Evaluation of self-efficacy in clinical performance of nurses initiate and management of anti-retroviral therapy by South African professional nurses
- Authors: Mangi, Nozuko Glenrose
- Date: 2017
- Subjects: Nursing assessment -- South Africa -- Eastern Cape Self-efficacy Nursing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4492 , vital:28344
- Description: Self-efficacy in clinical performance is a very important aspect in quality of health care, because it is the ability of the person to produce the desired outcomes. The aim of the study was to evaluate self-efficacy in clinical performance of NIMART programme by professional nurses in Buffalo City Metropolitan in Eastern Cape Province South Africa. A quantitative, descriptive survey design was used to examine self-efficacy in clinical performance during implementation of NIMART programme. A purposive sample of 358 NIMART programme trained professional nurses was included in the study. Analysis of the finding was done using SPSS version 21.0. Descriptive statistics (frequencies, percentage, mean and standard deviations) were used to analyse categorical variables. To reduce data volume, factor analysis was used to identify six variable clusters: Evaluation; planning, assessment, implementation, and patient care mentoring. Factor 1 (evaluation) was highly loaded on patient driven results (0.63); nursing interventions (0.70); breakdown point location (0.80); prognosis based care decisions (0.79); prognosis based outcome monitoring (0.70); and prognosis based settings adjustment (0.70). These items collectively define evaluation of self-efficacy clinical performance of the participants. Factor 2 (planning) was termed planning of patient care in a clinical setting was significantly loaded on these items: data driven nursing diagnosis (0.51); patient driven nursing diagnosis (0.52); settings based nursing diagnosis (0.49); overall care plan formulation (0.52); short-term patients care formulation (0.58); long-term patient care formulation (0.66); goal based measurable outcomes (0.80); goal based daily patient care plan (0.79); settings based daily patient care plan (0.73). Factor 3 (assessment) which was termed assessment in clinical performance was not significantly loaded in some of the items: physical assessment (0.64); patient history (0.65); energy restoration (0.56); time management (0.71); objective patient health data (0.61); subjective patient health data (0.49); data collection documentation (0.44). Factor 4 (implementation) data source correlation; patient health data analysis (0.45); patient strength (0.46); nurse-patient/family communication (0.55); nurse patient collaboration (0.64); Experience driven decision making (0.58). Factor 5 (patient care) patient care plan adherence (0.65); setting based overall patient care (0.74); resource based overall patient care (0.59). Factor 6 (mentoring) patient’s concerns identification (0.48); patient problems prioritisation (0.46); mentor/colleague advice (0.43); mentor/colleague feedback use (0.61); patient discharge strategies (0.71); continuous reporting/documenting (0.63). The mean scores produced by the Kruskal-Wallis test showed the lowest scoring pattern as follows: 20122013201120142010. This order was the same for all the variables, confirming that the 2010 group scored significantly higher than any other group on all the variables. The overall results of the study revealed that professional nurses have high self-efficacy in clinical performance in implementation of NIMART programme, except in evaluation aspect of self-efficacy where they scored lessor. Professional nurses trained by FPD scored higher in the aspects of self-efficacy in clinical performance compared to RTC trained; but scored lower in evaluative ability of self-efficacy in both institutions (FPD and RTC). The findings of this study showed that the overall self-efficacy of the professional nurses trained on NIMART programme performed clinically satisfactorily. It is recommended that in-service education or continuous professional development for professional nurses working in PHC’s should not only concentrate on updating clinical skills, but also create opportunity for reflection and strengthening of professional nurses’ self-efficacy in clinical performance. Also, further study on other processes of goal realisation will aid our understanding of self-efficacy in achieving the desirable goals of the professional nurses for patient quality care. Further research is also needed to evaluate clients’ satisfaction during care based on the NIMART intervention programme.
- Full Text:
- Authors: Mangi, Nozuko Glenrose
- Date: 2017
- Subjects: Nursing assessment -- South Africa -- Eastern Cape Self-efficacy Nursing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4492 , vital:28344
- Description: Self-efficacy in clinical performance is a very important aspect in quality of health care, because it is the ability of the person to produce the desired outcomes. The aim of the study was to evaluate self-efficacy in clinical performance of NIMART programme by professional nurses in Buffalo City Metropolitan in Eastern Cape Province South Africa. A quantitative, descriptive survey design was used to examine self-efficacy in clinical performance during implementation of NIMART programme. A purposive sample of 358 NIMART programme trained professional nurses was included in the study. Analysis of the finding was done using SPSS version 21.0. Descriptive statistics (frequencies, percentage, mean and standard deviations) were used to analyse categorical variables. To reduce data volume, factor analysis was used to identify six variable clusters: Evaluation; planning, assessment, implementation, and patient care mentoring. Factor 1 (evaluation) was highly loaded on patient driven results (0.63); nursing interventions (0.70); breakdown point location (0.80); prognosis based care decisions (0.79); prognosis based outcome monitoring (0.70); and prognosis based settings adjustment (0.70). These items collectively define evaluation of self-efficacy clinical performance of the participants. Factor 2 (planning) was termed planning of patient care in a clinical setting was significantly loaded on these items: data driven nursing diagnosis (0.51); patient driven nursing diagnosis (0.52); settings based nursing diagnosis (0.49); overall care plan formulation (0.52); short-term patients care formulation (0.58); long-term patient care formulation (0.66); goal based measurable outcomes (0.80); goal based daily patient care plan (0.79); settings based daily patient care plan (0.73). Factor 3 (assessment) which was termed assessment in clinical performance was not significantly loaded in some of the items: physical assessment (0.64); patient history (0.65); energy restoration (0.56); time management (0.71); objective patient health data (0.61); subjective patient health data (0.49); data collection documentation (0.44). Factor 4 (implementation) data source correlation; patient health data analysis (0.45); patient strength (0.46); nurse-patient/family communication (0.55); nurse patient collaboration (0.64); Experience driven decision making (0.58). Factor 5 (patient care) patient care plan adherence (0.65); setting based overall patient care (0.74); resource based overall patient care (0.59). Factor 6 (mentoring) patient’s concerns identification (0.48); patient problems prioritisation (0.46); mentor/colleague advice (0.43); mentor/colleague feedback use (0.61); patient discharge strategies (0.71); continuous reporting/documenting (0.63). The mean scores produced by the Kruskal-Wallis test showed the lowest scoring pattern as follows: 20122013201120142010. This order was the same for all the variables, confirming that the 2010 group scored significantly higher than any other group on all the variables. The overall results of the study revealed that professional nurses have high self-efficacy in clinical performance in implementation of NIMART programme, except in evaluation aspect of self-efficacy where they scored lessor. Professional nurses trained by FPD scored higher in the aspects of self-efficacy in clinical performance compared to RTC trained; but scored lower in evaluative ability of self-efficacy in both institutions (FPD and RTC). The findings of this study showed that the overall self-efficacy of the professional nurses trained on NIMART programme performed clinically satisfactorily. It is recommended that in-service education or continuous professional development for professional nurses working in PHC’s should not only concentrate on updating clinical skills, but also create opportunity for reflection and strengthening of professional nurses’ self-efficacy in clinical performance. Also, further study on other processes of goal realisation will aid our understanding of self-efficacy in achieving the desirable goals of the professional nurses for patient quality care. Further research is also needed to evaluate clients’ satisfaction during care based on the NIMART intervention programme.
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Diet of the yellow mongoose (Cynictis penicillata) in the Albany Thicket Biome of South Africa
- Authors: Bizani, Mfundo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11796 , http://hdl.handle.net/10353/d1019840
- Description: The dietary habits of the yellow mongoose Cynictis penicillata were studied in the Albany Thicket Biome of South Africa (Great Fish River Reserve, Eastern Cape). The diet was investigated through the analysis of 1,056 scats that were sampled over a period of 7 years (2005−2009 and 2011−2012) mainly in three similar sites (Kelarny, Grasslands and Junction 10) that were used by at least three families or groups of yellow mongooses. Scats were collected near latrine sites, labelled and stored in a freezer. In the laboratory, scats were oven dried for a period of 24 hours at 50 C. Diet was determined by identifying undigested food remains in the scats. Hair samples were examined under the compound microscope to identify which mammals were ingested. In the field, both arthropod and small mammal abundance were determined in order to evaluate whether yellow mongooses are opportunistic or specialist feeders. Furthermore, inter-annual (2006–2008) and inter-group/inter-site variations in the diet were assessed. Based on faecal analysis, arthropods were the principal prey, while small mammals acted as supplementary food item. Other food categories like vegetation, reptiles and birds were only ingested or preyed upon infrequently. Intermediate dietary diversity, and low standardised diet breadth indices were obtained for all seasons, as well as for the whole sampling period. The diet overlaps calculated for pairs of seasons were very high and did not differ substantially. However, the diet of the yellow mongoose varied seasonally, yearly and between groups (sites), mostly due to variations in arthropod and small mammal consumption. Food availability displayed an increase in biomass of both small mammals and arthropods in summer and autumn. Results obtained in this study could suggest that the yellow mongoose at the GFRR is insectivorous by preferring to feed on insects (and arthropods in general) when both insects and rodents are abundant. However the fact that its diet varies both seasonally, yearly and locally, as well as the presence of remains of other food categories in the scats, indicates that this species is rather an opportunistic, generalist feeder than an insect specialist.
- Full Text:
- Authors: Bizani, Mfundo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11796 , http://hdl.handle.net/10353/d1019840
- Description: The dietary habits of the yellow mongoose Cynictis penicillata were studied in the Albany Thicket Biome of South Africa (Great Fish River Reserve, Eastern Cape). The diet was investigated through the analysis of 1,056 scats that were sampled over a period of 7 years (2005−2009 and 2011−2012) mainly in three similar sites (Kelarny, Grasslands and Junction 10) that were used by at least three families or groups of yellow mongooses. Scats were collected near latrine sites, labelled and stored in a freezer. In the laboratory, scats were oven dried for a period of 24 hours at 50 C. Diet was determined by identifying undigested food remains in the scats. Hair samples were examined under the compound microscope to identify which mammals were ingested. In the field, both arthropod and small mammal abundance were determined in order to evaluate whether yellow mongooses are opportunistic or specialist feeders. Furthermore, inter-annual (2006–2008) and inter-group/inter-site variations in the diet were assessed. Based on faecal analysis, arthropods were the principal prey, while small mammals acted as supplementary food item. Other food categories like vegetation, reptiles and birds were only ingested or preyed upon infrequently. Intermediate dietary diversity, and low standardised diet breadth indices were obtained for all seasons, as well as for the whole sampling period. The diet overlaps calculated for pairs of seasons were very high and did not differ substantially. However, the diet of the yellow mongoose varied seasonally, yearly and between groups (sites), mostly due to variations in arthropod and small mammal consumption. Food availability displayed an increase in biomass of both small mammals and arthropods in summer and autumn. Results obtained in this study could suggest that the yellow mongoose at the GFRR is insectivorous by preferring to feed on insects (and arthropods in general) when both insects and rodents are abundant. However the fact that its diet varies both seasonally, yearly and locally, as well as the presence of remains of other food categories in the scats, indicates that this species is rather an opportunistic, generalist feeder than an insect specialist.
