Socio-ecological, contextual effects in Raven’s Colour Progressive Matrices scores: Developing an index for guiding test selection and interpretation
- Authors: August, Justin Oswin
- Date: 2020
- Subjects: Ecological Systems Theory
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46401 , vital:39563
- Description: With the changing landscape in South Africa to a full democracy, increased research has been undertaken in the psychometric field on local and national normative studies regarding various assessment measures. Given that the Raven’s Coloured Progressive Matrices (CPM)is purported to be culture-free and not heavily dependent on verbal and language skills;it has been extensively normed throughout the world for various population groups. While norms for normal populations of children have been developed in South Africa, these studies were based on race and gender predominantly and without taking into consideration the effects of socio-ecological factors on test performance. The research study aimed to understand the influence of socio-ecological factors on the expression of cognitive scores amongst a geographically diverse sample of South African learners. Through this study, research on the interplay between context and cognition was to be located within the Ecological Systems model of Bronfenbrenner. A secondary aim of the study was to develop an index that will guide test selection and interpretation of assessment results, taking into account the influence of socio-ecological factors and providing a conceptual framework for future test development. The study employed a quantitative methodology on a South African sample consisting of primary school children aged between the ages of 6 years to 11 years. The sample was drawn from schools in the Port Elizabeth areain South Africa that wereclassified into low, medium and high opportunity, based on context. The results indicated that the type of school had a significant impact on test performance, suggesting that contextual factors were influential in this process.The item analysisconductedfurther indicated that learners from a low opportunity school performed significantly lower than the other two schoolsin the sample. The index development provides a foundation for further research that would enhance the interpretation of test results. In the South African context, this is considered important, given our political history and our diversity wherea“one size fits all” approach is not possible.
- Full Text:
- Date Issued: 2020
- Authors: August, Justin Oswin
- Date: 2020
- Subjects: Ecological Systems Theory
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46401 , vital:39563
- Description: With the changing landscape in South Africa to a full democracy, increased research has been undertaken in the psychometric field on local and national normative studies regarding various assessment measures. Given that the Raven’s Coloured Progressive Matrices (CPM)is purported to be culture-free and not heavily dependent on verbal and language skills;it has been extensively normed throughout the world for various population groups. While norms for normal populations of children have been developed in South Africa, these studies were based on race and gender predominantly and without taking into consideration the effects of socio-ecological factors on test performance. The research study aimed to understand the influence of socio-ecological factors on the expression of cognitive scores amongst a geographically diverse sample of South African learners. Through this study, research on the interplay between context and cognition was to be located within the Ecological Systems model of Bronfenbrenner. A secondary aim of the study was to develop an index that will guide test selection and interpretation of assessment results, taking into account the influence of socio-ecological factors and providing a conceptual framework for future test development. The study employed a quantitative methodology on a South African sample consisting of primary school children aged between the ages of 6 years to 11 years. The sample was drawn from schools in the Port Elizabeth areain South Africa that wereclassified into low, medium and high opportunity, based on context. The results indicated that the type of school had a significant impact on test performance, suggesting that contextual factors were influential in this process.The item analysisconductedfurther indicated that learners from a low opportunity school performed significantly lower than the other two schoolsin the sample. The index development provides a foundation for further research that would enhance the interpretation of test results. In the South African context, this is considered important, given our political history and our diversity wherea“one size fits all” approach is not possible.
- Full Text:
- Date Issued: 2020
Strategies for the facilitation of implementation of best practice guidelines in operating theatres at public hospitals
- Owolabi, Olukemi Olufunmilayo
- Authors: Owolabi, Olukemi Olufunmilayo
- Date: 2020
- Subjects: Operating rooms—Safety measures
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46422 , vital:39594
- Description: Best practice guidelines (BPGs) are the use of scientific evidence to direct patient care and guide clinical care to integrate best patient outcomes. The implementation of BPGs in operating theatre nursing improves patient safety and quality of care and enhances patient outcomes. Although BPGs are crucial, the implementation thereof is not well operationalised in clinical practice, especially in an area such as the operating theatres in public hospitals in the Nelson Mandela Bay Health District(NMHD)in the Eastern Cape Province. The study thus developed strategies that could be used to facilitate the implementation of best practice guidelines in the operating theatres at public hospitals in the NMBHD. Understanding registered nurses’ knowledge, attitudes, and practices (KAP) with regard to implementing BPGs in the operating theatre is important, as it will assist in the development of strategies to facilitate the implementation of BPGs.The study was conducted in three phases. Phase One comprised of a quantitative approach. Data collection was achieved by means of a self-administered questionnaire which was distributed to registered nurses in the operating theatres of public hospitals in the NMBHD. The purpose of the questionnaire was to establish their knowledge, attitude and practice with regard to best practice guidelines and the implementation thereof. Recommendations made by participants for strategies to facilitate the implementation of BPGs in operating theatres were also explored. Descriptive and inferential statistics were utilised to analyse and describe the data. Descriptive statistics were used to describe the profile of the sample, including the demographic data measures of central tendency, for example the mean and standard deviation (SD) and correlation techniques.Chi²analysis was performed to test for significance of the associations between the registered nurses’ demographic variables and their KAP. Data were categorised into three levels, namely lower (score < quartile 1 i.e. bottom 25%). Middle (quartile1 ≤ score ≤quartile i.e. in the middle 50%) and higher (score > quartile 3 i.e. top 25%).Findings from this research study revealed the limited knowledge, attitude and practice of OT nurses about BPGs. During Phase Two an integrative literature review approach was followed in order to identify the best available evidence with regard to the facilitation of the implementation of best practice guidelines in operating theatres. Lastly, Phase Three: strategies that could be used to facilitate the implementation of best practice guidelines in operating theatres were developed. The researcher developed the conceptual framework using the six elements of Dickoff, James and Weidenbach (1968:422). The conceptual framework informed the development of strategies. The strategies are a synthesis of the conclusions drawn from the research findings (phase one and two) and the conceptualization thereof. The strategies were reviewed by six-panel members. Each panel member was supplied with the format for evaluation of the strategies which was based on the criteria established by Chinn and Kramer (2018:156) the results of which included in chapter 7. The researcher ensured that the data obtained was valid and reliable, necessary to assist the researcher to produce quality research. Ethical considerations were maintained throughout. In general, the results of this thesis indicate that the developed strategies that could be used to facilitate the implementation of best practice guidelines, in operating theatres at public hospitals in the NMBHDare unique and could be implemented in theatres in public hospitals. The researcher succeeded in achieving the purpose for this study, because the strategies which are understandable, clear, simple, applicable and significant to operating theatre unit has been developed for use by operating theatre nurses, to facilitate the implementation of best practice guidelines in operating theatres at public hospitals in the NMBHD.
- Full Text:
- Date Issued: 2020
- Authors: Owolabi, Olukemi Olufunmilayo
- Date: 2020
- Subjects: Operating rooms—Safety measures
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46422 , vital:39594
- Description: Best practice guidelines (BPGs) are the use of scientific evidence to direct patient care and guide clinical care to integrate best patient outcomes. The implementation of BPGs in operating theatre nursing improves patient safety and quality of care and enhances patient outcomes. Although BPGs are crucial, the implementation thereof is not well operationalised in clinical practice, especially in an area such as the operating theatres in public hospitals in the Nelson Mandela Bay Health District(NMHD)in the Eastern Cape Province. The study thus developed strategies that could be used to facilitate the implementation of best practice guidelines in the operating theatres at public hospitals in the NMBHD. Understanding registered nurses’ knowledge, attitudes, and practices (KAP) with regard to implementing BPGs in the operating theatre is important, as it will assist in the development of strategies to facilitate the implementation of BPGs.The study was conducted in three phases. Phase One comprised of a quantitative approach. Data collection was achieved by means of a self-administered questionnaire which was distributed to registered nurses in the operating theatres of public hospitals in the NMBHD. The purpose of the questionnaire was to establish their knowledge, attitude and practice with regard to best practice guidelines and the implementation thereof. Recommendations made by participants for strategies to facilitate the implementation of BPGs in operating theatres were also explored. Descriptive and inferential statistics were utilised to analyse and describe the data. Descriptive statistics were used to describe the profile of the sample, including the demographic data measures of central tendency, for example the mean and standard deviation (SD) and correlation techniques.Chi²analysis was performed to test for significance of the associations between the registered nurses’ demographic variables and their KAP. Data were categorised into three levels, namely lower (score < quartile 1 i.e. bottom 25%). Middle (quartile1 ≤ score ≤quartile i.e. in the middle 50%) and higher (score > quartile 3 i.e. top 25%).Findings from this research study revealed the limited knowledge, attitude and practice of OT nurses about BPGs. During Phase Two an integrative literature review approach was followed in order to identify the best available evidence with regard to the facilitation of the implementation of best practice guidelines in operating theatres. Lastly, Phase Three: strategies that could be used to facilitate the implementation of best practice guidelines in operating theatres were developed. The researcher developed the conceptual framework using the six elements of Dickoff, James and Weidenbach (1968:422). The conceptual framework informed the development of strategies. The strategies are a synthesis of the conclusions drawn from the research findings (phase one and two) and the conceptualization thereof. The strategies were reviewed by six-panel members. Each panel member was supplied with the format for evaluation of the strategies which was based on the criteria established by Chinn and Kramer (2018:156) the results of which included in chapter 7. The researcher ensured that the data obtained was valid and reliable, necessary to assist the researcher to produce quality research. Ethical considerations were maintained throughout. In general, the results of this thesis indicate that the developed strategies that could be used to facilitate the implementation of best practice guidelines, in operating theatres at public hospitals in the NMBHDare unique and could be implemented in theatres in public hospitals. The researcher succeeded in achieving the purpose for this study, because the strategies which are understandable, clear, simple, applicable and significant to operating theatre unit has been developed for use by operating theatre nurses, to facilitate the implementation of best practice guidelines in operating theatres at public hospitals in the NMBHD.
- Full Text:
- Date Issued: 2020
Synthesis of novel heterocyclic systems as potential inhibitors of HIV-1 enzymes
- Authors: Sekgota, Khethobole Cassius
- Date: 2020
- Subjects: Protease inhibitors , Heterocyclic compounds , HIV (Viruses) , Quinoline , Amides , Nuclear magnetic resonance , Antiretroviral agents , AIDS vaccines , Nitrobenzaldehyde , Propylphosphonic acid anhydride
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146502 , vital:38531
- Description: This study has focussed on the application of Baylis-Hillman methodology in the development of efficient synthetic pathways to libraries of novel 3-[(N-cycloalkylbenzamido)methyl]-2-quinolones and indolizine-2-carboxamides and on an exploration of their medicinal potential. The approach to 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones involved a six-step pathway comprising: Baylis-Hillman reaction of 2-nitrobenzaldehyde derivatives and methyl acrylate to afford nitro-Baylis-Hillman adducts; thermal cyclisation of the adducts to give a range of 3-(acetoxymethyl)-2(1H)-quinolones in good to excellent yields; hydrolysis of the acetates; conversion of the resulting alcohols to the 3-chloromethyl analogues; amination; and, finally, acylation to afford the target amides. Variable temperature NMR methods were used to facilitate analysis of the ¹H and ¹³C NMR spectra which were complicated by internal rotation and cycloalkyl ring-flipping effects. On the other hand, the indolizine-2-carboxamides were obtained in several steps commencing with the Baylis-Hillman reaction of pyridine-2-carboxaldehyde and methyl acrylate. Thermal cyclisation of the Baylis-Hillman adduct afforded indolizine esters, hydrolysis of which gave the corresponding acids which served as precursors to the target indolizine-2-carboxamides. The final amidation step, however, proved to be particularly challenging. Various coupling strategies were explored to access indolizine-2-carboxamides. These included the use of 2,2,2-trifluoroethyl borate which showed limited promise, but propylphosphonic acid anhydride (T3P) proved to be the most effective coupling agent, permitting the formation of 24 novel indolizine-2-carboxamides from hydrazines, aliphatic amines and a range of heterocyclic amines. A high-field NMR-based kinetic study of the mechanism of the Baylis-Hillman reaction of pyridine-4-carboxaldehyde and methyl acrylate in the presence of 3-hydroxyquinuclidine in deuterated chloroform was initiated, reaction progress being followed by the automated collection of ¹H and DEPT 135 NMR spectra over ca. 24 hours using a high-field (600 MHz) NMR instrument. The results have provided critical new insights into the mechanism. NMR analysis has also been used to elucidate the multiplicity of signals associated with rotameric equilibria observed at ambient probe temperature. Variable temperature 1D- and 2D-NMR spectra were used to facilitate the unambiguous characterisation of the 2-quinolone benzamides and some of the indolizine-2-carboxamides. The 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones, together with selected precursors, and a number of the indolizine-2-carboxamides have been screened in vitro as potential HIV-1 enzyme inhibitors. A survey of the activity of the 2-quinolones against HIV-1 integrase, protease and reverse transcriptase revealed selective inhibition of HIV-1 integrase with the most active IN inhibitor, 3-[(cyclopentylamino)methyl-6-methoxy-2(1H)-quinolone 115e, producing residual enzyme activity of 40% at a concentration of 20 μM. Many of the 2-quinolones exhibited no significant cytotoxicity against HEK 293 cells at 20 μM concentrations. 3-[(N-Cyclohexylamino)methyl]-6-methoxy-2(1H)-quinolone 114e was the only compound to exhibit ant-plasmodial activity (55% pfLDH activity). The survey of indolizine-2-carboxamides also revealed encouraging inhibition against HIV-1 integrase. None of these compounds exhibited cytotoxicity at 20 μM against HEK 293 cells, while a number of them exhibited some activity against Plasmodium falciparum (3D7 strain) and Trypanosoma brucei. Selected indolizine-2-carboxamides exhibited significant anti-tubercular activity in the 7H9 CAS GLU Tx and 7H9 ADC GLU Tw media. In view of the inherent fluorescent character and biological potential of the synthesised indolizine-2-carboxamides, their photophysical properties were explored to establish their possible dual use as bio-imaging and therapeutic agents. The major absorption and corresponding emission bands, and the associated molar absorption coefficients (Ɛ) expressed in the form of log Ɛ were determined. Their high extinction coefficients, large Stokes shift and red-shifted emissions in the visible region indicate their potential for use as fluorophores.
