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
Molecular and morphological approaches reveal hidden diversity in the genus hippopotamyrus pappenheim, 1906 (teleostei: mormyridae) in southern Africa
- Authors: Mutizwa, Tadiwa, Isaac
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164546 , vital:41128
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Department of Icthyology and Fisheries Science, 2020
- Full Text:
- Date Issued: 2020
- Authors: Mutizwa, Tadiwa, Isaac
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164546 , vital:41128
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Department of Icthyology and Fisheries Science, 2020
- Full Text:
- Date Issued: 2020
Guidelines for designing personal health dashboards
- Authors: Chabana, Chabana Ernst
- Date: 2022-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419137 , vital:71619
- Description: The healthcare industry is realising the value of providing ordinary individuals with their personal health data for self-care and self-management purposes, however, these individuals are faced with the challenge of going through, understanding and extracting insights from large volumes of complex personal health data. A dashboard (coupled with data visualization) is regarded as a suitable way to present personal health data effectively, to inform self-care and self- management-based decisions. However, there is no homogeneous (i.e. “one-size-fits-all”) approach to designing dashboards; therefore, this research aimed at creating a set of design guidelines that can be used as a foundation for tailoring dashboards that support the presentation of personal health data. The Design Science Research methodology was used to systematically develop and evaluate the set of dashboard design guidelines. Within this methodology, literature was reviewed and focus groups with participants were conducted to extract insights and inform the development of the initial set (proposed) design guidelines. The proposed design guidelines were then used to develop a medium-fidelity personal health dashboard prototype. Usability testing with the dashboard prototype was conducted to evaluate the efficacy and utility of these design guidelines. The evaluation provided insights that strengthened the quality of the design guidelines. The evaluation indicated that the proposed set of guidelines are suitable for designing a dashboard that presents personal health data effectively. These design guidelines can be adapted in order to inform the process of tailoring dashboards for accommodating different personal health data presentation needs. , Thesis (MCOM) -- Faculty of Commerce, Information Systems, 2023
- Full Text:
- Date Issued: 2022-11
- Authors: Chabana, Chabana Ernst
- Date: 2022-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419137 , vital:71619
- Description: The healthcare industry is realising the value of providing ordinary individuals with their personal health data for self-care and self-management purposes, however, these individuals are faced with the challenge of going through, understanding and extracting insights from large volumes of complex personal health data. A dashboard (coupled with data visualization) is regarded as a suitable way to present personal health data effectively, to inform self-care and self- management-based decisions. However, there is no homogeneous (i.e. “one-size-fits-all”) approach to designing dashboards; therefore, this research aimed at creating a set of design guidelines that can be used as a foundation for tailoring dashboards that support the presentation of personal health data. The Design Science Research methodology was used to systematically develop and evaluate the set of dashboard design guidelines. Within this methodology, literature was reviewed and focus groups with participants were conducted to extract insights and inform the development of the initial set (proposed) design guidelines. The proposed design guidelines were then used to develop a medium-fidelity personal health dashboard prototype. Usability testing with the dashboard prototype was conducted to evaluate the efficacy and utility of these design guidelines. The evaluation provided insights that strengthened the quality of the design guidelines. The evaluation indicated that the proposed set of guidelines are suitable for designing a dashboard that presents personal health data effectively. These design guidelines can be adapted in order to inform the process of tailoring dashboards for accommodating different personal health data presentation needs. , Thesis (MCOM) -- Faculty of Commerce, Information Systems, 2023
- Full Text:
- Date Issued: 2022-11
Global climate justice: the case of climate migrants
- Van Heerden, Samantha Jane Ashburner
- Authors: Van Heerden, Samantha Jane Ashburner
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406749 , vital:70304
- Description: Climate change is predicted to displace thousands of people across the globe. Due to their geographical location and limited resources available for adaptation, this will particularly impact those in developing states, who might have to flee from the growing frequency and severity of rising sea levels, drought and desertification, and acute natural disasters such as floods, wildfires, and hurricanes. This is likely to have pervasive effects on the moral interests of those affected, threatening loss of life, the deterioration of livelihoods, and for small island states even complete or substantial loss of state territory. In this thesis I will argue that we should conceive of this situation as a problem of global justice. Though some argue that questions of justice only arise within the state, I will argue that global economic and political institutions have contributed to the plight of climate migrants, and that following from Darrel Moellendorf’s theory of associational justice, this enduring impact results in an association and duties of justice that transcend state borders. To respect the dignity of climate migrants, such an unjust association needs to be rectified by establishing ethical principles that could be reasonably endorsed by everyone affected. Drawing from Gillian Brock, I will argue that the best way to rectify the situation is through establishing a principle of distributive justice which focuses on ‘agency needs’: needs whose fulfilment is necessary for human agency. Using this framework, I then provide some recommendations of what is owed to climate migrants to achieve justice for them. I also consider how these duties of justice should be distributed, first critiquing a dominant approach that attributes duties primarily to polluters. In the end, I recommend that duties should be dispersed between all those who support the global institutions responsible, those who have been high polluters since 1990, and the most affluent in the world. As the effects of climate change become increasingly pronounced within the next fifty years, establishing what is owed to those displaced is of utmost importance, and I hope this thesis shows how normative philosophy can help us think through these urgent questions. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Van Heerden, Samantha Jane Ashburner
