Design ethnography: methodological considerations for rebalancing socio-technical phenomena in CMS performativity
- Authors: Jordaan, Leandra
- Date: 2020
- Subjects: Database management -- Social aspects , Information technology -- Social aspects , Management information systems -- Social aspects , Database management -- Philosophy , Information technology -- Philosophy , Management information systems -- Philosophy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164781 , vital:41164
- Description: As a practitioner, I had been part of two Content Management System (CMS) Projects in a particular setting that did not deliver on the expected outcomes. The expected outcomes of the projects included streamlined processes, better access to information, functionalities to drive engagement, reduced time searching for information, and improved reusability of content. As I began to reflect on the projects, a certain discomfort developed when the social aspect was ignored in favour of the technological. I sought a better understanding, but I was unaware of the fact at first. The techno-centricity as a concept found in literature and my experience as content management (CM) practitioner – together informed my interest in rebalancing the social and the technological. Thus, I focused on conduct in performing of tasks and emphasised attention on the practices of experts who gave insight into context of CM and use. The research participants are communication practitioners who have the responsibility to communicate internally and externally on behalf of a publicly-funded university in South Africa. Guided by the abductive argument and literature, the key themes for the research focused on technology, individuals and the organisation. The focus on technology (CMS as a subfield of Information Systems) began with my involvement in two CMS Projects. What came to the fore was that the practitioner perspective, and thus their experiential knowledge are neglected in research and that it may be an over-emphasis on techno-centrism in CMS research. I sought to better balance the social and technological aspects. The second focus on individuals (communication practitioners) was to value the stakeholder who was considered representative of the worldviews of the community. I sought to support corporate communication practices in the task of relationship building with stakeholders. The findings showed that the culture of informatio sharing was low at the University. The third focus on the organisation (the University) was to prioritise the success of the communication undertaken by the University. I interrogated the role of power. I demonstrated how the role of power could be seen as productive and positive in the context of HE, the social reality of CUT, and this IS research itself. I positioned the research as interpretivistic. I used hermeneutics as a mode of analysis because as researcher-practitioner, I am part of the social reality of the research. A safeguard against my subjectivity was the use of Phronesis as an orientation to knowledge. An organisation with a shared understanding of ethics and values will balance instrumental rationality (scientific and technical reasoning) with value-rationality (moral reasoning about right and wrong actions). Phronesis is the virtue that should ensure ethical behaviour in actions, yet over time, social science research, in a quest to mimic the natural sciences, centred on episteme and techne. I constructed the lens by particularising the four value-rational questions of Flyvbjerg’s contemporary Phronesis to the performative perspective of the research. My interest in social reality, as well as socio-technical aspects, have led to design-ethnography (D-E) to emerge as the most suitable and most appropriate approach to the research. D-E asked the prescriptive ‘How’ and descriptive ‘What’ questions, whilst the Flyvbjergian Phronesis lens brought focus on the ‘Why’ question. D-E emphasised the betterment of the interaction and synergy between research conducted and practice. My status as an immersed researcher needed careful consideration, and D-E accepted that a certain level of immersion is necessary, D-E has short interventional fieldwork, and D-E has future-oriented engagement. The contemporary Phronesis used in the research is to enact D-E and not an all-encompassing guide for doing Phronesis research The key contributions to the research are predominantly methodological. The claims draw on evidence focused on the three themes technology, individuals and organisation, and the phenomena of interest which are to rebalance the social and the technological in CM practices. The first claim is that immersion in the context is possible and supported by the specific particularised approaches to the research. The second claim suggests a way to rebalance the socio-technical nature of Information Systems (IS). The third claim suggests that there is a viewpoint for power that is not focused on power’s oppressive nature which could see a diverging focus on power in IS research in future. In this viewpoint, the status quo of social reality is not questioned, nor are their emancipatory ambitions. The fourth and final claim suggests that Phronesis as a lens could enact D-E, which in turn is a method that assists in valuing the experience of the practitioner and the support of collaborative work. The research is recommended for IT/IS practitioners who prefer to value participants’ views in design. The approaches used could be of value for researchers who consider the context of their research to be of higher importance than the generalisation of outcomes. Researchers who find themselves in the position of being immersed in the context but question the correctness of active engagement in the field may discover some value from the research approaches and my experience. Also, researchers or practitioners who have an interest in the balance between social and the technological aspects of IS projects. Researchers or practitioners interested in Phronesis, and perhaps the viewpoint of a lens may also find value in this research.
- Full Text:
- Date Issued: 2020
- Authors: Jordaan, Leandra
- Date: 2020
- Subjects: Database management -- Social aspects , Information technology -- Social aspects , Management information systems -- Social aspects , Database management -- Philosophy , Information technology -- Philosophy , Management information systems -- Philosophy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164781 , vital:41164
- Description: As a practitioner, I had been part of two Content Management System (CMS) Projects in a particular setting that did not deliver on the expected outcomes. The expected outcomes of the projects included streamlined processes, better access to information, functionalities to drive engagement, reduced time searching for information, and improved reusability of content. As I began to reflect on the projects, a certain discomfort developed when the social aspect was ignored in favour of the technological. I sought a better understanding, but I was unaware of the fact at first. The techno-centricity as a concept found in literature and my experience as content management (CM) practitioner – together informed my interest in rebalancing the social and the technological. Thus, I focused on conduct in performing of tasks and emphasised attention on the practices of experts who gave insight into context of CM and use. The research participants are communication practitioners who have the responsibility to communicate internally and externally on behalf of a publicly-funded university in South Africa. Guided by the abductive argument and literature, the key themes for the research focused on technology, individuals and the organisation. The focus on technology (CMS as a subfield of Information Systems) began with my involvement in two CMS Projects. What came to the fore was that the practitioner perspective, and thus their experiential knowledge are neglected in research and that it may be an over-emphasis on techno-centrism in CMS research. I sought to better balance the social and technological aspects. The second focus on individuals (communication practitioners) was to value the stakeholder who was considered representative of the worldviews of the community. I sought to support corporate communication practices in the task of relationship building with stakeholders. The findings showed that the culture of informatio sharing was low at the University. The third focus on the organisation (the University) was to prioritise the success of the communication undertaken by the University. I interrogated the role of power. I demonstrated how the role of power could be seen as productive and positive in the context of HE, the social reality of CUT, and this IS research itself. I positioned the research as interpretivistic. I used hermeneutics as a mode of analysis because as researcher-practitioner, I am part of the social reality of the research. A safeguard against my subjectivity was the use of Phronesis as an orientation to knowledge. An organisation with a shared understanding of ethics and values will balance instrumental rationality (scientific and technical reasoning) with value-rationality (moral reasoning about right and wrong actions). Phronesis is the virtue that should ensure ethical behaviour in actions, yet over time, social science research, in a quest to mimic the natural sciences, centred on episteme and techne. I constructed the lens by particularising the four value-rational questions of Flyvbjerg’s contemporary Phronesis to the performative perspective of the research. My interest in social reality, as well as socio-technical aspects, have led to design-ethnography (D-E) to emerge as the most suitable and most appropriate approach to the research. D-E asked the prescriptive ‘How’ and descriptive ‘What’ questions, whilst the Flyvbjergian Phronesis lens brought focus on the ‘Why’ question. D-E emphasised the betterment of the interaction and synergy between research conducted and practice. My status as an immersed researcher needed careful consideration, and D-E accepted that a certain level of immersion is necessary, D-E has short interventional fieldwork, and D-E has future-oriented engagement. The contemporary Phronesis used in the research is to enact D-E and not an all-encompassing guide for doing Phronesis research The key contributions to the research are predominantly methodological. The claims draw on evidence focused on the three themes technology, individuals and organisation, and the phenomena of interest which are to rebalance the social and the technological in CM practices. The first claim is that immersion in the context is possible and supported by the specific particularised approaches to the research. The second claim suggests a way to rebalance the socio-technical nature of Information Systems (IS). The third claim suggests that there is a viewpoint for power that is not focused on power’s oppressive nature which could see a diverging focus on power in IS research in future. In this viewpoint, the status quo of social reality is not questioned, nor are their emancipatory ambitions. The fourth and final claim suggests that Phronesis as a lens could enact D-E, which in turn is a method that assists in valuing the experience of the practitioner and the support of collaborative work. The research is recommended for IT/IS practitioners who prefer to value participants’ views in design. The approaches used could be of value for researchers who consider the context of their research to be of higher importance than the generalisation of outcomes. Researchers who find themselves in the position of being immersed in the context but question the correctness of active engagement in the field may discover some value from the research approaches and my experience. Also, researchers or practitioners who have an interest in the balance between social and the technological aspects of IS projects. Researchers or practitioners interested in Phronesis, and perhaps the viewpoint of a lens may also find value in this research.
- Full Text:
- Date Issued: 2020
Design of Immunobiosensors for Detection of Tumor-Associated Anti-P53 Autoantibodies: Method Development
- Authors: Adeniyi, Omotayo Kayode
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162988 , vital:41002 , 10.21504/10962/162988
- Description: Introduction -- Experimental -- Label-Free Impedimetric Sensing of Anti-P53ab... -- Fluorescent detection of Anti-P53ab -- Peroxidase-like activity of Fe3O4@SiNP-APTES-Au@Pd... -- Colorimetric detection of Anti-P53ab , Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020. , Detection and profiling of circulating tumor-associated autoantibodies (TAAbs) are useful for screening and early-stage diagnosis of asymptomatic lung cancer. Immunobiosensor technologies aimed to accomplish the highly sensitive, rapid and low-cost detection of TAAbs can improve the early-stage detection of lung cancer. Immunobiosensors for the detection of anti-P53-tumour associated autoantibodies have been developed in this work. The design of sensing interfaces with immobilized P53 protein (P53ag) as a sensing element layer on a solid interface was investigated. Several methods of detecting anti-P53-antibodies (anti-P53ab) were investigated. These methods are label-free detection using electrochemical impedance spectroscopy (EIS) and two label techniques. The label-free electrochemical techniques utilize gold electrode pre-modified with a conducting layer of electrochemically grafted phenylethylamine for covalent immobilization of P53ag. The limit of anti-P53ab detection with the label-free EIS was 103.0 pg.ml-1. The labeled technique developed utilizes fluorescent, and peroxidase-like nanomaterial labeled antibody as a detection probe. For the fluorescence detection, fluorescent silica nanoparticles were synthesized by overloading FITC into the silica matrix and conjugated to detection antibody (anti-IgG). The detection of the anti-P53ab was based on the dissolution of the silica nanoparticles to release the loaded dye as a signal amplification strategy. The fluorescence detection was carried out on a microplate, and magnetic bead modified P53-antigen platforms and limit of detection (LoD) were 42.0 fg.ml-1 and 3.3 fg.ml-1 for anti-P53ab; respectively. Fe3O4@SiNP-APTES-Au@Pd hybrid nanoparticles were synthesized, and their peroxidase-like activity and colorimetric detection were evaluated. The Fe3O4@SiNP-APTES-Au@Pd exhibited comparable activity to HRP. The Fe3O4@SiNP-APTES-Au@Pd was conjugated to protein-G-anti-IgG for the detection of anti-P53ab on a microplate and cellulose paper platforms. The LoD was 20.0 fg.ml-1 and 63.0 fg.ml-1 for the microplate and cellulose paper platform; respectively. The potential application of the designed immunobiosensor was evaluated in simulated serum samples. The developed sensors showed higher detection sensitivity, stability and had a lower detection limit for anti-P53ab when compared with the ELISA based detection. The results have provided alternative and effective quantification approaches to ELISA and a promising future for multiplexed detection of tumor-associated autoantibodies. The developed methodologies in this thesis could be applied for the detection of other autoantibodies in other cancer types and auto-immune diseases.