- Full Text:
- Date Issued: 2020
- Authors: Sekgota, Khethobole Cassius
- Date: 2020
- Subjects: Protease inhibitors , Heterocyclic compounds , HIV (Viruses) , Quinoline , Amides , Nuclear magnetic resonance , Antiretroviral agents , AIDS vaccines , Nitrobenzaldehyde , Propylphosphonic acid anhydride
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146502 , vital:38531
- Description: This study has focussed on the application of Baylis-Hillman methodology in the development of efficient synthetic pathways to libraries of novel 3-[(N-cycloalkylbenzamido)methyl]-2-quinolones and indolizine-2-carboxamides and on an exploration of their medicinal potential. The approach to 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones involved a six-step pathway comprising: Baylis-Hillman reaction of 2-nitrobenzaldehyde derivatives and methyl acrylate to afford nitro-Baylis-Hillman adducts; thermal cyclisation of the adducts to give a range of 3-(acetoxymethyl)-2(1H)-quinolones in good to excellent yields; hydrolysis of the acetates; conversion of the resulting alcohols to the 3-chloromethyl analogues; amination; and, finally, acylation to afford the target amides. Variable temperature NMR methods were used to facilitate analysis of the ¹H and ¹³C NMR spectra which were complicated by internal rotation and cycloalkyl ring-flipping effects. On the other hand, the indolizine-2-carboxamides were obtained in several steps commencing with the Baylis-Hillman reaction of pyridine-2-carboxaldehyde and methyl acrylate. Thermal cyclisation of the Baylis-Hillman adduct afforded indolizine esters, hydrolysis of which gave the corresponding acids which served as precursors to the target indolizine-2-carboxamides. The final amidation step, however, proved to be particularly challenging. Various coupling strategies were explored to access indolizine-2-carboxamides. These included the use of 2,2,2-trifluoroethyl borate which showed limited promise, but propylphosphonic acid anhydride (T3P) proved to be the most effective coupling agent, permitting the formation of 24 novel indolizine-2-carboxamides from hydrazines, aliphatic amines and a range of heterocyclic amines. A high-field NMR-based kinetic study of the mechanism of the Baylis-Hillman reaction of pyridine-4-carboxaldehyde and methyl acrylate in the presence of 3-hydroxyquinuclidine in deuterated chloroform was initiated, reaction progress being followed by the automated collection of ¹H and DEPT 135 NMR spectra over ca. 24 hours using a high-field (600 MHz) NMR instrument. The results have provided critical new insights into the mechanism. NMR analysis has also been used to elucidate the multiplicity of signals associated with rotameric equilibria observed at ambient probe temperature. Variable temperature 1D- and 2D-NMR spectra were used to facilitate the unambiguous characterisation of the 2-quinolone benzamides and some of the indolizine-2-carboxamides. The 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones, together with selected precursors, and a number of the indolizine-2-carboxamides have been screened in vitro as potential HIV-1 enzyme inhibitors. A survey of the activity of the 2-quinolones against HIV-1 integrase, protease and reverse transcriptase revealed selective inhibition of HIV-1 integrase with the most active IN inhibitor, 3-[(cyclopentylamino)methyl-6-methoxy-2(1H)-quinolone 115e, producing residual enzyme activity of 40% at a concentration of 20 μM. Many of the 2-quinolones exhibited no significant cytotoxicity against HEK 293 cells at 20 μM concentrations. 3-[(N-Cyclohexylamino)methyl]-6-methoxy-2(1H)-quinolone 114e was the only compound to exhibit ant-plasmodial activity (55% pfLDH activity). The survey of indolizine-2-carboxamides also revealed encouraging inhibition against HIV-1 integrase. None of these compounds exhibited cytotoxicity at 20 μM against HEK 293 cells, while a number of them exhibited some activity against Plasmodium falciparum (3D7 strain) and Trypanosoma brucei. Selected indolizine-2-carboxamides exhibited significant anti-tubercular activity in the 7H9 CAS GLU Tx and 7H9 ADC GLU Tw media. In view of the inherent fluorescent character and biological potential of the synthesised indolizine-2-carboxamides, their photophysical properties were explored to establish their possible dual use as bio-imaging and therapeutic agents. The major absorption and corresponding emission bands, and the associated molar absorption coefficients (Ɛ) expressed in the form of log Ɛ were determined. Their high extinction coefficients, large Stokes shift and red-shifted emissions in the visible region indicate their potential for use as fluorophores.
- Full Text:
- Date Issued: 2020
Synthesis, characterisation and antitumour activities of lanthanide complexes with hydrazones and carboxylic acid ligands
- Authors: Madanhire, Tatenda
- Date: 2020
- Subjects: Organic acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48456 , vital:40878
- Description: The tridentate hydrazone ligands, (E)-N'-(2-hydroxybenzylidene)benzohydrazide (H2phen) and (E)-N'-(2-hydroxybenzylidene)nicotinohydrazide (H2Nic), were synthesised and complexed to Ln(III) acetates. The centrosymmetric, acetato-bridged dinuclear coordination compounds with the formulae, [La2(Hphen)2(OAc)4(H2O)2]·DMF·H2O (1), [Ln2(HNic)2(OAc)4(H2O)2]·DMF·H2O (Ln = La (2) and Nd (3)) and [Ln2(HNic)2(OAc)4(H2O)2]·DMF (Ln = Er (4) and Yb (5)) were isolated and characterised by elemental analyses, IR spectroscopy, UV-Vis spectroscopy, X-ray diffraction studies and SHAPE 2.1. The nine-coordinate complexes 1–3 crystallise in the triclinic space group P-1, with the metal centres having the distorted spherical capped square antiprism geometry (C4v), while the eight-coordinate Er(III) and Yb(III) complexes (monoclinic system, space group P21/c) display the geometry of distorted triangular dodecahedron (D2d). Geometry optimisation of the monoanionic forms of the hydrazone ligands (Hphen– and HNic– ) were performed using Density Functional Theory (DFT) with Becke’s three parameter hybrid method and correlation functional of Lee, Yang and Parr (B3LYP) with augcc-pVTZ basis set. Natural population analysis (NPA) and molecular electrostatic potential (MEP) maps indicated that the most preferred sites for electrophilic attack in the anionic ligands are the phenolate and carbonyl oxygens, and the azomethine nitrogens. The evaluation of the cytotoxic activity of the compounds on breast cancer (MCF-7), the endometrial carcinoma (HEC-1A) and the human monocytic (THP-1) cell lines using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay revealed that the hydrazone ligands and complexes 1–4 are partially cytotoxic against MCF-7 cells, while the Schiff bases and complexes 3–5 significantly inhibit cell growth in HEC-1A cells. The complexation reactions of Ce(III), Nd(III), Gd(III) and Er(III) with the chelating/ bridging monoanionic ligand N-(2,6-dimethylphenyl)oxamate (Hpma– ) in basic media were performed in view of the potential applications of oxamate derivatives as cytotoxic agents. The coordination compounds were characterised by different Abstract T. Madanhire Nelson Mandela University xxvi physico-chemical techniques: elemental analysis, conductivity measurements, IR, 1 H NMR and UV-Vis-NIR spectroscopy. The anionic Hpma– was obtained through conversion of the proligand ethyl (2,6-dimethylphenylcarbamoyl)formate (Hdmp). The reactions afforded lanthanide(III)–oxamate coordination polymers of formulae: {[Ln(Hpma)3(MeOH)(H2O)]∙2MeOH}n (Ln = Ce (1) and Nd (2)), {[Gd2(Hpma)6(MeOH)4]∙6MeOH}n (3), {[Er2(Hpma)6(MeOH)(H2O)3]∙2MeOH}n (4) and [Ln2Na2(Hpma)8(EtOH)(H2O)6]n (Ln = Nd (5) and Gd (6)). The polymeric complexes feature Ln-Hpma moieties bridged by μ2-η 1 :η 1 :η 1 Hpma– , giving onedimensional zig-zag chains of the –Ln–O–C–O–Ln– type. Atomic charge analysis and the MEP map of the Hpma– moiety done using the DFT/B3LYP method were found to be consistent with the chelating and bridging modes of the anionic ligand through all the oxygen atoms. The evaluation of the cytotoxic activities of the metal salts, the proligand and the novel lanthanide complexes on MCF-7, HEC-1A and THP-1 cell lines revealed that only the rare-earth metal salts [Ce(NO3)3∙6H2O] and [Nd(NO3)3∙6H2O] showed modest cytotoxicity against MCF-7 and HEC-1A cells, respectively.
- Full Text:
- Date Issued: 2020
- Authors: Madanhire, Tatenda
- Date: 2020
- Subjects: Organic acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48456 , vital:40878
- Description: The tridentate hydrazone ligands, (E)-N'-(2-hydroxybenzylidene)benzohydrazide (H2phen) and (E)-N'-(2-hydroxybenzylidene)nicotinohydrazide (H2Nic), were synthesised and complexed to Ln(III) acetates. The centrosymmetric, acetato-bridged dinuclear coordination compounds with the formulae, [La2(Hphen)2(OAc)4(H2O)2]·DMF·H2O (1), [Ln2(HNic)2(OAc)4(H2O)2]·DMF·H2O (Ln = La (2) and Nd (3)) and [Ln2(HNic)2(OAc)4(H2O)2]·DMF (Ln = Er (4) and Yb (5)) were isolated and characterised by elemental analyses, IR spectroscopy, UV-Vis spectroscopy, X-ray diffraction studies and SHAPE 2.1. The nine-coordinate complexes 1–3 crystallise in the triclinic space group P-1, with the metal centres having the distorted spherical capped square antiprism geometry (C4v), while the eight-coordinate Er(III) and Yb(III) complexes (monoclinic system, space group P21/c) display the geometry of distorted triangular dodecahedron (D2d). Geometry optimisation of the monoanionic forms of the hydrazone ligands (Hphen– and HNic– ) were performed using Density Functional Theory (DFT) with Becke’s three parameter hybrid method and correlation functional of Lee, Yang and Parr (B3LYP) with augcc-pVTZ basis set. Natural population analysis (NPA) and molecular electrostatic potential (MEP) maps indicated that the most preferred sites for electrophilic attack in the anionic ligands are the phenolate and carbonyl oxygens, and the azomethine nitrogens. The evaluation of the cytotoxic activity of the compounds on breast cancer (MCF-7), the endometrial carcinoma (HEC-1A) and the human monocytic (THP-1) cell lines using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay revealed that the hydrazone ligands and complexes 1–4 are partially cytotoxic against MCF-7 cells, while the Schiff bases and complexes 3–5 significantly inhibit cell growth in HEC-1A cells. The complexation reactions of Ce(III), Nd(III), Gd(III) and Er(III) with the chelating/ bridging monoanionic ligand N-(2,6-dimethylphenyl)oxamate (Hpma– ) in basic media were performed in view of the potential applications of oxamate derivatives as cytotoxic agents. The coordination compounds were characterised by different Abstract T. Madanhire Nelson Mandela University xxvi physico-chemical techniques: elemental analysis, conductivity measurements, IR, 1 H NMR and UV-Vis-NIR spectroscopy. The anionic Hpma– was obtained through conversion of the proligand ethyl (2,6-dimethylphenylcarbamoyl)formate (Hdmp). The reactions afforded lanthanide(III)–oxamate coordination polymers of formulae: {[Ln(Hpma)3(MeOH)(H2O)]∙2MeOH}n (Ln = Ce (1) and Nd (2)), {[Gd2(Hpma)6(MeOH)4]∙6MeOH}n (3), {[Er2(Hpma)6(MeOH)(H2O)3]∙2MeOH}n (4) and [Ln2Na2(Hpma)8(EtOH)(H2O)6]n (Ln = Nd (5) and Gd (6)). The polymeric complexes feature Ln-Hpma moieties bridged by μ2-η 1 :η 1 :η 1 Hpma– , giving onedimensional zig-zag chains of the –Ln–O–C–O–Ln– type. Atomic charge analysis and the MEP map of the Hpma– moiety done using the DFT/B3LYP method were found to be consistent with the chelating and bridging modes of the anionic ligand through all the oxygen atoms. The evaluation of the cytotoxic activities of the metal salts, the proligand and the novel lanthanide complexes on MCF-7, HEC-1A and THP-1 cell lines revealed that only the rare-earth metal salts [Ce(NO3)3∙6H2O] and [Nd(NO3)3∙6H2O] showed modest cytotoxicity against MCF-7 and HEC-1A cells, respectively.
- Full Text:
- Date Issued: 2020
Synthesis, characterisation and electrocatalytic behaviour of three series of Metal Organic Frameworks
- Authors: Murinzi, Tafadzwa Wendy
- Date: 2020
- Subjects: Electrochemistry , Metal-organic frameworks , Polyoxometalates , Fourier transform infrared spectroscopy , Electrocatalysis , Cysteine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167598 , vital:41495
- Description: Metal organic frameworks (MOFs) have received a lot of attention over the past few years due to their vast range of interesting properties and applications, such as catalysis, environmental sensing and storage. This wide range of potential applications is afforded by careful selection and manipulation of the components chosen in assembling of MOFs. In this study, three series of MOFs were synthesized from Co(II), Cu(II) and Mo(VI) polyoxometallates with either 1,3,5-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid or 2,6- pyridinedicarboxylic acid as the ligands. In series 1, the common 1,3,5- benzenetricarboxylic acid MOF, HKUST-1, and POM modified HKUST-1 compounds involving encapsulation and encorporation of the POM were utilised. In series 2, flexible cobalt(II) benzenepolycarboxylate MOFs which investigated the effect of varying the degree of carboxylate substituent were utilised. In series 3, flexibly reduced heterocyclic polycarboxylate MOFs using 2,6-pyridine dicarboxylate were utilised. Solvothermal and slow evaporation synthesis conditions were employed. Where single crystals of good quality were produced, single crystal X-ray diffraction (SC-XRD) was employed for structural elucidation. In the absence of such crystals, a combination of elemental analysis, inductively coupled plasma optical emission spectrometry (ICP-OES) and powder X-ray diffraction (PXRD) was used. Characterization of the MOFs was done by Fourier transform infrared spectrometry (FTIR) and thermal methods, namely thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The electrocatalytic potential of the compounds in the oxidation of L-cysteine was then investigated using a variety of techniques. Cyclic voltammetry was used for L-cysteine detection whilst chronoamperometry and differential pulse voltammetry were used to determine the nanoprobes’ sensitivity, rate constants and detection limits. Electrochemical impedence spectroscopy was used to investigate the charge transfer resistance (RCT) and electron transfer kinetics. Of the three, series 3 gave the best signals and sensitivities for electrocatalysis of L-cysteine followed by series 2 and lastly series 1. Series 2 showed the highest stability and series 1 required the least overpotential. The results highlight the effects of different metal centres and ligands on electrocatalysis. The application of MOFs in electrochemistry is a relatively new field making the findings of this study a significant addition to the body of knowledge.
