Executing a process enhancement intervention on the processing lines at Seavuna Fishing Company
- Authors: Abdullah, Philip Rodger
- Date: 2017
- Subjects: Organizational effectiveness -- South Africa , Small business -- South Africa Workflow -- South Africa -- Management Business planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/13592 , vital:27255
- Description: The fresh hake processing lines at Seavuna fishing company in Mossel Bay are not consistently achieving their volume output standards and this is resulting in higher processing costs and loss of processing opportunities. The company’s senior management are concerned about this trend and require a complete review of the effectiveness of the resources deployed on the lines. This with the view of establishing the causes of poor process volume output. In order to resolve the process inefficiency challenges mentioned, this study used both empirical and time studies to investigate the effectiveness of the company’s resources directly deployed in the processing unit. The study focused on investigating the human factor, machinery and equipment, the environment and the current efficiency standards. Relevant literature in the field of process efficiency improvement was consulted to assist in identifying factors that are known to cause process inefficiencies, and also to establish which improvement techniques would be relevant in correcting the situation. From the Literature reviewed, it was evident that a ‘one size fits all’ solution to resolving inefficiencies is almost non-existent and that a solution that is relevant to the problem is more effective. In addition, a benchmarking exercise was also done to establish how Seavuna’s current volume output standards fair against its major rivals. Once data from both studies were collected, the results were analysed using the some of the basic quality tools. Thereafter, lean manufacturing principles were used to attempt to resolve the current efficiency challenges. The study recommended that the company construct a business strategy and a corresponding organisational culture to direct its continuous improvement interventions. The use of strategic quality planning would go a long way in assisting the company to execute some of the interventions recommended.
- Full Text:
- Date Issued: 2017
- Authors: Abdullah, Philip Rodger
- Date: 2017
- Subjects: Organizational effectiveness -- South Africa , Small business -- South Africa Workflow -- South Africa -- Management Business planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/13592 , vital:27255
- Description: The fresh hake processing lines at Seavuna fishing company in Mossel Bay are not consistently achieving their volume output standards and this is resulting in higher processing costs and loss of processing opportunities. The company’s senior management are concerned about this trend and require a complete review of the effectiveness of the resources deployed on the lines. This with the view of establishing the causes of poor process volume output. In order to resolve the process inefficiency challenges mentioned, this study used both empirical and time studies to investigate the effectiveness of the company’s resources directly deployed in the processing unit. The study focused on investigating the human factor, machinery and equipment, the environment and the current efficiency standards. Relevant literature in the field of process efficiency improvement was consulted to assist in identifying factors that are known to cause process inefficiencies, and also to establish which improvement techniques would be relevant in correcting the situation. From the Literature reviewed, it was evident that a ‘one size fits all’ solution to resolving inefficiencies is almost non-existent and that a solution that is relevant to the problem is more effective. In addition, a benchmarking exercise was also done to establish how Seavuna’s current volume output standards fair against its major rivals. Once data from both studies were collected, the results were analysed using the some of the basic quality tools. Thereafter, lean manufacturing principles were used to attempt to resolve the current efficiency challenges. The study recommended that the company construct a business strategy and a corresponding organisational culture to direct its continuous improvement interventions. The use of strategic quality planning would go a long way in assisting the company to execute some of the interventions recommended.
- Full Text:
- Date Issued: 2017
Comparative studies of different ant-hypertensive treatments used for cardiovascular disease patients : a case study of public health facility in the Eastern Cape South Africa
- Abiodun, Oluwatoyin Victoria
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
- Full Text:
- Date Issued: 2017
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
- Full Text:
- Date Issued: 2017
Family interaction patterns in maternal alcohol abuse: an application of Murray Bowen's family system theory
- Authors: Abraham, Hanlie
- Date: 2017
- Subjects: Family psychotherapy , Social psychology Bowen, Murray, -- 1913-1990 Women -- Alcohol use Alcoholism -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/13669 , vital:27293
- Description: The aim of this study was to explore and describe the intergenerational interactional patterns in a Coloured family where the mother has abused alcohol. Researchers have found that drinking behaviours of parents can have major effects on the children’s lives throughout generations. Substance abuse of a parent has major influences on the family, their interactions, and relationships, mostly between the parent and the child. There is a major gap in the study of the Coloured families and how substance abuse affects their families and children. The study employed Bowen’s constructs of differentiation of self, multigenerational transmission process, triangulation, emotional cut-off, nuclear family emotional system, sibling position, family projection process, and societal regression and utilized analytical generalization of the concepts to achieve its aim. The mother, an older sibling and maternal mother were the main sources of data although the perspective of the mother herself was privileged in the study. Semi-structured interviews were utilized to gather the data. This allowed participants to freely narrate their personal perceptions and experiences of interaction in both the family of origin and the current nuclear family. The research used a single case study of a purposively sampled family. The researcher is a Coloured female who had specific interest in this specific cultural group and their interactional patterns, which optimised cultural familiarity during the research process and reduced the likelihood of potential discriminatory racial bias of the participants. The findings demonstrate that perceptions of interactional patterns in the nuclear family and family of origin coincided with certain of Bowen’s Family Systems concepts, particularly, triangulation and differentiation. However, the need for further exploration of concepts such as the nuclear family emotional system and the family projection process in Coloured families are still needed in future studies. The findings provided insight into the functioning of the relationships and FAMILY INTERACTION IN MATERNAL ALCOHOL ABUSE interactions in both the nuclear family and the family of origin. Limitations of the current study are identified and recommendations for future studies in this field are also offered.
- Full Text:
- Date Issued: 2017
- Authors: Abraham, Hanlie
- Date: 2017
- Subjects: Family psychotherapy , Social psychology Bowen, Murray, -- 1913-1990 Women -- Alcohol use Alcoholism -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/13669 , vital:27293
- Description: The aim of this study was to explore and describe the intergenerational interactional patterns in a Coloured family where the mother has abused alcohol. Researchers have found that drinking behaviours of parents can have major effects on the children’s lives throughout generations. Substance abuse of a parent has major influences on the family, their interactions, and relationships, mostly between the parent and the child. There is a major gap in the study of the Coloured families and how substance abuse affects their families and children. The study employed Bowen’s constructs of differentiation of self, multigenerational transmission process, triangulation, emotional cut-off, nuclear family emotional system, sibling position, family projection process, and societal regression and utilized analytical generalization of the concepts to achieve its aim. The mother, an older sibling and maternal mother were the main sources of data although the perspective of the mother herself was privileged in the study. Semi-structured interviews were utilized to gather the data. This allowed participants to freely narrate their personal perceptions and experiences of interaction in both the family of origin and the current nuclear family. The research used a single case study of a purposively sampled family. The researcher is a Coloured female who had specific interest in this specific cultural group and their interactional patterns, which optimised cultural familiarity during the research process and reduced the likelihood of potential discriminatory racial bias of the participants. The findings demonstrate that perceptions of interactional patterns in the nuclear family and family of origin coincided with certain of Bowen’s Family Systems concepts, particularly, triangulation and differentiation. However, the need for further exploration of concepts such as the nuclear family emotional system and the family projection process in Coloured families are still needed in future studies. The findings provided insight into the functioning of the relationships and FAMILY INTERACTION IN MATERNAL ALCOHOL ABUSE interactions in both the nuclear family and the family of origin. Limitations of the current study are identified and recommendations for future studies in this field are also offered.