- Full Text:
- Date Issued: 2020
- Authors: Adeniyi, Omotayo Kayode
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162988 , vital:41002 , 10.21504/10962/162988
- Description: Introduction -- Experimental -- Label-Free Impedimetric Sensing of Anti-P53ab... -- Fluorescent detection of Anti-P53ab -- Peroxidase-like activity of Fe3O4@SiNP-APTES-Au@Pd... -- Colorimetric detection of Anti-P53ab , Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020. , Detection and profiling of circulating tumor-associated autoantibodies (TAAbs) are useful for screening and early-stage diagnosis of asymptomatic lung cancer. Immunobiosensor technologies aimed to accomplish the highly sensitive, rapid and low-cost detection of TAAbs can improve the early-stage detection of lung cancer. Immunobiosensors for the detection of anti-P53-tumour associated autoantibodies have been developed in this work. The design of sensing interfaces with immobilized P53 protein (P53ag) as a sensing element layer on a solid interface was investigated. Several methods of detecting anti-P53-antibodies (anti-P53ab) were investigated. These methods are label-free detection using electrochemical impedance spectroscopy (EIS) and two label techniques. The label-free electrochemical techniques utilize gold electrode pre-modified with a conducting layer of electrochemically grafted phenylethylamine for covalent immobilization of P53ag. The limit of anti-P53ab detection with the label-free EIS was 103.0 pg.ml-1. The labeled technique developed utilizes fluorescent, and peroxidase-like nanomaterial labeled antibody as a detection probe. For the fluorescence detection, fluorescent silica nanoparticles were synthesized by overloading FITC into the silica matrix and conjugated to detection antibody (anti-IgG). The detection of the anti-P53ab was based on the dissolution of the silica nanoparticles to release the loaded dye as a signal amplification strategy. The fluorescence detection was carried out on a microplate, and magnetic bead modified P53-antigen platforms and limit of detection (LoD) were 42.0 fg.ml-1 and 3.3 fg.ml-1 for anti-P53ab; respectively. Fe3O4@SiNP-APTES-Au@Pd hybrid nanoparticles were synthesized, and their peroxidase-like activity and colorimetric detection were evaluated. The Fe3O4@SiNP-APTES-Au@Pd exhibited comparable activity to HRP. The Fe3O4@SiNP-APTES-Au@Pd was conjugated to protein-G-anti-IgG for the detection of anti-P53ab on a microplate and cellulose paper platforms. The LoD was 20.0 fg.ml-1 and 63.0 fg.ml-1 for the microplate and cellulose paper platform; respectively. The potential application of the designed immunobiosensor was evaluated in simulated serum samples. The developed sensors showed higher detection sensitivity, stability and had a lower detection limit for anti-P53ab when compared with the ELISA based detection. The results have provided alternative and effective quantification approaches to ELISA and a promising future for multiplexed detection of tumor-associated autoantibodies. The developed methodologies in this thesis could be applied for the detection of other autoantibodies in other cancer types and auto-immune diseases.
- Full Text:
- Date Issued: 2020
Design of immunosensor for the detection of C-reactive protein using oriented antibody immobilization
- Authors: Adesina, Abiola Olanike
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163080 , vital:41010 , https://dx.doi.org/10.21504/10962/163080
- Description: Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Adesina, Abiola Olanike
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163080 , vital:41010 , https://dx.doi.org/10.21504/10962/163080
- Description: Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020.
- Full Text:
- Date Issued: 2020
Design, formulation and evalauation of liposomes co-loaded with human serum Albumin and Rifampicin
- Authors: Bapolisi, Alain Murhimalika
- Date: 2020
- Subjects: Liposomes , Serum albumin , Rifampin , Mycobacterium tuberculosis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/161780 , vital:40670
- Description: Tuberculosis (TB) is a devastating infectious disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious agent. The high morbidity and mortality rates of TB are partly due to factors such as the lengthy regimen (of 6–24 months), the development of drug resistance, and the pathogen location within the macrophages. These, with poor physiochemical properties of existing drugs hamper the effectiveness of the treatment despite the existence of potent antibiotics such as Rifampicin (Rif). Hydrophobicity plagues many drugs, including Rif, which are then particularly affected due to inherently poor intracellular availability. Novel drug delivery approaches are therefore needed in order to optimize the cytotoxic potential of said antitubercular drugs. To improve the bioavailability of hydrophobic drugs, numerous delivery strategies have been developed. Amongst these, the coordination of cytotoxic drugs to therapeutic proteins have shown some success for improved efficacy in the management of illnesses including infectious diseases. Of therapeutic proteins, Human Serum Albumin (HSA) is an attractive drug carrier with interestingbenefits such as low immunogenicity, antioxidant properties and improving cellular uptake ofdrugs through HSA-specific binding sites which are expressed on most cells including macrophages, where M. tuberculosis often resides. Hence, combination of Rif to HSA (Rif-HSA)seems a promising approach for improved intracellular delivery of Rif. However, the in vivo stability of colloidal protein-based therapeutics is mostly challenging and an effective vehicle is needed to control the biological fate of such conjugates.Liposomes seem to be appropriate carriers for the Rif-HSA complex due to their reputable applicability for encapsulating diverse materials (i.e., hydrophobic and hydrophilic compounds or small and complex molecules) and preventing chemical and biological degradation of the cargo. Therefore, the main objective of this study was to simultaneously encapsulate Rif and HSA in liposomes, which, to the best of our knowledge, has not been done before. The dual liposomes (Rif-HSA-lip) were made by a modified “Reverse Phase Evaporation” method (REV), following a Design of Experiments (DOE) approach to determine which factors impact the formulation. In addition, liposomes were made from crude soybean lecithin (CSL), rather than expensive and highly purified lipids. The liposomes were fully characterised, and the encapsulation efficiency (î) was monitored using high-performance liquid chromatography (HPLC). The results were correlated with factors such as organic and aqueous phase composition, as well as the in vitro release profile of Rif. Transmission electron microscopy (TEM) results confirmed the formation of spherical dual liposomes nanoparticles of roughly 200 nm. Dynamic light scattering (DLS) and Zeta potential measurements showed a negative charge (<–45 mV) and with satisfactory polydispersity (PDI<0.5). HSA dramatically improved the aqueous solubility of Rif (from1.9 mg/ml in water to around 4.3 mg/ml in HSA 10% solution) mainly due to Rif-HSA hydrophobic interactions. This resulted in a good î of almost 60% for Rif, despite the presence of bulky HSA in the lipid bilayer. These details were confirmed using proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). Furthermore, energy dispersive X-ray (EDX) and DLS data suggested the presence of HSA poking out on the surface of liposomes, which is encouraging for potential targeted delivery in the future. The in vitro release studies also depicted a substantial improvement in the diffusion of Rif in dual liposomes versus free Rif, from 65% after 12 hours for free Rif to 95% after only 5 hours for Rif- HSA-lip. Finally, stability studies conducted over 30 days at room temperature, showed that the freeze-dried formulations of Rif-HSA-lip exhibited good shelf stability over liposomes with no HSA. This study represents an illustrative example of co-loading of antibiotics and proteins into liposomes, which could encourage further development of novel nanoparticulate tools for the effective management of both drug-susceptible and -resistant infectious diseases such as TB.
- Full Text:
- Date Issued: 2020
- Authors: Bapolisi, Alain Murhimalika
- Date: 2020
- Subjects: Liposomes , Serum albumin , Rifampin , Mycobacterium tuberculosis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/161780 , vital:40670
- Description: Tuberculosis (TB) is a devastating infectious disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious agent. The high morbidity and mortality rates of TB are partly due to factors such as the lengthy regimen (of 6–24 months), the development of drug resistance, and the pathogen location within the macrophages. These, with poor physiochemical properties of existing drugs hamper the effectiveness of the treatment despite the existence of potent antibiotics such as Rifampicin (Rif). Hydrophobicity plagues many drugs, including Rif, which are then particularly affected due to inherently poor intracellular availability. Novel drug delivery approaches are therefore needed in order to optimize the cytotoxic potential of said antitubercular drugs. To improve the bioavailability of hydrophobic drugs, numerous delivery strategies have been developed. Amongst these, the coordination of cytotoxic drugs to therapeutic proteins have shown some success for improved efficacy in the management of illnesses including infectious diseases. Of therapeutic proteins, Human Serum Albumin (HSA) is an attractive drug carrier with interestingbenefits such as low immunogenicity, antioxidant properties and improving cellular uptake ofdrugs through HSA-specific binding sites which are expressed on most cells including macrophages, where M. tuberculosis often resides. Hence, combination of Rif to HSA (Rif-HSA)seems a promising approach for improved intracellular delivery of Rif. However, the in vivo stability of colloidal protein-based therapeutics is mostly challenging and an effective vehicle is needed to control the biological fate of such conjugates.Liposomes seem to be appropriate carriers for the Rif-HSA complex due to their reputable applicability for encapsulating diverse materials (i.e., hydrophobic and hydrophilic compounds or small and complex molecules) and preventing chemical and biological degradation of the cargo. Therefore, the main objective of this study was to simultaneously encapsulate Rif and HSA in liposomes, which, to the best of our knowledge, has not been done before. The dual liposomes (Rif-HSA-lip) were made by a modified “Reverse Phase Evaporation” method (REV), following a Design of Experiments (DOE) approach to determine which factors impact the formulation. In addition, liposomes were made from crude soybean lecithin (CSL), rather than expensive and highly purified lipids. The liposomes were fully characterised, and the encapsulation efficiency (î) was monitored using high-performance liquid chromatography (HPLC). The results were correlated with factors such as organic and aqueous phase composition, as well as the in vitro release profile of Rif. Transmission electron microscopy (TEM) results confirmed the formation of spherical dual liposomes nanoparticles of roughly 200 nm. Dynamic light scattering (DLS) and Zeta potential measurements showed a negative charge (<–45 mV) and with satisfactory polydispersity (PDI<0.5). HSA dramatically improved the aqueous solubility of Rif (from1.9 mg/ml in water to around 4.3 mg/ml in HSA 10% solution) mainly due to Rif-HSA hydrophobic interactions. This resulted in a good î of almost 60% for Rif, despite the presence of bulky HSA in the lipid bilayer. These details were confirmed using proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). Furthermore, energy dispersive X-ray (EDX) and DLS data suggested the presence of HSA poking out on the surface of liposomes, which is encouraging for potential targeted delivery in the future. The in vitro release studies also depicted a substantial improvement in the diffusion of Rif in dual liposomes versus free Rif, from 65% after 12 hours for free Rif to 95% after only 5 hours for Rif- HSA-lip. Finally, stability studies conducted over 30 days at room temperature, showed that the freeze-dried formulations of Rif-HSA-lip exhibited good shelf stability over liposomes with no HSA. This study represents an illustrative example of co-loading of antibiotics and proteins into liposomes, which could encourage further development of novel nanoparticulate tools for the effective management of both drug-susceptible and -resistant infectious diseases such as TB.
