Psychological well-being of institutionalised and non-institutionalised isiXhosa and English ethnic speaking elderly south African residing within the Buffalo City area
- Authors: Ntozini, Anathi
- Date: 2017
- Subjects: Self-actualization (Psychology) in old age Older people -- Institutional care -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/6368 , vital:29593
- Description: Background: International research has clearly indicated that the world’s population is ageing: almost all countries in the world are experiencing a significant growth in the proportion of older persons in their population. This is also true for developing countries such as South Africa that are beginning to show signs and symptoms of an ageing population. Among Southern African Development Communities (SADC), South Africa has the highest number of ‘senior citizens’. Population reports indicate that the population of old people rose from paltry 2.8 million in 1996 to more than 4 million in 2011 and this is expected to skyrocket to seven million by 2030. In spite of the increasing number of senior citizens in socio-structural landscapes in South Africa, there is still lack of adequate, workable and effective policy frameworks for the wellbeing of the elderly. There is also paucity of psychological data of the elderly, especially along racial divides to determine whether the after-effects of apartheid still hold sway or not in post-apartheid South Africa. This study was conceived to investigate the psychological well-being of the elderly in Buffalo City, Eastern Cape, South Africa between two racial-ethnic elderly groups. The specific objectives of the study were to explore the relationship between the socio-demographic characteristics and psychological well-being of the black (Xhosa) and white (English) elderly in Buffalo City, South Africa and second, to validate the relationship between psychological well-being and physical activity, loneliness, spirituality/religiosity as well as ageism among the sampled population. The set-point theory, selective optimisation compensation theory (SOCT) as well as the continuity theory were employed to guide the conduct of the study. Method: Psychological measuring instruments were deployed to collect data for the study from a total of 301 elderly respondents in retirement and private individual homes (191 isiXhosa and 110 English speaking elderly). Both simple random sampling (SRS) and purposive sampling procedures were used to select the respondents. The measuring instruments included the Ryff Scales of Psychological Well-being (RSPWB), Physical Activity Scale for the Elderly (PASE), Assessment of Spiritual and Religious Sentiments Scale (ASPIRES), University of California at Los Angeles (UCLA) Loneliness Scale, the Palmore Ageism Survey scale and a biographical questionnaire. Data was analysed using MANOVA, One-way variance analysis and regression coefficient. The racial differences logically influenced the selection of the respondents for the study. Results: The study revealed a significant statistical relationship between physical activity (PA) and psychological well-being of the elderly, regardless of the sociodemographic variables. PA showed a significant relationship with psychological wellbeing of the elderly. The study also discovered that loneliness correlates significantly with all four of the psychological well-being scales. It shows that the higher the levels of loneliness experienced by the elderly, socio-demographic variables controlled, the lower the levels of psychological well-being in terms of autonomy, environmental mastery, purpose in life, and self-acceptance. However, with the exception of the relationship between loneliness and purpose in life, ethnic affiliation moderates autonomy, environmental mastery and self-acceptance. English elderly constantly experienced higher levels of autonomy than the isiXhosa elderly do with an increase in loneliness. The study also found a positive relationship between ageism and psychological well- being. However, with low levels of ageism, the English elderly, in comparison with the isiXhosa elderly, is likely to show higher levels of autonomy. In addition, a significant statistical relationship between ageism and environmental mastery and purpose in life was found among the isiXhosa elderly. Although, with an increase in ageism, there is a slight increase in autonomy in both groups, the English elderly throughout showed higher levels of autonomy than the isiXhosa elderly showed. The study found a positive relationship between religiosity/spirituality and psychological well-being of the elderly. However, race could moderate the relationship between prayer fulfillment and psychological well-being at all four levels (autonomy, environmental mastery, purpose in life, and self-acceptance). With an increase in prayer fulfillment, the autonomy of the English elderly increases fairly quickly, while the autonomy of the isiXhosa elderly decreases slightly. Comparatively, the study found that isiXhosa elderly reported lower levels of psychological well-being than the English elderly. Conclusion/Recommendation: The study concludes that there is the need to develop a solid national data bases on needs and use of services, and process of ageing in order to access research data to assist planning, dissemination, delivery and evaluation of effective service delivery for the elderly population in South Africa, especially along racial divides.
