstream), Site 2 (Tsitsa downstream), Site 3 (Qurana tributary), Site 4 (Pot River upstream), Site 5 (Pot River downstream), Site 6 (Little Pot River), Site 7 (Millstream upstream) and Site 8 (Millstream downstream). The methods used in this study involved the analysis of water physico-chemical variables as well as sediment characteristics, derivation of five EPOT metrics, EPOT species-level taxonomic analysis, individual EPOT trait analysis and the development of a novel trait-based approach using a combination of traits. The sampling of EPOT taxa was done using the SASS5 protocols. Identification of EPOT was done to genus/species level and all data were subjected to relevant statistical analysis. The results of ecological categories derived for the physico-chemical variables generally indicated the ecological categories A and B, which was indicative of good water quality conditions. The result of sediment particle analysis revealed four distinct site groups: site group 1 (Tsitsa River upstream and Qurana tributary), site group 2 (Tsitsa River downstream and Millstream upstream), site group 3 (Pot River, both upstream and downstream, and Millstream downstream) and site group 4 (Little Pot River). The species-level taxonomic analysis of EPOT revealed that site group 1 was the most sediment-influenced sites whereas site group 4 was the least sediment-influenced. Species such as Paragopmhus sp., Aeshna sp. and Baetis sp. were considered sediment-tolerant with strong positive association with site group 1. The novel trait-based approach developed in this study proved useful in predicting the responses of EPOT species to sediment stress, and further discriminated between the study sites. The approach was used to group EPOT species into four vulnerability classes. The result showed that filter feeding EPOT species that have filamentous gills, preferring stone biotopes and feeding on detritus (FPOM) were mostly classified as highly vulnerable to sediment stress and indicated no significant association with the highly sediment-influenced site group 1. The TBA largely corresponded well to the predictions made with the relative abundance of the vulnerable class decreasing in the sediment-influenced sites compared to the tolerant and highly tolerant classes. Overall, the study revealed the importance of the complementary use of taxonomic and trait-based approaches to biomonitoring.
- Full Text:
- Date Issued: 2019
Specialist workforce development through mentoring: comparing collaborative programme evaluation using action research and realist evaluation
- Akhurst, Jacqueline E, Lawson, Sally
- Authors: Akhurst, Jacqueline E , Lawson, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143771 , vital:38281 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This Workforce Innovations Programme (WIP) was for healthcare practitioners working in north east England. The innovative mentoring-focused WIP aimed to increase capacity and capability, and to improve services and outcomes for people living with long term neurological conditions. Mentors were matched with practitioners outside of their specialisms and focused on community and partnership working as alternatives to dominant modes of practice. This paper will highlight key outcomes and contextual challenges. It will explore collaborative action research for practitioner development, evidencing the participants’ learning. A medium term realist evaluation then provides data about the value of the WIP; and illustrates ways the programme worked for practitioners and people who used services, to support the drive for improved outcomes. It will compare and contrast the contributions of both forms of programme evaluation, and critique some of the discourses of workforce improvement initiatives.
- Full Text:
- Date Issued: 2015
- Authors: Akhurst, Jacqueline E , Lawson, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143771 , vital:38281 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This Workforce Innovations Programme (WIP) was for healthcare practitioners working in north east England. The innovative mentoring-focused WIP aimed to increase capacity and capability, and to improve services and outcomes for people living with long term neurological conditions. Mentors were matched with practitioners outside of their specialisms and focused on community and partnership working as alternatives to dominant modes of practice. This paper will highlight key outcomes and contextual challenges. It will explore collaborative action research for practitioner development, evidencing the participants’ learning. A medium term realist evaluation then provides data about the value of the WIP; and illustrates ways the programme worked for practitioners and people who used services, to support the drive for improved outcomes. It will compare and contrast the contributions of both forms of programme evaluation, and critique some of the discourses of workforce improvement initiatives.
- Full Text:
- Date Issued: 2015
Characterization of polymeric film of a new manganese phthalocyanine complex octa-substituted with 2-diethylaminoethanethiol, and its use for the electrochemical detection of bentazon
- Akinbulu, Isaac A, Nyokong, Tebello
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262568 , vital:53534 , xlink:href="https://doi.org/10.1016/j.electacta.2009.07.074"
- Description: Manganese acetate octakis-(2-diethyaminoethanethiol) phthalocyanine (AcMnODEAETPc) was newly synthesized and characterized by spectroscopic and electrochemical methods. Solution electrochemistry of the complex showed three redox processes assigned to MnIIIPc−1/MnIIIPc−2, MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 species. The new molecule was polymerized onto a glassy carbon electrode (GCE) to form thin films of different thickness, giving poly-10-AcMnODEAETPc-GCE, poly-20-AcMnODEAETPc-GCE and poly-30-AcMnODEAETPc-GCE, where 10, 20 and 30 represent the number of voltammetry scans during polymerization. Three distinct redox processes were observed on the modified electrode in 0.1 M phosphate buffer solution, pH 5, which confirmed the formation of the polymer. The current signal due to the herbicide, bentazon, was dependent on film thickness; the best signal was obtained on poly-20-AcMnODEAETPc-GCE while poly-10-AcMnODEAETPc-GCE gave the least signal. However, the signals due to the herbicide were better on the different films compared to the bare electrode. Electrochemical impedance spectroscopy (EIS) technique revealed that differences in film thickness offered different charge transfer resistances, Rct, hence difference in current signals for bentazon oxidation were observed on these films. A Tafel slope of 77 mV/decade, obtained for the herbicide on poly-20-AcMnODEAETPc-GCE, denotes a fast one electron transfer followed by a slow chemical step in the electro-oxidation of bentazon. The voltammetry signals of the herbicide on the films indicated the likely involvement of ring-based redox processes in the detection of the herbicide. A plot of background corrected current response, on this film, versus the concentration of bentazon was linear within the range 50–750 μM with a detection limit of 2.48 × 10−7 M.