- Full Text:
- Date Issued: 2020
- Authors: Murinzi, Tafadzwa Wendy
- Date: 2020
- Subjects: Electrochemistry , Metal-organic frameworks , Polyoxometalates , Fourier transform infrared spectroscopy , Electrocatalysis , Cysteine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167598 , vital:41495
- Description: Metal organic frameworks (MOFs) have received a lot of attention over the past few years due to their vast range of interesting properties and applications, such as catalysis, environmental sensing and storage. This wide range of potential applications is afforded by careful selection and manipulation of the components chosen in assembling of MOFs. In this study, three series of MOFs were synthesized from Co(II), Cu(II) and Mo(VI) polyoxometallates with either 1,3,5-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid or 2,6- pyridinedicarboxylic acid as the ligands. In series 1, the common 1,3,5- benzenetricarboxylic acid MOF, HKUST-1, and POM modified HKUST-1 compounds involving encapsulation and encorporation of the POM were utilised. In series 2, flexible cobalt(II) benzenepolycarboxylate MOFs which investigated the effect of varying the degree of carboxylate substituent were utilised. In series 3, flexibly reduced heterocyclic polycarboxylate MOFs using 2,6-pyridine dicarboxylate were utilised. Solvothermal and slow evaporation synthesis conditions were employed. Where single crystals of good quality were produced, single crystal X-ray diffraction (SC-XRD) was employed for structural elucidation. In the absence of such crystals, a combination of elemental analysis, inductively coupled plasma optical emission spectrometry (ICP-OES) and powder X-ray diffraction (PXRD) was used. Characterization of the MOFs was done by Fourier transform infrared spectrometry (FTIR) and thermal methods, namely thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The electrocatalytic potential of the compounds in the oxidation of L-cysteine was then investigated using a variety of techniques. Cyclic voltammetry was used for L-cysteine detection whilst chronoamperometry and differential pulse voltammetry were used to determine the nanoprobes’ sensitivity, rate constants and detection limits. Electrochemical impedence spectroscopy was used to investigate the charge transfer resistance (RCT) and electron transfer kinetics. Of the three, series 3 gave the best signals and sensitivities for electrocatalysis of L-cysteine followed by series 2 and lastly series 1. Series 2 showed the highest stability and series 1 required the least overpotential. The results highlight the effects of different metal centres and ligands on electrocatalysis. The application of MOFs in electrochemistry is a relatively new field making the findings of this study a significant addition to the body of knowledge.
- Full Text:
- Date Issued: 2020
Synthesis, crystal structures and molecular modelling of rare earth complexes with bis(2-pyridylmethyl)amine and its derivatives : a quantum chemical investigation of ligand conformational space, complex intramolecular rearrangement and stability
- Authors: Matthews, Cameron
- Date: 2020
- Subjects: Rare earths , Complex compounds , Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46229 , vital:39517
- Description: Limited research has been performed on the coordination behaviour of hybrid aliphatic and heterocyclic polyamines with trivalent rare earth elements. The rare earth coordination properties of several Nalkylated derivatives of the tridentate ligand bis(2-pyridylmethyl)amine (DPA, HL1) backbone - involving the rare earth elements Y, La-Nd, Sm, Eu and Tb-Lu - have been investigated in this study However, the structural and energetic characteristics of DPA coordination with rare earth elements (REE) have not been studied thus far. Potential applications of DPA-based rare earth complexes are primarily dependent on their electronic and magnetic characteristics, which are affected weakly by the coordination environment, where potential applications may include use as Lanthanide Shift Reagents (LSR), Luminescence probes and small-molecule magnets (SMM). A systematic conformational search of DPA was carried out in this study in order to identify the global minimum conformer and for comparison of the free and coordinated geometries, using the M06(D3) functional belonging to the Density Functional Theory (DFT) family of model chemistries. An understanding of the aforementioned would play an important role in analysis of bulk characterization and the prediction of the reactivity of DPA. Final geometries and electronic energies were obtained from the ‘domain based local pair natural orbital’ (DLPNO)-Møller-Plesset and -coupled cluster theoretical methods, as follows: DLPNO-CCSD(T0)/aug-cc-pVQZ//DLPNO-MP2/aug-cc-pVTZ. Fifteen Single-crystal X-ray diffractometer (SC-XRD) crystal structures of mononuclear rare earth chloride coordination complexes with DPA (RE = La-Nd, Sm, Eu, Tb-Lu and Y) were obtained and geometrically analysed in this study. Three isostructural series of constitutional isomers were identified, consisting of one series of nine-coordinate molecule (M1) and two series of eight-coordinate ion pairs (M2 and M3). This conformational diversity is most likely due the flexible nature of the DPA backbone, as well as the additional stability gained from reduced coordination spheres as a function of decreasing rare earth ionic radii across the lanthanide series (Lanthanide contraction). A Quantum Theory of Atoms-in-Molecules (QTAIM) topological analysis was performed in order to identify and characterise potential hydrogen bonding interactions in H-optimised crystal structures. The crystal structures of five dinuclear (RE = Tb-Tm) and two tetranuclear (RE = Yb and Lu) rare earth chloride complexes with DPA have also been structurally analysed. Furthermore, one mononuclear (RE = Dy), two dinuclear complexes (RE = Dy and Lu) with EtDPA, and one mononuclear complex with the DPA-derivative HL4 (RE = Dy) were structurally characterised. A DFT study of the theoretical interconversion of one real- and two hypothetical- mononuclear lanthanum containing isostructural series (cf. aforementioned crystal structures) was undertaken in order to gain a deeper understanding of the processes involved, in terms of the participating minimum energy paths (MEPs), intermediates and transition states – as determined via the Nudged-Elastic Band (NEB) procedure. This hypothesis is supported by the well-known conformational lability of rare earth complexes, due to the weak/minor covalency of their coordination bonds. An attempt was made to determine the respective energies of one real- and two hypothetical diamagnetic or ‘closed-shell’ constitutional isomers containing the rare earth ions La3+(M1), Y3+(M2) and Lu3+ (M3). It was assumed that the most stable isomers have a greater probability of being observed as the asymmetric unit of the complex crystal structure – assuming weak contributions of lattice or intermolecular interactions towards the geometry of the asymmetric unit.
- Full Text:
- Date Issued: 2020
- Authors: Matthews, Cameron
- Date: 2020
- Subjects: Rare earths , Complex compounds , Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46229 , vital:39517
- Description: Limited research has been performed on the coordination behaviour of hybrid aliphatic and heterocyclic polyamines with trivalent rare earth elements. The rare earth coordination properties of several Nalkylated derivatives of the tridentate ligand bis(2-pyridylmethyl)amine (DPA, HL1) backbone - involving the rare earth elements Y, La-Nd, Sm, Eu and Tb-Lu - have been investigated in this study However, the structural and energetic characteristics of DPA coordination with rare earth elements (REE) have not been studied thus far. Potential applications of DPA-based rare earth complexes are primarily dependent on their electronic and magnetic characteristics, which are affected weakly by the coordination environment, where potential applications may include use as Lanthanide Shift Reagents (LSR), Luminescence probes and small-molecule magnets (SMM). A systematic conformational search of DPA was carried out in this study in order to identify the global minimum conformer and for comparison of the free and coordinated geometries, using the M06(D3) functional belonging to the Density Functional Theory (DFT) family of model chemistries. An understanding of the aforementioned would play an important role in analysis of bulk characterization and the prediction of the reactivity of DPA. Final geometries and electronic energies were obtained from the ‘domain based local pair natural orbital’ (DLPNO)-Møller-Plesset and -coupled cluster theoretical methods, as follows: DLPNO-CCSD(T0)/aug-cc-pVQZ//DLPNO-MP2/aug-cc-pVTZ. Fifteen Single-crystal X-ray diffractometer (SC-XRD) crystal structures of mononuclear rare earth chloride coordination complexes with DPA (RE = La-Nd, Sm, Eu, Tb-Lu and Y) were obtained and geometrically analysed in this study. Three isostructural series of constitutional isomers were identified, consisting of one series of nine-coordinate molecule (M1) and two series of eight-coordinate ion pairs (M2 and M3). This conformational diversity is most likely due the flexible nature of the DPA backbone, as well as the additional stability gained from reduced coordination spheres as a function of decreasing rare earth ionic radii across the lanthanide series (Lanthanide contraction). A Quantum Theory of Atoms-in-Molecules (QTAIM) topological analysis was performed in order to identify and characterise potential hydrogen bonding interactions in H-optimised crystal structures. The crystal structures of five dinuclear (RE = Tb-Tm) and two tetranuclear (RE = Yb and Lu) rare earth chloride complexes with DPA have also been structurally analysed. Furthermore, one mononuclear (RE = Dy), two dinuclear complexes (RE = Dy and Lu) with EtDPA, and one mononuclear complex with the DPA-derivative HL4 (RE = Dy) were structurally characterised. A DFT study of the theoretical interconversion of one real- and two hypothetical- mononuclear lanthanum containing isostructural series (cf. aforementioned crystal structures) was undertaken in order to gain a deeper understanding of the processes involved, in terms of the participating minimum energy paths (MEPs), intermediates and transition states – as determined via the Nudged-Elastic Band (NEB) procedure. This hypothesis is supported by the well-known conformational lability of rare earth complexes, due to the weak/minor covalency of their coordination bonds. An attempt was made to determine the respective energies of one real- and two hypothetical diamagnetic or ‘closed-shell’ constitutional isomers containing the rare earth ions La3+(M1), Y3+(M2) and Lu3+ (M3). It was assumed that the most stable isomers have a greater probability of being observed as the asymmetric unit of the complex crystal structure – assuming weak contributions of lattice or intermolecular interactions towards the geometry of the asymmetric unit.
- Full Text:
- Date Issued: 2020
Teachers’ perceptions, experiences and challenges related to using ICTs in teaching Social Sciences in marginalised classrooms in the Eastern Cape Province, South Africa
- Authors: Gunzo, Fortunate Takawira
- Date: 2020
- Subjects: Educational technology -- South Africa -- Eastern Cape , Teachers -- In-service training -- South Africa -- Eastern Cape , Social sciences -- Study and teaching -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Technological innovations -- Employee participation -- South Africa -- Eastern Cape , Teachers -- Attitudes , Technological innovations -- Economic aspects -- South Africa -- Eastern Cape , Technology Acceptance Model , Teacher Cognitions theory
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146964 , vital:38581
- Description: This study seeks to examine teachers’ perceptions and experiences of using Information and Communication Technology (ICT) in teaching as the basis for actual use in the classroom. I conducted an eclectic study with a multidisciplinary theoretical viewpoint combining theories from Information Technology (IT) and education to examine how perceptions and prior experiences with ICT influence cross-curriculum ICT integration. Specific aspects of five theories and models were used in different phases of this study. I drew on the Technology Acceptance Model (TAM) and Teacher Cognitions theory to understand teachers’ perceptions towards ICT in general and towards ICT in the classroom. The classroom observations were conducted using an observation guide informed by Activity theory. I then utilised the Adoption of Innovation and the Diffusion of Innovation theories to explain why and how ICT was utilised in the classrooms. A mixed methods research approach located within a pragmatic paradigm was chosen. Three data sets were collected. First, a questionnaire of attitudes and perceptions towards ICT was conducted with 183 teachers (mainly working at marginalised schools in the Eastern Cape Province of South Africa). Questionnaire data was analysed using descriptive statistics and a chi-square correlations test. Second, teachers enrolled in an in-service Advanced Certificate in Education specializing in ICT (ACE-ICT) at Rhodes University were supported in planning and implementing an intervention involving the use of a mobile computer lab in rural and peri-urban schools. Three key participants were observed while teaching in class using ICT for the first time and they were subsequently interviewed. Third, drawing from lessons learnt from this experience, students in the in-service education bachelor’s degree in ICT (BEd-ICT) – which replaced the in-service ACE-ICT – were supported and encouraged to experiment with cross-curriculum integration using ICT already at their disposal. Planning and reflections by three in-service BEd-ICT teachers were subjected to theory-based document thematic analysis. Findings indicate that the vast majority of the teachers had positive attitudes towards ICT and perceived ICT as useful, mainly as a productivity tool in teaching. ICT was used mostly for administration, planning and preparation of lessons and not for teaching or as a cognitive tool. Despite all key participants having access to similar ICTs and support, their experiences of teaching with ICT were different based on their personal commitment, access to and frequency of use of ICTs in their personal lives. Teachers who were self-motivated to use ICT in their teaching made efforts to do so regardless of infrastructure and resource challenges they faced at their schools. The main barriers to the use of ICT in the classroom appear to be lack of technical support and time constraints.
- Full Text:
- Date Issued: 2020
- Authors: Gunzo, Fortunate Takawira
- Date: 2020
- Subjects: Educational technology -- South Africa -- Eastern Cape , Teachers -- In-service training -- South Africa -- Eastern Cape , Social sciences -- Study and teaching -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Technological innovations -- Employee participation -- South Africa -- Eastern Cape , Teachers -- Attitudes , Technological innovations -- Economic aspects -- South Africa -- Eastern Cape , Technology Acceptance Model , Teacher Cognitions theory
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146964 , vital:38581
- Description: This study seeks to examine teachers’ perceptions and experiences of using Information and Communication Technology (ICT) in teaching as the basis for actual use in the classroom. I conducted an eclectic study with a multidisciplinary theoretical viewpoint combining theories from Information Technology (IT) and education to examine how perceptions and prior experiences with ICT influence cross-curriculum ICT integration. Specific aspects of five theories and models were used in different phases of this study. I drew on the Technology Acceptance Model (TAM) and Teacher Cognitions theory to understand teachers’ perceptions towards ICT in general and towards ICT in the classroom. The classroom observations were conducted using an observation guide informed by Activity theory. I then utilised the Adoption of Innovation and the Diffusion of Innovation theories to explain why and how ICT was utilised in the classrooms. A mixed methods research approach located within a pragmatic paradigm was chosen. Three data sets were collected. First, a questionnaire of attitudes and perceptions towards ICT was conducted with 183 teachers (mainly working at marginalised schools in the Eastern Cape Province of South Africa). Questionnaire data was analysed using descriptive statistics and a chi-square correlations test. Second, teachers enrolled in an in-service Advanced Certificate in Education specializing in ICT (ACE-ICT) at Rhodes University were supported in planning and implementing an intervention involving the use of a mobile computer lab in rural and peri-urban schools. Three key participants were observed while teaching in class using ICT for the first time and they were subsequently interviewed. Third, drawing from lessons learnt from this experience, students in the in-service education bachelor’s degree in ICT (BEd-ICT) – which replaced the in-service ACE-ICT – were supported and encouraged to experiment with cross-curriculum integration using ICT already at their disposal. Planning and reflections by three in-service BEd-ICT teachers were subjected to theory-based document thematic analysis. Findings indicate that the vast majority of the teachers had positive attitudes towards ICT and perceived ICT as useful, mainly as a productivity tool in teaching. ICT was used mostly for administration, planning and preparation of lessons and not for teaching or as a cognitive tool. Despite all key participants having access to similar ICTs and support, their experiences of teaching with ICT were different based on their personal commitment, access to and frequency of use of ICTs in their personal lives. Teachers who were self-motivated to use ICT in their teaching made efforts to do so regardless of infrastructure and resource challenges they faced at their schools. The main barriers to the use of ICT in the classroom appear to be lack of technical support and time constraints.