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Synthesis and structural studies of NiS and PdS nanoparticles/nanocomposites from dithiocarbamates single source precursors
- Authors: Nqombolo, Azile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11359 , http://hdl.handle.net/10353/d1021326
- Description: The main aim of this research is to synthesize Ni(II) and Pd(II) dithiocarbamate complexes and use them as single source precursors for the synthesis of NiS and PdS nanoparticles and metal sulphides potato starch nanocomposites. Four dithiocarbamate ligands were synthesized and characterized using elemental analysis and spectroscopic techniques. The ligands were used to prepared homoleptic Ni(II) and Pd(II) complexes of the dithiocarbamate ligands. The metal complexes were characterized with elemental analysis, UV-Vis, FTIR and 1H-NMR spectroscopic techniques. Conductivity measurements indicate that all the complexes are non-electrolytes in solution and results from the electronic spectra studies confirmed the proposed 4-coordinate square planar geometry around the metal ions. The nickel complexes showed d-d transitions around 477 nm while in the palladium complexes, no d-d transitions were observed but the compounds showed strong metal to ligand charge transfer transitions. From the FTIR spectra studies, it can be confirmed that the complexes were successfully synthesised because all peaks of interest were observed at expected regions from the literature. The νC-N was observed around 1469-1495 cm-1, νC=S around 1101-1188 cm-1 and νC-S around 738-1060 cm-1 for both Ni(II) and Pd(II) complexes. νNi-S was observed around 375-543 cm-1 and νPd-S around 529-545 cm-1. The FTIR also confirmed that the dithiocarbamate ligands act as bidentate chelating ligands through the sulfur atoms. The complexes were used as single source precursors and thermolysed in hexadecylamine (HDA) at 220 °C to prepare four HDA-capped nickel sulfide nanoparticles and four palladium sulfide nanoparticles. The as-prepared nanoparticles were studied with optical absorption spectra, photoluminescence, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The optical studies results showed that NiS have large band gaps that are greater than that of the bulk, therefore they are found to be blue shifted relative to the bulk, which shows that they have small particle size and thus confirming their quantum confinement effect. PL spectra reveal that the emission peaks are red shifted compared to the absorption band edges of the nanoparticles. The XRD patterns confirmed the formation of cubic and rhombohedral phase for NiS nanoparticles and cubic phase for PdS nanoparticles. SEM images of both NiS and PdS show uniform surface morphology at low and high magnification with different shapes. EDS analyses confirmed the presence of Ni, S, and Pd in each of the spectrum indicating that the nanoparticles were successfully synthesized. TEM images showed that the synthesised nanoparticles have uniform and narrow size distribution with no agglomeration. The sizes of the NiS nanoparticles were found to be in the range of 12-38 nm for NiS1, 8-11 nm for NiS2, 9-16 nm for NiS3 and 4-9 nm for NiS4. The TEM images for the as-prepared PdS nanoparticles showed that the average crystallite sizes are 6.94-9.62 nm for PdS1, 8-11 nm for PdS2, 9-16 nm for PdS3 and 4-9 nm for PdS4 respectively. The nanoparticles were used to prepare potato starch nanocomposites and SEM images indicate that the surface morphology of starch polymer nanocomposites compose of potato starch and few particles in between the pores of the matrix, this is due to the small ratio of nanoparticles used.
- Full Text:
- Authors: Nqombolo, Azile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11359 , http://hdl.handle.net/10353/d1021326
- Description: The main aim of this research is to synthesize Ni(II) and Pd(II) dithiocarbamate complexes and use them as single source precursors for the synthesis of NiS and PdS nanoparticles and metal sulphides potato starch nanocomposites. Four dithiocarbamate ligands were synthesized and characterized using elemental analysis and spectroscopic techniques. The ligands were used to prepared homoleptic Ni(II) and Pd(II) complexes of the dithiocarbamate ligands. The metal complexes were characterized with elemental analysis, UV-Vis, FTIR and 1H-NMR spectroscopic techniques. Conductivity measurements indicate that all the complexes are non-electrolytes in solution and results from the electronic spectra studies confirmed the proposed 4-coordinate square planar geometry around the metal ions. The nickel complexes showed d-d transitions around 477 nm while in the palladium complexes, no d-d transitions were observed but the compounds showed strong metal to ligand charge transfer transitions. From the FTIR spectra studies, it can be confirmed that the complexes were successfully synthesised because all peaks of interest were observed at expected regions from the literature. The νC-N was observed around 1469-1495 cm-1, νC=S around 1101-1188 cm-1 and νC-S around 738-1060 cm-1 for both Ni(II) and Pd(II) complexes. νNi-S was observed around 375-543 cm-1 and νPd-S around 529-545 cm-1. The FTIR also confirmed that the dithiocarbamate ligands act as bidentate chelating ligands through the sulfur atoms. The complexes were used as single source precursors and thermolysed in hexadecylamine (HDA) at 220 °C to prepare four HDA-capped nickel sulfide nanoparticles and four palladium sulfide nanoparticles. The as-prepared nanoparticles were studied with optical absorption spectra, photoluminescence, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The optical studies results showed that NiS have large band gaps that are greater than that of the bulk, therefore they are found to be blue shifted relative to the bulk, which shows that they have small particle size and thus confirming their quantum confinement effect. PL spectra reveal that the emission peaks are red shifted compared to the absorption band edges of the nanoparticles. The XRD patterns confirmed the formation of cubic and rhombohedral phase for NiS nanoparticles and cubic phase for PdS nanoparticles. SEM images of both NiS and PdS show uniform surface morphology at low and high magnification with different shapes. EDS analyses confirmed the presence of Ni, S, and Pd in each of the spectrum indicating that the nanoparticles were successfully synthesized. TEM images showed that the synthesised nanoparticles have uniform and narrow size distribution with no agglomeration. The sizes of the NiS nanoparticles were found to be in the range of 12-38 nm for NiS1, 8-11 nm for NiS2, 9-16 nm for NiS3 and 4-9 nm for NiS4. The TEM images for the as-prepared PdS nanoparticles showed that the average crystallite sizes are 6.94-9.62 nm for PdS1, 8-11 nm for PdS2, 9-16 nm for PdS3 and 4-9 nm for PdS4 respectively. The nanoparticles were used to prepare potato starch nanocomposites and SEM images indicate that the surface morphology of starch polymer nanocomposites compose of potato starch and few particles in between the pores of the matrix, this is due to the small ratio of nanoparticles used.
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Managing personal archives in specialised repositories: a case study of Phillip Valentine Tobias collection(s) at the University of the Witwatersrand
- Authors: Marima, Elizabeth Nakai
- Date: 2019
- Subjects: Archives management , Institutional repositories
- Language: English
- Type: Thesis , Masters , M LIS
- Identifier: http://hdl.handle.net/10353/11473 , vital:39075
- Description: Personal archives are noncurrent records created by individuals that are selected and kept for their enduring value. They are a record of the past and stand as evidence of what transpired. They make part of repository holdings together with public archives in organisational repositories. Public archives document transactions, statutes, procedures, and regulations. Personal archives contain the documentation of individual lives, emotions, values, experiences and human personality. They seek to reflect the character of the individual who created them. Management of personal archives in repositories refers to their acquisition, collection, arrangement, description, preservation, conservation, creation if access and use. Therefore, the main purpose of this study is to investigate the managing of personal archives in specialized repositories: A case study of Phillip Valentine Tobias Collection(s) at the University of the Witwatersrand, Johannesburg. The study sought to investigate the legal framework that regulates managing of personal archives and the experiences, perceptions and expectations of people managing the personal archives. Furthermore, the study sought to identify strategies of improving the management of personal archives at University of the Witwatersrand, Johannesburg. The study was motivated by the archival theory that conceptualizes grouping of records together for their content and contextual value as evidence with the aim of restating the past. The theory further defines personal archives as records of continued value created by an individual which accumulated naturally, impartially and without prejudice in order to accurately witness the past. The study used a qualitative methodology and was guided by the interpretivist research paradigm. Data was collected using open-ended questions to conduct semi-structured interviews. To complement data, a document analysis, focus group and casual observation were also used. The site of study was University of the Witwatersrand. The total population constituted 41 staff members working in six special repositories with the Phillip Tobias collections at University of the Witwatersrand. The sample size was 25 staff members working in three special repositories. The qualitative data was reported verbartim and the Constant Comparative method was used for data analysis. The findings indicated challenges to the archival theory as the contextual grouping of personal archives was distorted. The study also showed that the archives were xv mismanaged due to framework irregularities, lack of top management support and limited resources. The major resources that were limited were infrastructure, archival ICT systems, human resources and training needs. From the interviews, the research identified strategies of improving the management of personal archives. The study recommended that the university benchmark for archival support strategies and to also engage in existence justification initiatives to harness top management’s attention towards the archive. Out of the identified strategies, the study suggested a tailor made strategy, which combined aspects of each strategy in order to avoid associated challenges.
- Full Text:
- Authors: Marima, Elizabeth Nakai
- Date: 2019
- Subjects: Archives management , Institutional repositories
- Language: English
- Type: Thesis , Masters , M LIS
- Identifier: http://hdl.handle.net/10353/11473 , vital:39075
- Description: Personal archives are noncurrent records created by individuals that are selected and kept for their enduring value. They are a record of the past and stand as evidence of what transpired. They make part of repository holdings together with public archives in organisational repositories. Public archives document transactions, statutes, procedures, and regulations. Personal archives contain the documentation of individual lives, emotions, values, experiences and human personality. They seek to reflect the character of the individual who created them. Management of personal archives in repositories refers to their acquisition, collection, arrangement, description, preservation, conservation, creation if access and use. Therefore, the main purpose of this study is to investigate the managing of personal archives in specialized repositories: A case study of Phillip Valentine Tobias Collection(s) at the University of the Witwatersrand, Johannesburg. The study sought to investigate the legal framework that regulates managing of personal archives and the experiences, perceptions and expectations of people managing the personal archives. Furthermore, the study sought to identify strategies of improving the management of personal archives at University of the Witwatersrand, Johannesburg. The study was motivated by the archival theory that conceptualizes grouping of records together for their content and contextual value as evidence with the aim of restating the past. The theory further defines personal archives as records of continued value created by an individual which accumulated naturally, impartially and without prejudice in order to accurately witness the past. The study used a qualitative methodology and was guided by the interpretivist research paradigm. Data was collected using open-ended questions to conduct semi-structured interviews. To complement data, a document analysis, focus group and casual observation were also used. The site of study was University of the Witwatersrand. The total population constituted 41 staff members working in six special repositories with the Phillip Tobias collections at University of the Witwatersrand. The sample size was 25 staff members working in three special repositories. The qualitative data was reported verbartim and the Constant Comparative method was used for data analysis. The findings indicated challenges to the archival theory as the contextual grouping of personal archives was distorted. The study also showed that the archives were xv mismanaged due to framework irregularities, lack of top management support and limited resources. The major resources that were limited were infrastructure, archival ICT systems, human resources and training needs. From the interviews, the research identified strategies of improving the management of personal archives. The study recommended that the university benchmark for archival support strategies and to also engage in existence justification initiatives to harness top management’s attention towards the archive. Out of the identified strategies, the study suggested a tailor made strategy, which combined aspects of each strategy in order to avoid associated challenges.
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Psychological capital as a moderator in the relationship between occupational stress and quality of work life among healthcare practitioners in Buffalo City Metropolitan Municipality
- Umenze , Catherine Chetachukwu
- Authors: Umenze , Catherine Chetachukwu
- Date: 2020
- Subjects: Job stress Human capital -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12536 , vital:39285
- Description: The study investigated psychological capital as a moderator in the relationship between occupational stress and quality of work life. The study used the explanatory survey research design. The convenience and purposive types of the non-probability sampling method were used to sample 150 male and female healthcare practitioners who participated in the study. Validated questionnaires were used to elicit information from the study’s participants. Four hypotheses were stated and analysed using the inferential statistical approach. The research findings showed that there was a significant positive relationship between occupational stress and quality of work life; there was a significant positive relationship between psychological capital and quality of work life; and there was a significant moderating influence of psychological capital on the relationship between occupational stress and quality of work life. And finally, there was no significant relationship between psychological capital and occupational stress. There is need for managers to focus on the four dimensions of psychological capital to help minimise occupational stress and improve quality of work life of healthcare practitioners. Management was also advised to devise optimal methods to curb stress and strengthen the mental and physical abilities of the employees’ outcomes. Future research should endeavour to apply a longitudinal research design in investigating the extent to which psychological capital can predict occupational stress, and in understanding its influence in the quality of work life of employees. The future study can spread the investigation to other districts as this study was conducted in just one district, which is a foremost limitation of the study.