- Full Text:
- Date Issued: 2009
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262568 , vital:53534 , xlink:href="https://doi.org/10.1016/j.electacta.2009.07.074"
- Description: Manganese acetate octakis-(2-diethyaminoethanethiol) phthalocyanine (AcMnODEAETPc) was newly synthesized and characterized by spectroscopic and electrochemical methods. Solution electrochemistry of the complex showed three redox processes assigned to MnIIIPc−1/MnIIIPc−2, MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 species. The new molecule was polymerized onto a glassy carbon electrode (GCE) to form thin films of different thickness, giving poly-10-AcMnODEAETPc-GCE, poly-20-AcMnODEAETPc-GCE and poly-30-AcMnODEAETPc-GCE, where 10, 20 and 30 represent the number of voltammetry scans during polymerization. Three distinct redox processes were observed on the modified electrode in 0.1 M phosphate buffer solution, pH 5, which confirmed the formation of the polymer. The current signal due to the herbicide, bentazon, was dependent on film thickness; the best signal was obtained on poly-20-AcMnODEAETPc-GCE while poly-10-AcMnODEAETPc-GCE gave the least signal. However, the signals due to the herbicide were better on the different films compared to the bare electrode. Electrochemical impedance spectroscopy (EIS) technique revealed that differences in film thickness offered different charge transfer resistances, Rct, hence difference in current signals for bentazon oxidation were observed on these films. A Tafel slope of 77 mV/decade, obtained for the herbicide on poly-20-AcMnODEAETPc-GCE, denotes a fast one electron transfer followed by a slow chemical step in the electro-oxidation of bentazon. The voltammetry signals of the herbicide on the films indicated the likely involvement of ring-based redox processes in the detection of the herbicide. A plot of background corrected current response, on this film, versus the concentration of bentazon was linear within the range 50–750 μM with a detection limit of 2.48 × 10−7 M.
- Full Text:
- Date Issued: 2009
Fabrication and characterization of single walled carbon nanotubes-iron phthalocyanine nano-composite
- Akinbulu, Isaac A, Nyokong, Tebello
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
- Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
- Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
- Full Text:
- Date Issued: 2010
Syntheses and investigation of the effects of position and nature of substituent on the spectral, electrochemical and spectroelectrochemical properties of new cobalt phthalocyanine complexes
- Akinbulu, Isaac A, Nyokong, Tebello
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261677 , vital:53434 , xlink:href="https://doi.org/10.1016/j.poly.2010.01.004"
- Description: The syntheses of new cobalt phthalocyanine (CoPc) complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral (complex 3b) positions, and with benzylmercapto at the non-peripheral position (complex 5), are reported. The effects of the nature and position of substituent on the spectral, electrochemical and spectroelectrochemical properties of these complexes are investigated. Solution electrochemistry of complex 3a showed three distinctly resolved redox processes attributed to CoIIIPc−2/CoIIPc−2 (E½ = +0.64 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.24 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.26 V versus Ag|AgCl) species. No ring oxidation was observed in complex 3a. Complex 3b showed both ring-based oxidation, attributed to CoIIIPc−1/CoIIIPc−2 species (Ep = +0.86 V versus Ag|AgCl), and ring-based reduction associated with CoIPc−2/CoIPc−3 species (E½ = −1.46 V versus Ag|AgCl), with the normal metal-based redox processes in CoPc complexes: CoIIIPc−2/CoIIPc−2 (Ep = +0.41 V versus Ag|AgCl) and CoIIPc−2/CoIPc−2 (E½ = −0.38 V versus Ag|AgCl). Solution electrochemistry of complex 5 showed the same type and number of species observed in complex 3a: CoIIIPc−2/CoIIPc−2 (Ep = +0.59 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.26 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.39 V versus Ag|AgCl) species. These processes were confirmed using spectroelectrochemistry.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261677 , vital:53434 , xlink:href="https://doi.org/10.1016/j.poly.2010.01.004"
- Description: The syntheses of new cobalt phthalocyanine (CoPc) complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral (complex 3b) positions, and with benzylmercapto at the non-peripheral position (complex 5), are reported. The effects of the nature and position of substituent on the spectral, electrochemical and spectroelectrochemical properties of these complexes are investigated. Solution electrochemistry of complex 3a showed three distinctly resolved redox processes attributed to CoIIIPc−2/CoIIPc−2 (E½ = +0.64 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.24 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.26 V versus Ag|AgCl) species. No ring oxidation was observed in complex 3a. Complex 3b showed both ring-based oxidation, attributed to CoIIIPc−1/CoIIIPc−2 species (Ep = +0.86 V versus Ag|AgCl), and ring-based reduction associated with CoIPc−2/CoIPc−3 species (E½ = −1.46 V versus Ag|AgCl), with the normal metal-based redox processes in CoPc complexes: CoIIIPc−2/CoIIPc−2 (Ep = +0.41 V versus Ag|AgCl) and CoIIPc−2/CoIPc−2 (E½ = −0.38 V versus Ag|AgCl). Solution electrochemistry of complex 5 showed the same type and number of species observed in complex 3a: CoIIIPc−2/CoIIPc−2 (Ep = +0.59 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.26 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.39 V versus Ag|AgCl) species. These processes were confirmed using spectroelectrochemistry.
- Full Text:
- Date Issued: 2010
The effects of point of substitution on the formation of manganese phthalocyanine-based molecular materials
- Akinbulu, Isaac Adebayo, Khene, Samson, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Khene, Samson , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249103 , vital:51778 , xlink:href="https://doi.org/10.1016/j.tsf.2010.08.145"
- Description: Molecular films of manganese phthalocyanine (MnPc) complexes, tetra-substituted with 2-diethylaminoethanethio at the peripheral (Mn(OAc)-β-TDEAETPc, 1) and non-peripheral (Mn(OAc)-α-TDEAETPc, 2) positions were formed on glassy carbon electrode by electropolymerization and electrodeposition respectively. Atomic force microscopy images confirmed the presence of the films and revealed significant morphological differences. The films exhibited an electrocatalytic activity towards the oxidation of the insecticide, bendiocarb. Hydrodynamic technique, using rotating disc electrode voltammetry, was used to investigate the kinetics of electro-oxidation of the insecticide. Morphological differences of the films significantly influenced kinetic parameters. Values of Tafel slopes, obtained from Tafel plots, suggested that catalysis of bendiocarb occurred via outer sphere mechanism.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac Adebayo , Khene, Samson , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249103 , vital:51778 , xlink:href="https://doi.org/10.1016/j.tsf.2010.08.145"
- Description: Molecular films of manganese phthalocyanine (MnPc) complexes, tetra-substituted with 2-diethylaminoethanethio at the peripheral (Mn(OAc)-β-TDEAETPc, 1) and non-peripheral (Mn(OAc)-α-TDEAETPc, 2) positions were formed on glassy carbon electrode by electropolymerization and electrodeposition respectively. Atomic force microscopy images confirmed the presence of the films and revealed significant morphological differences. The films exhibited an electrocatalytic activity towards the oxidation of the insecticide, bendiocarb. Hydrodynamic technique, using rotating disc electrode voltammetry, was used to investigate the kinetics of electro-oxidation of the insecticide. Morphological differences of the films significantly influenced kinetic parameters. Values of Tafel slopes, obtained from Tafel plots, suggested that catalysis of bendiocarb occurred via outer sphere mechanism.