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406749 , vital:70304
- Description: Climate change is predicted to displace thousands of people across the globe. Due to their geographical location and limited resources available for adaptation, this will particularly impact those in developing states, who might have to flee from the growing frequency and severity of rising sea levels, drought and desertification, and acute natural disasters such as floods, wildfires, and hurricanes. This is likely to have pervasive effects on the moral interests of those affected, threatening loss of life, the deterioration of livelihoods, and for small island states even complete or substantial loss of state territory. In this thesis I will argue that we should conceive of this situation as a problem of global justice. Though some argue that questions of justice only arise within the state, I will argue that global economic and political institutions have contributed to the plight of climate migrants, and that following from Darrel Moellendorf’s theory of associational justice, this enduring impact results in an association and duties of justice that transcend state borders. To respect the dignity of climate migrants, such an unjust association needs to be rectified by establishing ethical principles that could be reasonably endorsed by everyone affected. Drawing from Gillian Brock, I will argue that the best way to rectify the situation is through establishing a principle of distributive justice which focuses on ‘agency needs’: needs whose fulfilment is necessary for human agency. Using this framework, I then provide some recommendations of what is owed to climate migrants to achieve justice for them. I also consider how these duties of justice should be distributed, first critiquing a dominant approach that attributes duties primarily to polluters. In the end, I recommend that duties should be dispersed between all those who support the global institutions responsible, those who have been high polluters since 1990, and the most affluent in the world. As the effects of climate change become increasingly pronounced within the next fifty years, establishing what is owed to those displaced is of utmost importance, and I hope this thesis shows how normative philosophy can help us think through these urgent questions. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-10-14
Investigating teachers’ perceptions on translanguaging pedagogy in a multilingual intermediate ESL classroom: a comparative study of two primary schools in Namibia
- Authors: Rheeder, Veneza Memory
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419760 , vital:71673
- Description: International literature has tested the effectiveness of translanguaging as a pedagogic tool to enhance learning in a bilingual classroom; however, with the recent curriculum reform and education sector policy, there is no direct claim in the National policy frameworks on the prominence of translanguaging as an effective tool in classroom pedagogy in Namibian schools. This research attempted to investigate the role of translanguaging as a pedagogic tool to enhance learning in the multilingual intermediate English Second Language (ESL) phase as the Language of Learning and Teaching (LoLT) for the intermediate phase, Grades 4-7, in the Erongo Region, Namibia. The study is within the interpretive paradigm and adopts a qualitative methodology using a qualitative multi-case study approach of exploring and understanding differences and similarities between cases. Data collection consisted mainly of open-ended interviews and observations (purposive sampling) of the participating teachers. The research sites and study participants were purposely selected as both schools, diversely located in urban and rural contexts of the region, are enacting the National Language Policy as proposed. This entails using Mother Tongue Instruction (MTI) from Grades 0-3 and then transitioning to English-monolingual instruction from Grades 4 onwards. The study was designed to investigate the role of translanguaging pedagogy in enhancing learning in the Second Language (L2) classroom, without prejudice of social classes - the elite and marginalized communities. It investigated the extent to which teachers’ use of translanguaging pedagogy enhances ESL learning as the LoLT to intermediate phase learners transitioning from MTI to English-only instruction. The main theories underpinning this study are the Vygotskian and Translanguaging theories supported by Krashen and Cummins’ Cognitive Underlying Proficiency (CUP) Model. The outcomes of the study reveal that in both schools translanguaging was supported by content subject teachers and English LoLT teachers and that it positively contributed to improving learner understanding of important concepts in several subjects. However, Mother Tongue (MT) teachers did not support the use of translanguaging and believed that it slowed down the learning of English. , Thesis (MEd) -- Faculty of Education, Institute for the Study of Englishes in Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Rheeder, Veneza Memory
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419760 , vital:71673
- Description: International literature has tested the effectiveness of translanguaging as a pedagogic tool to enhance learning in a bilingual classroom; however, with the recent curriculum reform and education sector policy, there is no direct claim in the National policy frameworks on the prominence of translanguaging as an effective tool in classroom pedagogy in Namibian schools. This research attempted to investigate the role of translanguaging as a pedagogic tool to enhance learning in the multilingual intermediate English Second Language (ESL) phase as the Language of Learning and Teaching (LoLT) for the intermediate phase, Grades 4-7, in the Erongo Region, Namibia. The study is within the interpretive paradigm and adopts a qualitative methodology using a qualitative multi-case study approach of exploring and understanding differences and similarities between cases. Data collection consisted mainly of open-ended interviews and observations (purposive sampling) of the participating teachers. The research sites and study participants were purposely selected as both schools, diversely located in urban and rural contexts of the region, are enacting the National Language Policy as proposed. This entails using Mother Tongue Instruction (MTI) from Grades 0-3 and then transitioning to English-monolingual instruction from Grades 4 onwards. The study was designed to investigate the role of translanguaging pedagogy in enhancing learning in the Second Language (L2) classroom, without prejudice of social classes - the elite and marginalized communities. It investigated the extent to which teachers’ use of translanguaging pedagogy enhances ESL learning as the LoLT to intermediate phase learners transitioning from MTI to English-only instruction. The main theories underpinning this study are the Vygotskian and Translanguaging theories supported by Krashen and Cummins’ Cognitive Underlying Proficiency (CUP) Model. The outcomes of the study reveal that in both schools translanguaging was supported by content subject teachers and English LoLT teachers and that it positively contributed to improving learner understanding of important concepts in several subjects. However, Mother Tongue (MT) teachers did not support the use of translanguaging and believed that it slowed down the learning of English. , Thesis (MEd) -- Faculty of Education, Institute for the Study of Englishes in Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