- Full Text:
- Date Issued: 2020
Temporal patterns and seasonal variation in microplastic loads in the water column and in the tissues of consumers along the southern and south-eastern coasts of South Africa
- Authors: Redelinghuys, Suzanne
- Date: 2020
- Subjects: Microplastics -- South Africa -- Eastern Cape , Plastic marine debris -- South Africa -- Eastern Cape , Marine pollution -- South Africa -- Eastern Cape , Ocean circulation -- South Africa -- Eastern Cape , Marine invertebrates -- Effect of pollution on -- South Africa -- Eastern Cape , Marine animals -- Effect of pollution on -- South Africa -- Eastern Cape , Mexilhao mussel -- Effect of pollution on -- South Africa -- Eastern Cape , Mytilus galloprovincialis -- Effect of pollution on -- South Africa -- Eastern Cape , Barnacles -- Effect of pollution on -- South Africa -- Eastern Cape , Tetraclita -- Effect of pollution on -- South Africa -- Eastern Cape , Octomeris angulosa -- Effect of pollution on -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115623 , vital:34201
- Description: Plastic pollution in the marine environment has become an environmental concern and a subject of ecological research. The field of microplastic pollution in particular has expanded dramatically in the last few years. Though much data exists on the spatial variability of microplastics in the marine environment globally, little is known about temporal variability, especially on short-term time scales in the southern hemisphere. Similarly, virtually nothing is known about the temporal patterns in microplastic ingestion by marine invertebrates, despite the fact that numerous studies have demonstrated that vertebrates and invertebrates routinely ingest microplastics with varied physiological effects. This study aimed to, 1) provide base-line data for microplastic loads in the nearshore environment along the Eastern Cape Province of South Africa over four short-term time scales: daily, weekly, monthly, and yearly; and, 2) assess whether there are any seasonal patterns in microplastics ingested by selected filter-feeding consumers at two sites along the southern and south-eastern Cape coastlines of South Africa. Results for part one of this study demonstrate no temporal patterns over the different time scales considered (ANOVA, p > 0.05 in all cases). Microplastic counts ranged on average from 55 ± 289 to 930 ± 462 microplastic particles.m-3. With the exception of two instances, microfibres constituted > 50 % (range: 47 to 97 %) of the total microplastic counts. Part two of this study assessed the size range of, and seasonal and spatial patterns in ingested microplastic. No significant differences were found in the number of microplastics ingested within seasons between the mussels Perna perna (Linnaeus, 1758) and Mytilus galloprovincialis (Lamarck, 1819), and the barnacles, Octomeris angulosa (Sowerby, 1825) and Tetraclita serrata (Darwin 1954) (Student’s t-test; d.f = 18; p > 0.05 in all cases), or between the two sites sampled, Kenton-on-Sea, Eastern Cape, and Wilderness, Western Cape (ANOVA; d.f. = 18; p > 0.05 in all cases). The nitric acid digestion technique was used to determine the presence of ingested microplastics. Microplastic loads ranged from 2 ± 1 to 33 ± 19 microplastics.g-1 wwt across all consumers, and the size of ingested microplastics ranged from 1 to 16 μm. Though highly variable, the absence of statistically significant differences in ingestion rates points to a ubiquity in the availability of microplastics within the water column over time and space.
- Full Text:
- Date Issued: 2020
- Authors: Redelinghuys, Suzanne
- Date: 2020
- Subjects: Microplastics -- South Africa -- Eastern Cape , Plastic marine debris -- South Africa -- Eastern Cape , Marine pollution -- South Africa -- Eastern Cape , Ocean circulation -- South Africa -- Eastern Cape , Marine invertebrates -- Effect of pollution on -- South Africa -- Eastern Cape , Marine animals -- Effect of pollution on -- South Africa -- Eastern Cape , Mexilhao mussel -- Effect of pollution on -- South Africa -- Eastern Cape , Mytilus galloprovincialis -- Effect of pollution on -- South Africa -- Eastern Cape , Barnacles -- Effect of pollution on -- South Africa -- Eastern Cape , Tetraclita -- Effect of pollution on -- South Africa -- Eastern Cape , Octomeris angulosa -- Effect of pollution on -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115623 , vital:34201
- Description: Plastic pollution in the marine environment has become an environmental concern and a subject of ecological research. The field of microplastic pollution in particular has expanded dramatically in the last few years. Though much data exists on the spatial variability of microplastics in the marine environment globally, little is known about temporal variability, especially on short-term time scales in the southern hemisphere. Similarly, virtually nothing is known about the temporal patterns in microplastic ingestion by marine invertebrates, despite the fact that numerous studies have demonstrated that vertebrates and invertebrates routinely ingest microplastics with varied physiological effects. This study aimed to, 1) provide base-line data for microplastic loads in the nearshore environment along the Eastern Cape Province of South Africa over four short-term time scales: daily, weekly, monthly, and yearly; and, 2) assess whether there are any seasonal patterns in microplastics ingested by selected filter-feeding consumers at two sites along the southern and south-eastern Cape coastlines of South Africa. Results for part one of this study demonstrate no temporal patterns over the different time scales considered (ANOVA, p > 0.05 in all cases). Microplastic counts ranged on average from 55 ± 289 to 930 ± 462 microplastic particles.m-3. With the exception of two instances, microfibres constituted > 50 % (range: 47 to 97 %) of the total microplastic counts. Part two of this study assessed the size range of, and seasonal and spatial patterns in ingested microplastic. No significant differences were found in the number of microplastics ingested within seasons between the mussels Perna perna (Linnaeus, 1758) and Mytilus galloprovincialis (Lamarck, 1819), and the barnacles, Octomeris angulosa (Sowerby, 1825) and Tetraclita serrata (Darwin 1954) (Student’s t-test; d.f = 18; p > 0.05 in all cases), or between the two sites sampled, Kenton-on-Sea, Eastern Cape, and Wilderness, Western Cape (ANOVA; d.f. = 18; p > 0.05 in all cases). The nitric acid digestion technique was used to determine the presence of ingested microplastics. Microplastic loads ranged from 2 ± 1 to 33 ± 19 microplastics.g-1 wwt across all consumers, and the size of ingested microplastics ranged from 1 to 16 μm. Though highly variable, the absence of statistically significant differences in ingestion rates points to a ubiquity in the availability of microplastics within the water column over time and space.
- Full Text:
- Date Issued: 2020
The characterization and application of novel xanthenyland thioxanthenyl-derived compounds as hosts in the presence of various applicable guest mixtures
- Authors: Jooste, Daniel Victor
- Date: 2020
- Subjects: Organic compounds -- Synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49104 , vital:41601
- Description: In this work, the host potential of four novel, structurally-related compounds, trans- N,N’-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine (1,2-DAX), trans-N,N’-bis(9- phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine (1,2-DAT), trans-N,N’-bis(9-phenyl- 9-xanthenyl)cyclohexane-1,4-diamine (1,4-DAX), and trans-N,N’-bis(9-phenyl-9- thioxanthenyl)cyclohexane-1,4-diamine (1,4-DAT), were investigated for their possible employment in the separation of isomers and other related compounds using host– guest chemistry. These hosts were synthesized following a Grignard reaction with phenylmagnesium bromide on either xanthone or thioxanthone. The resultant alcohol was treated with perchloric acid, before finally being linked with either trans-1,2- or trans-1,4-diaminocyclohexane to afford the four title host compounds. Initially, the feasibility of these hosts for separating isomers and related compounds was investigated by recrystallizing each one independently from various guest compounds including the methylpyridines and pyridine, xylenes and ethylbenzene, heterocyclic six-membered ring compounds, aniline, N-methylaniline and N,Ndimethylaniline, and also the alkylbenzenes toluene, cumene and ethylbenzene. 1HNMR spectroscopy was used to ascertain if inclusion of the guest species had occurred in this manner and, if so, the host:guest ratio of the complex. Guest–guest competitions were subsequently conducted in order to establish the selectivity of the hosts when presented with a mixture of guests, and if the host would be able to discriminate between them. Gas chromatography-mass spectrometry (GC-MS) was the analytical method of choice here if 1H-NMR spectroscopy was not suitable owing to guest–guest signal overlap. Here, the host was recrystallized from binary, ternary and quaternary mixed guests, where each was present in equimolar amounts. Additionally, binary competition experiments were conducted in mixed guest solvents where the molar ratios of the guests were varied, and host selectivity for these guests evaluated visually by means of selectivity profiles. Single crystal X-ray diffraction (SC-XRD) and thermal analysis were performed on any complexes that afforded crystals of suitable quality in order to relate inherent host–guest interactions and thermal stability to the observed host selectivity from the competition experiments. The more prevalent interactions that were evident in these inclusion complexes between host and guest species were, more usually, and interactions, as well as other short contacts. Hydrogen bonding interactions were observed in only a few of the complexes. Guest accommodation type was also investigated, and these species resided in either discrete cavities or channels within the host crystal, depending on the guest. For the most part, traces obtained from thermal analyses were highly convoluted and difficult to interpret. As a result, guest release onset temperatures could not be determined for all of the inclusion complexes. In some cases, however, this temperature was successfully measured and correlated directly with the observed selectivity order of the host suggested by the competition experiments. Both enhanced and contrasting results were obtained for the four host compounds. In all cases, 1,2-DAX and 1,2-DAT successfully formed complexes with each of the guest species from each series. Interestingly, the 1,4-derived hosts, however, were more selective in that 1,4-DAX did not complex with only one of the guest solvents, while 1,4-DAT did not enclathrate as many as ten of these solvents. The competition investigations showed that, in most of these experiments, the host compounds displayed selectivity for one of the guests present in the mixture, and in some cases, this selectivity was pronounced, alluding to the feasibility of separating related guests from one another through host–guest chemistry principles. Computational calculations were, additionally, conducted on each of the host molecules in order to gain a better understanding of their geometries, and to compare these with the apohost crystal structures. Significant geometry differences were noted between the calculated and crystal structures.
- Full Text:
- Date Issued: 2020
- Authors: Jooste, Daniel Victor
- Date: 2020
- Subjects: Organic compounds -- Synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49104 , vital:41601
- Description: In this work, the host potential of four novel, structurally-related compounds, trans- N,N’-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine (1,2-DAX), trans-N,N’-bis(9- phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine (1,2-DAT), trans-N,N’-bis(9-phenyl- 9-xanthenyl)cyclohexane-1,4-diamine (1,4-DAX), and trans-N,N’-bis(9-phenyl-9- thioxanthenyl)cyclohexane-1,4-diamine (1,4-DAT), were investigated for their possible employment in the separation of isomers and other related compounds using host– guest chemistry. These hosts were synthesized following a Grignard reaction with phenylmagnesium bromide on either xanthone or thioxanthone. The resultant alcohol was treated with perchloric acid, before finally being linked with either trans-1,2- or trans-1,4-diaminocyclohexane to afford the four title host compounds. Initially, the feasibility of these hosts for separating isomers and related compounds was investigated by recrystallizing each one independently from various guest compounds including the methylpyridines and pyridine, xylenes and ethylbenzene, heterocyclic six-membered ring compounds, aniline, N-methylaniline and N,Ndimethylaniline, and also the alkylbenzenes toluene, cumene and ethylbenzene. 1HNMR spectroscopy was used to ascertain if inclusion of the guest species had occurred in this manner and, if so, the host:guest ratio of the complex. Guest–guest competitions were subsequently conducted in order to establish the selectivity of the hosts when presented with a mixture of guests, and if the host would be able to discriminate between them. Gas chromatography-mass spectrometry (GC-MS) was the analytical method of choice here if 1H-NMR spectroscopy was not suitable owing to guest–guest signal overlap. Here, the host was recrystallized from binary, ternary and quaternary mixed guests, where each was present in equimolar amounts. Additionally, binary competition experiments were conducted in mixed guest solvents where the molar ratios of the guests were varied, and host selectivity for these guests evaluated visually by means of selectivity profiles. Single crystal X-ray diffraction (SC-XRD) and thermal analysis were performed on any complexes that afforded crystals of suitable quality in order to relate inherent host–guest interactions and thermal stability to the observed host selectivity from the competition experiments. The more prevalent interactions that were evident in these inclusion complexes between host and guest species were, more usually, and interactions, as well as other short contacts. Hydrogen bonding interactions were observed in only a few of the complexes. Guest accommodation type was also investigated, and these species resided in either discrete cavities or channels within the host crystal, depending on the guest. For the most part, traces obtained from thermal analyses were highly convoluted and difficult to interpret. As a result, guest release onset temperatures could not be determined for all of the inclusion complexes. In some cases, however, this temperature was successfully measured and correlated directly with the observed selectivity order of the host suggested by the competition experiments. Both enhanced and contrasting results were obtained for the four host compounds. In all cases, 1,2-DAX and 1,2-DAT successfully formed complexes with each of the guest species from each series. Interestingly, the 1,4-derived hosts, however, were more selective in that 1,4-DAX did not complex with only one of the guest solvents, while 1,4-DAT did not enclathrate as many as ten of these solvents. The competition investigations showed that, in most of these experiments, the host compounds displayed selectivity for one of the guests present in the mixture, and in some cases, this selectivity was pronounced, alluding to the feasibility of separating related guests from one another through host–guest chemistry principles. Computational calculations were, additionally, conducted on each of the host molecules in order to gain a better understanding of their geometries, and to compare these with the apohost crystal structures. Significant geometry differences were noted between the calculated and crystal structures.