- Full Text:
- Date Issued: 2010
The effects of point of substitution on the electrochemical behavior of new manganese phthalocyanines, tetra-substituted with diethylaminoethanethiol
- Akinbulu, Isaac Adebayo, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249137 , vital:51781 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.003"
- Description: The syntheses and comparative studies of the spectral, voltammetry and spectroelectrochemical properties of new manganese phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral positions (complex 3b) are reported. Solution electrochemistry of complex 3a showed quasi-reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.07 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.78 V vs. Ag|AgCl) reductions, but no ring-based oxidation. However, complex 3b showed weak irreversible ring-oxidation signal (Ep = +0.86 vs. Ag|AgCl). Reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.04 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.68 V vs. Ag|AgCl) reductions were also observed for complex 3b. Spectroelectrochemistry was used to confirm these processes. Reduction process involving the metal (MnIIIPc−2/MnIIPc−2) was associated with the formation of manganese μ-oxo complex in complex 3a.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249137 , vital:51781 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.003"
- Description: The syntheses and comparative studies of the spectral, voltammetry and spectroelectrochemical properties of new manganese phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral positions (complex 3b) are reported. Solution electrochemistry of complex 3a showed quasi-reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.07 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.78 V vs. Ag|AgCl) reductions, but no ring-based oxidation. However, complex 3b showed weak irreversible ring-oxidation signal (Ep = +0.86 vs. Ag|AgCl). Reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.04 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.68 V vs. Ag|AgCl) reductions were also observed for complex 3b. Spectroelectrochemistry was used to confirm these processes. Reduction process involving the metal (MnIIIPc−2/MnIIPc−2) was associated with the formation of manganese μ-oxo complex in complex 3a.
- Full Text:
- Date Issued: 2010
Formation, surface characterization, and electrocatalytic application of self-assembled monolayer films of tetra-substituted manganese, iron, and cobalt benzylthio phthalocyanine complexes
- Akinbulu, Isaac Adebayo, Ozoemena, Kenneth Iyke, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Ozoemena, Kenneth Iyke , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247163 , vital:51552 , xlink:href="https://doi.org/10.1007/s10008-010-1243-1"
- Description: Molecular thin films of manganese (SAM-2), iron (SAM-3), and cobalt (SAM-4) phthalocyanine complexes, non-peripherally tetra-substituted with benzylmercapto, were formed on polycrystalline gold disc electrode by self-assembly technique. Surface characteristics of the films were interrogated by cyclic voltammetry. Significant passivation of voltammetry processes associated with bare gold surface (gold oxidation and underpotential deposition of copper) confirmed formation of the films. Electrocatalytic property of the films was evidenced from better voltammetry responses (less positive oxidation potential and better current signal) of the insecticide, carbofuran, on these films, relative to that on bare gold electrode. In terms of less positive oxidation potential, the FePc derivative (3) gave the best response, while the best current signal was observed on SAM-2-modified gold electrode. The average heterogeneous rate constant, k, for the oxidation of carbofuran was 3.6 × 10−2 cm s−1 on the SAM film with the best current signal (SAM-2).
- Full Text:
- Date Issued: 2011
- Authors: Akinbulu, Isaac Adebayo , Ozoemena, Kenneth Iyke , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247163 , vital:51552 , xlink:href="https://doi.org/10.1007/s10008-010-1243-1"
- Description: Molecular thin films of manganese (SAM-2), iron (SAM-3), and cobalt (SAM-4) phthalocyanine complexes, non-peripherally tetra-substituted with benzylmercapto, were formed on polycrystalline gold disc electrode by self-assembly technique. Surface characteristics of the films were interrogated by cyclic voltammetry. Significant passivation of voltammetry processes associated with bare gold surface (gold oxidation and underpotential deposition of copper) confirmed formation of the films. Electrocatalytic property of the films was evidenced from better voltammetry responses (less positive oxidation potential and better current signal) of the insecticide, carbofuran, on these films, relative to that on bare gold electrode. In terms of less positive oxidation potential, the FePc derivative (3) gave the best response, while the best current signal was observed on SAM-2-modified gold electrode. The average heterogeneous rate constant, k, for the oxidation of carbofuran was 3.6 × 10−2 cm s−1 on the SAM film with the best current signal (SAM-2).