Characterisation of two novel ferrocenyl benzoxazines as in vitro triple-negative breast cancer inhibitors
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Harry Potter: a discourse analytic approach to ‘the boy who lived’ and his attachments
- Authors: Nel, Derryn Joy
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192641 , vital:45245
- Description: Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Nel, Derryn Joy
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192641 , vital:45245
- Description: Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
The elucidation of nickel and zinc based Metal Organic Frameworks (MOFs) using a polycarboxylate-benzene ligand: a synthetic, spectroscopic, and thermoanalytical study
- Authors: Hodgson, Ivan Mark
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/290877 , vital:56795
- Description: Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Hodgson, Ivan Mark
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/290877 , vital:56795
- Description: Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
Investigation of microbial fuel cell technologies for flexible, small-scale domestic and educational use
- Authors: Mpofu, Trisha Lerato
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192539 , vital:45235
- Description: Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mpofu, Trisha Lerato
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192539 , vital:45235
- Description: Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
Ritualised discourse practices of feedback in a university foundation programme: a critical investigation
- Authors: Richardson, Amy
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/164955 , vital:41187
- Description: In order for students to become true members of academic communities of practice they need epistemological access, including guidance on central institutional knowledge-producing processes and mastery of key academic literacy practices. A powerful source of guidance is marker feedback. Drawing on key insights from the New Literacy Studies and taking up the mandate of Critical Ethnography to improve the status quo, this thesis reports on the feedback practices in a university foundation programme. The findings are based on three micro-case studies compiled and analysed by means of methods drawn from Ethnography, Sociolinguistics and Critical Analysis in conjunction with an expanded, multimodal, APPRAISAL analysis, including adjusted categories and the author’s own feedback typologies. Two major arguments emerge: the feedback provided amounts to a set of ritualised discourse practices and its effects can be likened to the product of the children’s game of Head-body-tail. Consequently, feedback conventions are opaque and, potentially, impede epistemological access. They further entrench five sets of ideologies: (1) Students must master basic English literacy before they are coached in more complex issues such as argumentation; an assumption which leads to differential socialisation. (2) There is a single set of literacy practices that is rewarded. (3) Students have different levels of authorial authority depending on their language abilities. (4) ‘Middle students’ may benefit the most from feedback. (5) Specific comments are preferred over general ones. Analysis of feedback, furthermore, shows that markers’ frames of reference shape their pedagogy and that draft and final versions of work may be framed differently by markers. These findings require a response and, in order to facilitate epistemological access, suggestions are made for improved marker training based on the problematisation of the ritual involved in marking students’ work in this university foundation programme. , Thesis (MA)--Rhodes University, Faculty of Humanities, Linguistics, 2012
- Full Text:
- Date Issued: 2012
- Authors: Richardson, Amy
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/164955 , vital:41187
- Description: In order for students to become true members of academic communities of practice they need epistemological access, including guidance on central institutional knowledge-producing processes and mastery of key academic literacy practices. A powerful source of guidance is marker feedback. Drawing on key insights from the New Literacy Studies and taking up the mandate of Critical Ethnography to improve the status quo, this thesis reports on the feedback practices in a university foundation programme. The findings are based on three micro-case studies compiled and analysed by means of methods drawn from Ethnography, Sociolinguistics and Critical Analysis in conjunction with an expanded, multimodal, APPRAISAL analysis, including adjusted categories and the author’s own feedback typologies. Two major arguments emerge: the feedback provided amounts to a set of ritualised discourse practices and its effects can be likened to the product of the children’s game of Head-body-tail. Consequently, feedback conventions are opaque and, potentially, impede epistemological access. They further entrench five sets of ideologies: (1) Students must master basic English literacy before they are coached in more complex issues such as argumentation; an assumption which leads to differential socialisation. (2) There is a single set of literacy practices that is rewarded. (3) Students have different levels of authorial authority depending on their language abilities. (4) ‘Middle students’ may benefit the most from feedback. (5) Specific comments are preferred over general ones. Analysis of feedback, furthermore, shows that markers’ frames of reference shape their pedagogy and that draft and final versions of work may be framed differently by markers. These findings require a response and, in order to facilitate epistemological access, suggestions are made for improved marker training based on the problematisation of the ritual involved in marking students’ work in this university foundation programme. , Thesis (MA)--Rhodes University, Faculty of Humanities, Linguistics, 2012
- Full Text:
- Date Issued: 2012
Formulation, characterisation and optimisation of self-nanoemulsifying drug delivery systems (SNEDDS) loaded with artemether and lumefantrine
- Authors: Mudyahoto, Tsitsi
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63503 , vital:28422
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: Mudyahoto, Tsitsi
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63503 , vital:28422
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