- Full Text:
- Authors: Umenze , Catherine Chetachukwu
- Date: 2020
- Subjects: Job stress Human capital -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12536 , vital:39285
- Description: The study investigated psychological capital as a moderator in the relationship between occupational stress and quality of work life. The study used the explanatory survey research design. The convenience and purposive types of the non-probability sampling method were used to sample 150 male and female healthcare practitioners who participated in the study. Validated questionnaires were used to elicit information from the study’s participants. Four hypotheses were stated and analysed using the inferential statistical approach. The research findings showed that there was a significant positive relationship between occupational stress and quality of work life; there was a significant positive relationship between psychological capital and quality of work life; and there was a significant moderating influence of psychological capital on the relationship between occupational stress and quality of work life. And finally, there was no significant relationship between psychological capital and occupational stress. There is need for managers to focus on the four dimensions of psychological capital to help minimise occupational stress and improve quality of work life of healthcare practitioners. Management was also advised to devise optimal methods to curb stress and strengthen the mental and physical abilities of the employees’ outcomes. Future research should endeavour to apply a longitudinal research design in investigating the extent to which psychological capital can predict occupational stress, and in understanding its influence in the quality of work life of employees. The future study can spread the investigation to other districts as this study was conducted in just one district, which is a foremost limitation of the study.
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Investigation of the NFC technology for mobile payments and the development of a prototype payment application in the context of marginalized rural areas
- Authors: Gurajena, Caroline
- Date: 2014
- Subjects: Mobile commerce -- South Africa Mobile communication systems -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/14071 , vital:39802
- Description: The Internet of Things (IoT) environment involves the interaction of numerous ‘things’. These ‘things’ are embedded with different kinds of technologies such as RFID technology, NFC technology and sensors. This causes IoT to bring into play many security risks apart from the ones that already exist in the current Internet, for example, embedded RFID tags can be easily triggered and send their content which could be private information. IoT also introduces internal attacks such as on-off attack, bad mouthing and white washing attacks into networks that already exist. These internal attacks cannot be solved by hard security mechanisms such as cryptographic algorithms and firewalls because they guarantee total trust. This eliminates uncertainty which should always be available where trust exist. That is, hard security mechanisms enable IoT ‘things’ to either trust another ‘thing’ completely or not and this makes them unsuitable for the IoT environment. When objects in any network are communicating, there is some element of uncertainty. Also, hard security mechanisms such as public key cryptography cause communication overheard in the already resource-constrained IoT devices and these conventional cryptography methods cannot deal with internal attacks. This brings about the need for a middleware that includes functions that will manage trust, privacy and security issues of all data exchange, communications and network connections. For IoT to be successful, the provision of trust, security and privacy measures are essential. Trust management may enhance the adoption and security measures in IoT. Trust helps in identifying trustworthy ‘things’ in the network and give ‘things’ in the network the ability to reason in all aspects concerning trust in the environment. Trust can be administered through a trust management model. This research notes that most of the trust models that have been proposed fail to address scalability challenges and lack suitable computation methods. It is on that premise that this research focuses on developing a suitable trust model for the IoT environment. The research also introduces new ways of creating relationships in IoT. This enables the creation of new cooperation opportunities in the environment. In overall, this research aimed to design and develop a generic trust and authority delegation model for the heterogonous IoT environment that is scalable and generalized to cater for the heterogeneous IoT environment. This research was conducted in three phases. The first phase reviewed literature in order to identify outstanding issues in IoT trust management and also identify the suitable computational method. This provided a critical analysis of different computational methods highlighting their advantages and limitations. In the second phase of the research, the proposed trust model was designed and tested. In the last phase, the feasibility of the proposed model was evaluated. The proposed model is based on fuzzy logic. Fuzzy logic was selected for trust computation because it is able to imitate the process of the human mind through the use of linguistic variables and it can handle uncertainty. The proposed model was tested in a simulated environment. The simulation results showed that the proposed model can identify selfish and malicious entities effectively. The results also showed that the model was able to deal with different types of behaviours of entities. The testing proved that the proposed trust model can support decision making in IoT based on trust. The results from the evaluation show that this research ameliorates the design and development of trust management solutions for the IoT environment.
- Full Text:
- Authors: Gurajena, Caroline
- Date: 2014
- Subjects: Mobile commerce -- South Africa Mobile communication systems -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/14071 , vital:39802
- Description: The Internet of Things (IoT) environment involves the interaction of numerous ‘things’. These ‘things’ are embedded with different kinds of technologies such as RFID technology, NFC technology and sensors. This causes IoT to bring into play many security risks apart from the ones that already exist in the current Internet, for example, embedded RFID tags can be easily triggered and send their content which could be private information. IoT also introduces internal attacks such as on-off attack, bad mouthing and white washing attacks into networks that already exist. These internal attacks cannot be solved by hard security mechanisms such as cryptographic algorithms and firewalls because they guarantee total trust. This eliminates uncertainty which should always be available where trust exist. That is, hard security mechanisms enable IoT ‘things’ to either trust another ‘thing’ completely or not and this makes them unsuitable for the IoT environment. When objects in any network are communicating, there is some element of uncertainty. Also, hard security mechanisms such as public key cryptography cause communication overheard in the already resource-constrained IoT devices and these conventional cryptography methods cannot deal with internal attacks. This brings about the need for a middleware that includes functions that will manage trust, privacy and security issues of all data exchange, communications and network connections. For IoT to be successful, the provision of trust, security and privacy measures are essential. Trust management may enhance the adoption and security measures in IoT. Trust helps in identifying trustworthy ‘things’ in the network and give ‘things’ in the network the ability to reason in all aspects concerning trust in the environment. Trust can be administered through a trust management model. This research notes that most of the trust models that have been proposed fail to address scalability challenges and lack suitable computation methods. It is on that premise that this research focuses on developing a suitable trust model for the IoT environment. The research also introduces new ways of creating relationships in IoT. This enables the creation of new cooperation opportunities in the environment. In overall, this research aimed to design and develop a generic trust and authority delegation model for the heterogonous IoT environment that is scalable and generalized to cater for the heterogeneous IoT environment. This research was conducted in three phases. The first phase reviewed literature in order to identify outstanding issues in IoT trust management and also identify the suitable computational method. This provided a critical analysis of different computational methods highlighting their advantages and limitations. In the second phase of the research, the proposed trust model was designed and tested. In the last phase, the feasibility of the proposed model was evaluated. The proposed model is based on fuzzy logic. Fuzzy logic was selected for trust computation because it is able to imitate the process of the human mind through the use of linguistic variables and it can handle uncertainty. The proposed model was tested in a simulated environment. The simulation results showed that the proposed model can identify selfish and malicious entities effectively. The results also showed that the model was able to deal with different types of behaviours of entities. The testing proved that the proposed trust model can support decision making in IoT based on trust. The results from the evaluation show that this research ameliorates the design and development of trust management solutions for the IoT environment.
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The role of migrants in the Pan Africanist struggle for liberation from 1962 to 1963 : the case of Cofimvaba
- Authors: Mwanda, Sindiswa Christina
- Date: 2018
- Subjects: South Africa -- History -- 1962-1963 South Africa -- Politics and government -- 1962-1963
- Language: English
- Type: Thesis , Masters , History
- Identifier: http://hdl.handle.net/10353/9883 , vital:35107
- Description: The perspective of South African liberation history needs to be balanced by recalling events that might otherwise be overshadowed by the subsequent electoral dominance of the African National Congress since 1994. This study is concerned with one such: the Cofimvaba struggles of 1962-3 which was organised by Cofimvaba migrants under the ideology of the Pan Africanist Congress. Whereas previous historians have based their accounts mainly on trial records, this thesis strives to recover the migrants’ own perspective through intensive and detailed interviews with the surviving veterans. It aims to provide an accurate historical account of the role played by migrant labourers, thereby correcting the historical distortions arising from overreliance on official sources to record the memories and perceptions of the struggle veterans, as exemplified by transcripts of interviews with and thereby provide some balance to the overall perspective of South African liberation history. The thesis opens with a description of the situation on the ground in Cofimvaba and Western Thembuland which gave rise to resistance. It continues with a discussion of the Pan-African Congress, especially in the Western Cape, the labour centre where most Cofimvaba migrants were concentrated. It proceeds to a detailed narrative of the events in Cofimvaba, more especially the battle of Ntlonze. The final chapter concludes with a critical reassessment of previous historical work, showing that the role of the migrants and the non-elite require greater appreciation and respect.
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- Authors: Mwanda, Sindiswa Christina
- Date: 2018
- Subjects: South Africa -- History -- 1962-1963 South Africa -- Politics and government -- 1962-1963
- Language: English
- Type: Thesis , Masters , History
- Identifier: http://hdl.handle.net/10353/9883 , vital:35107
- Description: The perspective of South African liberation history needs to be balanced by recalling events that might otherwise be overshadowed by the subsequent electoral dominance of the African National Congress since 1994. This study is concerned with one such: the Cofimvaba struggles of 1962-3 which was organised by Cofimvaba migrants under the ideology of the Pan Africanist Congress. Whereas previous historians have based their accounts mainly on trial records, this thesis strives to recover the migrants’ own perspective through intensive and detailed interviews with the surviving veterans. It aims to provide an accurate historical account of the role played by migrant labourers, thereby correcting the historical distortions arising from overreliance on official sources to record the memories and perceptions of the struggle veterans, as exemplified by transcripts of interviews with and thereby provide some balance to the overall perspective of South African liberation history. The thesis opens with a description of the situation on the ground in Cofimvaba and Western Thembuland which gave rise to resistance. It continues with a discussion of the Pan-African Congress, especially in the Western Cape, the labour centre where most Cofimvaba migrants were concentrated. It proceeds to a detailed narrative of the events in Cofimvaba, more especially the battle of Ntlonze. The final chapter concludes with a critical reassessment of previous historical work, showing that the role of the migrants and the non-elite require greater appreciation and respect.
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Influence of mite predation on the efficacy of the gall midge Dasineura sp. as a biocontrol agent of Australian myrtle Leptospermum laevigatum (Myrtaceae) in South Africa
- Mdlangu, Thabisa Lynette Honey
- Authors: Mdlangu, Thabisa Lynette Honey
- Date: 2010
- Subjects: Dasyneura leguminicola , Myrtaceae -- South Africa , Mites as biological pest control agents , Pests -- Biological control , Biological pest control agents , Predation (Biology)
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11789 , http://hdl.handle.net/10353/272 , Dasyneura leguminicola , Myrtaceae -- South Africa , Mites as biological pest control agents , Pests -- Biological control , Biological pest control agents , Predation (Biology)
- Description: Dasineura sp. is a gall forming midge that was introduced into South Africa for the biocontrol of the Australian myrtle, Leptospermum laevigatum. It causes galls on both the vegetative and reproductive buds of the plant. Although Dasineura sp. was initially regarded as a potentially successful agent, galling up to 99 percent of the buds of the host plant, it has been preyed on by native opportunistic mites, which caused a decline in the performance of the midge as a biocontrol agent of L. laevigatum. This raised a concern about whether this fly will be able to perform effectively in the presence of its new natural enemies. Therefore, the objectives of this study were to: 1) ascertain whether mite abundance has seasonal variations; 2) determine if plant density and plant size have an effect on midge predation by the mites; and 3) determine if midge predation varies in different locations. The study was conducted at three sites in the Hermanus area, Western Cape Province. Every three weeks for thirteen months, galls were collected and dissected so as to count and record the numbers of midge larvae, pupae, adults and mites that were found. Data collected showed that predation varied with season, and the mites were scarce during the flowering season. Predation also varied among the study sites and plant density had an effect on midge predation. Midges in smaller plants (saplings) were more vulnerable to predation than those in the bigger plants (plants from isolates and thickets). It was concluded that although mites have an effect on midge populations, they do not prevent their establishment on the plant. Therefore, a survey should be done in two to three years time to check if the midges are still persisting on the plant, vi and recommendations are that a new agent should be released to supplement the midges.