- Full Text:
- Date Issued: 2011
Water restriction and vitamin c supplementation on Xhosa goats during summer: Effect on growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat quality
- Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Authors: Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Date: 2020-08
- Subjects: Goats -- Nutrition , Goats -- Feeding and feeds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22710 , vital:52664
- Description: This study aimed to evaluate the effect of single and extra vitamin C (VC) supplementation on water-stressed Xhosa goats during the summer by evaluating their growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat qualities. The objectives were to assess the effect of water restriction and vitamin C supplementation by evaluating: firstly, growth performance, heat tolerance responses, and blood metabolites; secondly, intake, nutrient digestibility, nitrogen and mineral balance; thirdly, stress indices, carcass characteristics and meat qualities parameters and lastly, fatty acid profile, oxidative stability of lipids and sensory attributes were evaluated. To achieve these objectives, forty-two (42) goats were divided equally into seven treatments (75-day trial); without water restriction (W0, control); water restriction of 70percent of ad libitum water intake WI (W70); water restriction of 50percent ad libitum WI (W50); water restriction of 70percent of ad libitum WI plus 3g VC daily (W70+); water restriction 50percent of ad libitum WI plus 3g VC daily (W50+); water restriction of 70percent of ad libitumWI plus 3g VC and extra 5gVC given every eight-day (70++); water restriction of 50percent of ad libitum WI plus 3g VC and extra 5gVC given every eight-day (W50++). In the first objective, growth performance parameters, body condition scores, rectal temperature, respiratory rate, heat tolerance response parameters and blood metabolites were measured.Weight loss due to water restriction was reduced by VC supplementation in treated groups. The attenuation effect of VC was significant (P<0.05) in responses to respiratory rate (RR), Na+, K+, Mg2+, Cl-, Ca2+ and urea. Supplementation of VC (either single or multiple) did not (P>0.05) improve the effect of water restriction on body condition scores (BCs), FAMACHA©, glucose, globulin, alanine aminotransferase (ALT) and high-density lipoprotein (HDL). In the second objective, intake, nutrient digestibility, nitrogen and mineral balance were evaluated. The reduced nutrient intake was similar (P>0.05) irrespective of water restrictions and VC supplementations. Water-restriction levels did not affect nutrient intake/metabolic weight. Retained nitrogen increased with water-restriction levels but not influenced by VC. NH3-N decreased with the levels of water restriction while the pH was similar across the water restricted groups. Supplementation of VC had no effect (P>0.05) on apparent digestibility and digestible nutrients induced by water restriction levels. The amount of Ca, K, Mg retained increased (P<0.05) with water-restriction levels. In the third objective, stress indices, carcass characteristics and meat quality parameters were evaluated. The level of plasma cortisol concentration due to water stress was lessened (P<0.05) by VC. Follicle stimulating hormone (FSH), Luteinizing hormone (LH) and insulin were not affected (P>0.05) by levels of water restriction. The hot and carcass weights were lower (P<0.05) in W70+ and W50+ compared to W70 and W50 respectively. Vitamin C treated goats had higher redness (a*) compared to W70, W50 and W0. The shear force and cooking loss increased (P<0.05) with water restriction levels, while thaw loss, pH45min and pH24h were not affected by water restriction levels. In the final objective, the treatments did not affect (P>0.05) the oxidative stability of lipids (TBARS). The moisture and fat content in the water restricted groups were lower (P<0.05) than W0. The consumer meat sensory appearance decreased (P<0.05) with levels of water restrictions. Regardless of VC concentration and supplementation, vaccenic, and docosahexaenoic acid increased (P<0.05) while linolenic acid decreased as the water restriction levels increased. Nonetheless, treatment did not affect (P>0.05) the saturated and unsaturated fatty acids. These studies showed that suboptimal water intake negatively affects the growth performance and nutrient intake of Xhosa goats. However, the reduction in body weight loss and decreased plasma cortisol (chief stress hormone) concentration following vitamin C supplementation (especially at a daily single dose [3g/d]) may well reduce the effect of water stress in goats. , Thesis (PhD) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-08
- Authors: Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Date: 2020-08
- Subjects: Goats -- Nutrition , Goats -- Feeding and feeds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22710 , vital:52664
- Description: This study aimed to evaluate the effect of single and extra vitamin C (VC) supplementation on water-stressed Xhosa goats during the summer by evaluating their growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat qualities. The objectives were to assess the effect of water restriction and vitamin C supplementation by evaluating: firstly, growth performance, heat tolerance responses, and blood metabolites; secondly, intake, nutrient digestibility, nitrogen and mineral balance; thirdly, stress indices, carcass characteristics and meat qualities parameters and lastly, fatty acid profile, oxidative stability of lipids and sensory attributes were evaluated. To achieve these objectives, forty-two (42) goats were divided equally into seven treatments (75-day trial); without water restriction (W0, control); water restriction of 70percent of ad libitum water intake WI (W70); water restriction of 50percent ad libitum WI (W50); water restriction of 70percent of ad libitum WI plus 3g VC daily (W70+); water restriction 50percent of ad libitum WI plus 3g VC daily (W50+); water restriction of 70percent of ad libitumWI plus 3g VC and extra 5gVC given every eight-day (70++); water restriction of 50percent of ad libitum WI plus 3g VC and extra 5gVC given every eight-day (W50++). In the first objective, growth performance parameters, body condition scores, rectal temperature, respiratory rate, heat tolerance response parameters and blood metabolites were measured.Weight loss due to water restriction was reduced by VC supplementation in treated groups. The attenuation effect of VC was significant (P<0.05) in responses to respiratory rate (RR), Na+, K+, Mg2+, Cl-, Ca2+ and urea. Supplementation of VC (either single or multiple) did not (P>0.05) improve the effect of water restriction on body condition scores (BCs), FAMACHA©, glucose, globulin, alanine aminotransferase (ALT) and high-density lipoprotein (HDL). In the second objective, intake, nutrient digestibility, nitrogen and mineral balance were evaluated. The reduced nutrient intake was similar (P>0.05) irrespective of water restrictions and VC supplementations. Water-restriction levels did not affect nutrient intake/metabolic weight. Retained nitrogen increased with water-restriction levels but not influenced by VC. NH3-N decreased with the levels of water restriction while the pH was similar across the water restricted groups. Supplementation of VC had no effect (P>0.05) on apparent digestibility and digestible nutrients induced by water restriction levels. The amount of Ca, K, Mg retained increased (P<0.05) with water-restriction levels. In the third objective, stress indices, carcass characteristics and meat quality parameters were evaluated. The level of plasma cortisol concentration due to water stress was lessened (P<0.05) by VC. Follicle stimulating hormone (FSH), Luteinizing hormone (LH) and insulin were not affected (P>0.05) by levels of water restriction. The hot and carcass weights were lower (P<0.05) in W70+ and W50+ compared to W70 and W50 respectively. Vitamin C treated goats had higher redness (a*) compared to W70, W50 and W0. The shear force and cooking loss increased (P<0.05) with water restriction levels, while thaw loss, pH45min and pH24h were not affected by water restriction levels. In the final objective, the treatments did not affect (P>0.05) the oxidative stability of lipids (TBARS). The moisture and fat content in the water restricted groups were lower (P<0.05) than W0. The consumer meat sensory appearance decreased (P<0.05) with levels of water restrictions. Regardless of VC concentration and supplementation, vaccenic, and docosahexaenoic acid increased (P<0.05) while linolenic acid decreased as the water restriction levels increased. Nonetheless, treatment did not affect (P>0.05) the saturated and unsaturated fatty acids. These studies showed that suboptimal water intake negatively affects the growth performance and nutrient intake of Xhosa goats. However, the reduction in body weight loss and decreased plasma cortisol (chief stress hormone) concentration following vitamin C supplementation (especially at a daily single dose [3g/d]) may well reduce the effect of water stress in goats. , Thesis (PhD) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-08