Medication adherence: a review of policy and education in South Africa
- Authors: Nyoni, Cynthia Nomagugu
- Date: 2023-10-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419548 , vital:71653
- Description: Medication adherence is a patient's active and voluntary participation in following all the recommendations and instructions agreed upon with a health care provider such as a pharmacist. Adherence is a multidimensional phenomenon determined by the interplay of five factors: patient-related factors, socioeconomic factors, condition-related factors, health system-related factors, and therapy-related factors. Medication non-adherence is a problem in many countries, especially low to middle-income countries, including South Africa (SA). In low to middle-income countries, non-adherence is often worse due to insufficient health resources and inequities in access to health care. Medication adherence is a global problem and has raised the need for research and review. Many healthcare professionals, especially pharmacists, have an essential role in promoting medication adherence. This study described, explained and evaluated the policies in SA relating to the pharmacist's role in promoting medication adherence. Furthermore, it described medication adherence-related education at four universities in South Africa. The study was qualitative, and a two-phased approach was employed. In the first phase, a document analysis of the pharmacist’s role in supporting medication adherence was conducted as described in national policies and guidelines in SA. A total of 38 documents were analysed, including critical documents such as the South African Pharmacy Council Good Pharmacy Practice Manual and Associated SAPC rules (GPP) manual, National Drug Policy (NDP), Standard treatment guidelines (STGS) and Integrated Adherence Guidelines. The READ approach was used in conducting the document analysis and involved (1) preparing materials, (2) extracting data, (3) analysing data, and (4) distilling findings. The critical roles of pharmacists in medication adherence that were identified were in drug use, supply and management, dispensing, therapeutic drug monitoring, pharmacovigilance, pharmaceutical care, and special programmes like antimicrobial stewardship (AMS), multi-drug resistant tuberculosis (MDR-TB) care and antiretroviral treatment (ARV) and chronic conditions. In the second phase, in-depth interviews were conducted with lecturers to investigate and report on the inclusion of medication adherence and the teaching thereof in the curriculum of the Bachelor of Pharmacy Degree (BPharm) in pharmacy institutions in SA. Purposive sampling was used, and seven lecturers from four different institutions participated in the interviews. The interviews were conducted via Zoom® and were transcribed and analysed using thematic analysis. The teaching of medication adherence in the BPharm curriculum of the respective interviewed pharmacy institutions was explored. It was found that the topic of medication adherence was integrated into all subjects throughout the curriculum and not taught as a formal course. Although medication adherence is taught in many disciplines, it is predominantly in pharmacy practice in all institutions. The teaching methods identified included lectures, case studies, workshops, tutorials, practicals, readings, tasks, assignments and videos. The perceived effectiveness of the teaching methods was explored; also the time spent teaching medication adherence and the time efficiency. Student understanding, interest and engagement with the topic were explored and determined through their assessment performance and class attendance. In conclusion, from policies, the pharmacist's role concerning adherence is indirectly integrated into many other roles. It is often not distinguishable from that of other healthcare professionals and is often implied as part of a more generic role. Pharmacy students are educated on medication adherence and the skills and knowledge required to identify, monitor and support patient adherence to therapy. However, there is scope to increase the course content on medication adherence. There is a need to identify effective strategies for preparing pharmacists to assist patients in medication adherence. , Thesis (MPharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-31
- Authors: Nyoni, Cynthia Nomagugu
- Date: 2023-10-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419548 , vital:71653
- Description: Medication adherence is a patient's active and voluntary participation in following all the recommendations and instructions agreed upon with a health care provider such as a pharmacist. Adherence is a multidimensional phenomenon determined by the interplay of five factors: patient-related factors, socioeconomic factors, condition-related factors, health system-related factors, and therapy-related factors. Medication non-adherence is a problem in many countries, especially low to middle-income countries, including South Africa (SA). In low to middle-income countries, non-adherence is often worse due to insufficient health resources and inequities in access to health care. Medication adherence is a global problem and has raised the need for research and review. Many healthcare professionals, especially pharmacists, have an essential role in promoting medication adherence. This study described, explained and evaluated the policies in SA relating to the pharmacist's role in promoting medication adherence. Furthermore, it described medication adherence-related education at four universities in South Africa. The study was qualitative, and a two-phased approach was employed. In the first phase, a document analysis of the pharmacist’s role in supporting medication adherence was conducted as described in national policies and guidelines in SA. A total of 38 documents were analysed, including critical documents such as the South African Pharmacy Council Good Pharmacy Practice Manual and Associated SAPC rules (GPP) manual, National Drug Policy (NDP), Standard treatment guidelines (STGS) and Integrated Adherence Guidelines. The READ approach was used in conducting the document analysis and involved (1) preparing materials, (2) extracting data, (3) analysing data, and (4) distilling findings. The critical roles of pharmacists in medication adherence that were identified were in drug use, supply and management, dispensing, therapeutic drug monitoring, pharmacovigilance, pharmaceutical care, and special programmes like antimicrobial stewardship (AMS), multi-drug resistant tuberculosis (MDR-TB) care and antiretroviral treatment (ARV) and chronic conditions. In the second phase, in-depth interviews were conducted with lecturers to investigate and report on the inclusion of medication adherence and the teaching thereof in the curriculum of the Bachelor of Pharmacy Degree (BPharm) in pharmacy institutions in SA. Purposive sampling was used, and seven lecturers from four different institutions participated in the interviews. The interviews were conducted via Zoom® and were transcribed and analysed using thematic analysis. The teaching of medication