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- Authors: Mdlangu, Thabisa Lynette Honey
- Date: 2010
- Subjects: Dasyneura leguminicola , Myrtaceae -- South Africa , Mites as biological pest control agents , Pests -- Biological control , Biological pest control agents , Predation (Biology)
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11789 , http://hdl.handle.net/10353/272 , Dasyneura leguminicola , Myrtaceae -- South Africa , Mites as biological pest control agents , Pests -- Biological control , Biological pest control agents , Predation (Biology)
- Description: Dasineura sp. is a gall forming midge that was introduced into South Africa for the biocontrol of the Australian myrtle, Leptospermum laevigatum. It causes galls on both the vegetative and reproductive buds of the plant. Although Dasineura sp. was initially regarded as a potentially successful agent, galling up to 99 percent of the buds of the host plant, it has been preyed on by native opportunistic mites, which caused a decline in the performance of the midge as a biocontrol agent of L. laevigatum. This raised a concern about whether this fly will be able to perform effectively in the presence of its new natural enemies. Therefore, the objectives of this study were to: 1) ascertain whether mite abundance has seasonal variations; 2) determine if plant density and plant size have an effect on midge predation by the mites; and 3) determine if midge predation varies in different locations. The study was conducted at three sites in the Hermanus area, Western Cape Province. Every three weeks for thirteen months, galls were collected and dissected so as to count and record the numbers of midge larvae, pupae, adults and mites that were found. Data collected showed that predation varied with season, and the mites were scarce during the flowering season. Predation also varied among the study sites and plant density had an effect on midge predation. Midges in smaller plants (saplings) were more vulnerable to predation than those in the bigger plants (plants from isolates and thickets). It was concluded that although mites have an effect on midge populations, they do not prevent their establishment on the plant. Therefore, a survey should be done in two to three years time to check if the midges are still persisting on the plant, vi and recommendations are that a new agent should be released to supplement the midges.
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Computational studies, synthesis and characterization of ruthenium (ii) anticancer complexes
- Authors: Adeniyi, Adebayo Azeez
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11338 , http://hdl.handle.net/10353/d1015577
- Description: This thesis is centred on the application of Ru-based complexes as a promising alternative to cis-platin in cancer chemotherapy. Cis-platin is known to be the most prescribed chemotherapy which has more than 70% application in cancer cases especially the testicular cancer. An insight is provided in Chapter One and Two into the literatures reports on the application of Ru(II)-based complexes in cancer chemotherapy. In order to address some of the pressing challenges in rational design of Ru-based anticancer complexes, section 3.3 and 3.4 deal with efforts to elucidate the complication of their chemistry and instability while in section 3.5 efforts are made to find solution to the lack of proper knowledge of their targets using different theoretical approaches as presented in Chapter Three. In addition to the theoretical study, this thesis also comprises of the synthesis of the bis-pyrazole derivatives type of ligands and the derivatives of their Ru(II)-based complexes as provided in Chapter Four and Five respectively. Also the computational methods were used to elucidate the structural and spectroscopic properties of the synthesised ligands and their Ru(II)-based complexes. The geometrical and electronic properties are studied in relation to the stability and the reported anticancer activities of Ru(II)-based complexes in section 3.3. In subsection 3.3.1, several quantum properties including the natural energy decomposition analysis (NEDA) and quantum theory of atoms in a molecule (QTAIM) are computed on three models of RAPTA-C complexes using DFT with hybrid functional and basis set with ECP and without ECP. The higher stability of Carbo-RAPTA-C and Oxalo-RAPTA-C over RAPTA-C comes from the lower exchange repulsion and higher polarization contributions to their stability which gives insight into experimental observation. A similar study was carried out in subsection 3.3.2 on half-sandwich Ru(II)-based anticancer complexes with 6-toluene and 6-trifluorotoluene.
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- Authors: Adeniyi, Adebayo Azeez
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11338 , http://hdl.handle.net/10353/d1015577
- Description: This thesis is centred on the application of Ru-based complexes as a promising alternative to cis-platin in cancer chemotherapy. Cis-platin is known to be the most prescribed chemotherapy which has more than 70% application in cancer cases especially the testicular cancer. An insight is provided in Chapter One and Two into the literatures reports on the application of Ru(II)-based complexes in cancer chemotherapy. In order to address some of the pressing challenges in rational design of Ru-based anticancer complexes, section 3.3 and 3.4 deal with efforts to elucidate the complication of their chemistry and instability while in section 3.5 efforts are made to find solution to the lack of proper knowledge of their targets using different theoretical approaches as presented in Chapter Three. In addition to the theoretical study, this thesis also comprises of the synthesis of the bis-pyrazole derivatives type of ligands and the derivatives of their Ru(II)-based complexes as provided in Chapter Four and Five respectively. Also the computational methods were used to elucidate the structural and spectroscopic properties of the synthesised ligands and their Ru(II)-based complexes. The geometrical and electronic properties are studied in relation to the stability and the reported anticancer activities of Ru(II)-based complexes in section 3.3. In subsection 3.3.1, several quantum properties including the natural energy decomposition analysis (NEDA) and quantum theory of atoms in a molecule (QTAIM) are computed on three models of RAPTA-C complexes using DFT with hybrid functional and basis set with ECP and without ECP. The higher stability of Carbo-RAPTA-C and Oxalo-RAPTA-C over RAPTA-C comes from the lower exchange repulsion and higher polarization contributions to their stability which gives insight into experimental observation. A similar study was carried out in subsection 3.3.2 on half-sandwich Ru(II)-based anticancer complexes with 6-toluene and 6-trifluorotoluene.
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Multi-temporal assessment of chlorophyll-a concentration in estuarine waters: a case study of sundays and swartkops estuaries, Eastern Cape Province
- Authors: Gwazani, Nothando
- Date: 2019
- Subjects: Chlorophyll -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Applied Remote Sensing & GIS)
- Identifier: http://hdl.handle.net/10353/11972 , vital:39123
- Description: Estuaries are productive and delicate marine systems, which are of commercial, recreational and aesthetic value as they reflect the land use of a catchment by creating “nutrient traps”, these nutrients are absorbed by water and later released into the coastal oceans. Disturbances in an estuary influence a wide variety of habitats and organisms in a marine ecosystem, for example, high chlorophyll-a affects marine species that utilize calm waters, food and turbid water found in estuaries. The degradation of South African estuaries is an on-going accelerating process; therefore, there is a need for preservation measures for estuarine ecosystems by means of monitoring nutrient flow. This research was aimed at assessing the use of OLCI ocean color products in monitoring chl-a concentration and impacts of the estuaries in Algoa Bay. OLCI on the Sentinel platforms, coupled with OCNN and OC4ME algorithms were employed to assess the distribution of chlorophyll-a in Swartkops and Sunday’s estuaries. OC4Me and OCNN are the default models designed for OLCI data. However, the OLCI resolution was not able to measure the chl-a concentration within these estuaries. Therefore, satellite product assessment was primarily focused on the Algoa bay scale due to the resolution of the available data. SNAP and Matlab were applied for the production of the final products. Accuracy assessment was used to check the agreement between the in situ datasets of chl-a and the final processed satellite products. Results of this investigation point that OCNN did not perform well in the study as compared to OC4Me and it did not produce accurate results in areas with very high biomass concentration. The research concludes by recommending the use of higher resolution data such as Sentinel 2 MSI (10m, 20m, and 60m resolution) for resolving chlorophyll-a within these estuaries.
- Full Text:
- Authors: Gwazani, Nothando
- Date: 2019
- Subjects: Chlorophyll -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Applied Remote Sensing & GIS)
- Identifier: http://hdl.handle.net/10353/11972 , vital:39123
- Description: Estuaries are productive and delicate marine systems, which are of commercial, recreational and aesthetic value as they reflect the land use of a catchment by creating “nutrient traps”, these nutrients are absorbed by water and later released into the coastal oceans. Disturbances in an estuary influence a wide variety of habitats and organisms in a marine ecosystem, for example, high chlorophyll-a affects marine species that utilize calm waters, food and turbid water found in estuaries. The degradation of South African estuaries is an on-going accelerating process; therefore, there is a need for preservation measures for estuarine ecosystems by means of monitoring nutrient flow. This research was aimed at assessing the use of OLCI ocean color products in monitoring chl-a concentration and impacts of the estuaries in Algoa Bay. OLCI on the Sentinel platforms, coupled with OCNN and OC4ME algorithms were employed to assess the distribution of chlorophyll-a in Swartkops and Sunday’s estuaries. OC4Me and OCNN are the default models designed for OLCI data. However, the OLCI resolution was not able to measure the chl-a concentration within these estuaries. Therefore, satellite product assessment was primarily focused on the Algoa bay scale due to the resolution of the available data. SNAP and Matlab were applied for the production of the final products. Accuracy assessment was used to check the agreement between the in situ datasets of chl-a and the final processed satellite products. Results of this investigation point that OCNN did not perform well in the study as compared to OC4Me and it did not produce accurate results in areas with very high biomass concentration. The research concludes by recommending the use of higher resolution data such as Sentinel 2 MSI (10m, 20m, and 60m resolution) for resolving chlorophyll-a within these estuaries.
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Incidence and antibiogram fingerprints of members of the Enterobacteriaceae family recovered from river water, hospital effluents and vegetables in Chris Hani and Amathole District Municipalities in the Eastern Cape Province
- Authors: Mpaka, Lindelwa
- Date: 2018
- Subjects: Enterobacteriaceae
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14549 , vital:40003
- Description: The worldwide problem of antimicrobial resistance has limited the spectrum of the current affordable and effective antimicrobials. Infections associated with resistant microorganisms impose a major threat to public health and economic stability. Globally, about 700 000 deaths every year can be accredited to antimicrobial resistance. The leading mechanism of resistance amid bacterial pathogens is the extended spectrum beta-lactamases production, which inhibits spectrum activity of several antimicrobial agents. The rise in antimicrobial resistance has compelled an urgent need of developing means of combatting resistance issue amid diseasecausing microbes. The main aim of this study is to evaluate the incidence and antibiogram fingerprints of Enterobacteriaceae recovered from hospital effluents, river water and vegetables in the Eastern Cape Province. A total of eighteen antibiotics from ten different antimicrobial classes were used to determine antibiogram profiles of the MALDI-TOF confirmed isolates. From the MALDI-TOF confirmed isolates, 60% of Enterobacter spp. and E. coli isolates displayed resistance against colistin, while Citrobacter spp. and Klebsiella spp. displayed 90% and 60% resistance against this antimicrobial respectively. These findings outline the need for the development of new antimicrobials. About 75.5% (25/33) of the presumptive Enterobacter spp. were confirmed by MALDI-TOF with 79.2% (19/24), 66.7% (2/3), 66.7% (4/6) been confirmed vegetables, hospital effluents and river water samples respectively. Likewise, about 77.8% (21/27) were confirmed as Citrobacter spp. of which 92.3% (12/13), 66.7% (2/3) and 63.6% (7/11) were from vegetables, hospital effluents and river water samples respectively. These results show that the selected vegetables were highly contaminated with resistant bacteria and thus unsafe to consume uncooked vegetable. Also river water was higly contaminated with resistant microbes, which also shows that these rivers are not fit to be used 17 as drinking water sources and recreational activities. Colistin is an antimicrobial used as a last resort of antibiotics because it exhibits broad-spectrum activity. However from the findings of the work at present, this is no longer the case. The spectrum of this antimicrobial is now reduced by Enterobacteriaceae members. To the best of my knowledge; relatively few resources have been provided to understanding, preventing, and controlling increasing antimicrobial resistance on global, national and local levels.
- Full Text:
- Authors: Mpaka, Lindelwa
- Date: 2018
- Subjects: Enterobacteriaceae
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14549 , vital:40003
- Description: The worldwide problem of antimicrobial resistance has limited the spectrum of the current affordable and effective antimicrobials. Infections associated with resistant microorganisms impose a major threat to public health and economic stability. Globally, about 700 000 deaths every year can be accredited to antimicrobial resistance. The leading mechanism of resistance amid bacterial pathogens is the extended spectrum beta-lactamases production, which inhibits spectrum activity of several antimicrobial agents. The rise in antimicrobial resistance has compelled an urgent need of developing means of combatting resistance issue amid diseasecausing microbes. The main aim of this study is to evaluate the incidence and antibiogram fingerprints of Enterobacteriaceae recovered from hospital effluents, river water and vegetables in the Eastern Cape Province. A total of eighteen antibiotics from ten different antimicrobial classes were used to determine antibiogram profiles of the MALDI-TOF confirmed isolates. From the MALDI-TOF confirmed isolates, 60% of Enterobacter spp. and E. coli isolates displayed resistance against colistin, while Citrobacter spp. and Klebsiella spp. displayed 90% and 60% resistance against this antimicrobial respectively. These findings outline the need for the development of new antimicrobials. About 75.5% (25/33) of the presumptive Enterobacter spp. were confirmed by MALDI-TOF with 79.2% (19/24), 66.7% (2/3), 66.7% (4/6) been confirmed vegetables, hospital effluents and river water samples respectively. Likewise, about 77.8% (21/27) were confirmed as Citrobacter spp. of which 92.3% (12/13), 66.7% (2/3) and 63.6% (7/11) were from vegetables, hospital effluents and river water samples respectively. These results show that the selected vegetables were highly contaminated with resistant bacteria and thus unsafe to consume uncooked vegetable. Also river water was higly contaminated with resistant microbes, which also shows that these rivers are not fit to be used 17 as drinking water sources and recreational activities. Colistin is an antimicrobial used as a last resort of antibiotics because it exhibits broad-spectrum activity. However from the findings of the work at present, this is no longer the case. The spectrum of this antimicrobial is now reduced by Enterobacteriaceae members. To the best of my knowledge; relatively few resources have been provided to understanding, preventing, and controlling increasing antimicrobial resistance on global, national and local levels.