- Full Text:
- Date Issued: 2020
Design, formulation and evaluation of liposomes co-loaded with human serum albumin and rifampicin
- Authors: Bapolisi, Alain Murhimalika
- Date: 2020
- Subjects: Liposomes , Rifampin , Antitubercular agents , Serum albumin , Albumins , Tuberculosis -- Treatment
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163179 , vital:41016
- Description: Tuberculosis (TB) is a devastating infectious disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious agent. The high morbidity and mortality rates of TB are partly due to factors such as the lengthy regimen (of 6–24 months), the development of drug resistance, and the pathogen location within the macrophages. These, with poor physiochemical properties of existing drugs hamper the effectiveness of the treatment despite the existence of potent antibiotics such as Rifampicin (Rif). Hydrophobicity plagues many drugs, including Rif, which are then particularly affected due to inherently poor intracellular availability. Novel drug delivery approaches are therefore needed in order to optimize the cytotoxic potential of said antitubercular drugs. To improve the bioavailability of hydrophobic drugs, numerous delivery strategies have been developed. Amongst these, the coordination of cytotoxic drugs to therapeutic proteins have shown some success for improved efficacy in the management of illnesses including infectious diseases. Of therapeutic proteins, Human Serum Albumin (HSA) is an attractive drug carrier with interesting benefits such as low immunogenicity, antioxidant properties and improving cellular uptake of drugs through HSA-specific binding sites which are expressed on most cells including macrophages, where M. tuberculosis often resides. Hence, combination of Rif to HSA (Rif-HSA) seems a promising approach for improved intracellular delivery of Rif. However, the in vivo stability of colloidal protein-based therapeutics is mostly challenging and an effective vehicle is needed to control the biological fate of such conjugates. Liposomes seem to be appropriate carriers for the Rif-HSA complex due to their reputable applicability for encapsulating diverse materials (i.e., hydrophobic and hydrophilic compounds or small and complex molecules) and preventing chemical and biological degradation of the cargo. Therefore, the main objective of this study was to simultaneously encapsulate Rif and HSA in liposomes, which, to the best of our knowledge, has not been done before. The dual liposomes (Rif-HSA-lip) were made by a modified “Reverse Phase Evaporation” method (REV), following a Design of Experiments (DOE) approach to determine which factors impact the formulation. In addition, liposomes were made from crude soybean lecithin (CSL), rather than expensive and highly purified lipids. iv The liposomes were fully characterised, and the encapsulation efficiency (î) was monitored using high-performance liquid chromatography (HPLC). The results were correlated with factors such as organic and aqueous phase composition, as well as the in vitro release profile of Rif. Transmission electron microscopy (TEM) results confirmed the formation of spherical dual liposomes nanoparticles of roughly 200 nm. Dynamic light scattering (DLS) and Zeta potential measurements showed a negative charge (<–45 mV) and with satisfactory polydispersity (PDI<0.5). HSA dramatically improved the aqueous solubility of Rif (from1.9 mg/ml in water to around 4.3 mg/ml in HSA 10% solution) mainly due to Rif-HSA hydrophobic interactions. This resulted in a good î of almost 60% for Rif, despite the presence of bulky HSA in the lipid bilayer. These details were confirmed using proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). Furthermore, energy dispersive X-ray (EDX) and DLS data suggested the presence of HSA poking out on the surface of liposomes, which is encouraging for potential targeted delivery in the future. The in vitro release studies also depicted a substantial improvement in the diffusion of Rif in dual liposomes versus free Rif, from 65% after 12 hours for free Rif to 95% after only 5 hours for Rif- HSA-lip. Finally, stability studies conducted over 30 days at room temperature, showed that the freeze-dried formulations of Rif-HSA-lip exhibited good shelf stability over liposomes with no HSA. This study represents an illustrative example of co-loading of antibiotics and proteins into liposomes, which could encourage further development of novel nanoparticulate tools for the effective management of both drug-susceptible and -resistant infectious diseases such as TB.
- Full Text:
- Date Issued: 2020
- Authors: Bapolisi, Alain Murhimalika
- Date: 2020
- Subjects: Liposomes , Rifampin , Antitubercular agents , Serum albumin , Albumins , Tuberculosis -- Treatment
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163179 , vital:41016
- Description: Tuberculosis (TB) is a devastating infectious disease caused by Mycobacterium tuberculosis and is the leading cause of death from a single infectious agent. The high morbidity and mortality rates of TB are partly due to factors such as the lengthy regimen (of 6–24 months), the development of drug resistance, and the pathogen location within the macrophages. These, with poor physiochemical properties of existing drugs hamper the effectiveness of the treatment despite the existence of potent antibiotics such as Rifampicin (Rif). Hydrophobicity plagues many drugs, including Rif, which are then particularly affected due to inherently poor intracellular availability. Novel drug delivery approaches are therefore needed in order to optimize the cytotoxic potential of said antitubercular drugs. To improve the bioavailability of hydrophobic drugs, numerous delivery strategies have been developed. Amongst these, the coordination of cytotoxic drugs to therapeutic proteins have shown some success for improved efficacy in the management of illnesses including infectious diseases. Of therapeutic proteins, Human Serum Albumin (HSA) is an attractive drug carrier with interesting benefits such as low immunogenicity, antioxidant properties and improving cellular uptake of drugs through HSA-specific binding sites which are expressed on most cells including macrophages, where M. tuberculosis often resides. Hence, combination of Rif to HSA (Rif-HSA) seems a promising approach for improved intracellular delivery of Rif. However, the in vivo stability of colloidal protein-based therapeutics is mostly challenging and an effective vehicle is needed to control the biological fate of such conjugates. Liposomes seem to be appropriate carriers for the Rif-HSA complex due to their reputable applicability for encapsulating diverse materials (i.e., hydrophobic and hydrophilic compounds or small and complex molecules) and preventing chemical and biological degradation of the cargo. Therefore, the main objective of this study was to simultaneously encapsulate Rif and HSA in liposomes, which, to the best of our knowledge, has not been done before. The dual liposomes (Rif-HSA-lip) were made by a modified “Reverse Phase Evaporation” method (REV), following a Design of Experiments (DOE) approach to determine which factors impact the formulation. In addition, liposomes were made from crude soybean lecithin (CSL), rather than expensive and highly purified lipids. iv The liposomes were fully characterised, and the encapsulation efficiency (î) was monitored using high-performance liquid chromatography (HPLC). The results were correlated with factors such as organic and aqueous phase composition, as well as the in vitro release profile of Rif. Transmission electron microscopy (TEM) results confirmed the formation of spherical dual liposomes nanoparticles of roughly 200 nm. Dynamic light scattering (DLS) and Zeta potential measurements showed a negative charge (<–45 mV) and with satisfactory polydispersity (PDI<0.5). HSA dramatically improved the aqueous solubility of Rif (from1.9 mg/ml in water to around 4.3 mg/ml in HSA 10% solution) mainly due to Rif-HSA hydrophobic interactions. This resulted in a good î of almost 60% for Rif, despite the presence of bulky HSA in the lipid bilayer. These details were confirmed using proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). Furthermore, energy dispersive X-ray (EDX) and DLS data suggested the presence of HSA poking out on the surface of liposomes, which is encouraging for potential targeted delivery in the future. The in vitro release studies also depicted a substantial improvement in the diffusion of Rif in dual liposomes versus free Rif, from 65% after 12 hours for free Rif to 95% after only 5 hours for Rif- HSA-lip. Finally, stability studies conducted over 30 days at room temperature, showed that the freeze-dried formulations of Rif-HSA-lip exhibited good shelf stability over liposomes with no HSA. This study represents an illustrative example of co-loading of antibiotics and proteins into liposomes, which could encourage further development of novel nanoparticulate tools for the effective management of both drug-susceptible and -resistant infectious diseases such as TB.
- Full Text:
- Date Issued: 2020
Detecting the transnational space: metaphysical detecting in Kazuo Ishiguro’s When we were orphans, Michiel Heyns’s Lost ground, and Amitav Gosh’s The Calcutta chromosome
- Authors: Botes, Niki
- Date: 2020
- Subjects: Literature and transnationalism , Detective and mystery stories -- History and criticism , Ishiguro, Kazuo, 1954- , Ishiguro, Kazuo, 1954- -- When we were orpahns , Heyns, Michiel , Heyns, Michiel -- Lost ground , Ghosh, Amitav, 1956- , Ghosh, Amitav, 1956- -- The Calcutta chromosome
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140971 , vital:37933
- Description: The transnational detectives in the three primary texts under scrutiny—Kazuo Ishiguro’s When We Were Orphans, Michiel Heyns’s Lost Ground, and Amitav Ghosh’s The Calcutta Chromosome—are regarded as metaphysical detectives in this thesis. As transnational figures, they criss-cross physical and national borders, but their investigations also often require the crossing of epistemological and ontological borders, as well as thinking outside of binaries. The fictional transnational, postcolonial worlds presented in these texts all feature a lack of change and the persistence of the socio-economic inequalities and discriminations of the colonial or, in the case of Lost Ground, the apartheid past. This thesis will argue that the three texts foreground the inability to break free from conceptual frameworks and a lack in human relationships as two possible reasons why the communities and societies in question have not been able to affect change. To solve the various mysteries in the texts, the transnational detectives need to find new ways of knowing and being. The lessons that these detectives learn and the personal changes they experience serve as synecdoche for how a better tomorrow for the transnational, postcolonial world could possibly be achieved. The methodology employed in this thesis involves a comparative reading of the three primary texts. To analyse and interpret these texts, this thesis draws on the philosophies of postmodern philosophers such as Martin Heidegger, Michel Foucault, Jacques Derrida, and Emmanuel Levinas, as well as postcolonial theorists like Edward Said, Gayatri Chakravorty Spivak, and Homi K. Bhabha. The thesis will contend that especially Derrida’s work on deconstruction, which forms the conceptual basis for Bhabha’s notion of the ‘third space,’ as well as Levinas’s anti-totalitarian approach with regard to the ethical relationship between the self and the other, are viable better ways of knowing and being in the transnational, postcolonial worlds presented in the texts. Derrida’s notion of différance and the trace, as well as Bhabha’s third space, this thesis contends, completely destabilises binary thinking and offers ways to think outside of the limited frameworks of ideological discourse. This thesis also posits that Levinas’s metaphysical and pluralistic interpretation of how the self should, and can, relate to the other, presents a better way of forming human relationships and has the potential to affect positive change.