adherence in the BPharm curriculum of the respective interviewed pharmacy institutions was explored. It was found that the topic of medication adherence was integrated into all subjects throughout the curriculum and not taught as a formal course. Although medication adherence is taught in many disciplines, it is predominantly in pharmacy practice in all institutions. The teaching methods identified included lectures, case studies, workshops, tutorials, practicals, readings, tasks, assignments and videos. The perceived effectiveness of the teaching methods was explored; also the time spent teaching medication adherence and the time efficiency. Student understanding, interest and engagement with the topic were explored and determined through their assessment performance and class attendance. In conclusion, from policies, the pharmacist's role concerning adherence is indirectly integrated into many other roles. It is often not distinguishable from that of other healthcare professionals and is often implied as part of a more generic role. Pharmacy students are educated on medication adherence and the skills and knowledge required to identify, monitor and support patient adherence to therapy. However, there is scope to increase the course content on medication adherence. There is a need to identify effective strategies for preparing pharmacists to assist patients in medication adherence. , Thesis (MPharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-31
Left-invariant optimal control problems of the Engel group: classification, stability, and integration
- Authors: McLean, Catherine Eve
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62949 , vital:28323 , http://doi.org/10.21504/10962/62949
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: McLean, Catherine Eve
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62949 , vital:28323 , http://doi.org/10.21504/10962/62949
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
The adoption of international financial reporting standards and foreign direct investment inflows: the moderating effect of the institutional environment in Africa
- Authors: Simbi, Chipo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419230 , vital:71627 , DOI 10.21504/10962/419230
- Description: Globalisation has created a need for an international accounting language to facilitate the smooth flow of trade across countries. In 2003, in an effort to establish a global financial reporting language, the International Accounting Standards Board (IASB) developed a single set of high-quality accounting principles known as the International Financial Reporting Standards (IFRS). Over the last decade, several African countries have adopted IFRS, and Africa has become the second-largest adopting continent after Europe. IFRS promotes improved quality of disclosure of accounting transactions, reduces information asymmetry between preparers and users of financial information, lowers the cost of investing, and breaks down information barriers to cross-border investment. Researchers suggest many benefits of IFRS adoption for macroeconomic indicators such as Foreign Direct Investment (FDI). The reduction in information acquisition and processing costs which translates into the reduction in investment costs, has been cited by most researchers. Researchers have argued, however, that the economic benefits of IFRS in Africa depend on the strength of the institutional environment. They also argue that the Western environment in which the IFRS was developed differs from the African environment. Thus, the universal approach of the IASB may not be appropriate due to the historical, social, economic and political context of African countries. The impact of the adoption of IFRS by African countries requires further examination, particularly as a weak institutional environment confronts many African countries. Three research questions are designed for this study; (1) Is there a significant change in FDI inflows for IFRS adopters in selected African countries after the adoption? (2) Is there a significant change in FDI inflows due to the institutional environment? (3) Does the institutional environment in IFRS-adopting countries moderate the effect of IFRS on FDI in selected African countries? The present study is underpinned by the new institutional theory, the information asymmetry theory, the eclectic theory and the signalling theory, each of which provide reasons why African countries have adopted IFRS. Nine hypotheses are developed, based on the research questions, and tested using the Systems General Method of Moments and the Difference-in-Difference method. The study uses data from 26 African countries, 15 adopting and 11 non-adopting countries, over the period 1996 - 2018. First, the study establishes that the adoption of IFRS positively and significantly affects FDI inflows into the selected sample of African countries. Second, the study concludes that legal enforcement, accounting and auditing standards enforcement, and language origin positively and significantly impact FDI inflows into these countries. Legal origin, however, has a positive but insignificant association with FDI inflows. Third, legal enforcement, historical ties, accounting and auditing enforcement and the quality of the institutional environment are found to moderate the effect of IFRS adoption on FDI inflows. These results indicate that IFRS is a crucial determinant of FDI inflows into African countries, but a supportive institutional environment is needed for African countries to attract FDI inflows after adoption. The results contribute to the accounting and finance literature on FDI into African countries, and may assist the investment community to assess the institutional risk associated with investing in IFRS adopting African countries. , Thesis (PhD) -- Faculty of Commerce, Accounting, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Simbi, Chipo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419230 , vital:71627 , DOI 10.21504/10962/419230
- Description: Globalisation has created a need for an international accounting language to facilitate the smooth flow of trade across countries. In 2003, in an effort to establish a global financial reporting language, the International Accounting Standards Board (IASB) developed a single set of high-quality accounting principles known as the International Financial Reporting Standards (IFRS). Over the last decade, several African countries have adopted IFRS, and Africa has become the second-largest adopting continent after Europe. IFRS promotes improved quality of disclosure of accounting transactions, reduces information asymmetry between preparers and users of financial information, lowers the cost of investing, and breaks down information barriers to cross-border investment. Researchers suggest many benefits of IFRS adoption for macroeconomic indicators such as Foreign Direct Investment (FDI). The reduction in information acquisition and processing costs which translates into the reduction in investment costs, has been cited by most researchers. Researchers have argued, however, that the