- Full Text:
- Date Issued: 2017
Financial inclusion in South Africa
- Authors: Abrahams, Rayghana
- Date: 2017
- Subjects: Financial services industry -- South Africa , Financial institutions -- South Africa Finance -- South Africa South Africa -- Economic conditions
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/13579 , vital:27240
- Description: The research for this study was guided by the question on whether the financial inclusion improvement strategies of the South African government adequately address the financial inclusion targets, as set out in the National Development Plan. This descriptive non-empirical study was conducted by means of a literature review. The secondary data used for the study were collected from a number of sources, namely: (i) the 2015 Brookings Financial and Digital Inclusion Project report; (ii) the 2014 Global Findex survey; (iii) the InterMedia surveys; (iv) Financial Access surveys; (v) various national FinScope surveys; and (iv) a number of working papers of the World Bank related to financial inclusion. The data revealed that South Africa, with its sophisticated financial sector, was early to adopt policies and initiatives to advance financial inclusion and the country has experienced a noticeable increase in financial inclusion from 61% in 2004 to 87% in 2015. South Africa is 3% away from its National Development Plan goal of 90% financial inclusion by 2030. This indicates that overall, the financial inclusion initiatives adopted by the South African government were successful.
- Full Text:
- Date Issued: 2017
- Authors: Abrahams, Rayghana
- Date: 2017
- Subjects: Financial services industry -- South Africa , Financial institutions -- South Africa Finance -- South Africa South Africa -- Economic conditions
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/13579 , vital:27240
- Description: The research for this study was guided by the question on whether the financial inclusion improvement strategies of the South African government adequately address the financial inclusion targets, as set out in the National Development Plan. This descriptive non-empirical study was conducted by means of a literature review. The secondary data used for the study were collected from a number of sources, namely: (i) the 2015 Brookings Financial and Digital Inclusion Project report; (ii) the 2014 Global Findex survey; (iii) the InterMedia surveys; (iv) Financial Access surveys; (v) various national FinScope surveys; and (iv) a number of working papers of the World Bank related to financial inclusion. The data revealed that South Africa, with its sophisticated financial sector, was early to adopt policies and initiatives to advance financial inclusion and the country has experienced a noticeable increase in financial inclusion from 61% in 2004 to 87% in 2015. South Africa is 3% away from its National Development Plan goal of 90% financial inclusion by 2030. This indicates that overall, the financial inclusion initiatives adopted by the South African government were successful.
- Full Text:
- Date Issued: 2017
Fluorescence behaviour of supramolecular hybrids containing graphene quantum dots and pyrene-derivatized phthalocyanines and porphyrins
- Achadu, Ojodomo John, Managa, Muthumuni, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
Application of graphene quantum dots functionalized with thymine and thymine-appended zinc phthalocyanine as novel photoluminescent nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
Graphene quantum dots decorated with maleimide and zinc tetramaleimido-phthalocyanine: Application in the design of “OFF-ON” fluorescence sensors for biothiols
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188282 , vital:44741 , xlink:href="https://doi.org/10.1016/j.talanta.2017.01.031"
- Description: The fabrication of maleimide-derivatized graphene quantum dots (M-GQDs) and zinc phthalocyanine (2) as novel sensor probes for the selective detection of biothiols (cysteine, homocysteine or glutathione) through the rapid and specific Michael addition reaction between biothiols and the maleimide-derivatized probes is presented in this study. GQDs directly functionalized with maleimide units (M-GQDs) were synthesized and deployed for biothiols recognition following the principle of Michael addition. M-GQDs probe was found to be highly sensitive and selective towards biothiols detection in the nanomolar range in aqueous solution and at physiological pH (7.0). On the other hand, non-covalent interaction between pristine GQDs and novel zinc tetramaleimido-derivatized phthalocyanine resulted in the quenching of the pristine GQDs fluorescence emission which was switched back to the “ON” mode by Michael addition mechanism in the presence of biothiols. Tested relevant biomolecules did not interfere in the quantitative recognition of the biothiols. The probes showed to be highly sensitive, specific and selective for biothiols sensing in simulated real samples.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188282 , vital:44741 , xlink:href="https://doi.org/10.1016/j.talanta.2017.01.031"
- Description: The fabrication of maleimide-derivatized graphene quantum dots (M-GQDs) and zinc phthalocyanine (2) as novel sensor probes for the selective detection of biothiols (cysteine, homocysteine or glutathione) through the rapid and specific Michael addition reaction between biothiols and the maleimide-derivatized probes is presented in this study. GQDs directly functionalized with maleimide units (M-GQDs) were synthesized and deployed for biothiols recognition following the principle of Michael addition. M-GQDs probe was found to be highly sensitive and selective towards biothiols detection in the nanomolar range in aqueous solution and at physiological pH (7.0). On the other hand, non-covalent interaction between pristine GQDs and novel zinc tetramaleimido-derivatized phthalocyanine resulted in the quenching of the pristine GQDs fluorescence emission which was switched back to the “ON” mode by Michael addition mechanism in the presence of biothiols. Tested relevant biomolecules did not interfere in the quantitative recognition of the biothiols. The probes showed to be highly sensitive, specific and selective for biothiols sensing in simulated real samples.
- Full Text:
- Date Issued: 2017
Graphene quantum dots coordinated to mercaptopyridine-substituted phthalocyanines: Characterization and application as fluorescence “turn ON” nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188293 , vital:44742 , xlink:href="https://doi.org/10.1016/j.saa.2016.11.043"
- Description: This study reports on the design of novel nanoconjugates of graphene quantum dots (GQDs) and tetra or octa-mercaptopyridine-substituted zinc and aluminium phthalocyanines (Pcs) deployed as fluorescence “turn ON” nanoprobes. The phthalocyanines were separately adsorbed onto the planar structure of graphene quantum dots (GQDs) via π-π stacking interaction to form GQDs-mercaptopyridine Pcs nanoconjugates. The quaternized Pc complexes could also interact with the GQDs through electrostatic attraction due to the positive charges on the Pcs ring substituents and the negative charges on the surface of GQDs. The fluorescence emission of the GQDs was quenched upon coordination to the respective Pcs. However, the fluorescence emission was “turned ON” in the presence of Hg2 + employed as a test analyte. The mechanism of the “turn ON” of the GQDs emission in the nanoconjugates is ascribed to the strong affinity of Hg2 + to bind with the bridging sulfur on the Pcs periphery thereby disrupting the π-π stacking interaction between the GQDs and the Pcs with a consequent “turn ON” of the coordinated GQDs' fluorescence.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188293 , vital:44742 , xlink:href="https://doi.org/10.1016/j.saa.2016.11.043"
- Description: This study reports on the design of novel nanoconjugates of graphene quantum dots (GQDs) and tetra or octa-mercaptopyridine-substituted zinc and aluminium phthalocyanines (Pcs) deployed as fluorescence “turn ON” nanoprobes. The phthalocyanines were separately adsorbed onto the planar structure of graphene quantum dots (GQDs) via π-π stacking interaction to form GQDs-mercaptopyridine Pcs nanoconjugates. The quaternized Pc complexes could also interact with the GQDs through electrostatic attraction due to the positive charges on the Pcs ring substituents and the negative charges on the surface of GQDs. The fluorescence emission of the GQDs was quenched upon coordination to the respective Pcs. However, the fluorescence emission was “turned ON” in the presence of Hg2 + employed as a test analyte. The mechanism of the “turn ON” of the GQDs emission in the nanoconjugates is ascribed to the strong affinity of Hg2 + to bind with the bridging sulfur on the Pcs periphery thereby disrupting the π-π stacking interaction between the GQDs and the Pcs with a consequent “turn ON” of the coordinated GQDs' fluorescence.