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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.
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- 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.
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The effect of muscle type and freezing on the evolution of physico-chemical properties during processing of South African biltong and its final textural properties
- Authors: Ngwendu, Nwabisa
- Date: 2020
- Subjects: Biltong Meat -- Quality -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12128 , vital:39154
- Description: The study investigated the effect of muscle type and freezing on evaluation of mass transfer during processing physico-chemical of South African biltong and its textural properties. In the first experimental phase of this study, mass transfers, physico-chemical and textural properties (hardness, cohesiveness, springiness, and chewiness) of commercially produced biltong from biceps femoris (BF) and semitendinosus (ST) (n=9) were measured. Biltong was dried at 30oC and 40% relative humidity until it had lost 50% of its initial weight. The initial moisture content, water activity (Aw) of BF muscles (74.3% and 0.992) were significantly lower compared those of ST muscles (75.4% and 0.994%). The fat content of BF (2.3%) muscles was higher (P<0.05) than in ST muscles (1.7%). The salt, weight and water gain for the BF muscle were 2.3%, -2.6% and -7.0% respectively and were significantly higher than those of ST muscles which were 2.1, -0.4 and -4.0, respectively. After drying, the moisture content, Aw, and pH were lower in BF (42.2, 0.886 and 5.29) than those of ST muscles (45.1, 0.911 and 5.42). The salt content was higher (P<0.05) in BF muscle than in ST. Among textural properties, hardness was significantly higher in biltong from the BF (233.0N), while the springiness was significantly lower compared to the ST muscle (178.2N). Therefore, it was concluded that the use of different muscles results in variation of biltong physicochemical characteristics. The second experiment investigated the effect of freezing and muscle type on mass transfers, lipid oxidation, physico-chemical and textural properties of biltong. In this experiment, the iii ST muscles were replaced with semimembranosus (SM) muscles. A total of 12 beef muscles were used, with six BF and six SM muscles frozen in a blast freezer at -40 oC till they reached -20oC; then they were transferred to -20oC for 14 days. The thawing loss for the BF and ST muscles was 1.3 and 2.4% respectively, but there were no significant (P>0.05) differences. The protein and salt content were significantly higher in frozen-thawed (24.3 and 0.13%) muscles than in fresh muscle (20.2 and 0.08%); whereas the fat content and pH were lower (P<0.05) in frozen-thawed (5.36) compared to fresh muscles (5.51). Between muscles, the moisture, salt content, and pH were higher in BF muscles than in SM muscles (73.2, 0.12% and 5.49). Aw was affected by the interaction between freezing and muscle type, with frozenthawed SM having lower Aw (0.990). During salting, salt, weight and water gain did not show any differences (P<0.05). There were no major significant differences after salting. There were lower TBARS and pH in frozen-thawed (1.5mgMDA/kg and 5.15) muscles than in fresh muscles (3.3mgMDA/kg and 5.19) as well as in SM muscles (1.8mgMDA/kg and 5.16) than in BF muscles (3.0mgMDA/kg and 5.19). The moisture was significantly lower in frozen-thawed SM (68.1%) than in fresh SM, BF and frozen-thawed BF (69.3,70.5 and 71.7%) after salting. On the final product, the interaction between muscle type and freezing affected the moisture content, TBARS, chewiness and the springiness of biltong, with the biltong from fresh SM (39.8%) having significantly lower moisture content compared frozenthawed BF and ST muscles as well fresh BF muscles (42.8% in average). The TBARS were higher in biltong from fresh BF muscles (5.1mgMDA/kg) compared to other muscles. Furthermore, the chewiness and springiness were higher (P<0.05) in biltong produced from SM frozen-thawed muscles (327.7N and 1.5). The WBSF was higher in biltong from the BF muscles (108.8N) than in the biltong from SM (80.1) but it was not affected by the freezing effect (P>0.05). Freezing did not show any major differences in biltong. iv The third experiment was conducted to determine the effect of freezing African buffalo carcasses on weight loss during salting, physico-chemical and textural properties of biltong. Five muscles (ST, SM, BF, LTL, and RF) were randomly selected from 30 carcasses (15 frozen-thawed and 15 fresh), cut along the grain, traditionally salted and dried at 26oC till they lost 45-50% of their initial weight. The salting weight loss was higher in frozen-thawed muscles (-1.45%) than in fresh muscles (-0.89%). The freezing treatment affected the physico-chemical properties of the biltong. The biltong produced from frozen-thawed muscles showed significantly higher protein and ash (47.6 and 7.6%) compared to fresh (43.9 and 7.1); whereas the moisture, fat, pH and Aw were lower (43.7, 2.1, 0.870 and 5.30, respectively) compared to those of biltong from fresh muscles (45.5%, 2.9%, 0.890 and 5.38). The moisture, pH and fat content were further affected by muscle type. The interactive effect was observed in salt content, with RF frozen-thawed showing higher salt content (8.2%) compared to all other muscles. The hardness and WBSF were significantly higher (P<0.05) in biltong frozen-thawed (204.1N and 135.0N) than in fresh muscles (146.2N and 113.1N). Moreover, the chewiness and springiness were affected (P<0.05) by muscle type, with RF muscle having higher springiness 0.89 and chewiness 171.1N than all the other muscles. Therefore, it can be concluded that freezing buffalo carcasses significantly influenced the quality characteristics of biltong. The fourth experiment studied the effect of drying methods on physico-chemical properties of traditional biltong produced from African buffalo muscles. The BF and SM muscles were randomly selected from 15 fresh carcasses, cut into strips, salted and divided into two batches per muscle. The first batch of each muscle type was dried in the ambient-air drier at 22oC average and the second batch in the cabinet drier at 26 oC till 45-50% weight loss. No differences (P>0.05) were observed in salting weight loss between the drying method and muscle type. The protein content was significantly higher in SM (46%) muscles compared to v BF (43%) but there was no effect (P>0.05) caused by the drying method. The interactions between the muscle type and drying method affected the fat content, with biltong from airdried BF muscles having significant lower (2.1%) fat content. There were no significant differences in other physico-chemical properties of biltong, with moisture content, salt, ash content, Aw and pH being 45.0%, 5.13%, 44.8%, 7.3%, 2.7%, 0.885 and 5.61 on average, respectively. Overall, the findings of the study show that freezing does have a significant effect on the final quality of biltong. However, it can be concluded that a significant effect on the physico-chemical properties of biltong depends on the changes of mass transfers during salting and drying.
- Full Text:
- Authors: Ngwendu, Nwabisa
- Date: 2020
- Subjects: Biltong Meat -- Quality -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12128 , vital:39154
- Description: The study investigated the effect of muscle type and freezing on evaluation of mass transfer during processing physico-chemical of South African biltong and its textural properties. In the first experimental phase of this study, mass transfers, physico-chemical and textural properties (hardness, cohesiveness, springiness, and chewiness) of commercially produced biltong from biceps femoris (BF) and semitendinosus (ST) (n=9) were measured. Biltong was dried at 30oC and 40% relative humidity until it had lost 50% of its initial weight. The initial moisture content, water activity (Aw) of BF muscles (74.3% and 0.992) were significantly lower compared those of ST muscles (75.4% and 0.994%). The fat content of BF (2.3%) muscles was higher (P<0.05) than in ST muscles (1.7%). The salt, weight and water gain for the BF muscle were 2.3%, -2.6% and -7.0% respectively and were significantly higher than those of ST muscles which were 2.1, -0.4 and -4.0, respectively. After drying, the moisture content, Aw, and pH were lower in BF (42.2, 0.886 and 5.29) than those of ST muscles (45.1, 0.911 and 5.42). The salt content was higher (P<0.05) in BF muscle than in ST. Among textural properties, hardness was significantly higher in biltong from the BF (233.0N), while the springiness was significantly lower compared to the ST muscle (178.2N). Therefore, it was concluded that the use of different muscles results in variation of biltong physicochemical characteristics. The second experiment investigated the effect of freezing and muscle type on mass transfers, lipid oxidation, physico-chemical and textural properties of biltong. In this experiment, the iii ST muscles were replaced with semimembranosus (SM) muscles. A total of 12 beef muscles were used, with six BF and six SM muscles frozen in a blast freezer at -40 oC till they reached -20oC; then they were transferred to -20oC for 14 days. The thawing loss for the BF and ST muscles was 1.3 and 2.4% respectively, but there were no significant (P>0.05) differences. The protein and salt content were significantly higher in frozen-thawed (24.3 and 0.13%) muscles than in fresh muscle (20.2 and 0.08%); whereas the fat content and pH were lower (P<0.05) in frozen-thawed (5.36) compared to fresh muscles (5.51). Between muscles, the moisture, salt content, and pH were higher in BF muscles than in SM muscles (73.2, 0.12% and 5.49). Aw was affected by the interaction between freezing and muscle type, with frozenthawed SM having lower Aw (0.990). During salting, salt, weight and water gain did not show any differences (P<0.05). There were no major significant differences after salting. There were lower TBARS and pH in frozen-thawed (1.5mgMDA/kg and 5.15) muscles than in fresh muscles (3.3mgMDA/kg and 5.19) as well as in SM muscles (1.8mgMDA/kg and 5.16) than in BF muscles (3.0mgMDA/kg and 5.19). The moisture was significantly lower in frozen-thawed SM (68.1%) than in fresh SM, BF and frozen-thawed BF (69.3,70.5 and 71.7%) after salting. On the final product, the interaction between muscle type and freezing affected the moisture content, TBARS, chewiness and the springiness of biltong, with the biltong from fresh SM (39.8%) having significantly lower moisture content compared frozenthawed BF and ST muscles as well fresh BF muscles (42.8% in average). The TBARS were higher in biltong from fresh BF muscles (5.1mgMDA/kg) compared to other muscles. Furthermore, the chewiness and springiness were higher (P<0.05) in biltong produced from SM frozen-thawed muscles (327.7N and 1.5). The WBSF was higher in biltong from the BF muscles (108.8N) than in the biltong from SM (80.1) but it was not affected by the freezing effect (P>0.05). Freezing did not show any major differences in biltong. iv The third experiment was conducted to determine the effect of freezing African buffalo carcasses on weight loss during salting, physico-chemical and textural properties of biltong. Five muscles (ST, SM, BF, LTL, and RF) were randomly selected from 30 carcasses (15 frozen-thawed and 15 fresh), cut along the grain, traditionally salted and dried at 26oC till they lost 45-50% of their initial weight. The salting weight loss was higher in frozen-thawed muscles (-1.45%) than in fresh muscles (-0.89%). The freezing treatment affected the physico-chemical properties of the biltong. The biltong produced from frozen-thawed muscles showed significantly higher protein and ash (47.6 and 7.6%) compared to fresh (43.9 and 7.1); whereas the moisture, fat, pH and Aw were lower (43.7, 2.1, 0.870 and 5.30, respectively) compared to those of biltong from fresh muscles (45.5%, 2.9%, 0.890 and 5.38). The moisture, pH and fat content were further affected by muscle type. The interactive effect was observed in salt content, with RF frozen-thawed showing higher salt content (8.2%) compared to all other muscles. The hardness and WBSF were significantly higher (P<0.05) in biltong frozen-thawed (204.1N and 135.0N) than in fresh muscles (146.2N and 113.1N). Moreover, the chewiness and springiness were affected (P<0.05) by muscle type, with RF muscle having higher springiness 0.89 and chewiness 171.1N than all the other muscles. Therefore, it can be concluded that freezing buffalo carcasses significantly influenced the quality characteristics of biltong. The fourth experiment studied the effect of drying methods on physico-chemical properties of traditional biltong produced from African buffalo muscles. The BF and SM muscles were randomly selected from 15 fresh carcasses, cut into strips, salted and divided into two batches per muscle. The first batch of each muscle type was dried in the ambient-air drier at 22oC average and the second batch in the cabinet drier at 26 oC till 45-50% weight loss. No differences (P>0.05) were observed in salting weight loss between the drying method and muscle type. The protein content was significantly higher in SM (46%) muscles compared to v BF (43%) but there was no effect (P>0.05) caused by the drying method. The interactions between the muscle type and drying method affected the fat content, with biltong from airdried BF muscles having significant lower (2.1%) fat content. There were no significant differences in other physico-chemical properties of biltong, with moisture content, salt, ash content, Aw and pH being 45.0%, 5.13%, 44.8%, 7.3%, 2.7%, 0.885 and 5.61 on average, respectively. Overall, the findings of the study show that freezing does have a significant effect on the final quality of biltong. However, it can be concluded that a significant effect on the physico-chemical properties of biltong depends on the changes of mass transfers during salting and drying.