economic benefits of IFRS in Africa depend on the strength of the institutional environment. They also argue that the Western environment in which the IFRS was developed differs from the African environment. Thus, the universal approach of the IASB may not be appropriate due to the historical, social, economic and political context of African countries. The impact of the adoption of IFRS by African countries requires further examination, particularly as a weak institutional environment confronts many African countries. Three research questions are designed for this study; (1) Is there a significant change in FDI inflows for IFRS adopters in selected African countries after the adoption? (2) Is there a significant change in FDI inflows due to the institutional environment? (3) Does the institutional environment in IFRS-adopting countries moderate the effect of IFRS on FDI in selected African countries? The present study is underpinned by the new institutional theory, the information asymmetry theory, the eclectic theory and the signalling theory, each of which provide reasons why African countries have adopted IFRS. Nine hypotheses are developed, based on the research questions, and tested using the Systems General Method of Moments and the Difference-in-Difference method. The study uses data from 26 African countries, 15 adopting and 11 non-adopting countries, over the period 1996 - 2018. First, the study establishes that the adoption of IFRS positively and significantly affects FDI inflows into the selected sample of African countries. Second, the study concludes that legal enforcement, accounting and auditing standards enforcement, and language origin positively and significantly impact FDI inflows into these countries. Legal origin, however, has a positive but insignificant association with FDI inflows. Third, legal enforcement, historical ties, accounting and auditing enforcement and the quality of the institutional environment are found to moderate the effect of IFRS adoption on FDI inflows. These results indicate that IFRS is a crucial determinant of FDI inflows into African countries, but a supportive institutional environment is needed for African countries to attract FDI inflows after adoption. The results contribute to the accounting and finance literature on FDI into African countries, and may assist the investment community to assess the institutional risk associated with investing in IFRS adopting African countries. , Thesis (PhD) -- Faculty of Commerce, Accounting, 2023
- Full Text:
- Date Issued: 2023-10-13
An investigation of the correlation of mitochondrial biogenesis, mitochondrial DNA methylation, mitochondrial network topology and adipogenesis in the human adipose-derived mesenchymal stromal stem cell model
- Authors: Kadye, Rose
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62637 , vital:28222
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Kadye, Rose
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62637 , vital:28222
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
A comprehensive review of the taxonomic diversity within the freshwater catfish genus Parauchenoglanis (Siluriformes, Auchenoglanididae)
- Authors: Sithole, Yonela
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/402992 , vital:69912
- Description: Thesis embargoed. To be released early 2026. , Thesis (PhD) -- Faculty of Science, Ichthyology & Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Sithole, Yonela
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/402992 , vital:69912
- Description: Thesis embargoed. To be released early 2026. , Thesis (PhD) -- Faculty of Science, Ichthyology & Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Rites of passage: Substance dependence and the negotiation of development tasks - a case study
- Authors: Roux, Catharina
- Date: 1991
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193242 , vital:45313
- Description: This thesis is an attempt to provide an understanding of drug addiction in its relation to the tasks and arrests which take place during the developmental process. Current theories of drug addiction are situated within the parameters of developmental theory; Object Relations Theory, Lacanian Structuralism and Freud’s concept of the Oedipus Complex are drawn on. The dual regressive and progressive function of drugs as it relates to developmental tasks and arrests is illustrated, the argument being that a very specific relationship exists between the compulsive use of drugs and the developmental tasks which need to be avoided as well as those which need to be negotiated. The case study research method is made use of in the attempt to illustrate the links between drug addiction and specific developmental tasks. I present an in-depth analysis of the developmental history of Rafiq Jaffer, an inpatient at the drug unit at Lentegeur Psychiatric Hospital, drawing on the material which was collected during nine months of individual therapy. As Borderline Personality Disorder is the primary diagnosis in the case of Rafiq Jaffer, the emphasis is by necessity put on borderline pathology. The primary aim of the thesis is, however, to highlight the need to understand the compulsive use of drugs within the context of the developmental process, thereby developing a conceptualisation against which further cases may be tested. , Thesis (MA) -- Faculty of Humanities, Psychology, 1991
- Full Text:
- Date Issued: 1991
- Authors: Roux, Catharina
- Date: 1991
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193242 , vital:45313
- Description: This thesis is an attempt to provide an understanding of drug addiction in its relation to the tasks and arrests which take place during the developmental process. Current theories of drug addiction are situated within the parameters of developmental theory; Object Relations Theory, Lacanian Structuralism and Freud’s concept of the Oedipus Complex are drawn on. The dual regressive and progressive function of drugs as it relates to developmental tasks and arrests is illustrated, the argument being that a very specific relationship exists between the compulsive use of drugs and the developmental tasks which need to be avoided as well as those which need to be negotiated. The case study research method is made use of in the attempt to illustrate the links between drug addiction and specific developmental tasks. I present an in-depth analysis of the developmental history of Rafiq Jaffer, an inpatient at the drug unit at Lentegeur Psychiatric Hospital, drawing on the material which was collected during nine months of individual therapy. As Borderline Personality Disorder is the primary diagnosis in the case of Rafiq Jaffer, the emphasis is by necessity put on borderline pathology. The primary aim of the thesis is, however, to highlight the need to understand the compulsive use of drugs within the context of the developmental process, thereby developing a conceptualisation against which further cases may be tested. , Thesis (MA) -- Faculty of Humanities, Psychology, 1991
- Full Text:
- Date Issued: 1991