- Full Text:
- Date Issued: 2020
The current role of palm species Hyphaene Coriacea and Phoenix Reclanata in local livelihoods in the Zitundo area, southern Mozambique
- Authors: Martins, Angelina R O
- Date: 2020
- Subjects: Ilala palm -- Economic aspects -- Mozambique , Palms -- Economic aspects -- Mozambique , Non-timber forest products industry -- Mozambique , Sustainable development -- Mozambique , Conservation of natural resources -- Mozambique
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/150613 , vital:38989
- Description: The majority of rural households in developing countries are heavily dependent on non-timber forest products (NTFPs) to fulfill much of their basic daily needs. In Mozambique more than 64% of the population lives in rural areas and depends heavily in the extraction of NTFPs to complement agricultural production. One substantial source of NTFPs are palm species. Palms are sources of food, building materials, cloth, ornaments, medicines, and are also used for cultural purposes. In southern Mozambique two important palms species used as NTFPs are Hyphaene coriacea and Phoenix reclinata. These two species provide an array of subsistence and commercial products. The sap, leaves and stems of these two palms are harvested by local people as sources of traditional beverages, weaving, roofing, fencing and furniture material as well as other household utensils. The effects (if any) of harvesting of these palm products on palm distribution, population structure, dynamics and viability have never been examined, and thus the sustainability of the practices and benefits flows to local livelihoods are unknow-n. Any effects harvesting effects may also be exacerbated by predicted climate change for the area. The present study aims to investigate the role of the palm species Hyphaene coriacea and Phoenix reclinata in the livelihoods of households in the Zitundo area, Matutuine district, southern Mozambique and under future climate scenarios. Specifically, this study: i) evaluates the abundance, population structure and harvesting selection of these species; ii) characterizes the ethnobotanical knowledge and use of the two species; iii) examines the local production and trade of palm wine in the area; iv) examines the contribution of palm income to livelihoods and income diversification in area; v) describes the local management practices and perceptions on palm productivity and abundance; and vi) models the current and future distribution of the these palm species in the area. To evaluate the abundance, population structure and stability of these two palm species a population census was carried out, and the size class distribution, Simpson index of dominance, permutation index and the quotient between successive size classes were calculated. I further calculated the preference ratio for specific size classes. Additionally a questionnaire survey was conducted with 179 randomly selected households from the 16 villages in the study area to characterize the ethnobotanical knowledge and use of these two species, as well as to examine the contribution of palm income to livelihoods and diversification. Standard ethnobotanical indices were used as measures of each palm species use and knowledge while principal component analysis and cluster analysis were applied to highlight the livelihood patterns and the role of diversification and of palm income in local livelihoods. Structured interviews with 37 palm tappers were additionally used to examine the local production and trade of palm wine in the area, while both the household survey and palm tappers interviews, were employed to investigate the local management practices and perceptions on palms productivity and abundance. Maxent Software was used to model the current and future under climate change distribution of the two palm species. Hyphaene coriacea was more abundant than Phoenix reclinata. Both species exhibited steep negative slopes in the regression analyses of size class distribution, indicating the presence of more individuals in shorter size classes. Although there was a dominance of shorter over taller size classes, limited recruitment was observed through low stem densities of seedlings and juveniles compared to the 1-50 cm size class The Simpson index of dominance, the permutation index, and the fluctuating quotients between the consecutive size classes showed a level of instability in both populations. Hyphaene coriacea appeared to be more resilient to tapping than Phoenix reclinata as showed by the higher rate of stem survival after tapping. Hyphaene coriacea was favored for tapping compared to Phoenix reclinata. The most preferred size class to tap for both species was between 101cm and 150 cm. Currently the distribution of Hyphaene coriacea and Phoenix reclinata was mostly confined to the eastern side of the study area. Most of the area was predicted as unsuitable for both palm species, with less than six percent predicted to be suitable or higher. The occurrence of both species appeared to be influenced mostly by water related variables, such as precipitation, and distance to rivers and distance to water bodies. The habitat suitability for Hyphaene coriacea was predicted to increase under future climate conditions scenarios, while little variation was predicted for Phoenix reclinata distribution. The knowledge about the uses of these two palm species was widespread in the area, although only 32% of respondents were engaged in palm exploitation. Thirteen palm products were exploited, with palm wine production from the sap of both palms being the dominant activity, followed by broom production from Phoenix reclinata stems and basket production from Hyphaene coriacea leaves. The cultural importance of these species included the production of anklets and skirts used during traditional dances and the use of palm wine in the traditional ritual of libation. Palm tapping was practiced year round in five of the sixteen villages in the area. Palm tapping was an important livelihood activity, contributing over 80% of tappers’ total annual income, and tappers earned up to three times more than the national minimum wage for the agricultural and forestry sector. Palm wine was also a highly commercial commodity in Zitundo area, with an average commercialization index above 60%. The income from palm wine sales showed an important role in mitigating the level of poverty in the area. Palm income accounted for over 60% reduction on poverty incidence among palm tappers. Households in Zitundo further engaged in some level of livelihood diversification. The majority of households adopted a wage-based strategy, although this strategy was among the less remunerative in terms of per capita cash income. A palm-based livelihood strategy, although adopted only by 11% of households, was one of the most remunerative strategies. Palm income played a vital role in enhancing household livelihoods and mitigating poverty in the area as shown by the lower poverty incidences among households engaged in the palm-based livelihood strategy than alternatives strategies. The village of household residency, along with household demographic and socio-economic characteristics appeared to determine the knowledge and exploitation level of palms as well as a households’ choice of livelihood strategy, level of palm wine returns, commercialization index and palm income dependency. The importance of palms in local livelihoods and poverty alleviation needs greater acknowledgement by government and development agencies in the area. Palm wine, broom and basket production have a high potential for income generation, and therefore should be included in future local development policies and poverty reduction strategies. Although palms are an open access resource in Zitundo area, the perception is that they are abundant and that tapping does not have many detrimental effects. However, this study found some negative impacts of tapping on the recruitment of both palms species. The inclusion of palm products in future development programs and poverty reduction strategies will require the design of participatory conservation and management strategies that involve all palm users groups and others stakeholders and include long-term participatory monitoring of the effect of palm use on the populations.
- Full Text:
- Date Issued: 2020
- Authors: Martins, Angelina R O
- Date: 2020
- Subjects: Ilala palm -- Economic aspects -- Mozambique , Palms -- Economic aspects -- Mozambique , Non-timber forest products industry -- Mozambique , Sustainable development -- Mozambique , Conservation of natural resources -- Mozambique
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/150613 , vital:38989
- Description: The majority of rural households in developing countries are heavily dependent on non-timber forest products (NTFPs) to fulfill much of their basic daily needs. In Mozambique more than 64% of the population lives in rural areas and depends heavily in the extraction of NTFPs to complement agricultural production. One substantial source of NTFPs are palm species. Palms are sources of food, building materials, cloth, ornaments, medicines, and are also used for cultural purposes. In southern Mozambique two important palms species used as NTFPs are Hyphaene coriacea and Phoenix reclinata. These two species provide an array of subsistence and commercial products. The sap, leaves and stems of these two palms are harvested by local people as sources of traditional beverages, weaving, roofing, fencing and furniture material as well as other household utensils. The effects (if any) of harvesting of these palm products on palm distribution, population structure, dynamics and viability have never been examined, and thus the sustainability of the practices and benefits flows to local livelihoods are unknow-n. Any effects harvesting effects may also be exacerbated by predicted climate change for the area. The present study aims to investigate the role of the palm species Hyphaene coriacea and Phoenix reclinata in the livelihoods of households in the Zitundo area, Matutuine district, southern Mozambique and under future climate scenarios. Specifically, this study: i) evaluates the abundance, population structure and harvesting selection of these species; ii) characterizes the ethnobotanical knowledge and use of the two species; iii) examines the local production and trade of palm wine in the area; iv) examines the contribution of palm income to livelihoods and income diversification in area; v) describes the local management practices and perceptions on palm productivity and abundance; and vi) models the current and future distribution of the these palm species in the area. To evaluate the abundance, population structure and stability of these two palm species a population census was carried out, and the size class distribution, Simpson index of dominance, permutation index and the quotient between successive size classes were calculated. I further calculated the preference ratio for specific size classes. Additionally a questionnaire survey was conducted with 179 randomly selected households from the 16 villages in the study area to characterize the ethnobotanical knowledge and use of these two species, as well as to examine the contribution of palm income to livelihoods and diversification. Standard ethnobotanical indices were used as measures of each palm species use and knowledge while principal component analysis and cluster analysis were applied to highlight the livelihood patterns and the role of diversification and of palm income in local livelihoods. Structured interviews with 37 palm tappers were additionally used to examine the local production and trade of palm wine in the area, while both the household survey and palm tappers interviews, were employed to investigate the local management practices and perceptions on palms productivity and abundance. Maxent Software was used to model the current and future under climate change distribution of the two palm species. Hyphaene coriacea was more abundant than Phoenix reclinata. Both species exhibited steep negative slopes in the regression analyses of size class distribution, indicating the presence of more individuals in shorter size classes. Although there was a dominance of shorter over taller size classes, limited recruitment was observed through low stem densities of seedlings and juveniles compared to the 1-50 cm size class The Simpson index of dominance, the permutation index, and the fluctuating quotients between the consecutive size classes showed a level of instability in both populations. Hyphaene coriacea appeared to be more resilient to tapping than Phoenix reclinata as showed by the higher rate of stem survival after tapping. Hyphaene coriacea was favored for tapping compared to Phoenix reclinata. The most preferred size class to tap for both species was between 101cm and 150 cm. Currently the distribution of Hyphaene coriacea and Phoenix reclinata was mostly confined to the eastern side of the study area. Most of the area was predicted as unsuitable for both palm species, with less than six percent predicted to be suitable or higher. The occurrence of both species appeared to be influenced mostly by water related variables, such as precipitation, and distance to rivers and distance to water bodies. The habitat suitability for Hyphaene coriacea was predicted to increase under future climate conditions scenarios, while little variation was predicted for Phoenix reclinata distribution. The knowledge about the uses of these two palm species was widespread in the area, although only 32% of respondents were engaged in palm exploitation. Thirteen palm products were exploited, with palm wine production from the sap of both palms being the dominant activity, followed by broom production from Phoenix reclinata stems and basket production from Hyphaene coriacea leaves. The cultural importance of these species included the production of anklets and skirts used during traditional dances and the use of palm wine in the traditional ritual of libation. Palm tapping was practiced year round in five of the sixteen villages in the area. Palm tapping was an important livelihood activity, contributing over 80% of tappers’ total annual income, and tappers earned up to three times more than the national minimum wage for the agricultural and forestry sector. Palm wine was also a highly commercial commodity in Zitundo area, with an average commercialization index above 60%. The income from palm wine sales showed an important role in mitigating the level of poverty in the area. Palm income accounted for over 60% reduction on poverty incidence among palm tappers. Households in Zitundo further engaged in some level of livelihood diversification. The majority of households adopted a wage-based strategy, although this strategy was among the less remunerative in terms of per capita cash income. A palm-based livelihood strategy, although adopted only by 11% of households, was one of the most remunerative strategies. Palm income played a vital role in enhancing household livelihoods and mitigating poverty in the area as shown by the lower poverty incidences among households engaged in the palm-based livelihood strategy than alternatives strategies. The village of household residency, along with household demographic and socio-economic characteristics appeared to determine the knowledge and exploitation level of palms as well as a households’ choice of livelihood strategy, level of palm wine returns, commercialization index and palm income dependency. The importance of palms in local livelihoods and poverty alleviation needs greater acknowledgement by government and development agencies in the area. Palm wine, broom and basket production have a high potential for income generation, and therefore should be included in future local development policies and poverty reduction strategies. Although palms are an open access resource in Zitundo area, the perception is that they are abundant and that tapping does not have many detrimental effects. However, this study found some negative impacts of tapping on the recruitment of both palms species. The inclusion of palm products in future development programs and poverty reduction strategies will require the design of participatory conservation and management strategies that involve all palm users groups and others stakeholders and include long-term participatory monitoring of the effect of palm use on the populations.
- Full Text:
- Date Issued: 2020
The determination of whether a Unified Communication System can be effective in supporting informal communication and collaboration in virtual teams
- Authors: Hill, Kyle
- Date: 2020
- Subjects: Telecommuting , Virtual work teams , Telecommunication systems , Computer networks
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146343 , vital:38517
- Description: The overall objective of the research is to determine whether a Unified Communication System intervention can be effective in supporting informal communication and collaboration in virtual teams. In so doing, this research is aimed at developing a current framework of critical success factors for facilitating informal collaboration and communication. As teams have evolved to the point where there is no longer a need for team members to be co-located, with a greater importance now being placed on how they collaborate, this framework will also highlight how it can support virtual teams due to the huge potential advantage they can provide to the organisation. A virtual communication and collaboration system will be selected based on the outputs of the current framework and interactions which occur through the system will be observed to provide quantitative and qualitative results. In conclusion, the research will suggest recommendations for the successful implementation of informal communication and collaboration technologies within the organisation. The research will also indicate to a limited degree, the impact of the implementation of these technologies, and the outcome for the organisation, whether positive or negative. Whilst conducting the research, it became apparent that while the UCS was capable of performing the processes and functions required, the individuals and teams engaging with the technology did not always make use of the full scope of the technology provided. Regardless, a UCS was observed to provide direct benefits to an organisation in increasing communication and collaboration in the organisation. These increases can be observed in both the physical and virtual sense. However, the converse is true for generating social capital which lead to the observation that there are a smaller number of interactions happening in the smaller teams, but these are of higher value when compared to the larger teams of this study. It is also clear that the larger a team becomes, the more the trend is to focus on adopting new technologies to make their roles more efficient. This adoption is not however translated into outputs such as social capital but is translated into stronger networks and the formation of new networks. It is also clear that most negative factors around the UCS are related to the respondent’s hardware rather than the solution itself. Cost reductions because of virtuality will also be observed and using the Developed Framework as a blue print, an organisation should be able to observe direct benefits for an organisation by being able to confirm the thesis of this research in that having a UCS intervention is effective in supporting informal communication and collaboration in virtual teams.
- Full Text:
- Date Issued: 2020
- Authors: Hill, Kyle
- Date: 2020
- Subjects: Telecommuting , Virtual work teams , Telecommunication systems , Computer networks
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146343 , vital:38517
- Description: The overall objective of the research is to determine whether a Unified Communication System intervention can be effective in supporting informal communication and collaboration in virtual teams. In so doing, this research is aimed at developing a current framework of critical success factors for facilitating informal collaboration and communication. As teams have evolved to the point where there is no longer a need for team members to be co-located, with a greater importance now being placed on how they collaborate, this framework will also highlight how it can support virtual teams due to the huge potential advantage they can provide to the organisation. A virtual communication and collaboration system will be selected based on the outputs of the current framework and interactions which occur through the system will be observed to provide quantitative and qualitative results. In conclusion, the research will suggest recommendations for the successful implementation of informal communication and collaboration technologies within the organisation. The research will also indicate to a limited degree, the impact of the implementation of these technologies, and the outcome for the organisation, whether positive or negative. Whilst conducting the research, it became apparent that while the UCS was capable of performing the processes and functions required, the individuals and teams engaging with the technology did not always make use of the full scope of the technology provided. Regardless, a UCS was observed to provide direct benefits to an organisation in increasing communication and collaboration in the organisation. These increases can be observed in both the physical and virtual sense. However, the converse is true for generating social capital which lead to the observation that there are a smaller number of interactions happening in the smaller teams, but these are of higher value when compared to the larger teams of this study. It is also clear that the larger a team becomes, the more the trend is to focus on adopting new technologies to make their roles more efficient. This adoption is not however translated into outputs such as social capital but is translated into stronger networks and the formation of new networks. It is also clear that most negative factors around the UCS are related to the respondent’s hardware rather than the solution itself. Cost reductions because of virtuality will also be observed and using the Developed Framework as a blue print, an organisation should be able to observe direct benefits for an organisation by being able to confirm the thesis of this research in that having a UCS intervention is effective in supporting informal communication and collaboration in virtual teams.