- Full Text:
- Date Issued: 2020
- Authors: Botes, Niki
- Date: 2020
- Subjects: Literature and transnationalism , Detective and mystery stories -- History and criticism , Ishiguro, Kazuo, 1954- , Ishiguro, Kazuo, 1954- -- When we were orpahns , Heyns, Michiel , Heyns, Michiel -- Lost ground , Ghosh, Amitav, 1956- , Ghosh, Amitav, 1956- -- The Calcutta chromosome
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140971 , vital:37933
- Description: The transnational detectives in the three primary texts under scrutiny—Kazuo Ishiguro’s When We Were Orphans, Michiel Heyns’s Lost Ground, and Amitav Ghosh’s The Calcutta Chromosome—are regarded as metaphysical detectives in this thesis. As transnational figures, they criss-cross physical and national borders, but their investigations also often require the crossing of epistemological and ontological borders, as well as thinking outside of binaries. The fictional transnational, postcolonial worlds presented in these texts all feature a lack of change and the persistence of the socio-economic inequalities and discriminations of the colonial or, in the case of Lost Ground, the apartheid past. This thesis will argue that the three texts foreground the inability to break free from conceptual frameworks and a lack in human relationships as two possible reasons why the communities and societies in question have not been able to affect change. To solve the various mysteries in the texts, the transnational detectives need to find new ways of knowing and being. The lessons that these detectives learn and the personal changes they experience serve as synecdoche for how a better tomorrow for the transnational, postcolonial world could possibly be achieved. The methodology employed in this thesis involves a comparative reading of the three primary texts. To analyse and interpret these texts, this thesis draws on the philosophies of postmodern philosophers such as Martin Heidegger, Michel Foucault, Jacques Derrida, and Emmanuel Levinas, as well as postcolonial theorists like Edward Said, Gayatri Chakravorty Spivak, and Homi K. Bhabha. The thesis will contend that especially Derrida’s work on deconstruction, which forms the conceptual basis for Bhabha’s notion of the ‘third space,’ as well as Levinas’s anti-totalitarian approach with regard to the ethical relationship between the self and the other, are viable better ways of knowing and being in the transnational, postcolonial worlds presented in the texts. Derrida’s notion of différance and the trace, as well as Bhabha’s third space, this thesis contends, completely destabilises binary thinking and offers ways to think outside of the limited frameworks of ideological discourse. This thesis also posits that Levinas’s metaphysical and pluralistic interpretation of how the self should, and can, relate to the other, presents a better way of forming human relationships and has the potential to affect positive change.
- Full Text:
- Date Issued: 2020
Determination of nonlinear optical properties of phthalocyanine regioisomers using computational models
- Date: 2020
- Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Nonlinear optics , Nonlinear optical spectroscopy , Refraction
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/166197 , vital:41337
- Description: This work investigates the effects of the nonlinear optical properties of four different constitutional isomers (C4h, C2v, Cs, and D2h) of a series of tetrasubstituted phthalocyanines (free-base 3-4-tert-butylphenoxyether phthalocyanines, free-base 4-4-tertbutylphenoxyether phthalocyanines, SnCl2 tetra substituted 3-4-tert-butylphenoxyether phthalocyanine, and SnCl2 tetra substituted 4-4-tert-butylphenoxyether phthalocyanine). The properties investigated were the real and imaginary components of the 3rd order hyperpolarizability, as well as the excited state absorption and refraction cross sections. The investigations were performed with a z-scan over a range of laser beam intensities. This work determined the imaginary component of the 3rd order hyperpolarizability for the free-base and SnCl2 3-4-tert-butylphenoxyether phthalocyanines and 4-4-tert-butylphenoxyether phthalocyanines to be highly dependent on the excited state cross sections. The refraction caused due to the real component of the 3rd order hyperpolarizability of the phthalocyanines was also investigated, however, the values found were strongly dependent on the laser beam intensity and the cause of this was investigated. A Five-level model was developed and run on GPGPU computing devices in order to isolate the absorption and refractive cross sections. Theeffects of the regio substitution on the excited state cross sections were also investigated, and the 1st singlet excited state and 1st triplet state absorption cross sections were calculated for all constitutional isomers. It was found that the symmetry of the constitutional isomers have a disproportionately large effect on the excited state absorption when compared to the ground state absorption. The nonlinear refractive properties of all constitutional isomers were also investigated, and the values of the parametric susceptibility are reported herein. The nonlinear refraction was found to have less effect than was seen in the nonlinear absorption. The 1st singlet excited state and 1st triplet state refractive cross sections of all constitutional isomer was determined. The results indicated that if more than one excited state was present and contributing to the nonlinear refraction, then more data than was collected here would be required. However, the 1st singlet excited state cross section were successfully determined for the free-base constitutional isomers. This work concluded that the region substitution affected the excited states more than the ground state.
- Full Text:
- Date Issued: 2020
- Date: 2020
- Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Nonlinear optics , Nonlinear optical spectroscopy , Refraction
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/166197 , vital:41337
- Description: This work investigates the effects of the nonlinear optical properties of four different constitutional isomers (C4h, C2v, Cs, and D2h) of a series of tetrasubstituted phthalocyanines (free-base 3-4-tert-butylphenoxyether phthalocyanines, free-base 4-4-tertbutylphenoxyether phthalocyanines, SnCl2 tetra substituted 3-4-tert-butylphenoxyether phthalocyanine, and SnCl2 tetra substituted 4-4-tert-butylphenoxyether phthalocyanine). The properties investigated were the real and imaginary components of the 3rd order hyperpolarizability, as well as the excited state absorption and refraction cross sections. The investigations were performed with a z-scan over a range of laser beam intensities. This work determined the imaginary component of the 3rd order hyperpolarizability for the free-base and SnCl2 3-4-tert-butylphenoxyether phthalocyanines and 4-4-tert-butylphenoxyether phthalocyanines to be highly dependent on the excited state cross sections. The refraction caused due to the real component of the 3rd order hyperpolarizability of the phthalocyanines was also investigated, however, the values found were strongly dependent on the laser beam intensity and the cause of this was investigated. A Five-level model was developed and run on GPGPU computing devices in order to isolate the absorption and refractive cross sections. Theeffects of the regio substitution on the excited state cross sections were also investigated, and the 1st singlet excited state and 1st triplet state absorption cross sections were calculated for all constitutional isomers. It was found that the symmetry of the constitutional isomers have a disproportionately large effect on the excited state absorption when compared to the ground state absorption. The nonlinear refractive properties of all constitutional isomers were also investigated, and the values of the parametric susceptibility are reported herein. The nonlinear refraction was found to have less effect than was seen in the nonlinear absorption. The 1st singlet excited state and 1st triplet state refractive cross sections of all constitutional isomer was determined. The results indicated that if more than one excited state was present and contributing to the nonlinear refraction, then more data than was collected here would be required. However, the 1st singlet excited state cross section were successfully determined for the free-base constitutional isomers. This work concluded that the region substitution affected the excited states more than the ground state.
- Full Text:
- Date Issued: 2020
Determination of speaker configuration for an immersive audio content creation system
- Authors: Lebusa, Motebang
- Date: 2020
- Subjects: Loudspeakers , Surround-sound systems , Algorithms , Coordinates
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/163375 , vital:41034
- Description: Various spatialisation algorithms require the knowledge of speaker locations to accurately localise sound in 3D environments. The rendering process uses speaker coordinates to feed into their algorithms so that they can render the immersive audio content as intended by an artist. The need to measure the loudspeaker coordinates becomes necessary, especially in environments where the speaker layouts change frequently. Manually measuring the coordinates, however, tends to be a laborious task that is prone to errors. This research provides an automated solution to the problem of speaker coordinates measurement. The solution system, SDIAS, is a client-server system that uses the capabilities provided by the Ethernet Audio Video Bridging standard to measure the 3D loudspeaker coordinates for immersive sound systems. SDIAS deploys commodity hardware and readily available software to implement the solution. A server sends a short tone to each speaker in the speaker configuration, at equal intervals. A microphone attached to a mobile device picks up these transmitted tones on the client side, from different locations. The transmission and reception times from both components of the system are used to measure the time of flight for each tone sent to a loudspeaker. These are then used to determine the 3D coordinates of each loudspeaker in the available layout. Tests were performed to determine the accuracy of the determination algorithm for SDIAS, and were compared to the manually measured coordinates. , Thesis (MSc) -- Faculty of Science, Computer Science, 2020
- Full Text:
- Date Issued: 2020
- Authors: Lebusa, Motebang
- Date: 2020
- Subjects: Loudspeakers , Surround-sound systems , Algorithms , Coordinates
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/163375 , vital:41034
- Description: Various spatialisation algorithms require the knowledge of speaker locations to accurately localise sound in 3D environments. The rendering process uses speaker coordinates to feed into their algorithms so that they can render the immersive audio content as intended by an artist. The need to measure the loudspeaker coordinates becomes necessary, especially in environments where the speaker layouts change frequently. Manually measuring the coordinates, however, tends to be a laborious task that is prone to errors. This research provides an automated solution to the problem of speaker coordinates measurement. The solution system, SDIAS, is a client-server system that uses the capabilities provided by the Ethernet Audio Video Bridging standard to measure the 3D loudspeaker coordinates for immersive sound systems. SDIAS deploys commodity hardware and readily available software to implement the solution. A server sends a short tone to each speaker in the speaker configuration, at equal intervals. A microphone attached to a mobile device picks up these transmitted tones on the client side, from different locations. The transmission and reception times from both components of the system are used to measure the time of flight for each tone sent to a loudspeaker. These are then used to determine the 3D coordinates of each loudspeaker in the available layout. Tests were performed to determine the accuracy of the determination algorithm for SDIAS, and were compared to the manually measured coordinates. , Thesis (MSc) -- Faculty of Science, Computer Science, 2020
- Full Text:
- Date Issued: 2020
Developing an organisational culture in support of organisational capacity for change: the case of a South African bank
- Authors: Dhoba, Howard
- Date: 2020
- Subjects: Corporate culture , Bank management , Organizational change
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/141247 , vital:37956
- Description: Business organisations are increasingly being exposed to challenging environmental pressures. It has been widely acknowledged and observed that an organisation that crafts an effective organisational culture should be well positioned to react to these threatening changes, and to proactively seize opportunities to adapt and learn. This research study seeks to investigate how an organisational culture that supports organisational capacity for change can be developed. It analyses what a banking organisation’s espoused culture is made up of and how it was formulated. A thematic analysis of how the bank’s aspirational and innovative culture contributes to the organisation’s capacity for change is also presented. Organisational management should take a leading role in developing the values and practices that foster participation, which are then imparted to the entire organisation. The research study thus only focused on analysing the development of organisational culture from the management perspective. An interpretivist research approach was adopted, with a case study design as the research method. Data was gathered through conducting personal interviews with twelve managers from a Retail and Business Banking cluster of one of the big South African banks. Numerous interventions were employed in the organisation to develop espoused values, aspirational culture and to encourage all employees to champion innovations and constantly search for better ways to offer delighting value propositions to clients. The research findings can assist managers and organisational leaders in building their organisational capacity for change through developing an effective organisational culture that supports change initiatives. Since the research study only focused on analysing the development of organisational culture from the perspective of management, further research studies may involve employees as well, due to the fact that everyone is expected to take an active role for an organisation to display the overall capability to effectively respond to a progressively volatile environment. The research was able to reveal how key initiatives that are designed from theoretical constructs can be used to deliver on an innovative organisational culture that contributes to organisational capability for change.