The regeneration of palmiet (prionium serratum) following hydrogeomorphic disturbance: a case study of the Kromme River wetland
- Authors: Van Eck, Caydon Daniël
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365555 , vital:65759
- Description: The Kromme River wetland in the Eastern Cape of South Africa occupies a broad valley (up to 350 m wide) with a gentle longitudinal slope of less than 2 % that has been formed by cut-and-fill cycles that are initiated by trunk-tributary interactions. These hydrogeomorphic disturbance events trigger gully erosion and generate sediments, the coarse fraction of which is deposited less than 2 km downstream, leading to depositional floodout features that fill gullies headwards. This process has been occurring at intervals for at least 10 000 years, and as such pre-dates the introduction of European farming practices in the area. Plants that regenerate by colonising these features are thought to have evolved adaptions necessary to colonise intermittently produced bare sandy sediments. This study aimed to examine the regeneration ecology of palmiet (Prionium serratum), the dominant vegetation community within these cut-and-fill wetlands, by relating its regeneration characteristics to environmental factors in a reach of the Kromme River wetland that has experienced a recent hydrogeomorphic disturbance event (approximately 10 years before the commencement of this study). Palmiet was found to be regenerating on sedimentary deposits on beds of gullies and on depositional bars on the margins of gully beds. The large depositional floodout downstream of a large gully also favoured palmiet regeneration, where it was found to be regenerating along not only the active channel, but also along old abandoned flow paths and sometimes areas well elevated above the channel. The geomorphic features that favoured palmiet regeneration were characterised by coarse-grained sediments (mean particle size approximately 310 μm) with low organic matter content (0.61 %), a low depth to the water table and low elevation above the thalweg (mean depth to water table is approximately 0.6 m), and a relatively close distance to the thalweg (< 10 m). This understanding of palmiet’s regeneration characteristics was viewed in relation to existing literature on undisturbed palmiet wetland plant communities and its reported contribution to conditions that favour wetland formation through gully filling, which allowed for the creation of a conceptual model of palmiet regeneration, colonisation and long-term persistence. This model was based on the Fluvial Biogeomorphic Succession concept. It suggests that palmiet’s interaction with the hydrogeomorphic environment throughout the different stages of its life cycle results in self-organising biogeomorphic landforms. Over hundreds of years, the reciprocal interactions between palmiet, sediments and water, fills gullies and restores valley bottoms, ultimately leading to the formation of a wetland landform. It is further proposed that through continued accretion, the geomorphic wetland landscape becomes more and more disconnected from the hydrogeomorphic dynamics of the fluvial system, such that the prevailing conditions begin to favour fynbos establishment, which may outcompete palmiet. , Thesis (MSc) -- Faculty of Science, Geography, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Van Eck, Caydon Daniël
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365555 , vital:65759
- Description: The Kromme River wetland in the Eastern Cape of South Africa occupies a broad valley (up to 350 m wide) with a gentle longitudinal slope of less than 2 % that has been formed by cut-and-fill cycles that are initiated by trunk-tributary interactions. These hydrogeomorphic disturbance events trigger gully erosion and generate sediments, the coarse fraction of which is deposited less than 2 km downstream, leading to depositional floodout features that fill gullies headwards. This process has been occurring at intervals for at least 10 000 years, and as such pre-dates the introduction of European farming practices in the area. Plants that regenerate by colonising these features are thought to have evolved adaptions necessary to colonise intermittently produced bare sandy sediments. This study aimed to examine the regeneration ecology of palmiet (Prionium serratum), the dominant vegetation community within these cut-and-fill wetlands, by relating its regeneration characteristics to environmental factors in a reach of the Kromme River wetland that has experienced a recent hydrogeomorphic disturbance event (approximately 10 years before the commencement of this study). Palmiet was found to be regenerating on sedimentary deposits on beds of gullies and on depositional bars on the margins of gully beds. The large depositional floodout downstream of a large gully also favoured palmiet regeneration, where it was found to be regenerating along not only the active channel, but also along old abandoned flow paths and sometimes areas well elevated above the channel. The geomorphic features that favoured palmiet regeneration were characterised by coarse-grained sediments (mean particle size approximately 310 μm) with low organic matter content (0.61 %), a low depth to the water table and low elevation above the thalweg (mean depth to water table is approximately 0.6 m), and a relatively close distance to the thalweg (< 10 m). This understanding of palmiet’s regeneration characteristics was viewed in relation to existing literature on undisturbed palmiet wetland plant communities and its reported contribution to conditions that favour wetland formation through gully filling, which allowed for the creation of a conceptual model of palmiet regeneration, colonisation and long-term persistence. This model was based on the Fluvial Biogeomorphic Succession concept. It suggests that palmiet’s interaction with the hydrogeomorphic environment throughout the different stages of its life cycle results in self-organising biogeomorphic landforms. Over hundreds of years, the reciprocal interactions between palmiet, sediments and water, fills gullies and restores valley bottoms, ultimately leading to the formation of a wetland landform. It is further proposed that through continued accretion, the geomorphic wetland landscape becomes more and more disconnected from the hydrogeomorphic dynamics of the fluvial system, such that the prevailing conditions begin to favour fynbos establishment, which may outcompete palmiet. , Thesis (MSc) -- Faculty of Science, Geography, 2022
- Full Text:
- Date Issued: 2022-10-14
The novobiocin-induced turnover of fibronectin via low density lipoprotein receptor-related protein 1 alters matrix morphology with physiological consequences on cell growth and migration
- Authors: Boёl, Natasha Marie-Eraine
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/114778 , vital:34034 , 10.21504/10962/114778