Agricultural entrepreneurship development as strategy for economic empowerment: The case of small-scale farmers in Eastern Cape Province of South Africa
- Authors: Akinwale, Olusola Mokayode
- Date: 2020-11
- Subjects: Sustainable development -- South Africa -- Eastern Cape , South Africa -- Economic conditions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20241 , vital:45637
- Description: This study emanated from the struggle for economic empowerment among small-scale farmers in South African. The study advocates for the establishment of a viable environment where agricultural entrepreneurship can thrive. While the South African Nation Development Plan (NDP) proposed to create one million jobs through agricultural sector by 2030, the majority of small-scale farmers in South Africa are struggling to grow beyond the level of subsistence farming, and the youths appear not to be interested in the farming. It is therefore become necessary to conduct this current study that is exploratory in nature; it explored several factors and barriers to agricultural entrepreneurship development, as well as factors that can contribute to the development of prosperous and sustainable agricultural entrepreneurship among small-scale farmers in South African. The study was conducted in two district municipalities of Eastern Cape Province of South Africa – OR Tambo and Chris Hani. Both quantitative and qualitative research methods were used to make findings. Findings from the study shows that economic empowerment can be achieved through agricultural entrepreneurship development by giving adequate attention to specific factors like individuals’ attitude, production skills, access to market and marketing skills, management skills. Empirically, basic components like personal interests, adequate training and background, efficient extension service, famers’ network and communication, specific goal-oriented, understanding market, farmers’ collaboration, and access to sufficient funding are few of the factors that will make the small-scale farmers grow to the level of commercial farming. The study concluded that prerequisite to developing a sustainable agricultural entrepreneurship climate among small-scale farmers in South African is the combination of basic components aforementioned. Suggestions were made for strong collaboration between government and private sectors to provide development assistance for small-scale farmers as they struggles to develop their small-scale farming to sustainable entrepreneurship level. , Thesis (DPhil) -- Faculty of Management and Commerce, 2020
- Full Text:
- Date Issued: 2020-11
- Authors: Akinwale, Olusola Mokayode
- Date: 2020-11
- Subjects: Sustainable development -- South Africa -- Eastern Cape , South Africa -- Economic conditions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20241 , vital:45637
- Description: This study emanated from the struggle for economic empowerment among small-scale farmers in South African. The study advocates for the establishment of a viable environment where agricultural entrepreneurship can thrive. While the South African Nation Development Plan (NDP) proposed to create one million jobs through agricultural sector by 2030, the majority of small-scale farmers in South Africa are struggling to grow beyond the level of subsistence farming, and the youths appear not to be interested in the farming. It is therefore become necessary to conduct this current study that is exploratory in nature; it explored several factors and barriers to agricultural entrepreneurship development, as well as factors that can contribute to the development of prosperous and sustainable agricultural entrepreneurship among small-scale farmers in South African. The study was conducted in two district municipalities of Eastern Cape Province of South Africa – OR Tambo and Chris Hani. Both quantitative and qualitative research methods were used to make findings. Findings from the study shows that economic empowerment can be achieved through agricultural entrepreneurship development by giving adequate attention to specific factors like individuals’ attitude, production skills, access to market and marketing skills, management skills. Empirically, basic components like personal interests, adequate training and background, efficient extension service, famers’ network and communication, specific goal-oriented, understanding market, farmers’ collaboration, and access to sufficient funding are few of the factors that will make the small-scale farmers grow to the level of commercial farming. The study concluded that prerequisite to developing a sustainable agricultural entrepreneurship climate among small-scale farmers in South African is the combination of basic components aforementioned. Suggestions were made for strong collaboration between government and private sectors to provide development assistance for small-scale farmers as they struggles to develop their small-scale farming to sustainable entrepreneurship level. , Thesis (DPhil) -- Faculty of Management and Commerce, 2020
- Full Text:
- Date Issued: 2020-11
A pilot wide-field VLBI survey of the GOODS-North field
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
Photophysical and photochemical parameters of octakis (benzylthio) phthalocyaninato zinc, aluminium and tin
- Akpe, Victor, Brismar, Hjalmar, Nyokong, Tebello, Osadebe, Patience Ogoamak
- Authors: Akpe, Victor , Brismar, Hjalmar , Nyokong, Tebello , Osadebe, Patience Ogoamak
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248472 , vital:51689 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.08.033"
- Description: This paper addresses the synthesis of octa-substituted benzylthio metallophthalocyanines (OBTMPcs) that contain the central metal ions of Zn2+, Al3+ and Sn4+. The ground state absorption of ZnPc(SR)8 (OBTZnPc) along with the ZnPc derivatives, well documented in literature were used to study a new concept called the red shift index (RsI). The concept is based on the empirical values of RsI of the different complexes in solvent media. Unequivocally, parameters used in this paper show strong correlations that are consistent with the results obtained. For instance, RsI of the complexes tend to increase as the refractive index, nD, and solvent donor, DN, of solvent increases. Photodegradation (photobleaching) quantum yield, ϕd measurements of these compounds show that they are highly photostable, ϕd (0.03–0.33 × 10−5). The triplet quantum yield, ϕT (0.40–0.53) and the triplet lifetime, τT (610–810 μs) are within the typical range for metallophthalocyanines in DMSO. The photosensitisation efficiency, SΔ, is relatively high for all the molecules (0.74–0.90).
- Full Text:
- Date Issued: 2010
- Authors: Akpe, Victor , Brismar, Hjalmar , Nyokong, Tebello , Osadebe, Patience Ogoamak
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248472 , vital:51689 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.08.033"
- Description: This paper addresses the synthesis of octa-substituted benzylthio metallophthalocyanines (OBTMPcs) that contain the central metal ions of Zn2+, Al3+ and Sn4+. The ground state absorption of ZnPc(SR)8 (OBTZnPc) along with the ZnPc derivatives, well documented in literature were used to study a new concept called the red shift index (RsI). The concept is based on the empirical values of RsI of the different complexes in solvent media. Unequivocally, parameters used in this paper show strong correlations that are consistent with the results obtained. For instance, RsI of the complexes tend to increase as the refractive index, nD, and solvent donor, DN, of solvent increases. Photodegradation (photobleaching) quantum yield, ϕd measurements of these compounds show that they are highly photostable, ϕd (0.03–0.33 × 10−5). The triplet quantum yield, ϕT (0.40–0.53) and the triplet lifetime, τT (610–810 μs) are within the typical range for metallophthalocyanines in DMSO. The photosensitisation efficiency, SΔ, is relatively high for all the molecules (0.74–0.90).