- Full Text:
- Date Issued: 2020
The development of a set of guidelines for the revision of psychological tests and the use of revised psychological tests
- Authors: Cronje, Johan Herman
- Date: 2020
- Subjects: Psychological tests
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46350 , vital:39567
- Description: The psychological testindustry has produced a wide variety of psychological tests that are used by professionals to facilitate measurement and decision-making. Tests are updated and revised periodically in order to remain current, valid and reliable in what is a competitive psychometric industry. Despite the prevalence of test revisions, especially in recent years, a number of authors have commented on the lack of comprehensive guidelines for test revision. Guidelines shouldcover aspects such as what the different types of revision are, when to embark on a revision, whatprocessto followand how test users should use revised tests. Test revision differs from test construction in a number of ways. There are external factors that affect the regularity with which a test should be revised. Test revision also involves more role players than test construction, including the opinions of those test users who may be resistant to any change in the previous test edition. Finally, revised tests sometimes have to contend with requirements from the test publisher who purchased the test or distribution rights from the developer. Test revision is expensive and time consuming, which leaves little scope for experimentation or trial-and-error. The availability of expertise, as well as the human and financial resources required to complete test revisionscan make such projects unaffordable, especiallyforprofessionals indeveloping countries, such as South Africa.It may be more feasible for such professionalsto collaborate with international revision projects. By doing so they cangain experience in test revision, contribute indigenous information that could shapethe revision ofan international test, increase opportunities to engage with international users, and potentially source international funding for research in their own country. The current studydevelopeda comprehensive and practical set of 30 guidelines to assist those involved in test revision. These guidelines were peer-reviewed and refined. Finally, the guidelines were field-tested using a case study of a recently revised ivdevelopmentaltest, the Griffiths III. Professionals from South Africa, including the present researcher,formed part of the international team for the extensive revision of the Griffiths III, which makes this test an ideal case study from both the perspectives of the developed test revision guidelines as well as collaboration of professionals from a developing country in an international test revision. The knowledge gainedfrom the development of guidelines and international collaboration in test revision is reflected on.
- Full Text:
- Date Issued: 2020
- Authors: Cronje, Johan Herman
- Date: 2020
- Subjects: Psychological tests
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46350 , vital:39567
- Description: The psychological testindustry has produced a wide variety of psychological tests that are used by professionals to facilitate measurement and decision-making. Tests are updated and revised periodically in order to remain current, valid and reliable in what is a competitive psychometric industry. Despite the prevalence of test revisions, especially in recent years, a number of authors have commented on the lack of comprehensive guidelines for test revision. Guidelines shouldcover aspects such as what the different types of revision are, when to embark on a revision, whatprocessto followand how test users should use revised tests. Test revision differs from test construction in a number of ways. There are external factors that affect the regularity with which a test should be revised. Test revision also involves more role players than test construction, including the opinions of those test users who may be resistant to any change in the previous test edition. Finally, revised tests sometimes have to contend with requirements from the test publisher who purchased the test or distribution rights from the developer. Test revision is expensive and time consuming, which leaves little scope for experimentation or trial-and-error. The availability of expertise, as well as the human and financial resources required to complete test revisionscan make such projects unaffordable, especiallyforprofessionals indeveloping countries, such as South Africa.It may be more feasible for such professionalsto collaborate with international revision projects. By doing so they cangain experience in test revision, contribute indigenous information that could shapethe revision ofan international test, increase opportunities to engage with international users, and potentially source international funding for research in their own country. The current studydevelopeda comprehensive and practical set of 30 guidelines to assist those involved in test revision. These guidelines were peer-reviewed and refined. Finally, the guidelines were field-tested using a case study of a recently revised ivdevelopmentaltest, the Griffiths III. Professionals from South Africa, including the present researcher,formed part of the international team for the extensive revision of the Griffiths III, which makes this test an ideal case study from both the perspectives of the developed test revision guidelines as well as collaboration of professionals from a developing country in an international test revision. The knowledge gainedfrom the development of guidelines and international collaboration in test revision is reflected on.
- Full Text:
- Date Issued: 2020
The effect of gamma radiation on the physical and chemical properties of wool
- Authors: Rapakgadi, Jim
- Date: 2020
- Subjects: Semiconductors -- Effect of radiation on
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/47668 , vital:40263
- Description: Pathogens (e.g. viruses, spores and bacteria) remain one of the biggest threats to trading and the economy of natural fibre products, such as wool, mohair and cotton. One of the means to kill or eliminate pathogens is by radiation sterilisation, involving electromagnetic radiation (e.g. gamma radiation and UV light). The research, reported in this thesis, was aimed at establishing the effect of gamma irradiation dosage on the various quality related physical and chemical characteristics of four different types of merino wool when treated in situ in scoured and greasy state in mini-bale form. Specific properties studied include wool colour (yellowness and brightness), solubility (alkali solubility and urea bisulphite solubility), fibre diameter and tensile properties (staple strength and bundle tenacity). Standard analytical and diagnostic techniques were used to assess changes, if any, in the above mentioned properties due to the radiation treatment. Nominal radiation dosages, ranging from 25 kGy to 75 kGy (actual measured from 0 kGy to 92.2 kGy) were used, 50 kGy normally being regarded as sufficient to destroy the pathogens in question. It was found that nominial gamma radiation dosages of up to 92.2 kGy did not significantly affect fibre diameter or staple length, indicating that no irreversible swelling of the wool fibres occurred as a result of gamma irradiation. Alkali and urea bisulphite solubility as well as yellowness, on the other hand, showed a systematic increase with an increase in irradiation dose, indicating that changes occurred at molecular level. Fibre tensile properties (staple strength and bundle tenacity) were also affected but to a much lesser extent than solubility and colour. The various merino wool types studied showed similar reactions to the radiation treatment, irrespective of the wool quality and type and also whether they were treated in greasy or scoured form.
- Full Text:
- Date Issued: 2020
- Authors: Rapakgadi, Jim
- Date: 2020
- Subjects: Semiconductors -- Effect of radiation on
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/47668 , vital:40263
- Description: Pathogens (e.g. viruses, spores and bacteria) remain one of the biggest threats to trading and the economy of natural fibre products, such as wool, mohair and cotton. One of the means to kill or eliminate pathogens is by radiation sterilisation, involving electromagnetic radiation (e.g. gamma radiation and UV light). The research, reported in this thesis, was aimed at establishing the effect of gamma irradiation dosage on the various quality related physical and chemical characteristics of four different types of merino wool when treated in situ in scoured and greasy state in mini-bale form. Specific properties studied include wool colour (yellowness and brightness), solubility (alkali solubility and urea bisulphite solubility), fibre diameter and tensile properties (staple strength and bundle tenacity). Standard analytical and diagnostic techniques were used to assess changes, if any, in the above mentioned properties due to the radiation treatment. Nominal radiation dosages, ranging from 25 kGy to 75 kGy (actual measured from 0 kGy to 92.2 kGy) were used, 50 kGy normally being regarded as sufficient to destroy the pathogens in question. It was found that nominial gamma radiation dosages of up to 92.2 kGy did not significantly affect fibre diameter or staple length, indicating that no irreversible swelling of the wool fibres occurred as a result of gamma irradiation. Alkali and urea bisulphite solubility as well as yellowness, on the other hand, showed a systematic increase with an increase in irradiation dose, indicating that changes occurred at molecular level. Fibre tensile properties (staple strength and bundle tenacity) were also affected but to a much lesser extent than solubility and colour. The various merino wool types studied showed similar reactions to the radiation treatment, irrespective of the wool quality and type and also whether they were treated in greasy or scoured form.
- Full Text:
- Date Issued: 2020
The effects of economic and political instability on decentralised secondary schools in Mashonaland Central Province, Zimbabwe: a case study
- Authors: Katsinde, Tapfuiwa James
- Date: 2020
- Subjects: Education, Secondary -- Political aspects -- Zimbabwe , Political violence -- Zimbabwe , Zimbabwe -- Economic conitions -- 1980- , Zimbabwe -- Politics and government -- 1980-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/165610 , vital:41263
- Description: The purpose of the study was to analyse the effects of economic and political instability on decentralised secondary schools in Mashonaland Central Province, Zimbabwe between 2000 and 2017. Previous studies in Zimbabwe and elsewhere have shown that schools were negatively affected by economic and political instability. This study adds to this literature by using habitus as a conceptual framework. This was a qualitative study which made use of a multi-case research design. Data was collected using focus group discussions, interviews and document analysis. Eight research sites in the form of secondary schools in four districts were used. Data analysis was done using theoretical prepositions guided by research objectives and research questions. Data presentations was characterised by quotes of participants. Trustworthiness based on dependability, credibility, transferability and conformability formed the basis of quality assurance measures. The study revealed that economic and political instability had similar negative results in the field of secondary schools in the province. Economic instability negatively affected school activities which included teaching and learning, administration and development work. In addition economic instability affected individual secondary school actors psychologically. Economic instability affected relations among the secondary school actors by aggravating already existing contestations amongst actors. Similarly, political instability affected secondary school activities such as teaching and learning, school administration, development, donations and social benefits. Secondary school actors were individually affected psychologically and through physical abuse and the way they responded to political instability. The study has shown that decentralised secondary schools found it difficult to solve the problems introduced by economic and political instability especially when the instabilities occurred within the difficulties of the broader Zimbabwean context. It is therefore recommended that decentralised secondary schools should be assisted financially and with resources to withstand economic challenges. There is a need to protect secondary schools from political activities and activists as these have devastating effects on education if allowed to have a free reign. Further similar research is recommended for other provinces in the country.
- Full Text:
- Date Issued: 2020
- Authors: Katsinde, Tapfuiwa James
- Date: 2020
- Subjects: Education, Secondary -- Political aspects -- Zimbabwe , Political violence -- Zimbabwe , Zimbabwe -- Economic conitions -- 1980- , Zimbabwe -- Politics and government -- 1980-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/165610 , vital:41263
- Description: The purpose of the study was to analyse the effects of economic and political instability on decentralised secondary schools in Mashonaland Central Province, Zimbabwe between 2000 and 2017. Previous studies in Zimbabwe and elsewhere have shown that schools were negatively affected by economic and political instability. This study adds to this literature by using habitus as a conceptual framework. This was a qualitative study which made use of a multi-case research design. Data was collected using focus group discussions, interviews and document analysis. Eight research sites in the form of secondary schools in four districts were used. Data analysis was done using theoretical prepositions guided by research objectives and research questions. Data presentations was characterised by quotes of participants. Trustworthiness based on dependability, credibility, transferability and conformability formed the basis of quality assurance measures. The study revealed that economic and political instability had similar negative results in the field of secondary schools in the province. Economic instability negatively affected school activities which included teaching and learning, administration and development work. In addition economic instability affected individual secondary school actors psychologically. Economic instability affected relations among the secondary school actors by aggravating already existing contestations amongst actors. Similarly, political instability affected secondary school activities such as teaching and learning, school administration, development, donations and social benefits. Secondary school actors were individually affected psychologically and through physical abuse and the way they responded to political instability. The study has shown that decentralised secondary schools found it difficult to solve the problems introduced by economic and political instability especially when the instabilities occurred within the difficulties of the broader Zimbabwean context. It is therefore recommended that decentralised secondary schools should be assisted financially and with resources to withstand economic challenges. There is a need to protect secondary schools from political activities and activists as these have devastating effects on education if allowed to have a free reign. Further similar research is recommended for other provinces in the country.
- Full Text:
- Date Issued: 2020
The Effects of exchange rates on bilateral trade balances of SACU members states with their trading partners
- Authors: Mhaka, Simbarashe
- Date: 2020
- Subjects: Economic development -- South Africa , Purchasing power parity -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50371 , vital:42152
- Description: The fluctuations of exchange rates prevent countries from achieving stability in their external account records. Appreciation or depreciation has effects on international trade. This thesis examines the relationship between exchange rate fluctuations on bilateral trade balances focusing on the SACU region. There are several theories made to explain the relationship between exchange rate and trade balances. In examining this phenomenon, this thesis will unveil if the purchasing power parity theory, the Marshall-Lerner condition and the J-curve effect holds in the Southern African Customs Union (SACU) countries. This analysis is divided into three parts. The first part examines the stability of the exchange rate in the SACU countries in the long run as given by the purchasing power parity. To test for the Purchasing Power Parity theory, the recently developed powerful unit root test was applied with multiple smooth structural breaks of Omay (2015), based on a Fractional Frequency Flexible Fourier Form (FFFFF) on unique data of SACU countries covering the monthly period of 1995M01-2017M11. The Purchasing Power Parity (PPP) results show that the nominal effective exchange rate (NEER) of all SACU members does not provide evidence for PPP theory. In terms of the real effective exchange rate (REER), the PPP condition holds in the case of South Africa only. Further unit root investigations were carried out using the panel data for all SACU members, NEER and REER. The FFFFF test results for panel data shows strong evidence of the PPP while the standard DF test rejects PPP theory in the SACU’s NEER. Both the standard DF and the FFFFF tests show strong evidence of PPP theory in the case of SACU’s REER. The second section of the analysis examines the Marshall-Lerner condition employing annual data from the period of 1980-2017. The import and export model were examined firstly in a time series format and then in a panel data format. The time series data was examined using the ARDL (PMG) model while the panel data used the panel ARDL, fully modified OLS (FMOLS) method and the Dynamic OLS (DOLS) method of estimation. The PMG/ARDL model shows no evidence to support the existence of the Marshall-Lerner condition in the short run for all SACU members. However, only two out of five countries show evidence of the Marshall-Lerner condition in the long run. There is strong evidence of the Marshall-Lerner condition in Namibia and Botswana in the long run using the PMG/ARDL model.