- Full Text:
- Date Issued: 2017
Graphene quantum dots anchored onto mercaptopyridine-substituted zinc phthalocyanine-Au@ Ag nanoparticle hybrid: Application as fluorescence “off-on-off” sensor for Hg2+ and biothiols
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
- Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
- Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
- Full Text:
- Date Issued: 2017
Student discourses: influences on identity and agency
- Authors: Ackerdien, Raeesah
- Date: 2017
- Subjects: English language -- Rhetoric -- Study and teaching (Higher) -- Psychological aspects , Psychoanalysis and education Identity (Psychology) in youth Educational sociology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/13625 , vital:27258
- Description: South Africa‟s racialised history dates back to a colonial period where South Africans were separated by race, language and laws which prevented people of colour from mixing with those who were termed White. 22 years after the end of apartheid, race and language remain a painful part of history and a topic which is always visible in our private and public discourses. Students, as of recent, have pointed to the challenges and legacies of apartheid they face in higher education and broader society. The lack of broader transformation and racial prejudice leave a great divide amongst different groups of students. Given this background, this study sought to examine how students were making sense of themselves and others. The participants of this study included 50 second year students from the Department of Language Studies at the Nelson Mandela Metropolitan University in Port Elizabeth. This research study focused on the identity development of students and how these factors impacted their identities taking into account aspects of race, language, sense of agency and those impacting their sense of agency and sense of self. This study used a qualitative research method which involves an interpretive approach to research as this method was best suited for this study‟s analysis of student narratives. This study is a case study of the single case of second year students. The research, furthermore, used a Poststructuralist approach as theoretical underpinning and Critical Discourse Analysis for analysis of the data. Relevant literature were read and reviewed to determine what studies were saying about factors impacting on youth identity. Student narratives were analysed in order to determine which factors impacted on their identity formation, as well as the perceptions of their own identities and those of others. The results of the findings showed that students‟ identity development was affected by factors such as cultural background, parents, death of loved ones, aesthetic interest, race and language. Socio-economic inequalities in South Africa, race and language strongly defined student identities. Identities were found to be multiple and dynamic. The impact on student agency was as a result of the influences of their parents but also because of the inequalities in society. The only commonality students identified as having with other students was study. Students revealed that they did not cross racial or language boundaries to socialise with other students. There were students who indicated that they resisted racial categorisations and spoke of the celebration of diversity in South Africa but these were in the minority. Unlike previous studies that showed students wanting to move on to a new unified South Africa while simultaneously using old apartheid discourses, this study showed that students remained rooted in these discourses but reverted to these discourses because of societal inequalities. They did not foresee any moves to a new unified South Africa if inequalities not addressed. They were more radical about what a new future looks like with the battle against privilege won. Language was identified as a barrier and the fallacies of English being linked to superior intelligence was pointed out. The divides between White and Black students were apparent in the data. The study therefore recommended that curriculation of modules be undertaken with teaching of fluidity of identities and providing of critical tools for students to deconstruct race and language. The South African context should be foregrounded in all faculty study areas so that students work to a public good that seeks to eradicate inequalities. Safe spaces need to be provided for debating of these issues as well as social spaces for interaction across racial divides.
- Full Text:
- Date Issued: 2017
- Authors: Ackerdien, Raeesah
- Date: 2017
- Subjects: English language -- Rhetoric -- Study and teaching (Higher) -- Psychological aspects , Psychoanalysis and education Identity (Psychology) in youth Educational sociology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/13625 , vital:27258
- Description: South Africa‟s racialised history dates back to a colonial period where South Africans were separated by race, language and laws which prevented people of colour from mixing with those who were termed White. 22 years after the end of apartheid, race and language remain a painful part of history and a topic which is always visible in our private and public discourses. Students, as of recent, have pointed to the challenges and legacies of apartheid they face in higher education and broader society. The lack of broader transformation and racial prejudice leave a great divide amongst different groups of students. Given this background, this study sought to examine how students were making sense of themselves and others. The participants of this study included 50 second year students from the Department of Language Studies at the Nelson Mandela Metropolitan University in Port Elizabeth. This research study focused on the identity development of students and how these factors impacted their identities taking into account aspects of race, language, sense of agency and those impacting their sense of agency and sense of self. This study used a qualitative research method which involves an interpretive approach to research as this method was best suited for this study‟s analysis of student narratives. This study is a case study of the single case of second year students. The research, furthermore, used a Poststructuralist approach as theoretical underpinning and Critical Discourse Analysis for analysis of the data. Relevant literature were read and reviewed to determine what studies were saying about factors impacting on youth identity. Student narratives were analysed in order to determine which factors impacted on their identity formation, as well as the perceptions of their own identities and those of others. The results of the findings showed that students‟ identity development was affected by factors such as cultural background, parents, death of loved ones, aesthetic interest, race and language. Socio-economic inequalities in South Africa, race and language strongly defined student identities. Identities were found to be multiple and dynamic. The impact on student agency was as a result of the influences of their parents but also because of the inequalities in society. The only commonality students identified as having with other students was study. Students revealed that they did not cross racial or language boundaries to socialise with other students. There were students who indicated that they resisted racial categorisations and spoke of the celebration of diversity in South Africa but these were in the minority. Unlike previous studies that showed students wanting to move on to a new unified South Africa while simultaneously using old apartheid discourses, this study showed that students remained rooted in these discourses but reverted to these discourses because of societal inequalities. They did not foresee any moves to a new unified South Africa if inequalities not addressed. They were more radical about what a new future looks like with the battle against privilege won. Language was identified as a barrier and the fallacies of English being linked to superior intelligence was pointed out. The divides between White and Black students were apparent in the data. The study therefore recommended that curriculation of modules be undertaken with teaching of fluidity of identities and providing of critical tools for students to deconstruct race and language. The South African context should be foregrounded in all faculty study areas so that students work to a public good that seeks to eradicate inequalities. Safe spaces need to be provided for debating of these issues as well as social spaces for interaction across racial divides.