- Full Text:
- Date Issued: 2010
“Un-silencing queer Nigeria”: Representations of queerness in contemporary Nigerian fiction
- Authors: Akram, Tahzeeb
- Date: 2021-10-29
- Subjects: Heterosexism in literature , Patriarchy in literature , Homophobia in literature , Sexual minorities in literature , Nigerian literature 21st century History and criticism , Queer theory Nigeria , Gender identity Law and legislation Nigeria , Gender identity Religious aspects , Sexual minorities Nigeria Social conditions , Nigeria. Same Sex Marriage (Prohibition) Act, 2013
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190668 , vital:45016
- Description: This thesis analyses contemporary queer Nigerian fiction, particularly queer representations regarding law, religion and culture in Nigeria’s heteropatriarchal and queerphobic society. I explore a number of authors’ use of different literary forms and platforms to promote and represent non-conforming genders and sexualities in queerphobic Nigeria. These narratives show queer people navigating the heteronormative society vis-à-vis marriage, family, intimacy, work, violence and rights activism. I draw on Western and African gender and queer theories for the concepts, definitions and critical terminologies used in this thesis. African queer theorists and activists are highlighted for their reclaiming queer history from among the early records in Africa as well as contemporary queer Nigerian literature and activism. Religion and queerness are crucial themes in Chinelo Okparanta’s same sex women’s novel, Under the Udala Trees. Using queer African Christian theology against Nigeria’s conservative socio-religious setting, I demonstrate that queerness is not a threat to Nigerian’s Christian faith, and that mutual coexistence of queer sexuality and Christianity advances queer rights in that society. Nnanna Ikpo’s Fimí Sílẹ̀ Forever: Heaven gave it to me’s problematises heteronormative masculinities and the manufacturing of heteropatriarchy and queer masculinities in Nigeria. I examine the protagonists who are both victims of and perpetrators in their queerphobic society. The socio-legal focus I employ examines the impact of the 2014 Same Sex Marriage Prohibition Act on Nigeria’s already marginalised and oppressed queer community. There are vast opportunities for queer Nigerian artists to create, publish and promote queer identities in the safe and enabling space of online platforms via physical distancing between the queer community and the queerphobic society. From the digitally published 14: An Anthology of Queer Art’s two volumes, five short stories are analysed regarding different forms of intimacies in queer men’s relationships. These queer contemporary fiction writers offer complex representations of queerness within Nigeria’s heteropatriarchal and queerphobic society that polices non-normative bodies through religion, culture and the law. Such literary texts, digital literary platforms and activism vitally provide queer Nigerians a progressive space to assert queer presence, voices lives and rights to educating and re-socialising their society towards humaneness. , Thesis (MA) -- Faculty of Humanities, Literary Studies in English, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Akram, Tahzeeb
- Date: 2021-10-29
- Subjects: Heterosexism in literature , Patriarchy in literature , Homophobia in literature , Sexual minorities in literature , Nigerian literature 21st century History and criticism , Queer theory Nigeria , Gender identity Law and legislation Nigeria , Gender identity Religious aspects , Sexual minorities Nigeria Social conditions , Nigeria. Same Sex Marriage (Prohibition) Act, 2013
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190668 , vital:45016
- Description: This thesis analyses contemporary queer Nigerian fiction, particularly queer representations regarding law, religion and culture in Nigeria’s heteropatriarchal and queerphobic society. I explore a number of authors’ use of different literary forms and platforms to promote and represent non-conforming genders and sexualities in queerphobic Nigeria. These narratives show queer people navigating the heteronormative society vis-à-vis marriage, family, intimacy, work, violence and rights activism. I draw on Western and African gender and queer theories for the concepts, definitions and critical terminologies used in this thesis. African queer theorists and activists are highlighted for their reclaiming queer history from among the early records in Africa as well as contemporary queer Nigerian literature and activism. Religion and queerness are crucial themes in Chinelo Okparanta’s same sex women’s novel, Under the Udala Trees. Using queer African Christian theology against Nigeria’s conservative socio-religious setting, I demonstrate that queerness is not a threat to Nigerian’s Christian faith, and that mutual coexistence of queer sexuality and Christianity advances queer rights in that society. Nnanna Ikpo’s Fimí Sílẹ̀ Forever: Heaven gave it to me’s problematises heteronormative masculinities and the manufacturing of heteropatriarchy and queer masculinities in Nigeria. I examine the protagonists who are both victims of and perpetrators in their queerphobic society. The socio-legal focus I employ examines the impact of the 2014 Same Sex Marriage Prohibition Act on Nigeria’s already marginalised and oppressed queer community. There are vast opportunities for queer Nigerian artists to create, publish and promote queer identities in the safe and enabling space of online platforms via physical distancing between the queer community and the queerphobic society. From the digitally published 14: An Anthology of Queer Art’s two volumes, five short stories are analysed regarding different forms of intimacies in queer men’s relationships. These queer contemporary fiction writers offer complex representations of queerness within Nigeria’s heteropatriarchal and queerphobic society that polices non-normative bodies through religion, culture and the law. Such literary texts, digital literary platforms and activism vitally provide queer Nigerians a progressive space to assert queer presence, voices lives and rights to educating and re-socialising their society towards humaneness. , Thesis (MA) -- Faculty of Humanities, Literary Studies in English, 2021
- Full Text:
- Date Issued: 2021-10-29
Behavioural activities and chemical composition of fresh leaf essential oil of Plectranthus aegyptiacus from Southwest Nigeria in mice
- Akuegbe, Enimeya Dressman, Oyemitan, Idris Ajayi, Oyedeji, Opeoluwa, Ogunlowo, Ifeoluwa Isaac, Miya, Gugulethu Mathew, Oyedeji, Adebola
- Authors: Akuegbe, Enimeya Dressman , Oyemitan, Idris Ajayi , Oyedeji, Opeoluwa , Ogunlowo, Ifeoluwa Isaac , Miya, Gugulethu Mathew , Oyedeji, Adebola
- Date: 2021-6
- Subjects: Acute toxicity testing , Carvacrol , Essential oil , Behaviour modification , Plectranthus
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6506 , vital:46434 , ("https://doi.org/10.30574/gscbps.2021.14.2.0030")
- Description: This study determined the chemical composition of essential oil obtained from fresh leaf of Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) and determine its mechanism(s) of action in mice. The oil was hydro-distillated, and analyzed using gas chromatography-mass spectrometry. The effects of the oil (50, 100 and 150 mg/kg; i.p., n=6) on novelty-induced behavioural was assessed using open field test and head dipping on hole board. Probable mechanism(s) were evaluated using antagonists: flumazenil, naloxone and cyproheptadine at 2 mg/kg each, atropine and yohimbine at 5 mg/kg and 1 mg/kg respectively. The LD50 values obtained were 2154 and 490 mg/kg for oral and intraperitoneal routes respectively. The oil (50, 100 and150 mg/kg) significantly (p less 0.05, 0.01 and 0.01) inhibited all NIB and head dips. Flumazenil significantly (p less than 0.05) reversed the effect of the oil on NIB; atropine, naloxone and cyproheptadine significantly (p less than 0.01, 0.01 and 0.001) potentiated inhibitory effect on NIB respectively, while yohimbine showed no significantly effect. The analyzed oil showed 61 compounds, and the major compounds were carvacrol, germacrene-D, p-cymene and [1,1'-Bicyclopentyl]-2,2'-diol. The study concluded that the oil possessed central nervous system depressant activity, which could be mediated mainly through augmentation of GABAergic neurotransmission, while cholinergic-(muscarinic), adrenergic and serotonergic pathways may be involved.