- Full Text:
- Date Issued: 2020
- Authors: Mhaka, Simbarashe
- Date: 2020
- Subjects: Economic development -- South Africa , Purchasing power parity -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50371 , vital:42152
- Description: The fluctuations of exchange rates prevent countries from achieving stability in their external account records. Appreciation or depreciation has effects on international trade. This thesis examines the relationship between exchange rate fluctuations on bilateral trade balances focusing on the SACU region. There are several theories made to explain the relationship between exchange rate and trade balances. In examining this phenomenon, this thesis will unveil if the purchasing power parity theory, the Marshall-Lerner condition and the J-curve effect holds in the Southern African Customs Union (SACU) countries. This analysis is divided into three parts. The first part examines the stability of the exchange rate in the SACU countries in the long run as given by the purchasing power parity. To test for the Purchasing Power Parity theory, the recently developed powerful unit root test was applied with multiple smooth structural breaks of Omay (2015), based on a Fractional Frequency Flexible Fourier Form (FFFFF) on unique data of SACU countries covering the monthly period of 1995M01-2017M11. The Purchasing Power Parity (PPP) results show that the nominal effective exchange rate (NEER) of all SACU members does not provide evidence for PPP theory. In terms of the real effective exchange rate (REER), the PPP condition holds in the case of South Africa only. Further unit root investigations were carried out using the panel data for all SACU members, NEER and REER. The FFFFF test results for panel data shows strong evidence of the PPP while the standard DF test rejects PPP theory in the SACU’s NEER. Both the standard DF and the FFFFF tests show strong evidence of PPP theory in the case of SACU’s REER. The second section of the analysis examines the Marshall-Lerner condition employing annual data from the period of 1980-2017. The import and export model were examined firstly in a time series format and then in a panel data format. The time series data was examined using the ARDL (PMG) model while the panel data used the panel ARDL, fully modified OLS (FMOLS) method and the Dynamic OLS (DOLS) method of estimation. The PMG/ARDL model shows no evidence to support the existence of the Marshall-Lerner condition in the short run for all SACU members. However, only two out of five countries show evidence of the Marshall-Lerner condition in the long run. There is strong evidence of the Marshall-Lerner condition in Namibia and Botswana in the long run using the PMG/ARDL model.
- Full Text:
- Date Issued: 2020
The forensic mental health profile of women offenders in the Eastern Cape, South Africa
- Authors: Nagdee, Mohammed
- Date: 2020
- Subjects: Female offenders -- Mental health , Female offenders -- South Africa -- Psychology , Female offenders -- South Africa -- Mental health , People with mental disabilities and crime , Women murderers -- South Africa , Forensic psychology -- South Africa , Fort England Psychiatric Hospital
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167109 , vital:41438
- Description: Introduction There is a dearth of research on mental health issues in women offenders in South Africa, especially regarding their socio-demographic backgrounds, offence characteristics, and forensic mental health profiles. Objectives This study examined the psychosocial and forensic mental health profile of women offenders referred by eastern Cape courts for forensic evaluation. A range of socio-demographic, criminological, clinical and forensic mental health variables were systematically explored. Methods A bi-phasic, mixed methods study design was adopted. The clinical and forensic records of all women referred for forensic evaluation to Fort England forensic psychiatric hospital in the Eastern Cape, South Africa were retrospectively reviewed, comprising 173 individual cases in the study period of 1993-2017. Inferential statistical analyses (chi-squared and multivariate logistic regression) were applied to explore relationships between variables and offending outcomes of nterest. Detailed semi-structured interviews were subsequently conducted with a sub-sample of 8 women with mental disorder and violent offending ackgrounds. Interview transcripts thematically analysed. Results Most women came from impoverished and disadvantaged backgrounds. Whilst the majority were first offenders, a high proportion had violent index offences, with murder, attempted murder and assault with intent to do grievous bodily harm accounting for over half of cases. The majority of victims of violence were well known to the perpetrator, especially as biological children, intimate male partners or close family members. Biological children in their first year of life were particularly vulnerable to being victims of homicidal violence. Disproportionately high rates of pre-offence mental illness, alcohol misuse, HIV infection and prior abuse of the offender (especially by intimate male partners) were present. High rates of severe mental disorders (especially psychiatric comorbidity and psychotic-spectrum disorders), and relatively low rates of personality disorders and substance disorders were diagnosed. The majority of women were declared to lack trial competence and criminal capacity, respectively, following forensic evaluation. Women who had backgrounds of prior abuse themselves had over three mes the odds of subsequent violent offending in general, and almost six times the odds of homicidal offending in particular. Homicidal offences were significantly more commonly committed by women with no prior psychiatric history and no psychiatric comorbidity. Women who committed homicide had over eleven times of killing children as opposed to adults. Women over the age of 30 years, and those without psychiatric comorbidity, were significantly less likely to have killed children. Thematic analysis of interviews emphasized the important roles played by gender, self-image, and mental health in violent offending pathways. Conclusions A complex array of socio-demographic, criminological, clinical and forensic variables interact in women offenders of the Eastern Cape referred by courts for forensic evaluation. Exploration of these factors improves understanding of the broader psychosocial context of female offending, and of the personal experiences of the women themselves. This in turn provides an enhanced gender-focus to guide the progressive changes required in policy, legislative, clinical and research endeavours in this field.
- Full Text:
- Date Issued: 2020
- Authors: Nagdee, Mohammed
- Date: 2020
- Subjects: Female offenders -- Mental health , Female offenders -- South Africa -- Psychology , Female offenders -- South Africa -- Mental health , People with mental disabilities and crime , Women murderers -- South Africa , Forensic psychology -- South Africa , Fort England Psychiatric Hospital
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167109 , vital:41438
- Description: Introduction There is a dearth of research on mental health issues in women offenders in South Africa, especially regarding their socio-demographic backgrounds, offence characteristics, and forensic mental health profiles. Objectives This study examined the psychosocial and forensic mental health profile of women offenders referred by eastern Cape courts for forensic evaluation. A range of socio-demographic, criminological, clinical and forensic mental health variables were systematically explored. Methods A bi-phasic, mixed methods study design was adopted. The clinical and forensic records of all women referred for forensic evaluation to Fort England forensic psychiatric hospital in the Eastern Cape, South Africa were retrospectively reviewed, comprising 173 individual cases in the study period of 1993-2017. Inferential statistical analyses (chi-squared and multivariate logistic regression) were applied to explore relationships between variables and offending outcomes of nterest. Detailed semi-structured interviews were subsequently conducted with a sub-sample of 8 women with mental disorder and violent offending ackgrounds. Interview transcripts thematically analysed. Results Most women came from impoverished and disadvantaged backgrounds. Whilst the majority were first offenders, a high proportion had violent index offences, with murder, attempted murder and assault with intent to do grievous bodily harm accounting for over half of cases. The majority of victims of violence were well known to the perpetrator, especially as biological children, intimate male partners or close family members. Biological children in their first year of life were particularly vulnerable to being victims of homicidal violence. Disproportionately high rates of pre-offence mental illness, alcohol misuse, HIV infection and prior abuse of the offender (especially by intimate male partners) were present. High rates of severe mental disorders (especially psychiatric comorbidity and psychotic-spectrum disorders), and relatively low rates of personality disorders and substance disorders were diagnosed. The majority of women were declared to lack trial competence and criminal capacity, respectively, following forensic evaluation. Women who had backgrounds of prior abuse themselves had over three mes the odds of subsequent violent offending in general, and almost six times the odds of homicidal offending in particular. Homicidal offences were significantly more commonly committed by women with no prior psychiatric history and no psychiatric comorbidity. Women who committed homicide had over eleven times of killing children as opposed to adults. Women over the age of 30 years, and those without psychiatric comorbidity, were significantly less likely to have killed children. Thematic analysis of interviews emphasized the important roles played by gender, self-image, and mental health in violent offending pathways. Conclusions A complex array of socio-demographic, criminological, clinical and forensic variables interact in women offenders of the Eastern Cape referred by courts for forensic evaluation. Exploration of these factors improves understanding of the broader psychosocial context of female offending, and of the personal experiences of the women themselves. This in turn provides an enhanced gender-focus to guide the progressive changes required in policy, legislative, clinical and research endeavours in this field.
- Full Text:
- Date Issued: 2020
The impact of the slum upgrading approach on the livelihoods of scheme participants in Uganda : using the sustainable livelihoods framework
- Authors: Karungi, Doreen
- Date: 2020
- Subjects: Slums -- Public welfare -- Uganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48412 , vital:40874
- Description: International and local agencies recommend implementing slum upgrading projects in slum areas for slum improvement. However, with no model or guiding principles provided to slum upgrading project implementers on how to upgrade a slum, slum clearance and redevelopment are implemented rather than slum upgrading consequently projects fail to benefit the target group, slum dwellers. Data collection, took place in five areas in Uganda that implemented slum upgrading. In depth interviews were held with project beneficiaries, local council officials and association executives, and government officials at the Ministry of Lands, Housing and Urban Development. Field observation, and document analysis was carried out. Data analysis involved the use of the sustainable livelihoods framework. This study demonstrates that the slum upgrading approach adopted in Uganda exhibited low sustainability and undercut the sustainability of livelihoods of scheme participants. Slum dwellers faced vulnerabilities from loss of land, characterized by rights based actions resulting in minimal to no compensation or eviction and loss of existing livelihoods. Slum upgrading projects introduced new livelihood opportunities that were too few for slum dwellers, were not sustainable and ended during or with project implementation, leaving beneficiaries without employment or income opportunities. Increased vulnerability was observed as slum dwellers that did not benefit from the project were displaced to worse conditions while slum dwellers that benefitted, project beneficiaries remained poor and in debt, with project loans to repay. Although project beneficiaries were provided with access to assets, they were unable to draw on these to build their livelihoods. Some beneficiaries sold plots and project houses allocated to them and moved to adjacent slums, where they lived in worse conditions. At the time of the current research, good quality houses in the slum upgrading areas did not belong to the original beneficiaries old dilapidated structures were occupied by project beneficiaries. This study shows that income earning activities carried out at the time of the study were similar to those carried out prior to the introduction of slum upgrading in project areas and were destroyed during project implementation or banned by implementers. These activities were however carried out in incomplete houses, vacant plots, temporary structures in project areas and in adjacent swamps and forest. Generally, after completion of slum upgrading projects, project areas, adjacent swamps and forest were characterized by haphazard developments including: rentals, informal businesses, farming, brewing and distilling local alcohol used by beneficiaries to derive livelihoods, in other words, slums were recreated, a problem slum upgrading project implementers set out to solve - except in one study area where the project was implemented differently as a result of persist rights based actions.
- Full Text:
- Date Issued: 2020
- Authors: Karungi, Doreen
- Date: 2020
- Subjects: Slums -- Public welfare -- Uganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48412 , vital:40874
- Description: International and local agencies recommend implementing slum upgrading projects in slum areas for slum improvement. However, with no model or guiding principles provided to slum upgrading project implementers on how to upgrade a slum, slum clearance and redevelopment are implemented rather than slum upgrading consequently projects fail to benefit the target group, slum dwellers. Data collection, took place in five areas in Uganda that implemented slum upgrading. In depth interviews were held with project beneficiaries, local council officials and association executives, and government officials at the Ministry of Lands, Housing and Urban Development. Field observation, and document analysis was carried out. Data analysis involved the use of the sustainable livelihoods framework. This study demonstrates that the slum upgrading approach adopted in Uganda exhibited low sustainability and undercut the sustainability of livelihoods of scheme participants. Slum dwellers faced vulnerabilities from loss of land, characterized by rights based actions resulting in minimal to no compensation or eviction and loss of existing livelihoods. Slum upgrading projects introduced new livelihood opportunities that were too few for slum dwellers, were not sustainable and ended during or with project implementation, leaving beneficiaries without employment or income opportunities. Increased vulnerability was observed as slum dwellers that did not benefit from the project were displaced to worse conditions while slum dwellers that benefitted, project beneficiaries remained poor and in debt, with project loans to repay. Although project beneficiaries were provided with access to assets, they were unable to draw on these to build their livelihoods. Some beneficiaries sold plots and project houses allocated to them and moved to adjacent slums, where they lived in worse conditions. At the time of the current research, good quality houses in the slum upgrading areas did not belong to the original beneficiaries old dilapidated structures were occupied by project beneficiaries. This study shows that income earning activities carried out at the time of the study were similar to those carried out prior to the introduction of slum upgrading in project areas and were destroyed during project implementation or banned by implementers. These activities were however carried out in incomplete houses, vacant plots, temporary structures in project areas and in adjacent swamps and forest. Generally, after completion of slum upgrading projects, project areas, adjacent swamps and forest were characterized by haphazard developments including: rentals, informal businesses, farming, brewing and distilling local alcohol used by beneficiaries to derive livelihoods, in other words, slums were recreated, a problem slum upgrading project implementers set out to solve - except in one study area where the project was implemented differently as a result of persist rights based actions.
- Full Text:
- Date Issued: 2020
The incidence of musculoskeletal disorders and stakeholder perceptions of work challenges in South-Eastern Nigerian quarry mining industry
- Authors: Egwuonwu, Victor Afamerfuna
- Date: 2020
- Subjects: Quarries and quarrying -- Health aspects -- Nigeria , Musculoskeletal system -- Diseases -- Nigeria , Miners -- Health and hygiene -- Nigeria
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/141263 , vital:37957
- Description: Musculoskeletal disorders (MSDs) are very common among industrial labourers, leading to sick leave absence, disability and low productivity at work. MSDs have multifactorial causes, thereby making it difficult to pinpoint the extent of the contributions of the various risks regarding the mechanism of its pathophysiology. Previously, attempts were made to study regional pain symptoms in varying occupational groups, disregarding the particularities of the different workplace situations. It is important to highlight, that quantifying physical exposure factors that contribute to MSDs occurrence using quantitative approach alone could be inadequate. It is therefore imperative to incorporate qualitative approach to unmask accompanying psychosocial stressors, which are mostly explanatory variables. The study investigated the following: 12-month retrospective prevalence of MSDs, prospective incidence, risk factors and pattern of MSDs in a 6-month follow-up survey of selected quarry mineworkers, who reported MSDs complaints at the mine clinic. The study also determined the level of psychosocial stress associated with working in the mine by understanding stakeholders’ perception of work challenges, and how it influenced recurrence of MSDs. The study utilised a mixed method design with two phases: phase 1 was an initial baseline retrospective prevalence and a prospective cohort-control incidence survey. The Cultural and Psychosocial Influence on Disability (CUPID) questionnaire was translated into an Igbo-language version, cross-culturally adapted and utilized. The instrument was administered via oral interview and sought information on the following: demographic characteristics; pain in different anatomical sites and associated disability for tasks of daily living; as well as information on any change of job and reason during the study period, recent pain in different anatomical sites and associated disability for tasks of daily living; distress from common somatic symptoms; mental health status, sickness absence in the past 5-months for musculoskeletal pain. Phase 2 was a qualitative focus group discussion that engaged mine stakeholders on their perceptions of work challenges. Descriptive statistics of mean and standard deviation was utilised to analyse sociodemographic characteristics of participants. MSD incidence rates were estimated and the patterns of MSD incidence at different anatomical sites were also determined. The Cox proportional regression analyses were utilised to compare hazard ratios of MSD risks between the exposed cohorts and unexposed cohorts in the phase one incidence survey, alpha level was set at 0.05. Transcription, thematic and content analyses with the aid of Nvivo version 11 for windows was used to interpret stakeholders’ perception of work challenges. The incidence of MSD was 6.2 per 1000, with shoulder pain being the most reported complaint (40% prevalence). This was followed by back pain with the distribution of back pain presented as follows: upper back (20.37%), lower back (45.50%) and both (34.13%). All participants reported previous medical history of back, shoulder and neck pain. The relative risk ratio of mineworkers to MSDs was 4.57, which implies that the mineworkers were approximately 5 times more at risk of developing MSDs compared to the recruited unexposed cohorts. Meanwhile, wrist pain (43.58%) was the highest MSD complaints which lead miners to be absent from work, followed by knee and back with 35.42% and 21% respectively. Physical job risks, such as III working underground and squatting or kneeling at work were all significantly associated with MSDs recurrence in all six body parts (HR: 1.12-1.92, 95%CI). Similarly, time pressure to complete task, low decision latitude, poor job satisfaction, somatisation and mental disorder, job insecurity, poor incentive system (HR: 1.01-1.75, 95%CI) were perceived by stakeholders’ and participants alike in the study to be significantly associated with MSDs incidence. Quarrymen are exposed to high MSD risks associated with elevated psychosocial stress from their difficult work situations. The South Eastern Nigerian mine stakeholders believed that the high incidence of MSDs may have a substantial impact on health and productivity in the near future. Necessitating a clear need for the promotion of stakeholder’s engagement concerning safe work policy implementation initiatives in the sector.