- Full Text:
- Date Issued: 2017
Photosynthetic and growth responses of C3 and C4 grasses to short- duration sunflecks and resultant consequences for their performance in understory environments
- Authors: Adams, Claire Elizabeth
- Date: 2017
- Subjects: Understory plants -- Effect of light on , Grasses -- Effect of light on -- South Africa , Erharta -- Effect of light on , Brachiara -- Effect of light on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/5016 , vital:20753
- Description: Low C4 grass species abundance in understory environments is thought to be as a result of their high-light requirements, lack of photosynthetic advantage relative to C3 species in cooler environments, and an inability to adequately utilise sunflecks. This study sets out to investigate this theory, hypothesizing that C3 grass species outperform C4 grass species under the canopy, not as a result of quantum efficiency temperature effects, but as a result of C4 species inability to utilize short-duration sunflecks. Short sunflecks could result in a breakdown in assimilate movement between the mesophyll (MSC) and bundle sheath (BSC) cells. The role of BSC leakiness, stomata and PSII efficiency on the ability of C3 and C4 Alloteropsis semialata to utilize short-duration sunflecks was investigated using gaseous exchange and chlorophyll fluorescence techniques, while the growth of both subspecies under a simulated flecking-light environment tested whether these measured responses translated into effects on growth. As C3 grasses are known to possess higher levels of stomatal conductance in relation to C4 species, results showed that C3 A. semialata was able to utilize short-duration sunflecks as a result of increased stomatal conductance and an ability to induce photosynthesis under various light flecking conditions. In contrast, C4 A. semialata was unable to utilize sunflecks possibly as a result of energetic limitations of the carboxylation mechanism (PSII) and not because of increased bundle sheath leakiness. These photosynthetic responses translated into growth differences when both types were grown in an artificially flecking light environment. The photosynthetic differences noted for C3 and C4 A.semialata were also evident in shade adapted understory grasses; Erharta erecta (C3), Dactylotenium australe (C4) and Brachiaria chusqueoides (C4). As photosynthetic induction was marginally more rapid in all species relative to A. semialata it suggests some degree of adaptation in shade grasses, however the inability of the C4 species to utilise short sunflecks remained. As a result, it was hypothesized that C3 shade adapted E. erecta and C4 B. chusqueoides, co-inhabiting the same forest understory, are able to do so because of differences in light micro-environments associated with each species. However, canopy openness and light profiles determined for theses micro-climates showed no differences and that both species have persisted within a relatively stable understory environment. The coexistence was possible as the understory was supplied with a significant proportion of its daily light in flecks sufficiently long as to not compromise C4 productivity. A survey of 10 species of grasses under various canopy densities and in the open showed a strong negative linear relationship between canopy openness and the rate at which photosynthesis was induced by flecking light, which has not been shown before. This did not result from the phylogenetic relationship between species and could be shown for a single species (E. erecta) growing in a range of light environments. This demonstrates that C4 grasses, despite adaptation, would be limited from sunfleck environments if a significant proportion of the daily light available consists of flecks of short-duration. The generation of such environments may occur as a result of woody thickening and could help explain the observed decline in C4 grasses under these conditions.
- Full Text:
- Date Issued: 2017
- Authors: Adams, Claire Elizabeth
- Date: 2017
- Subjects: Understory plants -- Effect of light on , Grasses -- Effect of light on -- South Africa , Erharta -- Effect of light on , Brachiara -- Effect of light on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/5016 , vital:20753
- Description: Low C4 grass species abundance in understory environments is thought to be as a result of their high-light requirements, lack of photosynthetic advantage relative to C3 species in cooler environments, and an inability to adequately utilise sunflecks. This study sets out to investigate this theory, hypothesizing that C3 grass species outperform C4 grass species under the canopy, not as a result of quantum efficiency temperature effects, but as a result of C4 species inability to utilize short-duration sunflecks. Short sunflecks could result in a breakdown in assimilate movement between the mesophyll (MSC) and bundle sheath (BSC) cells. The role of BSC leakiness, stomata and PSII efficiency on the ability of C3 and C4 Alloteropsis semialata to utilize short-duration sunflecks was investigated using gaseous exchange and chlorophyll fluorescence techniques, while the growth of both subspecies under a simulated flecking-light environment tested whether these measured responses translated into effects on growth. As C3 grasses are known to possess higher levels of stomatal conductance in relation to C4 species, results showed that C3 A. semialata was able to utilize short-duration sunflecks as a result of increased stomatal conductance and an ability to induce photosynthesis under various light flecking conditions. In contrast, C4 A. semialata was unable to utilize sunflecks possibly as a result of energetic limitations of the carboxylation mechanism (PSII) and not because of increased bundle sheath leakiness. These photosynthetic responses translated into growth differences when both types were grown in an artificially flecking light environment. The photosynthetic differences noted for C3 and C4 A.semialata were also evident in shade adapted understory grasses; Erharta erecta (C3), Dactylotenium australe (C4) and Brachiaria chusqueoides (C4). As photosynthetic induction was marginally more rapid in all species relative to A. semialata it suggests some degree of adaptation in shade grasses, however the inability of the C4 species to utilise short sunflecks remained. As a result, it was hypothesized that C3 shade adapted E. erecta and C4 B. chusqueoides, co-inhabiting the same forest understory, are able to do so because of differences in light micro-environments associated with each species. However, canopy openness and light profiles determined for theses micro-climates showed no differences and that both species have persisted within a relatively stable understory environment. The coexistence was possible as the understory was supplied with a significant proportion of its daily light in flecks sufficiently long as to not compromise C4 productivity. A survey of 10 species of grasses under various canopy densities and in the open showed a strong negative linear relationship between canopy openness and the rate at which photosynthesis was induced by flecking light, which has not been shown before. This did not result from the phylogenetic relationship between species and could be shown for a single species (E. erecta) growing in a range of light environments. This demonstrates that C4 grasses, despite adaptation, would be limited from sunfleck environments if a significant proportion of the daily light available consists of flecks of short-duration. The generation of such environments may occur as a result of woody thickening and could help explain the observed decline in C4 grasses under these conditions.
- Full Text:
- Date Issued: 2017
A discourse analysis of the construction of gendered relationships in grade 10-12 Life Orientation textbooks in the Eastern Cape
- Authors: Adams, Luvo
- Date: 2017
- Subjects: Sex instruction -- South Africa -- Eastern Cape Life skills -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5532 , vital:29315
- Description: School-based sexuality education has been the subject of research in the social sciences and pedagogical spheres globally. In South Africa, growing interest among social scientists in the topic, were ignited by the introduction of sexuality education as a compulsory part of Life Orientation (LO) by the late 1990s. However, the implementation of LO has been problematic. Reviewed literature in the current study, reveals how the dominance of the heterosex discourse is foregrounded in LO content on gender and sexuality. The current study was aimed at examining the construction of gendered relationships in LO textbooks. The study sampled LO textbooks for Grades 10-12, learners in these grades are between the mean ages 16-18 years. This group is the target group, because they are legally afforded the right to consent to sexual activity with peers, within the same age bracket. Conducted from a social constructionist perspective, the current study employed qualitative methods of inquiry (textual analysis). Against the backdrop of heterosexuality as norm, it was the aim of the current study to understand the subject positions made available for female learners to construct themselves, within the discursive spaces in LO content. Findings suggest that two discourses namely: the heterosex discourse and the discourse of danger and disease, dominate in LO content on gender and sexuality. This leads to the construction of gendered relationships a s inherently heterosexual, leading to the marginalisation of relationships that fall outside of the norm. The female learner is positioned as a passive-victim, incapable of exercising sexual agency, while young men are positioned as inherently more powerful members of the intimate relationships or dangerous sexual predators. In the discourse of danger and disease, she is also positioned as a potential victim but the focus is on equipping her with skills, in a way which positioned her as an active-resistor in refusing sexual activity; and being in control of decision-making on issues of safety in relationships. The implications of these contradictions, is that they focus on the individual and disallow her taking up of sexual agency, and disregard the context in which she has to do so.