- Full Text:
- Date Issued: 2020
- Authors: Dhoba, Howard
- Date: 2020
- Subjects: Corporate culture , Bank management , Organizational change
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/141247 , vital:37956
- Description: Business organisations are increasingly being exposed to challenging environmental pressures. It has been widely acknowledged and observed that an organisation that crafts an effective organisational culture should be well positioned to react to these threatening changes, and to proactively seize opportunities to adapt and learn. This research study seeks to investigate how an organisational culture that supports organisational capacity for change can be developed. It analyses what a banking organisation’s espoused culture is made up of and how it was formulated. A thematic analysis of how the bank’s aspirational and innovative culture contributes to the organisation’s capacity for change is also presented. Organisational management should take a leading role in developing the values and practices that foster participation, which are then imparted to the entire organisation. The research study thus only focused on analysing the development of organisational culture from the management perspective. An interpretivist research approach was adopted, with a case study design as the research method. Data was gathered through conducting personal interviews with twelve managers from a Retail and Business Banking cluster of one of the big South African banks. Numerous interventions were employed in the organisation to develop espoused values, aspirational culture and to encourage all employees to champion innovations and constantly search for better ways to offer delighting value propositions to clients. The research findings can assist managers and organisational leaders in building their organisational capacity for change through developing an effective organisational culture that supports change initiatives. Since the research study only focused on analysing the development of organisational culture from the perspective of management, further research studies may involve employees as well, due to the fact that everyone is expected to take an active role for an organisation to display the overall capability to effectively respond to a progressively volatile environment. The research was able to reveal how key initiatives that are designed from theoretical constructs can be used to deliver on an innovative organisational culture that contributes to organisational capability for change.
- Full Text:
- Date Issued: 2020
Developing macroinvertebrate trait- and taxonomically-based approaches for biomonitoring wadeable riverine systems in the Niger delta, Nigeria
- Authors: Edegbene, Ovie Augustine
- Date: 2020
- Subjects: Water – Pollution -- Nigeria -- Niger River Delta , Stream health -- Nigeria -- Niger River Delta , Water -- Pollution -- Measurement , Environmental monitoring -- Nigeria -- Niger River Delta , Water quality -- Nigeria -- Niger River Delta , Water quality biological assessment -- Nigeria -- Niger River Delta , Aquatic invertebrates -- Nigeria -- Niger River Delta , Stream restoration -- Nigeria -- Niger River Delta , Urban agriculture -- Nigeria -- Niger River Delta , Stream ecology -- Nigeria -- Niger River Delta
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140660 , vital:37907
- Description: Riverine systems are increasingly subjected to pollution due to rapid urbanisation, industrialisation, and agricultural activities. Increasing pollution in freshwater systems impairs water quality, causes biodiversity loss and impairs aquatic ecosystem functionality and supply of ecosystem services. Rivers in the Niger Delta region of Nigeria are particularly vulnerable to urban pollution and agricultural activities as natural forests are increasingly replaced by urbanisation and agriculture. The differential effects of these pressures on the ecological processes of these river systems are poorly explored, as is the development of appropriate biomonitoring tools for routine monitoring of river health. In this study, a physico-chemically-based approach and macroinvertebrate trait- and taxonomic- approaches were developed to better understand the effects of multiple pressures on riverine systems, while developing multimetric indices to enable sustainable management of rivers within the region. Sixty-six stations in 20 river systems within the Edo and Delta States of the Niger Delta ecoregion were monitored seasonally for a period of five (2008–2012) years. The physico-chemically based approach makes apparent the extent of degradation of rivers and streams in the Niger Delta. For each dominant land use type, river stations were classified into least impacted stations (LIS), moderately impacted stations (MIS) or heavily impacted stations (HIS). Of 11 stations within urban catchments, only two were considered least impacted, suggesting that urgent measures are necessary to revise the current trajectories of urban rivers within the region. Most of the stations designated as MIS and HIS in the urban and urban-agriculture catchments were found to be significantly correlated with increased nutrients, EC and BOD5. Characteristics of most of the MIS and HIS within rivers in urban catchments evidenced the so-called urban stream syndrome, a state of persistent degradation of urban streams. The results of the traits and ecological preferences approach showed traits sensitive to urban and urban-agriculture pollution. Traits and ecological preferences that were associated with the LIS include the possession of hardshell, moderate and high sensitivities to oxygen depletion, very large body sized individuals (>20-40mm), swimmers, flattened body shape, a preference for temporary attachment, crawling, respiration with aerial/vegetation, possession of breathing tubes, possession of strap or other apparatus for respiration, streamlined body, and a high sensitivity to oxygen depletion. Permanent attachment as an ecological preference associated with LIS was also positively correlated with increasing dissolved oxygen (DO) and was deemed a pollution sensitive ecological preference. The possession of very small body size (<5mm), associated with HIS, was deemed a pollution-tolerant trait and was negatively correlated with DO, confirming the deteriorating state of the urban and urban-agricultural rivers. The impact of urban-forestry pollution on the distribution pattern of macroinvertebrate traits and ecological preferences was also explored in the selected rivers. Traits and ecological preferences such as possession of hard-shell, large body size, and grazing as a feeding preference which were significantly positively associated with the LIS, were also either significantly positively correlated with DO, or significantly negatively correlated with increasing any two of flow velocity, water temperature, BOD5 and nutrient. These traits and ecological preferences were deemed sensitive in forested rivers receiving urban pollution. Further, burrowing, the pupa aquatic stage, and predation which were significantly positively associated with HIS on the RLQ ordination, were also significantly negatively associated with DO. These traits were deemed tolerant of forested systems receiving urban pollution. Multimetric indices (MMI) were developed, validated and applied for urban, urban-agriculture and urban-forested (MMI-urban, MMI-urban-agric and urban-forest) areas. Of the 26 metrics that satisfactorily discriminated between the LIS, the MIS, and the HIS for MMI-urban, only five metric were retained for integration into MMI-urban, they are log VeL, Hemiptera abundance, % Coleoptera + Hemiptera, % Chironomidae + Oligochaeta and Evenness index. Further, of the 18 metrics that satisfactorily discriminated between the LIS, the MIS, and the HIS for MMI-urban-agric, only 12 metrics were retained and nine proved to be redundant. The nine metrics represent different measures; two of them were retained in addition to Chironomidae/Diptera abundance, % Odonata and Oligochaeta richness. The two metrics selected in addition to the hironomidae/Diptera abundance, % Odonata and Oligochaeta richness were the Margalef index and the logarithm of relative abundance of sprawler. For the MMI-urban-forest, 14 metrics satisfactorily discriminated between the LIS, the MIS, and the HIS, and 12 metrics were retained and 11 proved to be redundant. The non-redundant metric was Trichoptera abundance. Three metrics were further selected in addition to the Trichoptera abundance which include % Chironomidae + Oligochaeta, Coleoptera + Hemiptera richness and Shannon diversity. The MMI-urban and MMI-urban-agric indices performed better for LIS designated stations compared to the MIS and HIS deignated stations. The developed indices proved effective as biomonitoring tools for assessing the ecological health of rivers in the urban and urban-agriculture catchments within the Niger Delta. Overall, the results of the macroinvertebrate traits and ecological preferences, and taxonomic approaches showed the strength in the complementarity of both approaches in developing biomonitoring tools for assessing levels of deterioration in riverine systems. The study contributes significantly to understanding the ecology of riverine systems in the Niger Delta, particularly those subject to urban stresses, agricultural activities and urban pollution in forested systems, and thus makes an important contribution to the science and practice of biomonitoring in Nigeria where such studies are sparse.