- Description: Fibronectin (FN), an extracellular matrix protein, is secreted as a soluble dimer which is assembled into an insoluble extracellular matrix. The dynamics of FN matrix assembly and degradation play a large role in cell migration and invasion thereby contributing to the metastatic potential of cancer cells. Previous studies have shown the direct binding of Heat Shock Protein 90 kDa (Hsp90) and FN in vitro, and that inhibition of Hsp90 with novobiocin (NOV) caused internalisation of the FN matrix. Low density lipoprotein receptor-related protein 1 (LRP1) is a ubiquitous receptor known to bind both Hsp90 and FN. Using an LRP1 expressing Hs578T breast cancer cell line and an isogenic mouse embryonic fibroblast (MEF) model system of differential LRP1 expression we demonstrate that LRP1 is involved in turnover of FN in response to C-terminal Hsp90 inhibition. The first objective of this study was to identify the mechanism of NOV-induced LRP1-mediated FN turnover. Our data show that NOV-mediated FN turnover via LRP1 did not require the activity of matrix metalloproteinases (MMPs), which play an important role in processing and degradation of the extracellular matrix and FN. In addition, the levels of the main FN receptor responsible for its extracellular assembly, β1-integrin, did not change in response to NOV. LRP1 is known to undergo regulated intramembrane proteolysis (RIP) which generates smaller fragments that may translocate to the nucleus and modulate gene transcription. Using inhibitors of LRP1 cleavage and nuclear fractionation we determined that LRP1 processing was not required for the NOV-induced FN response suggesting that a mechanism unrelated to LRP1 RIP is involved. A possible mechanism may be in altered Hsp90-LRP1 cell signalling as we observed disruption of the FN-Hsp90-LRP1 complex at the cell surface in NOV treated cells. How this affects downstream eHsp90-LRP1 signalling is still to be determined but may be related to a significant increase in phospho-AKT and loss of phospho-ERK upon NOV-treatment; two key signalling proteins involved in FN matrix regulation and which are downstream of LRP1 signalling. The second objective of this study was to determine the physiological consequences associated with FN turnover in response to NOV treatment. Using migration assays we demonstrated that levels of insoluble matrix-associated FN and FN concentration are not solely responsible for migratory capacity of cells on decellularized extracellular matrices, but rather that structural composition and integrity of the matrix plays a bigger role. Using confocal and scanning electron microscopy, we identified NOV treated matrices to be flatter, less mature and contain thicker, rope-like FN fibrils to which cells adhered better but were generally less proliferative. Comparatively, cells adhered less to the more mature and 3-dimensional untreated matrices but exhibited increased spreading and cell growth, which may in part be due to the thinner fibrils and web-like matrix. In summary, this study substantiates the role of LRP1 in NOV-mediated FN turnover, and provides new insights into the possible mechanisms of the Hsp90-LRP1 mediated loss of FN matrix. This is the first study to demonstrate some of the functional consequences related to FN turnover by NOV at the ECM level. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text: false
- Date Issued: 2020
- Authors: Boёl, Natasha Marie-Eraine
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/114778 , vital:34034 , 10.21504/10962/114778
- Description: Fibronectin (FN), an extracellular matrix protein, is secreted as a soluble dimer which is assembled into an insoluble extracellular matrix. The dynamics of FN matrix assembly and degradation play a large role in cell migration and invasion thereby contributing to the metastatic potential of cancer cells. Previous studies have shown the direct binding of Heat Shock Protein 90 kDa (Hsp90) and FN in vitro, and that inhibition of Hsp90 with novobiocin (NOV) caused internalisation of the FN matrix. Low density lipoprotein receptor-related protein 1 (LRP1) is a ubiquitous receptor known to bind both Hsp90 and FN. Using an LRP1 expressing Hs578T breast cancer cell line and an isogenic mouse embryonic fibroblast (MEF) model system of differential LRP1 expression we demonstrate that LRP1 is involved in turnover of FN in response to C-terminal Hsp90 inhibition. The first objective of this study was to identify the mechanism of NOV-induced LRP1-mediated FN turnover. Our data show that NOV-mediated FN turnover via LRP1 did not require the activity of matrix metalloproteinases (MMPs), which play an important role in processing and degradation of the extracellular matrix and FN. In addition, the levels of the main FN receptor responsible for its extracellular assembly, β1-integrin, did not change in response to NOV. LRP1 is known to undergo regulated intramembrane proteolysis (RIP) which generates smaller fragments that may translocate to the nucleus and modulate gene transcription. Using inhibitors of LRP1 cleavage and nuclear fractionation we determined that LRP1 processing was not required for the NOV-induced FN response suggesting that a mechanism unrelated to LRP1 RIP is involved. A possible mechanism may be in altered Hsp90-LRP1 cell signalling as we observed disruption of the FN-Hsp90-LRP1 complex at the cell surface in NOV treated cells. How this affects downstream eHsp90-LRP1 signalling is still to be determined but may be related to a significant increase in phospho-AKT and loss of phospho-ERK upon NOV-treatment; two key signalling proteins involved in FN matrix regulation and which are downstream of LRP1 signalling. The second objective of this study was to determine the physiological consequences associated with FN turnover in response to NOV treatment. Using migration assays we demonstrated that levels of insoluble matrix-associated FN and FN concentration are not solely responsible for migratory capacity of cells on decellularized extracellular matrices, but rather that structural composition and integrity of the matrix plays a bigger role. Using confocal and scanning electron microscopy, we identified NOV treated matrices to be flatter, less mature and contain thicker, rope-like FN fibrils to which cells adhered better but were generally less proliferative. Comparatively, cells adhered less to the more mature and 3-dimensional untreated matrices but exhibited increased spreading and cell growth, which may in part be due to the thinner fibrils and web-like matrix. In summary, this study substantiates the role of LRP1 in NOV-mediated FN turnover, and provides new insights into the possible mechanisms of the Hsp90-LRP1 mediated loss of FN matrix. This is the first study to demonstrate some of the functional consequences related to FN turnover by NOV at the ECM level. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text: false
- Date Issued: 2020
Rainwater and alternative potable water microbial water quality and DRM implications in Makana Local Municipality
- Authors: Nhokodi, Tererai
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232227 , vital:49973
- Description: Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Nhokodi, Tererai
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232227 , vital:49973
- Description: Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06