- Full Text:
- Date Issued: 2021-6
- Authors: Akuegbe, Enimeya Dressman , Oyemitan, Idris Ajayi , Oyedeji, Opeoluwa , Ogunlowo, Ifeoluwa Isaac , Miya, Gugulethu Mathew , Oyedeji, Adebola
- Date: 2021-6
- Subjects: Acute toxicity testing , Carvacrol , Essential oil , Behaviour modification , Plectranthus
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6506 , vital:46434 , ("https://doi.org/10.30574/gscbps.2021.14.2.0030")
- Description: This study determined the chemical composition of essential oil obtained from fresh leaf of Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) and determine its mechanism(s) of action in mice. The oil was hydro-distillated, and analyzed using gas chromatography-mass spectrometry. The effects of the oil (50, 100 and 150 mg/kg; i.p., n=6) on novelty-induced behavioural was assessed using open field test and head dipping on hole board. Probable mechanism(s) were evaluated using antagonists: flumazenil, naloxone and cyproheptadine at 2 mg/kg each, atropine and yohimbine at 5 mg/kg and 1 mg/kg respectively. The LD50 values obtained were 2154 and 490 mg/kg for oral and intraperitoneal routes respectively. The oil (50, 100 and150 mg/kg) significantly (p less 0.05, 0.01 and 0.01) inhibited all NIB and head dips. Flumazenil significantly (p less than 0.05) reversed the effect of the oil on NIB; atropine, naloxone and cyproheptadine significantly (p less than 0.01, 0.01 and 0.001) potentiated inhibitory effect on NIB respectively, while yohimbine showed no significantly effect. The analyzed oil showed 61 compounds, and the major compounds were carvacrol, germacrene-D, p-cymene and [1,1'-Bicyclopentyl]-2,2'-diol. The study concluded that the oil possessed central nervous system depressant activity, which could be mediated mainly through augmentation of GABAergic neurotransmission, while cholinergic-(muscarinic), adrenergic and serotonergic pathways may be involved.
- Full Text:
- Date Issued: 2021-6
Effect of pomegranate (Punica granatum L) peel powder meal on growth performance, gut integrity, haemato-biochemical indices, meat, and bone quality of broiler chickens
- Akuru, Eunice Amaka https://orcid.org/0000-0002-3093-0247
- Authors: Akuru, Eunice Amaka https://orcid.org/0000-0002-3093-0247
- Date: 2022-04
- Subjects: Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23611 , vital:58218
- Description: The objective of the current study was to investigate the overall response of broiler birds to varying dietary levels of pomegranate (Punica granatum L) peel powder meal (PPPM). A total of 432-day-old Cobb 500 broiler chicks were randomly divided into six experimental groups of four replications with 18 birds per replicate in a completely randomized design (CRD). The birds were fed isonitrogenous and isocaloric experimental diets designated as: T1-control diet with 0percent additives (negative control; NEGCON); T2- control diet supplemented with α-tocopherol acetate at 200g per ton (positive control; POSCON): T3, T4, T5 and T6-control diet supplemented with 2, 4, 6 and 8g/kg PPPM (PPPM2, PPPM4, PPPM6, PPPM8). The phytochemical, nutritional and antioxidant properties of the pomegranate peel powder were determined. Results showed that the South African-grown pomegranate peel (“Wonderful” variety) had rich protein and trace mineral contents. Higher (p < 0.05) antioxidant and hepatic anti-lipid peroxidative activities were recorded in the ethanol and acetone extracts than the water extract, whereas the three extracts had no toxic effects on liver and kidney cells (p > 0.05). The dietary effects of PPPM supplementation on growth performance, digestibility, carcass, and organ weight indices of Cobb 500 birds were determined. The POSCON diet enhanced (p < 0.05) feed conversion ratio (FCR) at week 3. The average final body weight and average daily weight gain were highest (p < 0.05) in birds fed PPPM2 and PPPM4 diets, whereas birds fed PPPM2 diet had enhanced (p < 0.05) FCR and protein efficiency ratio when compared with birds on POSCON. Thigh and breast weights were highest (p < 0.05) in birds on PPPM4 and PPPM8 diets, whereas birds fed PPPM4 diet had enhanced (p < 0.05) nutrient digestibility compared with those on POSCON. The antioxidant status and breast meat quality of Cobb 500 broiler birds fed diets supplemented with PPPM were determined. Meat from birds fed PPPM8 diet had the highest (p < 0.05) thawing loss, while cooking loss was lowest (p < 0.05) in the PPPM2 group. The highest (p < 0.05) ability to scavenge ABTS [(2, 2-azinobis (3ethylbenzothiazoline-6 sulfonic acid))] radical cation (ABTS+) was recorded in the PPPM2 and PPPM4 meat while PPPM8 meat had increased (p < 0.05) catalase activity. The fatty acid composition, oxidative status, and drip loss in breast meat of Cobb 500 broiler birds fed graded levels of PPPM was determined. Meat from birds fed PPPM4 diet had the lowest (p < 0.05) margaric (C17:0) and arachidic (C20:0) acids, while meat from birds fed PPPM8 diet had higher (p < 0.05) levels of eicosadenoic (C20:2, n-6) and arachidonic (AA, 20:4) acids. The POSCON had higher (p < 0.05) ability to reduce TBARS levels in meat on day-1 and day-16 of storage than the NEGCON and PPPM diets, whereas TBARS levels were lowest (p < 0.05) in PPPM6 meat on day-16. The gut pH, histology, haematology, serum-biochemical indices, and bone quality parameters of Cobb 500 broiler birds fed diets supplemented with PPPM was determined. Birds fed POSCON, PPM2 and PPPM4 diets had the lowest (p < 0.05) pH in the duodenum, jejunum, and caecum, whereas duodenal pH values were lowest (p < 0.05) in birds fed PPPM2 and PPPM4 diets compared with birds on NEGCON. Birds fed PPPM4 diet had the highest (p < 0.01) duodenal, jejunal and ileal villi height (VH), and the highest (p < 0.01) VH to crypt depth (CD) ratio in