- Full Text:
- Date Issued: 2017
- Authors: Adams, Luvo
- Date: 2017
- Subjects: Sex instruction -- South Africa -- Eastern Cape Life skills -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5532 , vital:29315
- Description: School-based sexuality education has been the subject of research in the social sciences and pedagogical spheres globally. In South Africa, growing interest among social scientists in the topic, were ignited by the introduction of sexuality education as a compulsory part of Life Orientation (LO) by the late 1990s. However, the implementation of LO has been problematic. Reviewed literature in the current study, reveals how the dominance of the heterosex discourse is foregrounded in LO content on gender and sexuality. The current study was aimed at examining the construction of gendered relationships in LO textbooks. The study sampled LO textbooks for Grades 10-12, learners in these grades are between the mean ages 16-18 years. This group is the target group, because they are legally afforded the right to consent to sexual activity with peers, within the same age bracket. Conducted from a social constructionist perspective, the current study employed qualitative methods of inquiry (textual analysis). Against the backdrop of heterosexuality as norm, it was the aim of the current study to understand the subject positions made available for female learners to construct themselves, within the discursive spaces in LO content. Findings suggest that two discourses namely: the heterosex discourse and the discourse of danger and disease, dominate in LO content on gender and sexuality. This leads to the construction of gendered relationships a s inherently heterosexual, leading to the marginalisation of relationships that fall outside of the norm. The female learner is positioned as a passive-victim, incapable of exercising sexual agency, while young men are positioned as inherently more powerful members of the intimate relationships or dangerous sexual predators. In the discourse of danger and disease, she is also positioned as a potential victim but the focus is on equipping her with skills, in a way which positioned her as an active-resistor in refusing sexual activity; and being in control of decision-making on issues of safety in relationships. The implications of these contradictions, is that they focus on the individual and disallow her taking up of sexual agency, and disregard the context in which she has to do so.
- Full Text:
- Date Issued: 2017
Assessment of national small and medium scale policy as a driver of local economic development : a case study of Ife Central Local government, Nigeria
- Authors: Adefemi, Adebayo Oluwaseun
- Date: 2017
- Subjects: Economic policy Economic development -- Nigeria
- Language: English
- Type: Thesis , Masters , M.Admin
- Identifier: http://hdl.handle.net/10353/12711 , vital:39301
- Description: This study, assessment of national small and medium scale policy as a driver of local economic development: a case study of Ife Central Local Government, Nigeria, was undertaken to find out if the National SME policy in Nigeria has performed its critical role of driving the local economic and if not, why, and also to identify measures to solve the problems that are hindering the implementation of the National SMEs policy. This study will therefore investigate the contributions of the Small and Medium Enterprises sub-sector of the Nigerian economy, its problems and prospects and also examine the National SME policy and the importance of the policy. The objective of this study is to explore the implementation of National SME policy as a driver of local economic development, analyse the challenges that are associated with implementing the National SME policy in Ife Central Local Government and make recommendations regarding the implementation of SME policy in Nigeria. A total of 5 MP’s were randomly selected from a cross section of 7 MP’s that represent Ife Central Local Government. Interviews was used to determine how the National SME policy is been implemented in there constituency and if they are facing any challenges as to the implementing the policy and how are they solving the problems that are associated with the policy. The major findings of this study include the following: the National SME policy is an important policy which if well implemented would help the development of SMEs and also have great impact on the local economic development. Among the problems associated with the policy according to the MP’s are financial problems, illiteracy level of people in their constituency, Land segmentation problem, marketing problems. This study therefore recommended that government should strengthen financial laws that mandates financial institutions to give low interest rate loans to SMEs with little or no collateral. The government should accelerated development and upgrade of rural roads and rail network and other infrastructural facilities and review taxies in favour of local manufacturers especially the SMEs.
- Full Text:
- Date Issued: 2017
- Authors: Adefemi, Adebayo Oluwaseun
- Date: 2017
- Subjects: Economic policy Economic development -- Nigeria
- Language: English
- Type: Thesis , Masters , M.Admin
- Identifier: http://hdl.handle.net/10353/12711 , vital:39301
- Description: This study, assessment of national small and medium scale policy as a driver of local economic development: a case study of Ife Central Local Government, Nigeria, was undertaken to find out if the National SME policy in Nigeria has performed its critical role of driving the local economic and if not, why, and also to identify measures to solve the problems that are hindering the implementation of the National SMEs policy. This study will therefore investigate the contributions of the Small and Medium Enterprises sub-sector of the Nigerian economy, its problems and prospects and also examine the National SME policy and the importance of the policy. The objective of this study is to explore the implementation of National SME policy as a driver of local economic development, analyse the challenges that are associated with implementing the National SME policy in Ife Central Local Government and make recommendations regarding the implementation of SME policy in Nigeria. A total of 5 MP’s were randomly selected from a cross section of 7 MP’s that represent Ife Central Local Government. Interviews was used to determine how the National SME policy is been implemented in there constituency and if they are facing any challenges as to the implementing the policy and how are they solving the problems that are associated with the policy. The major findings of this study include the following: the National SME policy is an important policy which if well implemented would help the development of SMEs and also have great impact on the local economic development. Among the problems associated with the policy according to the MP’s are financial problems, illiteracy level of people in their constituency, Land segmentation problem, marketing problems. This study therefore recommended that government should strengthen financial laws that mandates financial institutions to give low interest rate loans to SMEs with little or no collateral. The government should accelerated development and upgrade of rural roads and rail network and other infrastructural facilities and review taxies in favour of local manufacturers especially the SMEs.
- Full Text:
- Date Issued: 2017
Photophysical properties of a series of alloyed and non-alloyed water-soluble l-cysteine-capped core quantum dots
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188486 , vital:44758 , xlink:href="https://doi.org/10.1016/j.jallcom.2016.10.276"
- Description: Photophysical properties of quantum dots (QDs) such as their photoluminescence (PL) quantum yield (QY), exciton lifetime and PL stability are important parameters used to unravel their chemical and physical characteristics. In this work, we have comparatively investigated the photophysical properties of a series of L-cysteine-capped non-alloyed (CdTe and CdSe) and alloyed (CdZnTe, CdSeS, CdSeTe and CdSeTeS) core QDs. Each of the QDs varied in their size and PL emission wavelength. We observe no physical relationship between the PL QY of the QDs and their PL stability. Based on the PL stability assessment, CdTe QDs with a high PL QY value of 88% exhibited poor PL stability while moderate PL stability was observed for CdZnTe (QY = 78%); CdSe (QY = 3%); and CdSeTe QDs (QY = ∼3%). Alloyed CdSeS (QY = ∼69%) and CdSeTeS (QY = 23%) QDs exhibited good PL stability and can serve as potential fluorophores for a wide range of chemical and biological applications. Generally, it is proposed that the structural nature of the QDs played a significant role in their overall photophysical properties. The information provided in this work will assist in the selection of core QDs suitable for different applications.
- Full Text:
- Date Issued: 2017
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188486 , vital:44758 , xlink:href="https://doi.org/10.1016/j.jallcom.2016.10.276"
- Description: Photophysical properties of quantum dots (QDs) such as their photoluminescence (PL) quantum yield (QY), exciton lifetime and PL stability are important parameters used to unravel their chemical and physical characteristics. In this work, we have comparatively investigated the photophysical properties of a series of L-cysteine-capped non-alloyed (CdTe and CdSe) and alloyed (CdZnTe, CdSeS, CdSeTe and CdSeTeS) core QDs. Each of the QDs varied in their size and PL emission wavelength. We observe no physical relationship between the PL QY of the QDs and their PL stability. Based on the PL stability assessment, CdTe QDs with a high PL QY value of 88% exhibited poor PL stability while moderate PL stability was observed for CdZnTe (QY = 78%); CdSe (QY = 3%); and CdSeTe QDs (QY = ∼3%). Alloyed CdSeS (QY = ∼69%) and CdSeTeS (QY = 23%) QDs exhibited good PL stability and can serve as potential fluorophores for a wide range of chemical and biological applications. Generally, it is proposed that the structural nature of the QDs played a significant role in their overall photophysical properties. The information provided in this work will assist in the selection of core QDs suitable for different applications.