- Full Text:
Development of a strategy to promote prenatal physical activity participation among women in Buffalo City Municipality, South Africa
- Okafor, Uchenna Benedine https://orcid.org/0000-0002-0435-2041
- Authors: Okafor, Uchenna Benedine https://orcid.org/0000-0002-0435-2041
- Date: 2022-03
- Subjects: Prenatal care , Exercise for pregnant women
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22919 , vital:53218
- Description: Research has proven that prenatal physical activity practice is associated with multiple health benefits; however, most women in South Africa rarely participate in prenatal physical activity. In contrast to more developed countries, there is dearth of research focusing specifically on prenatal physical activity and exercise among South African women. Nevertheless, in order to effectively, and strategically promote such prenatal activity, such information is important to plan for an intervention strategy. The main aim of this study was to assess the level, patterns, and associated factors of prenatal physical activity; beliefs, knowledge, attitudes, perceived benefits, and sources of information women received during pregnancy; and, furthermore, to develop an effective and relevant intervention strategy to facilitate the participation in this particular activity in Buffalo City Municipality, Eastern Cape, South Africa. Methods The study was a mixed-method, cross-sectional study design with both quantitative and qualitative data collection and analyses. The sequential explanatory design was adopted to merge and mix different datasets to be collected and analysed. The quantitative data involved a convenient sample of 1082 pregnant women in 12 randomly selected primary healthcare clinics offering antenatal health services in Buffalo City, Eastern Cape. The Pregnancy Physical Activity Questionnaire was interviewer-administered to women at each antenatal health clinic on pre-specified days, in a designated room allocated to the primary researcher by the health facility manager. The descriptive statistics were frequency distribution, percentages, mean and standard deviation. Furthermore, the bivariate and multivariate analyses were performed on two categories of participants, namely inactive or active, to determine the factors affecting prenatal physical activity behaviour. Furthermore, multiple logistic regression analyses were used to assess associations between physical activity and the predictor variables during pregnancy. Adjusted odds ratios with 95% confidence interval were applied to estimate factors associated with physical activity levels, and the associations between prenatal physical activity levels and socio-demographic, lifestyle, and obstetrics characteristics were determined using a chi-squared analyses. The significance level was set at p = 0.05. In addition, a qualitative descriptive approach was applied, using semi-structured face-to-face interviews with 15 purposively selected pregnant women, as well as 17 midwives offering antenatal health-care services to pregnant women in the 12 selected healthcare clinics. Qualitative data were analysed using a thematic content analysis. To develop the physical activity strategy for the promotion of prenatal physical activity practice, three frameworks were applied, namely the Strength, Weakness, Opportunity and Threat (SWOT), the Political, Economic Growth, Socio-Cultural, Technological, Laws and Environmental (PESTLE), and, lastly, the Build, Overcome, Explore and Minimise (BOEM) analytical frameworks. To facilitate the validation of the strategy, the findings were additionally analysed, after which, appropriate intervention strategies promoting prenatal physical activity were developed by again using the SWOT and PESTLE analytical strategic frameworks. This process involved a purposive sampling of seven experts with knowledge of and a proven academic and scholarly background in prenatal physical activity and maternal health. Next, the developed physical activity strategy was presented to various stakeholders, which included six primary healthcare managers, two midwives, and pregnant women purposively selected in each of the 12 chosen antenatal health clinics for the validation process. The stakeholders discussed, deliberated on, and provided comments and opinions of the feasibility and implementation of the developed prenatal physical activity for promotion of physical activity practices in the Eastern Cape Province. Results The findings of this particular study demonstrated low levels of prenatal physical activity among pregnant women, and, further indicated that the most preferred form of activity was light-intensity and household activities. Only 278 of the women (25.7%) met recommendations for prenatal activity (≥150 min moderate intensity exercise per week). The average time spent in moderate–vigorous physical activity was 151.6 min (95% CI: 147.2– 156.0). Most of the women participated in light exercises with a mean of 65.9% (95% CI: 64.8–67.0), and 47.6% (95% CI: 46.3–48.9) participated in household activities. The majority of the women did not receive physical activity advice during prenatal care sessions (64.7%). Lower age (<19 years) (adjusted odd ratio (AOR) = 0.3; CI: 0.16–0.76), semi-urban residence (AOR = 0.8; CI: 0.55–1.03), lower educational level (AOR = 0.5; CI: 0.20–0.71), unemployment (AOR = 0.5; CI: 0.29–0.77) and nulliparity (AOR = 0.6; CI: 0.28–1.31) were negatively associated with prenatal physical activity, while prenatal physical activity was positively associated with starting physical activity in the first trimester (AOR = 1.9; CI: 1.06–3.31) compared to other trimesters. In addition, the pregnant women were aware of the safety (88.2%) and benefits of physical activity for both mother and baby (79.6%), improved labour and delivery (93.1%), promote energy (89.0%), and should be discontinued when tired (76.6%). However, they also held the contradictory belief that pregnancy is “a time to rest” (56.5%). Furthermore, the most common sources of information about prenatal physical activity were the media, television, the radio and Internet-based websites (70.2%). Most women affirmed that prenatal physical activity reduced infant weight (61.4%), lessen moodiness (90.4), decreased risk of gestational diabetes mellitus (92.9%), pregnancy-induced hypertension (92.5%), and complications at birth (97.8%), while common negative perceptions included musculoskeletal discomfort (82.7%), and back pain (85.7%). The majority of women indicated that prenatal physical activity improved self-image (95.7%), sleep patterns (94.2%), and respiratory function (95.8%). The results from the quantitative data revealed that the major modifiable barriers to prenatal physical activity were tiredness (73.3%), lack of advice from healthcare professionals (nurses/midwives) (64.7%), low energy (64.5%), and non-accessibility to physical activity facilities (63.0%). The results were confirmed in the qualitative data, based on the Ecological Model, in which women also mentioned tiredness, work and household responsibilities, a lack of motivation, and the lack of physical activity advice and information on the relevant recommendations and guidelines. Overall, 62.4% women had high knowledge regarding prenatal physical activity; and half of the women showed a positive attitude toward it (50.1%). Whilst participants had knowledge of other types of antenatal exercises, 80.9% of the women had no knowledge of swimming exercise. Negative attitudes towards physical activity included the feeling of tiredness (67.7%), lack of interest (64.8%), and inadequate information on physical activity (59.5%). In addition, the study highlighted that midwives rarely educate and counsel pregnant women about prenatal physical activity during scheduled antenatal visits, which was attributed largely to the shortage of midwives handling many responsibilities at clinics. Nevertheless, the midwives did express a willingness to provide effective physical activity education and counselling on prenatal physical activity, if supported by relevant training and workshops. Furthermore, they further recommended the use of the Mom Connect application, which is a technological device designed by the National Department of Health, to distribute relevant information about maternal and child health. The prenatal physical activity strategies developed to address the above-mentioned and other barriers associated with prenatal physical activity include the use of scientific and technological innovations to provide basic information on prenatal physical activity to pregnant women by means of Mom Connect, and, by collaborating with the various cellphone and network companies in South Africa. Another strategy was to integrate prenatal physical activity training into the curricula of the existing higher institutions of learning that provide teaching of maternal health in the Eastern Cape Province. Additional strategies included the documentation and subsequent clarification of misconceptions about the safety concerns often associated with prenatal physical activity by making the documents accessible to all women at the clinics in the form of a small pamphlet or booklet. Lastly, stakeholders suggested that the government offer periodic prenatal physical activity campaigns, which should be presented in local community town halls and clinics and by other stakeholders to address the current lack of awareness and effectively eliminate misrepresentations and falsehoods around the safety of prenatal physical activity within geographical setting of the Eastern Cape Province. Conclusion Despite the advantages of prenatal physical activity practices, most pregnant women in South Africa do not participate in moderate-intensity physical activity. Notably, while women perceive prenatal physical activity as beneficial to both mother and baby, such theoretical knowledge is not easily translatable into practice. The predominant sources of information on prenatal physical activity are the television, the radio, and other media, which may be potentially misleading or contradictory to evidence-based physical activity practice. Furthermore, tiredness, a lack of time, work and household responsibilities, and a lack of motivation were major modifiable barriers to prenatal physical activity by the women. In addition, pregnant women rarely receive information on prenatal physical activity. Consequently, to address the needs of the pregnant women as highlighted in this study, a prenatal physical activity intervention strategy was developed and validated by key stakeholders to promote prenatal physical activity and exercise practice among women, taken in account the local context. , Thesis (PhD) -- Faculty of Health Sciences, 2022
- Full Text:
- Authors: Okafor, Uchenna Benedine https://orcid.org/0000-0002-0435-2041
- Date: 2022-03
- Subjects: Prenatal care , Exercise for pregnant women
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22919 , vital:53218
- Description: Research has proven that prenatal physical activity practice is associated with multiple health benefits; however, most women in South Africa rarely participate in prenatal physical activity. In contrast to more developed countries, there is dearth of research focusing specifically on prenatal physical activity and exercise among South African women. Nevertheless, in order to effectively, and strategically promote such prenatal activity, such information is important to plan for an intervention strategy. The main aim of this study was to assess the level, patterns, and associated factors of prenatal physical activity; beliefs, knowledge, attitudes, perceived benefits, and sources of information women received during pregnancy; and, furthermore, to develop an effective and relevant intervention strategy to facilitate the participation in this particular activity in Buffalo City Municipality, Eastern Cape, South Africa. Methods The study was a mixed-method, cross-sectional study design with both quantitative and qualitative data collection and analyses. The sequential explanatory design was adopted to merge and mix different datasets to be collected and analysed. The quantitative data involved a convenient sample of 1082 pregnant women in 12 randomly selected primary healthcare clinics offering antenatal health services in Buffalo City, Eastern Cape. The Pregnancy Physical Activity Questionnaire was interviewer-administered to women at each antenatal health clinic on pre-specified days, in a designated room allocated to the primary researcher by the health facility manager. The descriptive statistics were frequency distribution, percentages, mean and standard deviation. Furthermore, the bivariate and multivariate analyses were performed on two categories of participants, namely inactive or active, to determine the factors affecting prenatal physical activity behaviour. Furthermore, multiple logistic regression analyses were used to assess associations between physical activity and the predictor variables during pregnancy. Adjusted odds ratios with 95% confidence interval were applied to estimate factors associated with physical activity levels, and the associations between prenatal physical activity levels and socio-demographic, lifestyle, and obstetrics characteristics were determined using a chi-squared analyses. The significance level was set at p = 0.05. In addition, a qualitative descriptive approach was applied, using semi-structured face-to-face interviews with 15 purposively selected pregnant women, as well as 17 midwives offering antenatal health-care services to pregnant women in the 12 selected healthcare clinics. Qualitative data were analysed using a thematic content analysis. To develop the physical activity strategy for the promotion of prenatal physical activity practice, three