the duodenum, jejunum, and ileum. The lowest (p < 0.05) CD in the duodenum, jejunum and ileum was also recorded in birds fed PPPM4 diet. Birds fed PPPM8 diet had higher (p < 0.05) values for white blood cell count, red blood cell count, haemoglobin concentration and packed cell volume, whereas the lowest (p < 0.05) concentration of serum aspartate transaminase was recorded in birds fed PPPM4 diet. Birds on PPM4 diet had longer (p < 0.05) bones. Bone weight and bone breaking strength were highest (p < 0.05) in birds fed PPPM8 diet. Tibia zinc and iron concentrations increased as the inclusion levels of pomegranate peel powder meal increased. It was concluded that broiler birds require 4 g/kg pomegranate peel powder for enhanced growth performance, nutrient digestibility, gut histology, quality, and antioxidant enzyme activity of meat, whereas 8 g/kg pomegranate peel powder meal supplementation is required for enhanced heamato-biochemical indices, bone quality, fatty acid composition and lipid peroxidative parameters in broiler birds. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Akuru, Eunice Amaka https://orcid.org/0000-0002-3093-0247
- Date: 2022-04
- Subjects: Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23611 , vital:58218
- Description: The objective of the current study was to investigate the overall response of broiler birds to varying dietary levels of pomegranate (Punica granatum L) peel powder meal (PPPM). A total of 432-day-old Cobb 500 broiler chicks were randomly divided into six experimental groups of four replications with 18 birds per replicate in a completely randomized design (CRD). The birds were fed isonitrogenous and isocaloric experimental diets designated as: T1-control diet with 0percent additives (negative control; NEGCON); T2- control diet supplemented with α-tocopherol acetate at 200g per ton (positive control; POSCON): T3, T4, T5 and T6-control diet supplemented with 2, 4, 6 and 8g/kg PPPM (PPPM2, PPPM4, PPPM6, PPPM8). The phytochemical, nutritional and antioxidant properties of the pomegranate peel powder were determined. Results showed that the South African-grown pomegranate peel (“Wonderful” variety) had rich protein and trace mineral contents. Higher (p < 0.05) antioxidant and hepatic anti-lipid peroxidative activities were recorded in the ethanol and acetone extracts than the water extract, whereas the three extracts had no toxic effects on liver and kidney cells (p > 0.05). The dietary effects of PPPM supplementation on growth performance, digestibility, carcass, and organ weight indices of Cobb 500 birds were determined. The POSCON diet enhanced (p < 0.05) feed conversion ratio (FCR) at week 3. The average final body weight and average daily weight gain were highest (p < 0.05) in birds fed PPPM2 and PPPM4 diets, whereas birds fed PPPM2 diet had enhanced (p < 0.05) FCR and protein efficiency ratio when compared with birds on POSCON. Thigh and breast weights were highest (p < 0.05) in birds on PPPM4 and PPPM8 diets, whereas birds fed PPPM4 diet had enhanced (p < 0.05) nutrient digestibility compared with those on POSCON. The antioxidant status and breast meat quality of Cobb 500 broiler birds fed diets supplemented with PPPM were determined. Meat from birds fed PPPM8 diet had the highest (p < 0.05) thawing loss, while cooking loss was lowest (p < 0.05) in the PPPM2 group. The highest (p < 0.05) ability to scavenge ABTS [(2, 2-azinobis (3ethylbenzothiazoline-6 sulfonic acid))] radical cation (ABTS+) was recorded in the PPPM2 and PPPM4 meat while PPPM8 meat had increased (p < 0.05) catalase activity. The fatty acid composition, oxidative status, and drip loss in breast meat of Cobb 500 broiler birds fed graded levels of PPPM was determined. Meat from birds fed PPPM4 diet had the lowest (p < 0.05) margaric (C17:0) and arachidic (C20:0) acids, while meat from birds fed PPPM8 diet had higher (p < 0.05) levels of eicosadenoic (C20:2, n-6) and arachidonic (AA, 20:4) acids. The POSCON had higher (p < 0.05) ability to reduce TBARS levels in meat on day-1 and day-16 of storage than the NEGCON and PPPM diets, whereas TBARS levels were lowest (p < 0.05) in PPPM6 meat on day-16. The gut pH, histology, haematology, serum-biochemical indices, and bone quality parameters of Cobb 500 broiler birds fed diets supplemented with PPPM was determined. Birds fed POSCON, PPM2 and PPPM4 diets had the lowest (p < 0.05) pH in the duodenum, jejunum, and caecum, whereas duodenal pH values were lowest (p < 0.05) in birds fed PPPM2 and PPPM4 diets compared with birds on NEGCON. Birds fed PPPM4 diet had the highest (p < 0.01) duodenal, jejunal and ileal villi height (VH), and the highest (p < 0.01) VH to crypt depth (CD) ratio in the duodenum, jejunum, and ileum. The lowest (p < 0.05) CD in the duodenum, jejunum and ileum was also recorded in birds fed PPPM4 diet. Birds fed PPPM8 diet had higher (p < 0.05) values for white blood cell count, red blood cell count, haemoglobin concentration and packed cell volume, whereas the lowest (p < 0.05) concentration of serum aspartate transaminase was recorded in birds fed PPPM4 diet. Birds on PPM4 diet had longer (p < 0.05) bones. Bone weight and bone breaking strength were highest (p < 0.05) in birds fed PPPM8 diet. Tibia zinc and iron concentrations increased as the inclusion levels of pomegranate peel powder meal increased. It was concluded that broiler birds require 4 g/kg pomegranate peel powder for enhanced growth performance, nutrient digestibility, gut histology, quality, and antioxidant enzyme activity of meat, whereas 8 g/kg pomegranate peel powder meal supplementation is required for enhanced heamato-biochemical indices, bone quality, fatty acid composition and lipid peroxidative parameters in broiler birds. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04