- Full Text:
- Date Issued: 2017
Evaluation of some pharmaceutical and personal care products and pesticide residues in selected wastewater treatment plants and receiving watersheds in Eastern Cape, South Africa
- Ademoyegun, Olufemi Temitope
- Authors: Ademoyegun, Olufemi Temitope
- Date: 2017
- Subjects: Emerging contaminants in water -- South Africa -- Eastern Cape Water treatment plants -- Waste disposal -- South Africa -- Eastern Cape Organic compounds -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/2922 , vital:28138
- Description: Emerging organic contaminants (EOCs) have been the focus of global environmental research for over three decades. EOCs have caused widespread concern due to their extensive use. As EOCs were designed to correct, enhance or protect a specific physiological, their target effects in humans and/or farm stocks are relatively well known and documented. However, there is limited knowledge about their unintended effects in the environment. To address the occurrence, distribution and fate of EOCs in the environment, efficient and reliable analytical methods are needed. The relatively low concentration, high polarity, and thermal lability of some EOCs, together with their interaction with complex environmental matrices, make their analysis challenging. Sample preparation followed by GC or HPLC separation and mass spectrometry (MS) detection has become the standard approach for evaluating EOCs in environmental samples. Physicochemical properties of EOCs range from highly water-soluble (hydrophylic) to highly water-insoluble (hydrophobic). Two groups of these EOCs were considered for study in this work. Pharmaceutical and personal care products (PPCPs) were comprehensively studied in five wastewater treatment plants and their receiving watersheds in Amathole districts in Eastern C ape, South Africa. PPCPs have been widely reported in wastewater influents, effluents, receiving rivers and biosolids, but reports of their occurrence in all these matrixes have been limited by the difficulty of analysis. Therefore, a comprehensive validation of methods was carried out on the influents, effluents, sludge and soil from the irrigated golf course where the effluent of one of the study sites was being used for over three decades now for irrigation. In all, thirteen PPCPs from five therapeutic groups were selected for study in this work because of their administering rate and availability of analytical instrument. Good limit of detection (LOD) and limit of quantification (LOQ) were achieved for the method used. The LOD for the aqueous Three different technologies were employed for the treatment of wastewater in the five selected wastewater treatment plants (WWTPs) and study was carried out to evaluate their ability to eliminate the selected compounds from the influents to the effluents using statistical analysis (ANOVA) at p<0.05 on the percentage removal rate across the three plants. The results had shown eight of the compounds having no significant difference among the treatment operations, whereas the remaining five compounds varied significantly among the treatment technologies under investigation. Principal component analysis was performed on the concentration of PPCPs, their removal rate and also on the physicochemical and treatment operation parameters. Hydraulic retention time (HRT) had correlation coefficient, r = 0.90 with the concentration of PPCPs and removal rates. Furthermore, occurrences, seasonal variation, mean concentration distribution pattern of the compounds, and temporal evaluation of the mean concentration of the pharmaceutical compounds in the five WWTPs during one year of sampling were considered. The results revealed that five products which were diclofenac, ibuprofen, paracetamol, triclosan and diethyl toluamide (DDET) were predominant among the PPCPs in all the WWTPs. The removal efficiency was highest in caffeine with 96 percent, and the lowest was obtained with carbamazepine (4 percent). Risk quotient of the concentration of PPCPs in the effluents and receiving waters was determined to assess their chronic toxicity at three trophic levels: fish, algae and matrixes studied ranged from 0.01 μg/L to 0.25 μg/L, and the LOQ from 0.02 μg/L to 0.78 μg/L. In the solid matrixes, LOD varied from 0.01 ng/g to 0.65 ng/g, and the LOQ between 0.08 ng/g and 5.17 ng/g. Better recovery efficiency was obtained with this mixture of solvents, acetone: dichloromethane (1:1), for the recovery of the five therapeutic groups in the solid matrixes using ultrasonication- assisted techniques. The results show percentage recovery values ranging from 68.8 percent to 107.5 percent diaphian. According to the environmental risk assessment results, ibuprofen and triclosan were found to be the most critical compounds due to their high risk quotient values. These findings will, therefore, help in the future evaluation of the efficiency of different treatment technologies in the removal of various PPCPs from the wastewater and their sustainable management in the aquatic resources in Eastern Cape, South Africa. For the lipophilic organochlorine pesticides (OCPs), the limits of detection (LODs) of the tested congeners varied from 0.04 ng/g (α-BHC) to 0.49 ng/g (endosulfan sulfate) and the limits of quantification ranging from 0.22 ng/g (aldrin) to 2.17 ng/g (δ-BHC).
- Full Text:
- Date Issued: 2017
- Authors: Ademoyegun, Olufemi Temitope
- Date: 2017
- Subjects: Emerging contaminants in water -- South Africa -- Eastern Cape Water treatment plants -- Waste disposal -- South Africa -- Eastern Cape Organic compounds -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/2922 , vital:28138
- Description: Emerging organic contaminants (EOCs) have been the focus of global environmental research for over three decades. EOCs have caused widespread concern due to their extensive use. As EOCs were designed to correct, enhance or protect a specific physiological, their target effects in humans and/or farm stocks are relatively well known and documented. However, there is limited knowledge about their unintended effects in the environment. To address the occurrence, distribution and fate of EOCs in the environment, efficient and reliable analytical methods are needed. The relatively low concentration, high polarity, and thermal lability of some EOCs, together with their interaction with complex environmental matrices, make their analysis challenging. Sample preparation followed by GC or HPLC separation and mass spectrometry (MS) detection has become the standard approach for evaluating EOCs in environmental samples. Physicochemical properties of EOCs range from highly water-soluble (hydrophylic) to highly water-insoluble (hydrophobic). Two groups of these EOCs were considered for study in this work. Pharmaceutical and personal care products (PPCPs) were comprehensively studied in five wastewater treatment plants and their receiving watersheds in Amathole districts in Eastern C ape, South Africa. PPCPs have been widely reported in wastewater influents, effluents, receiving rivers and biosolids, but reports of their occurrence in all these matrixes have been limited by the difficulty of analysis. Therefore, a comprehensive validation of methods was carried out on the influents, effluents, sludge and soil from the irrigated golf course where the effluent of one of the study sites was being used for over three decades now for irrigation. In all, thirteen PPCPs from five therapeutic groups were selected for study in this work because of their administering rate and availability of analytical instrument. Good limit of detection (LOD) and limit of quantification (LOQ) were achieved for the method used. The LOD for the aqueous Three different technologies were employed for the treatment of wastewater in the five selected wastewater treatment plants (WWTPs) and study was carried out to evaluate their ability to eliminate the selected compounds from the influents to the effluents using statistical analysis (ANOVA) at p<0.05 on the percentage removal rate across the three plants. The results had shown eight of the compounds having no significant difference among the treatment operations, whereas the remaining five compounds varied significantly among the treatment technologies under investigation. Principal component analysis was performed on the concentration of PPCPs, their removal rate and also on the physicochemical and treatment operation parameters. Hydraulic retention time (HRT) had correlation coefficient, r = 0.90 with the concentration of PPCPs and removal rates. Furthermore, occurrences, seasonal variation, mean concentration distribution pattern of the compounds, and temporal evaluation of the mean concentration of the pharmaceutical compounds in the five WWTPs during one year of sampling were considered. The results revealed that five products which were diclofenac, ibuprofen, paracetamol, triclosan and diethyl toluamide (DDET) were predominant among the PPCPs in all the WWTPs. The removal efficiency was highest in caffeine with 96 percent, and the lowest was obtained with carbamazepine (4 percent). Risk quotient of the concentration of PPCPs in the effluents and receiving waters was determined to assess their chronic toxicity at three trophic levels: fish, algae and matrixes studied ranged from 0.01 μg/L to 0.25 μg/L, and the LOQ from 0.02 μg/L to 0.78 μg/L. In the solid matrixes, LOD varied from 0.01 ng/g to 0.65 ng/g, and the LOQ between 0.08 ng/g and 5.17 ng/g. Better recovery efficiency was obtained with this mixture of solvents, acetone: dichloromethane (1:1), for the recovery of the five therapeutic groups in the solid matrixes using ultrasonication- assisted techniques. The results show percentage recovery values ranging from 68.8 percent to 107.5 percent diaphian. According to the environmental risk assessment results, ibuprofen and triclosan were found to be the most critical compounds due to their high risk quotient values. These findings will, therefore, help in the future evaluation of the efficiency of different treatment technologies in the removal of various PPCPs from the wastewater and their sustainable management in the aquatic resources in Eastern Cape, South Africa. For the lipophilic organochlorine pesticides (OCPs), the limits of detection (LODs) of the tested congeners varied from 0.04 ng/g (α-BHC) to 0.49 ng/g (endosulfan sulfate) and the limits of quantification ranging from 0.22 ng/g (aldrin) to 2.17 ng/g (δ-BHC).