- Full Text:
- Date Issued: 2020
- Authors: Edegbene, Ovie Augustine
- Date: 2020
- Subjects: Water – Pollution -- Nigeria -- Niger River Delta , Stream health -- Nigeria -- Niger River Delta , Water -- Pollution -- Measurement , Environmental monitoring -- Nigeria -- Niger River Delta , Water quality -- Nigeria -- Niger River Delta , Water quality biological assessment -- Nigeria -- Niger River Delta , Aquatic invertebrates -- Nigeria -- Niger River Delta , Stream restoration -- Nigeria -- Niger River Delta , Urban agriculture -- Nigeria -- Niger River Delta , Stream ecology -- Nigeria -- Niger River Delta
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140660 , vital:37907
- Description: Riverine systems are increasingly subjected to pollution due to rapid urbanisation, industrialisation, and agricultural activities. Increasing pollution in freshwater systems impairs water quality, causes biodiversity loss and impairs aquatic ecosystem functionality and supply of ecosystem services. Rivers in the Niger Delta region of Nigeria are particularly vulnerable to urban pollution and agricultural activities as natural forests are increasingly replaced by urbanisation and agriculture. The differential effects of these pressures on the ecological processes of these river systems are poorly explored, as is the development of appropriate biomonitoring tools for routine monitoring of river health. In this study, a physico-chemically-based approach and macroinvertebrate trait- and taxonomic- approaches were developed to better understand the effects of multiple pressures on riverine systems, while developing multimetric indices to enable sustainable management of rivers within the region. Sixty-six stations in 20 river systems within the Edo and Delta States of the Niger Delta ecoregion were monitored seasonally for a period of five (2008–2012) years. The physico-chemically based approach makes apparent the extent of degradation of rivers and streams in the Niger Delta. For each dominant land use type, river stations were classified into least impacted stations (LIS), moderately impacted stations (MIS) or heavily impacted stations (HIS). Of 11 stations within urban catchments, only two were considered least impacted, suggesting that urgent measures are necessary to revise the current trajectories of urban rivers within the region. Most of the stations designated as MIS and HIS in the urban and urban-agriculture catchments were found to be significantly correlated with increased nutrients, EC and BOD5. Characteristics of most of the MIS and HIS within rivers in urban catchments evidenced the so-called urban stream syndrome, a state of persistent degradation of urban streams. The results of the traits and ecological preferences approach showed traits sensitive to urban and urban-agriculture pollution. Traits and ecological preferences that were associated with the LIS include the possession of hardshell, moderate and high sensitivities to oxygen depletion, very large body sized individuals (>20-40mm), swimmers, flattened body shape, a preference for temporary attachment, crawling, respiration with aerial/vegetation, possession of breathing tubes, possession of strap or other apparatus for respiration, streamlined body, and a high sensitivity to oxygen depletion. Permanent attachment as an ecological preference associated with LIS was also positively correlated with increasing dissolved oxygen (DO) and was deemed a pollution sensitive ecological preference. The possession of very small body size (<5mm), associated with HIS, was deemed a pollution-tolerant trait and was negatively correlated with DO, confirming the deteriorating state of the urban and urban-agricultural rivers. The impact of urban-forestry pollution on the distribution pattern of macroinvertebrate traits and ecological preferences was also explored in the selected rivers. Traits and ecological preferences such as possession of hard-shell, large body size, and grazing as a feeding preference which were significantly positively associated with the LIS, were also either significantly positively correlated with DO, or significantly negatively correlated with increasing any two of flow velocity, water temperature, BOD5 and nutrient. These traits and ecological preferences were deemed sensitive in forested rivers receiving urban pollution. Further, burrowing, the pupa aquatic stage, and predation which were significantly positively associated with HIS on the RLQ ordination, were also significantly negatively associated with DO. These traits were deemed tolerant of forested systems receiving urban pollution. Multimetric indices (MMI) were developed, validated and applied for urban, urban-agriculture and urban-forested (MMI-urban, MMI-urban-agric and urban-forest) areas. Of the 26 metrics that satisfactorily discriminated between the LIS, the MIS, and the HIS for MMI-urban, only five metric were retained for integration into MMI-urban, they are log VeL, Hemiptera abundance, % Coleoptera + Hemiptera, % Chironomidae + Oligochaeta and Evenness index. Further, of the 18 metrics that satisfactorily discriminated between the LIS, the MIS, and the HIS for MMI-urban-agric, only 12 metrics were retained and nine proved to be redundant. The nine metrics represent different measures; two of them were retained in addition to Chironomidae/Diptera abundance, % Odonata and Oligochaeta richness. The two metrics selected in addition to the hironomidae/Diptera abundance, % Odonata and Oligochaeta richness were the Margalef index and the logarithm of relative abundance of sprawler. For the MMI-urban-forest, 14 metrics satisfactorily discriminated between the LIS, the MIS, and the HIS, and 12 metrics were retained and 11 proved to be redundant. The non-redundant metric was Trichoptera abundance. Three metrics were further selected in addition to the Trichoptera abundance which include % Chironomidae + Oligochaeta, Coleoptera + Hemiptera richness and Shannon diversity. The MMI-urban and MMI-urban-agric indices performed better for LIS designated stations compared to the MIS and HIS deignated stations. The developed indices proved effective as biomonitoring tools for assessing the ecological health of rivers in the urban and urban-agriculture catchments within the Niger Delta. Overall, the results of the macroinvertebrate traits and ecological preferences, and taxonomic approaches showed the strength in the complementarity of both approaches in developing biomonitoring tools for assessing levels of deterioration in riverine systems. The study contributes significantly to understanding the ecology of riverine systems in the Niger Delta, particularly those subject to urban stresses, agricultural activities and urban pollution in forested systems, and thus makes an important contribution to the science and practice of biomonitoring in Nigeria where such studies are sparse.
- Full Text:
- Date Issued: 2020
Developing social indicators for the evaluation of natural resource management programmes using a capability approach in the Eastern Cape, South Africa
- Authors: Human, Johanna Susanna
- Date: 2020
- Subjects: Environmental education -- South Africa -- Eastern Cape , Natural resources -- Management -- Study and teaching (Continuing education) -- South Africa -- Eastern Cape , Sustainable development -- Study and teaching (Continuing education) -- South Africa -- Eastern Cape , Environmental economics -- Study and teaching (Continuing education) -- South Africa -- Eastern Cape , Subsistence farming -- South Africa -- Eastern Cape , Watersheds -- South Africa -- Eastern Cape , Capabilities approach (Social sciences) , Tsitsa River Catchment (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/147348 , vital:38628
- Description: The dissertation investigates how the capability approach can be used to develop social indicators for a natural resource management (NRM) programme. The study aimed to develop an understanding of what the beneficiaries of the programme value being and doing to guide the development of social indicators that will take into consideration their personal development aspirations. These valued beings and doings were then overlaid with the programme goals and objectives to identify and select the final indicators. The study was situated in the Tsitsa catchment in the Eastern Cape, South Africa and was part of a natural resource management programme, focused on land restoration and avoided degradation. Methods used to collect data for this study and develop an understanding of what the residents’ valued beings and doings were, included semi-structured interviews, workshops and document analysis. The research population was non-homogenous. I tried to include voices representing different prominent groups of land users in the study. This included established commercial farmers, emerging commercial farmers, commercial forestry, residents residing in communal areas and engaged with subsistence farming and residents from these communal areas who are now residing elsewhere but continue to have connections to the catchment. Understanding the voices of these different groups who reside in the catchment was important to develop an inclusive understanding of what residents of the catchment valued beings and doings were. The research process was supported by participatory approaches. This process, and the lessons learnt during the research process, were valuable for the further development and implementation of the planned participatory monitoring evaluation reflection and learning (PMERL) framework. The research process involved learning from the research participants about their valued beings and doings and what was important for the programme implementers. Some of the research participants from the Rhodes University implementation team (RUIT) were also involved in selecting the indicators they thought the programme should monitor. Overall, using the capability approach helped me to gain insight and understanding with regard to what the valued beings and doings are for the residents of the catchment and what they would like development programmes, such as the Tsitsa Project, to address. It was surprising to find many areas of overlap between the valued beings and doings of the different residents in the catchment, as well as the similarities between these and the goals and objectives of the Tsitsa Project. In conclusion, using the capability approach was useful to learn what was important for the residents of the catchment to help develop the social indicators but also to learn how to guide and steer participatory monitoring and evaluation processes in the future.
- Full Text:
- Date Issued: 2020
- Authors: Human, Johanna Susanna
- Date: 2020
- Subjects: Environmental education -- South Africa -- Eastern Cape , Natural resources -- Management -- Study and teaching (Continuing education) -- South Africa -- Eastern Cape , Sustainable development -- Study and teaching (Continuing education) -- South Africa -- Eastern Cape , Environmental economics -- Study and teaching (Continuing education) -- South Africa -- Eastern Cape , Subsistence farming -- South Africa -- Eastern Cape , Watersheds -- South Africa -- Eastern Cape , Capabilities approach (Social sciences) , Tsitsa River Catchment (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/147348 , vital:38628
- Description: The dissertation investigates how the capability approach can be used to develop social indicators for a natural resource management (NRM) programme. The study aimed to develop an understanding of what the beneficiaries of the programme value being and doing to guide the development of social indicators that will take into consideration their personal development aspirations. These valued beings and doings were then overlaid with the programme goals and objectives to identify and select the final indicators. The study was situated in the Tsitsa catchment in the Eastern Cape, South Africa and was part of a natural resource management programme, focused on land restoration and avoided degradation. Methods used to collect data for this study and develop an understanding of what the residents’ valued beings and doings were, included semi-structured interviews, workshops and document analysis. The research population was non-homogenous. I tried to include voices representing different prominent groups of land users in the study. This included established commercial farmers, emerging commercial farmers, commercial forestry, residents residing in communal areas and engaged with subsistence farming and residents from these communal areas who are now residing elsewhere but continue to have connections to the catchment. Understanding the voices of these different groups who reside in the catchment was important to develop an inclusive understanding of what residents of the catchment valued beings and doings were. The research process was supported by participatory approaches. This process, and the lessons learnt during the research process, were valuable for the further development and implementation of the planned participatory monitoring evaluation reflection and learning (PMERL) framework. The research process involved learning from the research participants about their valued beings and doings and what was important for the programme implementers. Some of the research participants from the Rhodes University implementation team (RUIT) were also involved in selecting the indicators they thought the programme should monitor. Overall, using the capability approach helped me to gain insight and understanding with regard to what the valued beings and doings are for the residents of the catchment and what they would like development programmes, such as the Tsitsa Project, to address. It was surprising to find many areas of overlap between the valued beings and doings of the different residents in the catchment, as well as the similarities between these and the goals and objectives of the Tsitsa Project. In conclusion, using the capability approach was useful to learn what was important for the residents of the catchment to help develop the social indicators but also to learn how to guide and steer participatory monitoring and evaluation processes in the future.