frameworks were applied, namely the Strength, Weakness, Opportunity and Threat (SWOT), the Political, Economic Growth, Socio-Cultural, Technological, Laws and Environmental (PESTLE), and, lastly, the Build, Overcome, Explore and Minimise (BOEM) analytical frameworks. To facilitate the validation of the strategy, the findings were additionally analysed, after which, appropriate intervention strategies promoting prenatal physical activity were developed by again using the SWOT and PESTLE analytical strategic frameworks. This process involved a purposive sampling of seven experts with knowledge of and a proven academic and scholarly background in prenatal physical activity and maternal health. Next, the developed physical activity strategy was presented to various stakeholders, which included six primary healthcare managers, two midwives, and pregnant women purposively selected in each of the 12 chosen antenatal health clinics for the validation process. The stakeholders discussed, deliberated on, and provided comments and opinions of the feasibility and implementation of the developed prenatal physical activity for promotion of physical activity practices in the Eastern Cape Province. Results The findings of this particular study demonstrated low levels of prenatal physical activity among pregnant women, and, further indicated that the most preferred form of activity was light-intensity and household activities. Only 278 of the women (25.7%) met recommendations for prenatal activity (≥150 min moderate intensity exercise per week). The average time spent in moderate–vigorous physical activity was 151.6 min (95% CI: 147.2– 156.0). Most of the women participated in light exercises with a mean of 65.9% (95% CI: 64.8–67.0), and 47.6% (95% CI: 46.3–48.9) participated in household activities. The majority of the women did not receive physical activity advice during prenatal care sessions (64.7%). Lower age (<19 years) (adjusted odd ratio (AOR) = 0.3; CI: 0.16–0.76), semi-urban residence (AOR = 0.8; CI: 0.55–1.03), lower educational level (AOR = 0.5; CI: 0.20–0.71), unemployment (AOR = 0.5; CI: 0.29–0.77) and nulliparity (AOR = 0.6; CI: 0.28–1.31) were negatively associated with prenatal physical activity, while prenatal physical activity was positively associated with starting physical activity in the first trimester (AOR = 1.9; CI: 1.06–3.31) compared to other trimesters. In addition, the pregnant women were aware of the safety (88.2%) and benefits of physical activity for both mother and baby (79.6%), improved labour and delivery (93.1%), promote energy (89.0%), and should be discontinued when tired (76.6%). However, they also held the contradictory belief that pregnancy is “a time to rest” (56.5%). Furthermore, the most common sources of information about prenatal physical activity were the media, television, the radio and Internet-based websites (70.2%). Most women affirmed that prenatal physical activity reduced infant weight (61.4%), lessen moodiness (90.4), decreased risk of gestational diabetes mellitus (92.9%), pregnancy-induced hypertension (92.5%), and complications at birth (97.8%), while common negative perceptions included musculoskeletal discomfort (82.7%), and back pain (85.7%). The majority of women indicated that prenatal physical activity improved self-image (95.7%), sleep patterns (94.2%), and respiratory function (95.8%). The results from the quantitative data revealed that the major modifiable barriers to prenatal physical activity were tiredness (73.3%), lack of advice from healthcare professionals (nurses/midwives) (64.7%), low energy (64.5%), and non-accessibility to physical activity facilities (63.0%). The results were confirmed in the qualitative data, based on the Ecological Model, in which women also mentioned tiredness, work and household responsibilities, a lack of motivation, and the lack of physical activity advice and information on the relevant recommendations and guidelines. Overall, 62.4% women had high knowledge regarding prenatal physical activity; and half of the women showed a positive attitude toward it (50.1%). Whilst participants had knowledge of other types of antenatal exercises, 80.9% of the women had no knowledge of swimming exercise. Negative attitudes towards physical activity included the feeling of tiredness (67.7%), lack of interest (64.8%), and inadequate information on physical activity (59.5%). In addition, the study highlighted that midwives rarely educate and counsel pregnant women about prenatal physical activity during scheduled antenatal visits, which was attributed largely to the shortage of midwives handling many responsibilities at clinics. Nevertheless, the midwives did express a willingness to provide effective physical activity education and counselling on prenatal physical activity, if supported by relevant training and workshops. Furthermore, they further recommended the use of the Mom Connect application, which is a technological device designed by the National Department of Health, to distribute relevant information about maternal and child health. The prenatal physical activity strategies developed to address the above-mentioned and other barriers associated with prenatal physical activity include the use of scientific and technological innovations to provide basic information on prenatal physical activity to pregnant women by means of Mom Connect, and, by collaborating with the various cellphone and network companies in South Africa. Another strategy was to integrate prenatal physical activity training into the curricula of the existing higher institutions of learning that provide teaching of maternal health in the Eastern Cape Province. Additional strategies included the documentation and subsequent clarification of misconceptions about the safety concerns often associated with prenatal physical activity by making the documents accessible to all women at the clinics in the form of a small pamphlet or booklet. Lastly, stakeholders suggested that the government offer periodic prenatal physical activity campaigns, which should be presented in local community town halls and clinics and by other stakeholders to address the current lack of awareness and effectively eliminate misrepresentations and falsehoods around the safety of prenatal physical activity within geographical setting of the Eastern Cape Province. Conclusion Despite the advantages of prenatal physical activity practices, most pregnant women in South Africa do not participate in moderate-intensity physical activity. Notably, while women perceive prenatal physical activity as beneficial to both mother and baby, such theoretical knowledge is not easily translatable into practice. The predominant sources of information on prenatal physical activity are the television, the radio, and other media, which may be potentially misleading or contradictory to evidence-based physical activity practice. Furthermore, tiredness, a lack of time, work and household responsibilities, and a lack of motivation were major modifiable barriers to prenatal physical activity by the women. In addition, pregnant women rarely receive information on prenatal physical activity. Consequently, to address the needs of the pregnant women as highlighted in this study, a prenatal physical activity intervention strategy was developed and validated by key stakeholders to promote prenatal physical activity and exercise practice among women, taken in account the local context. , Thesis (PhD) -- Faculty of Health Sciences, 2022
- Full Text:
Ruthenium (II) complexes of mixed bipyridyl and dithiolate/thiourea ligands :|bsynthesis, characterization, photophysical and electrochemical studies
- Authors: Nkombi, Pelokazi
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10134 , vital:35358
- Description: Energy is one of the most important factor to influence human lives. The increased in energy demand as well as the detrimental effects posed by emission of greenhouse gases due to continue use of fossil fuels for electricity generation has led to a renewed focus on energy production using renewable energy sources which are relatively cheap, clean and environmentally sustainable. Among the various renewable energy sources used so far, the Dye Synthesized Solar Cells (DSSCs), a form of photovoltaic device is reported for their better efficiencies despite their low cost of production and ability to work relatively under low light conditions. A recent report on the solar-to-electricity conversion efficiency of a typical DSSC sensitizer made from zinc based porphyrin dye coupled with sintered titanium(IV) oxide as semiconductor was 13 percent. In this study, 2,2-bipyridyl-4,4-dicarboxylic acid (bpydc) was used as mixed ligand and four dithiolate ligands; L1 = dipotassium ethoxycarbonyl-1-cyanoethylene-2,2-dithiolate, L2 = dipotassium bis(ethoxycarbonyl)ethane-2,2-dithiolate, L3 = dipotassium cyanodithio imidocarbonate and L4 = dipotassium 2,2-dicyanoethylene-2,2-dithiolate were synthesized while four alkyl thiourea ligands, L5 = 1,3-dimethyl thiourea, L6 = 1,3-diethyl thiourea, L7 = 1,3-diisopropyl thiourea and L8 = 1-methyl thiourea were purchased and used as supplied without further purification. These ligands were used to prepare eight ruthenium(II) complexes of mixed bipyridyl/dithiolate/thiourea. The compounds were characterised by elemental analysis and spectroscopic techniques, namely: Fourier transform infrared (FTIR), Nuclear Magnetic Resonance (NMR), ultraviolet-visible and photoluminescence (PL). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used for the electrochemical studies. Photoluminescence and UV-Vis spectroscopies were used for geometric and photophysical studies of the complexes respectively. FTIR spectra confirmed presence of functional groups in ligands and coordination of these ligands to ruthenium(II) ions to form complexes. The UV-Vis confirmed that the Ru(II) dithiolene complexes exhibited square planar geometries while the Ru(II) thiourea complexes gave octahedral geometries, this was deduced from the transitions assigned to the complexes. All the ruthenium(II) complexes synthesized showed photoluminescence properties that are suitable for light harvesting and application for dye-sensitized solar cells. Cyclic and square wave voltammetry show Ru(II) thiourea complexes have better redox properties when compared to Ru(II) dithiolate complexes which is ascribed to ligand strength field possibly due to contribution from the two bonded NCS groups.
- Full Text:
- Authors: Nkombi, Pelokazi
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10134 , vital:35358
- Description: Energy is one of the most important factor to influence human lives. The increased in energy demand as well as the detrimental effects posed by emission of greenhouse gases due to continue use of fossil fuels for electricity generation has led to a renewed focus on energy production using renewable energy sources which are relatively cheap, clean and environmentally sustainable. Among the various renewable energy sources used so far, the Dye Synthesized Solar Cells (DSSCs), a form of photovoltaic device is reported for their better efficiencies despite their low cost of production and ability to work relatively under low light conditions. A recent report on the solar-to-electricity conversion efficiency of a typical DSSC sensitizer made from zinc based porphyrin dye coupled with sintered titanium(IV) oxide as semiconductor was 13 percent. In this study, 2,2-bipyridyl-4,4-dicarboxylic acid (bpydc) was used as mixed ligand and four dithiolate ligands; L1 = dipotassium ethoxycarbonyl-1-cyanoethylene-2,2-dithiolate, L2 = dipotassium bis(ethoxycarbonyl)ethane-2,2-dithiolate, L3 = dipotassium cyanodithio imidocarbonate and L4 = dipotassium 2,2-dicyanoethylene-2,2-dithiolate were synthesized while four alkyl thiourea ligands, L5 = 1,3-dimethyl thiourea, L6 = 1,3-diethyl thiourea, L7 = 1,3-diisopropyl thiourea and L8 = 1-methyl thiourea were purchased and used as supplied without further purification. These ligands were used to prepare eight ruthenium(II) complexes of mixed bipyridyl/dithiolate/thiourea. The compounds were characterised by elemental analysis and spectroscopic techniques, namely: Fourier transform infrared (FTIR), Nuclear Magnetic Resonance (NMR), ultraviolet-visible and photoluminescence (PL). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used for the electrochemical studies. Photoluminescence and UV-Vis spectroscopies were used for geometric and photophysical studies of the complexes respectively. FTIR spectra confirmed presence of functional groups in ligands and coordination of these ligands to ruthenium(II) ions to form complexes. The UV-Vis confirmed that the Ru(II) dithiolene complexes exhibited square planar geometries while the Ru(II) thiourea complexes gave octahedral geometries, this was deduced from the transitions assigned to the complexes. All the ruthenium(II) complexes synthesized showed photoluminescence properties that are suitable for light harvesting and application for dye-sensitized solar cells. Cyclic and square wave voltammetry show Ru(II) thiourea complexes have better redox properties when compared to Ru(II) dithiolate complexes which is ascribed to ligand strength field possibly due to contribution from the two bonded NCS groups.
- Full Text:
The title goes here
- Authors: Surname, Firstnames
- Date: 20xx
- Subjects: Folk music -- Zimbabwe
- Language: English
- Type: Thesis , Masters/Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/12043 , vital:39130
- Description: abstract with a full stop.
- Full Text:
- Authors: Surname, Firstnames
- Date: 20xx
- Subjects: Folk music -- Zimbabwe
- Language: English
- Type: Thesis , Masters/Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/12043 , vital:39130
- Description: abstract with a full stop.