- Full Text:
- Date Issued: 2017
Beyond health care providers’recommendations: understandinginfluences on infant feeding choices ofwomen with HIV in the Eastern Cape,South Africa
- Adeniyi, Oladele Vincent, Ajayi, Anthony Idowu, Issah, Moshood, Owolabi, Eyitayo Omolara, Ter Goon, Daniel, Avramovic, Gordana, Lambert, John
- Authors: Adeniyi, Oladele Vincent , Ajayi, Anthony Idowu , Issah, Moshood , Owolabi, Eyitayo Omolara , Ter Goon, Daniel , Avramovic, Gordana , Lambert, John
- Date: 2017
- Subjects: Africa Infant Feeding Sub-sahara
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6063 , vital:45109 , https://doi.org/10.1186/s13006-019-0201-5
- Description: Background: Despite the array of studies on infant feeding practices of HIV-infected women, gaps still exist in the understanding of the underlying reasons for their infant feeding choices. Potential for behavioural change exists, especially in the light of the 2016 updated World Health Organization guideline on HIV and infant feeding. The aim of this paper is to determine the rate of adoption of exclusive breastfeeding in this cohort, examine the determinants of infant feeding choices of HIV-infected women and assess the underlying reasons for these choices. Methods: This was a mixed methods study conducted between September 2015 and May 2016. It analyses the quantitative and qualitative data of 1662 peripartum women enrolled in the East London Prospective Cohort Study across three large maternity services in the Eastern Cape. Women with HIV reported their preferred choices of infant feeding. In addition, participants explained the underlying reasons for their choices. Descriptive and inferential statistics summarised the quantitative data, while thematic content analysis was performed on qualitative data. Results: Of the 1662 women with complete responses, 80.3% opted to exclusively breastfeed their babies. In the adjusted model, up to grade 12 education level (AOR: 1.81; 95% CI: 1.14, 2.86), rural/peri-urban residence (AOR:1.44; 95% CI: 1.05, 1.96), alcohol use (AOR: 1.65; 95% CI: 1.25, 2.18), negative or unknown HIV status at booking (AOR:1.85; 95% CI:1.27, 2.70), currently married (AOR:1.43; 95% CI:1.01, 2.02) and WHO Clinical Stage 2–4 (AOR:1.77; 95% CI: 1.15, 2.72) were significantly associated with the decision to exclusively breastfeed. Health care providers’ recommendations, perceived benefits of breastfeeding, unaffordability of formula feeding, and coercion were the underlying reasons for wanting to breastfeed; while work/school-related demands, breast-related issues, and fear of infecting the baby influenced their decision to formula feed. Conclusion: The majority of HIV-infected women chose to breastfeed their babies in the Eastern Cape. Following up on these women to ensure they breastfeed exclusively, while also addressing their possible concerns, could be an important policy intervention. Future studies should focus on how early infant feeding decisions change over time, as well as the health outcomes for mother and child. Keywords: Exclusive breastfeeding, Infant feeding practice, infant formula feeding, HIV-infected peripartum women, South Africa, WHO guideline
- Full Text:
- Date Issued: 2017
- Authors: Adeniyi, Oladele Vincent , Ajayi, Anthony Idowu , Issah, Moshood , Owolabi, Eyitayo Omolara , Ter Goon, Daniel , Avramovic, Gordana , Lambert, John
- Date: 2017
- Subjects: Africa Infant Feeding Sub-sahara
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6063 , vital:45109 , https://doi.org/10.1186/s13006-019-0201-5
- Description: Background: Despite the array of studies on infant feeding practices of HIV-infected women, gaps still exist in the understanding of the underlying reasons for their infant feeding choices. Potential for behavioural change exists, especially in the light of the 2016 updated World Health Organization guideline on HIV and infant feeding. The aim of this paper is to determine the rate of adoption of exclusive breastfeeding in this cohort, examine the determinants of infant feeding choices of HIV-infected women and assess the underlying reasons for these choices. Methods: This was a mixed methods study conducted between September 2015 and May 2016. It analyses the quantitative and qualitative data of 1662 peripartum women enrolled in the East London Prospective Cohort Study across three large maternity services in the Eastern Cape. Women with HIV reported their preferred choices of infant feeding. In addition, participants explained the underlying reasons for their choices. Descriptive and inferential statistics summarised the quantitative data, while thematic content analysis was performed on qualitative data. Results: Of the 1662 women with complete responses, 80.3% opted to exclusively breastfeed their babies. In the adjusted model, up to grade 12 education level (AOR: 1.81; 95% CI: 1.14, 2.86), rural/peri-urban residence (AOR:1.44; 95% CI: 1.05, 1.96), alcohol use (AOR: 1.65; 95% CI: 1.25, 2.18), negative or unknown HIV status at booking (AOR:1.85; 95% CI:1.27, 2.70), currently married (AOR:1.43; 95% CI:1.01, 2.02) and WHO Clinical Stage 2–4 (AOR:1.77; 95% CI: 1.15, 2.72) were significantly associated with the decision to exclusively breastfeed. Health care providers’ recommendations, perceived benefits of breastfeeding, unaffordability of formula feeding, and coercion were the underlying reasons for wanting to breastfeed; while work/school-related demands, breast-related issues, and fear of infecting the baby influenced their decision to formula feed. Conclusion: The majority of HIV-infected women chose to breastfeed their babies in the Eastern Cape. Following up on these women to ensure they breastfeed exclusively, while also addressing their possible concerns, could be an important policy intervention. Future studies should focus on how early infant feeding decisions change over time, as well as the health outcomes for mother and child. Keywords: Exclusive breastfeeding, Infant feeding practice, infant formula feeding, HIV-infected peripartum women, South Africa, WHO guideline
- Full Text:
- Date Issued: 2017
Omics-based molecular techniques in oral pathology centred cancer: prospect and challenges in Africa
- Adeola, Henry A., Soyele, Olujide.O., Adefuye, Anthonio O., Jimoh, Sikiru A., Butali, Azeez
- Authors: Adeola, Henry A. , Soyele, Olujide.O. , Adefuye, Anthonio O. , Jimoh, Sikiru A. , Butali, Azeez
- Date: 2017
- Subjects: Eastern Cape, South Africa Oral mucosa--Cancer Oral Pathology Cancer Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5857 , vital:44658 , https://DOI10.1186/s12935-017-0432-8
- Description: Background:The completion of the human genome project and the accomplished milestones in the human proteome project; as well as the progress made so far in computational bioinformatics and “big data” processing have contributed immensely to individualized/personalized medicine in the developed world.Main body:At the dawn of precision medicine, various omics-based therapies and bioengineering can now be applied accurately for the diagnosis, prognosis, treatment, and risk stratification of cancer in a manner that was hitherto not thought possible. The widespread introduction of genomics and other omics-based approaches into the postgraduate training curriculum of diverse medical and dental specialties, including pathology has improved the proficiency of practitioners in the use of novel molecular signatures in patient management. In addition, intricate details about disease disparity among different human populations are beginning to emerge. This would facilitate the use of tailor-made novel theranostic methods based on emerging molecular evidences.Conclusion:In this review, we examined the challenges and prospects of using currently available omics-based technologies vis-à-vis oral pathology as well as prompt cancer diagnosis and treatment in a resource limited setting.Keywords:Omics-based, Molecular, Developing world, Oral pathology, Challenges