- Full Text:
- Date Issued: 2020
Developing voice and leadership amongst a group of class captains
- Nehunga, Jacobina Taukondjele
- Authors: Nehunga, Jacobina Taukondjele
- Date: 2020
- Subjects: Educational leadership -- Namibia , Transformational leadership -- Namibia , Leadership in adolescents -- Namibia , Rural schools -- Namibia , School children – Namibia -- Attitudes , School management and organization – Namibia , Cultural Historical Activity Theory
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/145034 , vital:38402
- Description: The notion that leadership can be reduced to that of a formal position such as principalship has become problematic in school leadership research and practice, globally and also in Namibia. It appears that when leadership is concentrated only at the level of a principal within schools, teachers and learners within the same school experience a lack of opportunities to contribute to leadership practices, thus losing a sense of ownership. Supporting a distributed leadership perspective and embracing transformative leadership, this study investigated how learner voice and learner leadership (see for example Mitra and Gross, 2009) can be developed within a group of class captains in a combined school in rural Namibia. Cultural Historical Activity Theory (CHAT) underpinned the study which is located within a critical paradigm. Findings of the study were captured into two phases whereby phase one generated contextual profiling findings through the adoption of qualitative methods such as questionnaires, interviews, document analysis and two other participatory methods of mapping and transect walks. Phase two findings were captured through expansive learning actions in Change Laboratory Workshops. Observation notes, video recording and photographs and informal discussions were used as data sources during this phase. Both inductive and abductive analysis were employed. The findings revealed that a few enabling conditions to class captainship practice existed, but generally there was limited participation of class captains in school leadership. Class captains were seen as merely class representatives and their leadership was confined to a classroom level in the school. They performed more managerial tasks than leadership. It was also revealed that class captainship is not a documented practice in Namibia and it lacks support. Against this backdrop, during phase two of the study, seven contradictions were identified and two contradictions were prioritised for resolution during the Change Laboratory Workshops. Some of the resolutions included the development of a school based guiding document for class captains; an establishment of a class captainship club; and the promotion of a yearly election campaign of class captains. The study recommends more interventionist studies to be conducted on class captainship in order to see the practice documented in terms of policy in Namibia, perhaps in the near future.
- Full Text:
- Date Issued: 2020
- Authors: Nehunga, Jacobina Taukondjele
- Date: 2020
- Subjects: Educational leadership -- Namibia , Transformational leadership -- Namibia , Leadership in adolescents -- Namibia , Rural schools -- Namibia , School children – Namibia -- Attitudes , School management and organization – Namibia , Cultural Historical Activity Theory
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/145034 , vital:38402
- Description: The notion that leadership can be reduced to that of a formal position such as principalship has become problematic in school leadership research and practice, globally and also in Namibia. It appears that when leadership is concentrated only at the level of a principal within schools, teachers and learners within the same school experience a lack of opportunities to contribute to leadership practices, thus losing a sense of ownership. Supporting a distributed leadership perspective and embracing transformative leadership, this study investigated how learner voice and learner leadership (see for example Mitra and Gross, 2009) can be developed within a group of class captains in a combined school in rural Namibia. Cultural Historical Activity Theory (CHAT) underpinned the study which is located within a critical paradigm. Findings of the study were captured into two phases whereby phase one generated contextual profiling findings through the adoption of qualitative methods such as questionnaires, interviews, document analysis and two other participatory methods of mapping and transect walks. Phase two findings were captured through expansive learning actions in Change Laboratory Workshops. Observation notes, video recording and photographs and informal discussions were used as data sources during this phase. Both inductive and abductive analysis were employed. The findings revealed that a few enabling conditions to class captainship practice existed, but generally there was limited participation of class captains in school leadership. Class captains were seen as merely class representatives and their leadership was confined to a classroom level in the school. They performed more managerial tasks than leadership. It was also revealed that class captainship is not a documented practice in Namibia and it lacks support. Against this backdrop, during phase two of the study, seven contradictions were identified and two contradictions were prioritised for resolution during the Change Laboratory Workshops. Some of the resolutions included the development of a school based guiding document for class captains; an establishment of a class captainship club; and the promotion of a yearly election campaign of class captains. The study recommends more interventionist studies to be conducted on class captainship in order to see the practice documented in terms of policy in Namibia, perhaps in the near future.
- Full Text:
- Date Issued: 2020
Development and assessment of a fixed dose combination of perindopril arginine and indapamide loaded microparticles
- Authors: Mandava, Tavonga Tyomai
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164413 , vital:41116
- Description: Thesis (MSc)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
- Authors: Mandava, Tavonga Tyomai
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164413 , vital:41116
- Description: Thesis (MSc)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
Development of a low-cost bioprinting system for engineering of Human Tumour Models
- Authors: Fanucci, Sidne
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163295 , vital:41026
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biotechnology Innovation Centre, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Fanucci, Sidne
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163295 , vital:41026
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biotechnology Innovation Centre, 2020.
- Full Text:
- Date Issued: 2020
Development of a protocol for extracting and quantifying the concentration of thiafentanil in blesbok (Damaliscus pygargus phillipsi) matrices 72-74 hours post administration
- Authors: Webber, Judith Tracy
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164738 , vital:41159
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
- Authors: Webber, Judith Tracy
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164738 , vital:41159
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
Development of graphene materials and phthalocyanines for application in dye-sensitized solar cells
- Authors: Chindeka, Francis
- Date: 2020
- Subjects: Dye-sensitized solar cells , Graphene , Phthalocyanines , Molecular orbitals , Impedance spectroscopy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166092 , vital:41328
- Description: Two sets of dye-sensitized solar cells (DSSCs) were fabricated. In the first set, dye-sensitized solar cells (DSSC) were fabricated by incorporating graphene materials as catalysts at the counter electrode. Platinum was also used as a catalyst for comparative purposes. Different phthalocyanines: hydroxyl indium tetracarboxyphenoxy phthalocyanine (1), chloro indium octacarboxy phthalocyanine (2) and dibenzoic acid silicon phthalocyanine (3) were used as dyes. Complex 3 gave the highest power conversion efficiency (η) of 3.19% when using nitrogen doped reduced graphene oxide nanosheets (NrGONS) as a catalyst at the counter electrode, and TiO2 containing rGONS at the anode. The value obtained is close to 3.8% obtained when using Pt catalyst instead of NrGONS at the cathode, thus confirming that NrGONS is a promising candidate to replace the more expensive Pt. The study also shows that placing rGONS on both the anode and cathode improves efficiency. In the second set, DSSCs were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc (4) photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69 % and 4.36 % respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) showed significant improvement on the performance of the DSSC compared to previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
- Authors: Chindeka, Francis
- Date: 2020
- Subjects: Dye-sensitized solar cells , Graphene , Phthalocyanines , Molecular orbitals , Impedance spectroscopy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166092 , vital:41328
- Description: Two sets of dye-sensitized solar cells (DSSCs) were fabricated. In the first set, dye-sensitized solar cells (DSSC) were fabricated by incorporating graphene materials as catalysts at the counter electrode. Platinum was also used as a catalyst for comparative purposes. Different phthalocyanines: hydroxyl indium tetracarboxyphenoxy phthalocyanine (1), chloro indium octacarboxy phthalocyanine (2) and dibenzoic acid silicon phthalocyanine (3) were used as dyes. Complex 3 gave the highest power conversion efficiency (η) of 3.19% when using nitrogen doped reduced graphene oxide nanosheets (NrGONS) as a catalyst at the counter electrode, and TiO2 containing rGONS at the anode. The value obtained is close to 3.8% obtained when using Pt catalyst instead of NrGONS at the cathode, thus confirming that NrGONS is a promising candidate to replace the more expensive Pt. The study also shows that placing rGONS on both the anode and cathode improves efficiency. In the second set, DSSCs were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc (4) photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69 % and 4.36 % respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) showed significant improvement on the performance of the DSSC compared to previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
Development of paper-based aptasensors for detection of Plasmodium falciparum lactate dehydrogenase in malaria
- Ogunmolasuyi, Adewoyin Martin
- Authors: Ogunmolasuyi, Adewoyin Martin
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164601 , vital:41147 , doi:10.21504/10962/164601
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biotechnology Innovation Centre, 2020
- Full Text:
- Date Issued: 2020
- Authors: Ogunmolasuyi, Adewoyin Martin
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164601 , vital:41147 , doi:10.21504/10962/164601
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biotechnology Innovation Centre, 2020
- Full Text:
- Date Issued: 2020
Digital media marketing and the consumption of sugar-sweetened beverages in Africa: A reception analysis of the multi-channel marketing of Coca-Cola among young Africans from the University of Lagos, Nigeria and Rhodes University, South Africa
- Authors: Akingbade, Olutobi Elijah
- Date: 2020
- Subjects: Carbonated beverages -- Health aspects -- South Africa , Carbonated beverages -- Marketing -- South Africa , Soft drinks -- Health aspects -- South Africa , Soft drinks -- Marketing -- South Africa , Carbonated beverages -- Health aspects -- Nigeria , Carbonated beverages -- Marketing -- Nigeria , Digital media -- Marketing -- Africa , Soft drinks -- Health aspects -- Nigeria , Soft drinks -- Marketing -- Nigeria , Digital media -- Marketing -- Nigeria , Obesity -- Africa , Nutritionally induced diseases -- Africa , Coca-Cola Company -- Marketing , Rhodes University -- Students -- Attitudes , University of Lagos -- Students -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/163125 , vital:41012