- Full Text:
Determination of physiochemical properties and metal levels in soil, water, and plant from Alice landfill site
- Authors: Maphuhla, N G
- Date: 2017
- Subjects: Heavy metals -- Environmental aspects Soil pollution Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6224 , vital:29521
- Description: The state of soil is of great significance because it is a common medium for plant growth, which provides important nutrients to plants. Water pollution is the build-up of harmful substances in water bodies to the level that results in health problems for people and animals. Heavy metal pollution (of soil, water, and plants) and their health effects on people is a persistent social issue, and several types of research have recognized health risks of residents living close to open dumpsites. Dump sites are sources of heavy metal impurity and toxicity to the surrounding environment. Analyses were done on water and soil samples for temperature, pH, Electrical conductivity (EC), Total dissolved solids (TDS), alkalinity, organic matter, organic carbon and total hardness. The pH results range from slightly acidic (6.79) to neutral soil pH (7.09), and have been recorded within the normal range from WHO. All the determined physicochemical properties in soil and water have been recorded within the normal range, except for EC in water which was found to be above the permissible limits by WHO. The heavy metals concentration was determined using the AAS technique. The results obtained shows that the dumpsite‘s soil consists of high metal concentration when compared to control site. The concentration in dumpsites ranges between 1.2783 ± 0.83 mg/kg to 26.3213 ± 6.37 mg/kg. The descending order for selected metal concentrations were in this following order Mn> Cu>Hg>Pb. The Pb and Hg mean concentration was recorded above permissible limits, while the Mn and Cu were within the normal range suggested by WHO. In both water and Acacia karroo samples the Cu was not detected. The trend of metal concentration in water sample was found to be in this order Hg> Mn > Pb> Cu, while in Acacia karroo metal concentration is Hg> Mn> Pb> Cu. The one-way ANOVA test was used to compare the mean concentration of selected metals in each sampling site. The results show that there is a statistically significant difference between the mean concentrations of selected metals; this is supported by the value of F-static and p-value (p <0.05)
- Full Text:
- Authors: Maphuhla, N G
- Date: 2017
- Subjects: Heavy metals -- Environmental aspects Soil pollution Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6224 , vital:29521
- Description: The state of soil is of great significance because it is a common medium for plant growth, which provides important nutrients to plants. Water pollution is the build-up of harmful substances in water bodies to the level that results in health problems for people and animals. Heavy metal pollution (of soil, water, and plants) and their health effects on people is a persistent social issue, and several types of research have recognized health risks of residents living close to open dumpsites. Dump sites are sources of heavy metal impurity and toxicity to the surrounding environment. Analyses were done on water and soil samples for temperature, pH, Electrical conductivity (EC), Total dissolved solids (TDS), alkalinity, organic matter, organic carbon and total hardness. The pH results range from slightly acidic (6.79) to neutral soil pH (7.09), and have been recorded within the normal range from WHO. All the determined physicochemical properties in soil and water have been recorded within the normal range, except for EC in water which was found to be above the permissible limits by WHO. The heavy metals concentration was determined using the AAS technique. The results obtained shows that the dumpsite‘s soil consists of high metal concentration when compared to control site. The concentration in dumpsites ranges between 1.2783 ± 0.83 mg/kg to 26.3213 ± 6.37 mg/kg. The descending order for selected metal concentrations were in this following order Mn> Cu>Hg>Pb. The Pb and Hg mean concentration was recorded above permissible limits, while the Mn and Cu were within the normal range suggested by WHO. In both water and Acacia karroo samples the Cu was not detected. The trend of metal concentration in water sample was found to be in this order Hg> Mn > Pb> Cu, while in Acacia karroo metal concentration is Hg> Mn> Pb> Cu. The one-way ANOVA test was used to compare the mean concentration of selected metals in each sampling site. The results show that there is a statistically significant difference between the mean concentrations of selected metals; this is supported by the value of F-static and p-value (p <0.05)
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Chemical constituents and biological studies of Tagetes minuta L. and Rauvolfia caffra Sond
- Authors: Mlala, Sithenkosi
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Organic Chemistry)
- Identifier: vital:11358 , http://hdl.handle.net/10353/d1021325
- Description: Consequently, specific parts or the whole plant can be used for various treatments. The aim of this study was to extract, isolate and characterize the biologically active volatile and non-volatile compounds from Tagetes minuta and Rauvolfia caffra respectively. Tagetes minuta plant was considered for extraction of essential oils using hydrodistillation method. Cis-β-ocimene (38.03%), caryophyllene oxide (18.04%), alloocimene (25.35 %), isopropyl tetradecanoate (17.02 %), cis-ocimene (38.14%) and trans-β-ocimene (37.03%) were the major components of essential oil analyzed from fresh stem, dried stem, fresh leaf, dried leaf, fresh flower and dried flower respectively. The volatile compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography (GC). Essential oil of dried stem leaf and flower parts of T. minuta exhibit antioxidant activity as demonstrated by the DPPH and FRAP bioassays. Crude extracts were extracted from R. caffra stem bark using sequence of solvents namely n-hexane, dichloromethane, ethyl acetate, methanol and ethanol. A white powder, a β-sitosterol (non-volatile compound) was isolated by column chromatography from ethyl acetate fractions of R. caffra stem bark and identified on various spectroscopic techniques such as FTIR and (1D and 2D) NMR. Melting point was also determined to be a sharp 129-130 ºC. DCM, EA, MetOH and EtOH fractions as well as β-Sitosterol (compound SM/01), showed antioxidant activity when tested on DPPH, FRAP, total phenolic and flavonoid bioassays. This antioxidant activity might be due to the presence of hydroxyl groups in the compound and crude fractions. On the other hand, T. minuta’s essential oil showed high antioxidant activity when evaluated on the DPPH and FRAP bioassays, which can be attributed to the presence of oxygenated monoterpenes and sesquiterpenes known to act as free radical scavenging and reducing agents. The use of R. caffra stem bark extracts against hypertension and other diseases by traditional healers could be attributed to the presence of phytochemicals (polyphenols and flavonoids) with known health benefits. Thus, it is recommended that the plant should be exploited further using modern techniques involving separation and purification of compounds that can be used for drug formulation. This study supports the use of T. minuta and R. caffra as the potential natural antioxidant source to manage various diseases including hypertension.
- Full Text:
- Authors: Mlala, Sithenkosi
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Organic Chemistry)
- Identifier: vital:11358 , http://hdl.handle.net/10353/d1021325
- Description: Consequently, specific parts or the whole plant can be used for various treatments. The aim of this study was to extract, isolate and characterize the biologically active volatile and non-volatile compounds from Tagetes minuta and Rauvolfia caffra respectively. Tagetes minuta plant was considered for extraction of essential oils using hydrodistillation method. Cis-β-ocimene (38.03%), caryophyllene oxide (18.04%), alloocimene (25.35 %), isopropyl tetradecanoate (17.02 %), cis-ocimene (38.14%) and trans-β-ocimene (37.03%) were the major components of essential oil analyzed from fresh stem, dried stem, fresh leaf, dried leaf, fresh flower and dried flower respectively. The volatile compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography (GC). Essential oil of dried stem leaf and flower parts of T. minuta exhibit antioxidant activity as demonstrated by the DPPH and FRAP bioassays. Crude extracts were extracted from R. caffra stem bark using sequence of solvents namely n-hexane, dichloromethane, ethyl acetate, methanol and ethanol. A white powder, a β-sitosterol (non-volatile compound) was isolated by column chromatography from ethyl acetate fractions of R. caffra stem bark and identified on various spectroscopic techniques such as FTIR and (1D and 2D) NMR. Melting point was also determined to be a sharp 129-130 ºC. DCM, EA, MetOH and EtOH fractions as well as β-Sitosterol (compound SM/01), showed antioxidant activity when tested on DPPH, FRAP, total phenolic and flavonoid bioassays. This antioxidant activity might be due to the presence of hydroxyl groups in the compound and crude fractions. On the other hand, T. minuta’s essential oil showed high antioxidant activity when evaluated on the DPPH and FRAP bioassays, which can be attributed to the presence of oxygenated monoterpenes and sesquiterpenes known to act as free radical scavenging and reducing agents. The use of R. caffra stem bark extracts against hypertension and other diseases by traditional healers could be attributed to the presence of phytochemicals (polyphenols and flavonoids) with known health benefits. Thus, it is recommended that the plant should be exploited further using modern techniques involving separation and purification of compounds that can be used for drug formulation. This study supports the use of T. minuta and R. caffra as the potential natural antioxidant source to manage various diseases including hypertension.
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In Silico analysis of Spermidine, Spermine and Putrescine interaction with selected heat shock proteins from Plasmodium falciparum 3D7 towards malaria drug development
- Authors: Godlo, Sesethu
- Date: 2022
- Subjects: Heat shock proteins , Malaria vaccine , Plasmodium falciparum
- Language: English
- Type: Master'stheses , text
- Identifier: http://hdl.handle.net/10353/27709 , vital:69395
- Description: Malaria is a mosquito-borne disease that affects around half of the world's population. It is one of the most common parasite infections that endangers human life. One of the most serious issues in malaria therapy is the emergence and spread of antimalarial drug-resistant Plasmodium parasites. This is due to the Plasmodium parasite's constant evolution and development of new methods of surviving medication toxicity. Studies of antimalarial drug development have been focused on polyamine biosynthesis by targeting precursors such as ornithine decarboxylase, adenosylmethionine decarboxylase, and spermidine synthase and protein-protein interactions between Plasmodium falciparum chaperones spotting out Hsp90, Hsp70, and Hsp40 as potential targets with little attention being paid to the interaction between polyamines and molecular chaperones. Therefore, this study seeks to identify interactions between polyamines and molecular chaperones present in the malarial parasite Plasmodium falciparum 3D7. The identification of these interactions might lead to the design of effective drugs to treat and eliminate malaria. Using computational analysis, this study aims to find interactions between polyamines and molecular chaperones found in the malarial parasite Plasmodium falciparum 3D7. The sequences of the selected heat proteins retrieved, and the 3D structures predicted and validated. These structures were docked with polyamines retrieved from PubChem and MD simulations on the docked interactions were performed. Docking revealed common amino acid residues with hydrogen bonds and salt bridges between all receptors and ligands, with glutamine and aspartic acid standing out. MD simulations revealed that when HSP20 and HSP40 transport the ligands, they pop up or are released too quickly. However, HSP60, HSP70, and HSP90 provide optimism since the ligands remain attached to the proteins for a specific amount of time. To further understand and confirm these interactions wet laboratory studies may be carried out in future. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Authors: Godlo, Sesethu
- Date: 2022
- Subjects: Heat shock proteins , Malaria vaccine , Plasmodium falciparum
- Language: English
- Type: Master'stheses , text
- Identifier: http://hdl.handle.net/10353/27709 , vital:69395
- Description: Malaria is a mosquito-borne disease that affects around half of the world's population. It is one of the most common parasite infections that endangers human life. One of the most serious issues in malaria therapy is the emergence and spread of antimalarial drug-resistant Plasmodium parasites. This is due to the Plasmodium parasite's constant evolution and development of new methods of surviving medication toxicity. Studies of antimalarial drug development have been focused on polyamine biosynthesis by targeting precursors such as ornithine decarboxylase, adenosylmethionine decarboxylase, and spermidine synthase and protein-protein interactions between Plasmodium falciparum chaperones spotting out Hsp90, Hsp70, and Hsp40 as potential targets with little attention being paid to the interaction between polyamines and molecular chaperones. Therefore, this study seeks to identify interactions between polyamines and molecular chaperones present in the malarial parasite Plasmodium falciparum 3D7. The identification of these interactions might lead to the design of effective drugs to treat and eliminate malaria. Using computational analysis, this study aims to find interactions between polyamines and molecular chaperones found in the malarial parasite Plasmodium falciparum 3D7. The sequences of the selected heat proteins retrieved, and the 3D structures predicted and validated. These structures were docked with polyamines retrieved from PubChem and MD simulations on the docked interactions were performed. Docking revealed common amino acid residues with hydrogen bonds and salt bridges between all receptors and ligands, with glutamine and aspartic acid standing out. MD simulations revealed that when HSP20 and HSP40 transport the ligands, they pop up or are released too quickly. However, HSP60, HSP70, and HSP90 provide optimism since the ligands remain attached to the proteins for a specific amount of time. To further understand and confirm these interactions wet laboratory studies may be carried out in future. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
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Synthesis, characterization and evaluation of photophysical and electrochemical properties of ruthenium(II) complexes for dye-sensitized solar cells
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
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