- Full Text:
- Date Issued: 2017
Omics-based molecular techniques in oral pathology centred cancer: prospect and challenges in Africa
- Authors: Adeola, Henry A. , Soyele, Olujide.O. , Adefuye, Anthonio O. , Jimoh, Sikiru A. , Butali, Azeez
- Date: 2017
- Subjects: Eastern Cape, South Africa Oral mucosa--Cancer Oral Pathology Cancer Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5857 , vital:44658 , https://DOI10.1186/s12935-017-0432-8
- Description: Background:The completion of the human genome project and the accomplished milestones in the human proteome project; as well as the progress made so far in computational bioinformatics and “big data” processing have contributed immensely to individualized/personalized medicine in the developed world.Main body:At the dawn of precision medicine, various omics-based therapies and bioengineering can now be applied accurately for the diagnosis, prognosis, treatment, and risk stratification of cancer in a manner that was hitherto not thought possible. The widespread introduction of genomics and other omics-based approaches into the postgraduate training curriculum of diverse medical and dental specialties, including pathology has improved the proficiency of practitioners in the use of novel molecular signatures in patient management. In addition, intricate details about disease disparity among different human populations are beginning to emerge. This would facilitate the use of tailor-made novel theranostic methods based on emerging molecular evidences.Conclusion:In this review, we examined the challenges and prospects of using currently available omics-based technologies vis-à-vis oral pathology as well as prompt cancer diagnosis and treatment in a resource limited setting.Keywords:Omics-based, Molecular, Developing world, Oral pathology, Challenges
- Full Text:
- Date Issued: 2017
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
Psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria
- Authors: Aderibigbe, John Kolawole
- Date: 2017
- Subjects: Psychology, Industrial Emotional intelligence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8642 , vital:33250
- Description: The study investigated psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria, using the explanatory cross-sectional (survey) research design and three sampling techniques (The Two-stage Cluster Sampling Method, The Convenience Sampling Method and The Purposive Sampling Technique) to sample 1532 male and female graduate employees in Nigeria. A structured validated questionnaire was used to collect data from the respondents. Six hypotheses were stated and tested in the study towards propounding a model, using Pearson Correlation Analysis, Multiple Regression Analysis and Structural Equation Modelling. The results show that there is a weak positive relationship between occupational stress and organisational citizenship behaviour, r = 0.070, p<0.01; there is a significant positive relationship between psychological capital and organisational citizenship behaviour, r = 0.588, p<0.01; there is a significant positive relationship between emotional intelligence and organisational citizenship behaviour, r = 0.473, p<0.01; psychological capital is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 8.514; R2= 0.011; p <.05; emotional intelligence is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 5.945; R2= 0.008; p <.05; psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour, F (1,1530) = 221.240; R2= 0.186; p <.05; psychological capital has a direct and significant positive effect on organisational citizenship behaviour, R= 0.657, p<.001; emotional intelligence has a direct and significant positive effect on organisational citizenship behaviour, R= 0.183, p<.001; psychological capital has a direct and significant positive effect on occupational stress, R= 0.100, p<.001; emotional intelligence has a direct and significant positive effect on psychological capital, R= 0.547, p<.001. Based on the results, the study concludes that psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour. The proposed model was, therefore, empirically confirmed. The researcher recommends that the empirical model of effective management of occupational stress and organisational citizenship behaviour, which has been propounded in the study, should be adopted and applied by teachers, lecturers, seminar facilitators, workshop trainers, supervisors and managers during their coaching or training sessions.
- Full Text:
- Date Issued: 2017
- Authors: Aderibigbe, John Kolawole
- Date: 2017
- Subjects: Psychology, Industrial Emotional intelligence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8642 , vital:33250
- Description: The study investigated psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria, using the explanatory cross-sectional (survey) research design and three sampling techniques (The Two-stage Cluster Sampling Method, The Convenience Sampling Method and The Purposive Sampling Technique) to sample 1532 male and female graduate employees in Nigeria. A structured validated questionnaire was used to collect data from the respondents. Six hypotheses were stated and tested in the study towards propounding a model, using Pearson Correlation Analysis, Multiple Regression Analysis and Structural Equation Modelling. The results show that there is a weak positive relationship between occupational stress and organisational citizenship behaviour, r = 0.070, p<0.01; there is a significant positive relationship between psychological capital and organisational citizenship behaviour, r = 0.588, p<0.01; there is a significant positive relationship between emotional intelligence and organisational citizenship behaviour, r = 0.473, p<0.01; psychological capital is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 8.514; R2= 0.011; p <.05; emotional intelligence is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 5.945; R2= 0.008; p <.05; psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour, F (1,1530) = 221.240; R2= 0.186; p <.05; psychological capital has a direct and significant positive effect on organisational citizenship behaviour, R= 0.657, p<.001; emotional intelligence has a direct and significant positive effect on organisational citizenship behaviour, R= 0.183, p<.001; psychological capital has a direct and significant positive effect on occupational stress, R= 0.100, p<.001; emotional intelligence has a direct and significant positive effect on psychological capital, R= 0.547, p<.001. Based on the results, the study concludes that psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour. The proposed model was, therefore, empirically confirmed. The researcher recommends that the empirical model of effective management of occupational stress and organisational citizenship behaviour, which has been propounded in the study, should be adopted and applied by teachers, lecturers, seminar facilitators, workshop trainers, supervisors and managers during their coaching or training sessions.
- Full Text:
- Date Issued: 2017