- Description: This study investigates and examines how Coca-Cola’s marketing communications, especially the newer forms of digital, social and mobile media marketing messages/campaigns, are received, understood and made sense of by two sets of purposefully selected young urban African students in Nigeria and South Africa. Embedded within a qualitative research design and underpinned by an interpretative phenomenological analysis (IPA) approach, this study was conducted against the backdrop of the recent surge in the consumption of Sugar Sweetened Beverages (SSBs) which has been directly implicated in the rise of obesity and a variety of non-communicable diseases (NCDs) in Africa. The thesis explores the role of multinational SSBs in this surge, as African countries have become key focus areas for multinational food and beverage companies seeking growth and profits, as home markets decline partly due to better health communications and, in some cases, the implementation of so-called ‘sugar taxes’ and the attendant negative publicity around these taxes. The focus on young Africans from Nigeria and South Africa was motivated by the similar rapid urbanisations in both countries, often accompanied by changes in diet and greater consumption of fast foods and SSBS, and by South Africa’s ranking as the country with the highest prevalence of overweight persons and obesity in Sub-Saharan Africa. Similar rises in national average weights are now also starting to be seen in Nigeria, as are surges of diet-related disease incidence and prevalence. The study is informed by Consumer Culture Theory (CCT) but also draws on other theories and some key concepts from marketing studies, health science and psychology. Methodologically, the study draws on in-person observations, focus group interviews and semi-structured individual in-depth interviews, to explore how Coca-Cola has created a deep and evocative historical ‘brandscape’ and how it has become a multicultural resource in both South Africa and Nigeria. Through an investigation into the lived experiences of study participants with regards to both their earliest and more recent engagements with Coca-Cola, as a brand and as a product, the study delineates the influence of older generations of Coke enthusiasts and consumers within participants’ households and newer spaces of interaction with Coke via interactive, highly personalised social media-centric campaigns. This study explores how the ubiquitous nature of Coca-Cola’s aesthetics and signage are engaged with – often in very ‘sub-conscious’ ways – by these students and how more recent social media campaigns evoke this multigenerational history. Unpacking study participants’ self-understandings of Coke and their often ‘sub-conscious’ engagements with the SSB, this study explicates the underpinning ideological grounding and how this is sustained over time to become an hegemonic code that does not only confine participants’ engagements with SSBs to Coke but also confines their reception of, and engagements with, Coke’s media marketing messages/campaigns to those that resonate with the multigenerational history evoked by the SSB. It is within this contextual background that this study brings to the fore participants ‘cognitive dissonance’ and scepticism and often rank disbelief of the health risks posed by their high levels of Coke consumption. The study concludes that attempts to raise awareness about the dangers inherent in excessive consumption of SSBs in Africa need to be reviewed and rethought. There is a need for long-term, consistent and much more proactive health journalism, alongside public health campaigns in both official and indigenous languages, to dispel the powerful myths created by SSB marketing and explain how SSBs are implicated in the rise of diet-related NCDs in Nigeria and South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Akingbade, Olutobi Elijah
- Date: 2020
- Subjects: Carbonated beverages -- Health aspects -- South Africa , Carbonated beverages -- Marketing -- South Africa , Soft drinks -- Health aspects -- South Africa , Soft drinks -- Marketing -- South Africa , Carbonated beverages -- Health aspects -- Nigeria , Carbonated beverages -- Marketing -- Nigeria , Digital media -- Marketing -- Africa , Soft drinks -- Health aspects -- Nigeria , Soft drinks -- Marketing -- Nigeria , Digital media -- Marketing -- Nigeria , Obesity -- Africa , Nutritionally induced diseases -- Africa , Coca-Cola Company -- Marketing , Rhodes University -- Students -- Attitudes , University of Lagos -- Students -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/163125 , vital:41012
- Description: This study investigates and examines how Coca-Cola’s marketing communications, especially the newer forms of digital, social and mobile media marketing messages/campaigns, are received, understood and made sense of by two sets of purposefully selected young urban African students in Nigeria and South Africa. Embedded within a qualitative research design and underpinned by an interpretative phenomenological analysis (IPA) approach, this study was conducted against the backdrop of the recent surge in the consumption of Sugar Sweetened Beverages (SSBs) which has been directly implicated in the rise of obesity and a variety of non-communicable diseases (NCDs) in Africa. The thesis explores the role of multinational SSBs in this surge, as African countries have become key focus areas for multinational food and beverage companies seeking growth and profits, as home markets decline partly due to better health communications and, in some cases, the implementation of so-called ‘sugar taxes’ and the attendant negative publicity around these taxes. The focus on young Africans from Nigeria and South Africa was motivated by the similar rapid urbanisations in both countries, often accompanied by changes in diet and greater consumption of fast foods and SSBS, and by South Africa’s ranking as the country with the highest prevalence of overweight persons and obesity in Sub-Saharan Africa. Similar rises in national average weights are now also starting to be seen in Nigeria, as are surges of diet-related disease incidence and prevalence. The study is informed by Consumer Culture Theory (CCT) but also draws on other theories and some key concepts from marketing studies, health science and psychology. Methodologically, the study draws on in-person observations, focus group interviews and semi-structured individual in-depth interviews, to explore how Coca-Cola has created a deep and evocative historical ‘brandscape’ and how it has become a multicultural resource in both South Africa and Nigeria. Through an investigation into the lived experiences of study participants with regards to both their earliest and more recent engagements with Coca-Cola, as a brand and as a product, the study delineates the influence of older generations of Coke enthusiasts and consumers within participants’ households and newer spaces of interaction with Coke via interactive, highly personalised social media-centric campaigns. This study explores how the ubiquitous nature of Coca-Cola’s aesthetics and signage are engaged with – often in very ‘sub-conscious’ ways – by these students and how more recent social media campaigns evoke this multigenerational history. Unpacking study participants’ self-understandings of Coke and their often ‘sub-conscious’ engagements with the SSB, this study explicates the underpinning ideological grounding and how this is sustained over time to become an hegemonic code that does not only confine participants’ engagements with SSBs to Coke but also confines their reception of, and engagements with, Coke’s media marketing messages/campaigns to those that resonate with the multigenerational history evoked by the SSB. It is within this contextual background that this study brings to the fore participants ‘cognitive dissonance’ and scepticism and often rank disbelief of the health risks posed by their high levels of Coke consumption. The study concludes that attempts to raise awareness about the dangers inherent in excessive consumption of SSBs in Africa need to be reviewed and rethought. There is a need for long-term, consistent and much more proactive health journalism, alongside public health campaigns in both official and indigenous languages, to dispel the powerful myths created by SSB marketing and explain how SSBs are implicated in the rise of diet-related NCDs in Nigeria and South Africa.
- Full Text:
- Date Issued: 2020
Disco
- Authors: Trantraal, Nathan
- Date: 2020
- Subjects: Kaaps , South African fiction (English) -- 21st century , South African poetry (English) -- 21st century , Afrikaans fiction -- 21st century , Afrikaans poetry -- 21st century
- Language: Afrikaans , English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145217 , vital:38419
- Description: Creative writing portfolio.
- Full Text:
- Date Issued: 2020
- Authors: Trantraal, Nathan
- Date: 2020
- Subjects: Kaaps , South African fiction (English) -- 21st century , South African poetry (English) -- 21st century , Afrikaans fiction -- 21st century , Afrikaans poetry -- 21st century
- Language: Afrikaans , English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145217 , vital:38419
- Description: Creative writing portfolio.
- Full Text:
- Date Issued: 2020
Discursive constructions of alcohol use and pregnancy among participants in intervention aimed at reducing Foetal Alcohol Spectrum Disorders
- Authors: Msomi, Nqobile Nomonde
- Date: 2020
- Subjects: Fetal alcohol spectrum disorders -- South Africa , Pregnancy -- Psychological aspects , Reproductive rights -- South Africa , Reproductive health -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140374 , vital:37883
- Description: South Africa’s socio-cultural and political history has had significant effects on maternal and reproductive health. The hazardous alcohol use patterns in the country have affected alcohol consumption during pregnancy. Antenatal exposure to alcohol may result in Foetal Alcohol Spectrum Disorders (FASD). The levels of FASD in particular areas of the country are the highest recorded in the world. Epidemiological studies have dominated pregnancy and FASD research in South Africa; however, recently critical scholarship seeking to contextualise the issue of drinking alcohol during pregnancy is emerging. This study forms part of a developmental/formative assessment of an alcohol and pregnancy intervention. Assessment is an important part of pilot interventions, and discourse is a key area of focus due to its constitutive role for the subjectivity of human beings and legitimation of institutional practices. Using a reproductive justice perspective and a Foucauldian approach to analysis, I identified five prominent discursive constructions of alcohol use during pregnancy produced during interviews with community educators. These interviews were conducted following training workshops with the community educators. Participants constructed their living environments as ‘wholly bad’ and ‘issue-ridden’ and positioned alcohol consumption as ‘a destroyer!’, ‘king’ and a social lubricant. They interpellated the foetus, the ‘FASD child’ and pregnant women into this context. They positioned themselves as transformed subjects able to effect change. The foetus was constructed as ‘vulnerable and important’, as opposed to the ‘defiled FASD child’. Pregnant women were constructed as ‘ignorant, preoccupied and unreceptive to knowledge’. These constructions hinged on so-called ‘scientific knowledge’ of biological processes in utero, demonstrating Foucault’s conception of the power/knowledge nexus and how its dynamics transforms knowledge of human beings. Whereas this ‘knowledge’ transformed alcohol consumption and the foetus into powerful and vulnerable subjects respectively, the circulating discourses had objectivising effects on pregnant women. The discourses of responsibilisation, the personification of the foetus, ‘the problem’ category of FASD, the discourse of difference, and the discourse of alcohol consumption as an entrenched practice were circulating around pregnant women. I suggest alterations to the identified constructions using principles of community psychology, the harm reduction model, a social model of disability and the reproductive justice perspective
- Full Text:
- Date Issued: 2020
- Authors: Msomi, Nqobile Nomonde
- Date: 2020
- Subjects: Fetal alcohol spectrum disorders -- South Africa , Pregnancy -- Psychological aspects , Reproductive rights -- South Africa , Reproductive health -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/140374 , vital:37883
- Description: South Africa’s socio-cultural and political history has had significant effects on maternal and reproductive health. The hazardous alcohol use patterns in the country have affected alcohol consumption during pregnancy. Antenatal exposure to alcohol may result in Foetal Alcohol Spectrum Disorders (FASD). The levels of FASD in particular areas of the country are the highest recorded in the world. Epidemiological studies have dominated pregnancy and FASD research in South Africa; however, recently critical scholarship seeking to contextualise the issue of drinking alcohol during pregnancy is emerging. This study forms part of a developmental/formative assessment of an alcohol and pregnancy intervention. Assessment is an important part of pilot interventions, and discourse is a key area of focus due to its constitutive role for the subjectivity of human beings and legitimation of institutional practices. Using a reproductive justice perspective and a Foucauldian approach to analysis, I identified five prominent discursive constructions of alcohol use during pregnancy produced during interviews with community educators. These interviews were conducted following training workshops with the community educators. Participants constructed their living environments as ‘wholly bad’ and ‘issue-ridden’ and positioned alcohol consumption as ‘a destroyer!’, ‘king’ and a social lubricant. They interpellated the foetus, the ‘FASD child’ and pregnant women into this context. They positioned themselves as transformed subjects able to effect change. The foetus was constructed as ‘vulnerable and important’, as opposed to the ‘defiled FASD child’. Pregnant women were constructed as ‘ignorant, preoccupied and unreceptive to knowledge’. These constructions hinged on so-called ‘scientific knowledge’ of biological processes in utero, demonstrating Foucault’s conception of the power/knowledge nexus and how its dynamics transforms knowledge of human beings. Whereas this ‘knowledge’ transformed alcohol consumption and the foetus into powerful and vulnerable subjects respectively, the circulating discourses had objectivising effects on pregnant women. The discourses of responsibilisation, the personification of the foetus, ‘the problem’ category of FASD, the discourse of difference, and the discourse of alcohol consumption as an entrenched practice were circulating around pregnant women. I suggest alterations to the identified constructions using principles of community psychology, the harm reduction model, a social model of disability and the reproductive justice perspective
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- Date Issued: 2020