- Full Text:
- Date Issued: 2020
- Authors: Egwuonwu, Victor Afamerfuna
- Date: 2020
- Subjects: Quarries and quarrying -- Health aspects -- Nigeria , Musculoskeletal system -- Diseases -- Nigeria , Miners -- Health and hygiene -- Nigeria
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/141263 , vital:37957
- Description: Musculoskeletal disorders (MSDs) are very common among industrial labourers, leading to sick leave absence, disability and low productivity at work. MSDs have multifactorial causes, thereby making it difficult to pinpoint the extent of the contributions of the various risks regarding the mechanism of its pathophysiology. Previously, attempts were made to study regional pain symptoms in varying occupational groups, disregarding the particularities of the different workplace situations. It is important to highlight, that quantifying physical exposure factors that contribute to MSDs occurrence using quantitative approach alone could be inadequate. It is therefore imperative to incorporate qualitative approach to unmask accompanying psychosocial stressors, which are mostly explanatory variables. The study investigated the following: 12-month retrospective prevalence of MSDs, prospective incidence, risk factors and pattern of MSDs in a 6-month follow-up survey of selected quarry mineworkers, who reported MSDs complaints at the mine clinic. The study also determined the level of psychosocial stress associated with working in the mine by understanding stakeholders’ perception of work challenges, and how it influenced recurrence of MSDs. The study utilised a mixed method design with two phases: phase 1 was an initial baseline retrospective prevalence and a prospective cohort-control incidence survey. The Cultural and Psychosocial Influence on Disability (CUPID) questionnaire was translated into an Igbo-language version, cross-culturally adapted and utilized. The instrument was administered via oral interview and sought information on the following: demographic characteristics; pain in different anatomical sites and associated disability for tasks of daily living; as well as information on any change of job and reason during the study period, recent pain in different anatomical sites and associated disability for tasks of daily living; distress from common somatic symptoms; mental health status, sickness absence in the past 5-months for musculoskeletal pain. Phase 2 was a qualitative focus group discussion that engaged mine stakeholders on their perceptions of work challenges. Descriptive statistics of mean and standard deviation was utilised to analyse sociodemographic characteristics of participants. MSD incidence rates were estimated and the patterns of MSD incidence at different anatomical sites were also determined. The Cox proportional regression analyses were utilised to compare hazard ratios of MSD risks between the exposed cohorts and unexposed cohorts in the phase one incidence survey, alpha level was set at 0.05. Transcription, thematic and content analyses with the aid of Nvivo version 11 for windows was used to interpret stakeholders’ perception of work challenges. The incidence of MSD was 6.2 per 1000, with shoulder pain being the most reported complaint (40% prevalence). This was followed by back pain with the distribution of back pain presented as follows: upper back (20.37%), lower back (45.50%) and both (34.13%). All participants reported previous medical history of back, shoulder and neck pain. The relative risk ratio of mineworkers to MSDs was 4.57, which implies that the mineworkers were approximately 5 times more at risk of developing MSDs compared to the recruited unexposed cohorts. Meanwhile, wrist pain (43.58%) was the highest MSD complaints which lead miners to be absent from work, followed by knee and back with 35.42% and 21% respectively. Physical job risks, such as III working underground and squatting or kneeling at work were all significantly associated with MSDs recurrence in all six body parts (HR: 1.12-1.92, 95%CI). Similarly, time pressure to complete task, low decision latitude, poor job satisfaction, somatisation and mental disorder, job insecurity, poor incentive system (HR: 1.01-1.75, 95%CI) were perceived by stakeholders’ and participants alike in the study to be significantly associated with MSDs incidence. Quarrymen are exposed to high MSD risks associated with elevated psychosocial stress from their difficult work situations. The South Eastern Nigerian mine stakeholders believed that the high incidence of MSDs may have a substantial impact on health and productivity in the near future. Necessitating a clear need for the promotion of stakeholder’s engagement concerning safe work policy implementation initiatives in the sector.
- Full Text:
- Date Issued: 2020
The international community’s implementation of the Responsibility to Protect (R2P) Principle: a Comparative Study of Sudan and Libya
- Authors: Nizeimana, John Bosco
- Date: 2020
- Subjects: Responsibility to protect (International law) , Humanitarian intervention -- Libya , Libya -- Foreign relations -- 1969- , Libya -- Politics and government -- 1969- , Humanitarian intervention -- Sudan , Sudan -- Foreign relations , Sudan -- Politics and government -- 1985-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162631 , vital:40962
- Description: In the history of international relations, the adoption of the R2P principle in 2005 was widely understood to be a break-through in the international community’s efforts to respond to massive human rights violations and atrocities. Despite this, the international community’s implementation of the R2P has been widely contested, including in relation to its application in Sudan and Libya. There is agreement in the literature that, in both cases, the implementation of the R2P failed to achieve its intended purpose of protecting civilian populations. This thesis addresses the question of why the R2P failed in Sudan and Libya. Most explanations concerning the failure of the R2P in Sudan and Libya tend to focus on the politics of big power countries. The study argues that the failure to implement the R2P is related to the interactions between regional organisations and the international community (global organisations like UN) in attempting to solve large-scale human rights violent conflict. The study is firmly embedded in scholarly debates about humanitarian intervention so as to demonstrate the fact that this study is part of efforts to advance knowledge of scholarly debates on humanitarian intervention in this contemporary world order. The study combines a case study approach and qualitative research approach to achieve a nuanced understanding of the reason why the R2P failed in Sudan and Libya. The study relied on the use of documentary reviews and in-depth interviews of experts to collect data which was analysed using critical discourse analysis. The thesis demonstrated that the implementation of the R2P was characterised by a breakdown of the relationship between regional actors like the AU and global institutions like the UN. This breakdown contributed to the failure of the R2P in Sudan and Libya. The lack of financial and operational capacity for rapid deployment, the internal divisions with the AU, and the lack of political will within the AU members states were also cited as obstacles to the realisation of the R2P efforts in Sudan. To establish in-depth knowledge the study revealed other factors related to the politics of big power countries and how they played a part in the failure of the R2P in Sudan and Libya. Among these factors include implementation inconsistencies, the ICC factor, the absence of UNSC consensus in the response over Darfur and Libya, and the veto power factor and its implications in the efforts of the international community in both cases. This study also showed that the implementation of the R2P may not work effectively if left only to international actors to implement. Regional and sub-regional actors are important stakeholders of the R2P, and their interactions with the international community in actualising the implmementation of the R2P on the ground are essential. The manner in which the R2P was applied in Sudan and Libya is an indication its implementation requires improved interaction between regional actors and the international community at all level of collaboration including at global, regional and sub-regional level. This can build a strong foundation to drive the effective implementation of the R2P in future interventions. The findings of this thesis will significantly improve the available literature on the reason why the R2P failed in Sudan and Libya, particularly by paying much attention to the role of regional and sub-regional actors.
- Full Text:
- Date Issued: 2020
- Authors: Nizeimana, John Bosco
- Date: 2020
- Subjects: Responsibility to protect (International law) , Humanitarian intervention -- Libya , Libya -- Foreign relations -- 1969- , Libya -- Politics and government -- 1969- , Humanitarian intervention -- Sudan , Sudan -- Foreign relations , Sudan -- Politics and government -- 1985-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162631 , vital:40962
- Description: In the history of international relations, the adoption of the R2P principle in 2005 was widely understood to be a break-through in the international community’s efforts to respond to massive human rights violations and atrocities. Despite this, the international community’s implementation of the R2P has been widely contested, including in relation to its application in Sudan and Libya. There is agreement in the literature that, in both cases, the implementation of the R2P failed to achieve its intended purpose of protecting civilian populations. This thesis addresses the question of why the R2P failed in Sudan and Libya. Most explanations concerning the failure of the R2P in Sudan and Libya tend to focus on the politics of big power countries. The study argues that the failure to implement the R2P is related to the interactions between regional organisations and the international community (global organisations like UN) in attempting to solve large-scale human rights violent conflict. The study is firmly embedded in scholarly debates about humanitarian intervention so as to demonstrate the fact that this study is part of efforts to advance knowledge of scholarly debates on humanitarian intervention in this contemporary world order. The study combines a case study approach and qualitative research approach to achieve a nuanced understanding of the reason why the R2P failed in Sudan and Libya. The study relied on the use of documentary reviews and in-depth interviews of experts to collect data which was analysed using critical discourse analysis. The thesis demonstrated that the implementation of the R2P was characterised by a breakdown of the relationship between regional actors like the AU and global institutions like the UN. This breakdown contributed to the failure of the R2P in Sudan and Libya. The lack of financial and operational capacity for rapid deployment, the internal divisions with the AU, and the lack of political will within the AU members states were also cited as obstacles to the realisation of the R2P efforts in Sudan. To establish in-depth knowledge the study revealed other factors related to the politics of big power countries and how they played a part in the failure of the R2P in Sudan and Libya. Among these factors include implementation inconsistencies, the ICC factor, the absence of UNSC consensus in the response over Darfur and Libya, and the veto power factor and its implications in the efforts of the international community in both cases. This study also showed that the implementation of the R2P may not work effectively if left only to international actors to implement. Regional and sub-regional actors are important stakeholders of the R2P, and their interactions with the international community in actualising the implmementation of the R2P on the ground are essential. The manner in which the R2P was applied in Sudan and Libya is an indication its implementation requires improved interaction between regional actors and the international community at all level of collaboration including at global, regional and sub-regional level. This can build a strong foundation to drive the effective implementation of the R2P in future interventions. The findings of this thesis will significantly improve the available literature on the reason why the R2P failed in Sudan and Libya, particularly by paying much attention to the role of regional and sub-regional actors.
- Full Text:
- Date Issued: 2020
The lived experiences of women with human immunodeficiency virus (HIV) in Malawi: an interpretative phenomenological analysis (IPA)
- Authors: Nkhalamba, Mathero Michelle
- Date: 2020
- Subjects: HIV-positive women -- Malawi , HIV infections -- Sex factors -- Malawi , HIV infections -- Social aspects -- Malawi , HIV-positive women -- Malawi -- Social conditions , HIV-positive women -- Malawi -- Economic conditions , Poverty -- Malawi , Antiretroviral agents -- Malawi , Phenomenological psychology
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145291 , vital:38425
- Description: Research on African women and HIV, particularly research that investigates their experiences of living with the virus, has been relatively peripheral. As a response to the apparent knowledge and research gaps, this project is a qualitative study involving women living with human immunodeficiency virus (WLHIV) and attending an anti-retroviral treatment (ART) clinic at Zomba Central Hospital in Southern Malawi. The study utilised an interpretative phenomenological analysis (IPA) approach, which informed all aspects of the data-collection and data-analysis processes. Using purposive sampling, 12 women were recruited and interviewed on three occasions over a period of six months. The interviews were conducted in Chichewa and audio recorded and later transcribed into English. Fourteen superordinate themes emerged from the analysis representing the women’s prominent life experiences, how they received their diagnosis, and how they contained the trauma of their diagnosis. The analysis also developed themes regarding how they coped with the challenges of living with the human immunodeficiency virus (HIV) and made sense of their experiences. The results showed that the women struggled with multiple challenges experienced through their various identities as WLHIV. The findings also pointed to interlocking disadvantages that put the women at risk of infection, and which were present from childhood. This has implications for more structural and multidisciplinary interventions for WLHIV.
- Full Text:
- Date Issued: 2020
- Authors: Nkhalamba, Mathero Michelle
- Date: 2020
- Subjects: HIV-positive women -- Malawi , HIV infections -- Sex factors -- Malawi , HIV infections -- Social aspects -- Malawi , HIV-positive women -- Malawi -- Social conditions , HIV-positive women -- Malawi -- Economic conditions , Poverty -- Malawi , Antiretroviral agents -- Malawi , Phenomenological psychology
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145291 , vital:38425
- Description: Research on African women and HIV, particularly research that investigates their experiences of living with the virus, has been relatively peripheral. As a response to the apparent knowledge and research gaps, this project is a qualitative study involving women living with human immunodeficiency virus (WLHIV) and attending an anti-retroviral treatment (ART) clinic at Zomba Central Hospital in Southern Malawi. The study utilised an interpretative phenomenological analysis (IPA) approach, which informed all aspects of the data-collection and data-analysis processes. Using purposive sampling, 12 women were recruited and interviewed on three occasions over a period of six months. The interviews were conducted in Chichewa and audio recorded and later transcribed into English. Fourteen superordinate themes emerged from the analysis representing the women’s prominent life experiences, how they received their diagnosis, and how they contained the trauma of their diagnosis. The analysis also developed themes regarding how they coped with the challenges of living with the human immunodeficiency virus (HIV) and made sense of their experiences. The results showed that the women struggled with multiple challenges experienced through their various identities as WLHIV. The findings also pointed to interlocking disadvantages that put the women at risk of infection, and which were present from childhood. This has implications for more structural and multidisciplinary interventions for WLHIV.
- Full Text:
- Date Issued: 2020