- Full Text:
- Date Issued: 2017
- Authors: Ntozini, Anathi
- Date: 2017
- Subjects: Self-actualization (Psychology) in old age Older people -- Institutional care -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/6368 , vital:29593
- Description: Background: International research has clearly indicated that the world’s population is ageing: almost all countries in the world are experiencing a significant growth in the proportion of older persons in their population. This is also true for developing countries such as South Africa that are beginning to show signs and symptoms of an ageing population. Among Southern African Development Communities (SADC), South Africa has the highest number of ‘senior citizens’. Population reports indicate that the population of old people rose from paltry 2.8 million in 1996 to more than 4 million in 2011 and this is expected to skyrocket to seven million by 2030. In spite of the increasing number of senior citizens in socio-structural landscapes in South Africa, there is still lack of adequate, workable and effective policy frameworks for the wellbeing of the elderly. There is also paucity of psychological data of the elderly, especially along racial divides to determine whether the after-effects of apartheid still hold sway or not in post-apartheid South Africa. This study was conceived to investigate the psychological well-being of the elderly in Buffalo City, Eastern Cape, South Africa between two racial-ethnic elderly groups. The specific objectives of the study were to explore the relationship between the socio-demographic characteristics and psychological well-being of the black (Xhosa) and white (English) elderly in Buffalo City, South Africa and second, to validate the relationship between psychological well-being and physical activity, loneliness, spirituality/religiosity as well as ageism among the sampled population. The set-point theory, selective optimisation compensation theory (SOCT) as well as the continuity theory were employed to guide the conduct of the study. Method: Psychological measuring instruments were deployed to collect data for the study from a total of 301 elderly respondents in retirement and private individual homes (191 isiXhosa and 110 English speaking elderly). Both simple random sampling (SRS) and purposive sampling procedures were used to select the respondents. The measuring instruments included the Ryff Scales of Psychological Well-being (RSPWB), Physical Activity Scale for the Elderly (PASE), Assessment of Spiritual and Religious Sentiments Scale (ASPIRES), University of California at Los Angeles (UCLA) Loneliness Scale, the Palmore Ageism Survey scale and a biographical questionnaire. Data was analysed using MANOVA, One-way variance analysis and regression coefficient. The racial differences logically influenced the selection of the respondents for the study. Results: The study revealed a significant statistical relationship between physical activity (PA) and psychological well-being of the elderly, regardless of the sociodemographic variables. PA showed a significant relationship with psychological wellbeing of the elderly. The study also discovered that loneliness correlates significantly with all four of the psychological well-being scales. It shows that the higher the levels of loneliness experienced by the elderly, socio-demographic variables controlled, the lower the levels of psychological well-being in terms of autonomy, environmental mastery, purpose in life, and self-acceptance. However, with the exception of the relationship between loneliness and purpose in life, ethnic affiliation moderates autonomy, environmental mastery and self-acceptance. English elderly constantly experienced higher levels of autonomy than the isiXhosa elderly do with an increase in loneliness. The study also found a positive relationship between ageism and psychological well- being. However, with low levels of ageism, the English elderly, in comparison with the isiXhosa elderly, is likely to show higher levels of autonomy. In addition, a significant statistical relationship between ageism and environmental mastery and purpose in life was found among the isiXhosa elderly. Although, with an increase in ageism, there is a slight increase in autonomy in both groups, the English elderly throughout showed higher levels of autonomy than the isiXhosa elderly showed. The study found a positive relationship between religiosity/spirituality and psychological well-being of the elderly. However, race could moderate the relationship between prayer fulfillment and psychological well-being at all four levels (autonomy, environmental mastery, purpose in life, and self-acceptance). With an increase in prayer fulfillment, the autonomy of the English elderly increases fairly quickly, while the autonomy of the isiXhosa elderly decreases slightly. Comparatively, the study found that isiXhosa elderly reported lower levels of psychological well-being than the English elderly. Conclusion/Recommendation: The study concludes that there is the need to develop a solid national data bases on needs and use of services, and process of ageing in order to access research data to assist planning, dissemination, delivery and evaluation of effective service delivery for the elderly population in South Africa, especially along racial divides.
- Full Text:
- Date Issued: 2017
The South African anaphora: the development of the anaphora of the South African Eucharistic rite
- Authors: Hinchliff, Peter Bingham
- Date: 1958
- Subjects: Church of the Province of South Africa. Book of common prayer -- History -- Sources Eucharistic prayers Eucharistic prayers -- Anglican Communion Anglican Communion -- Liturgy -- History -- Sources Anglican Communion -- South Africa -- Liturgy -- History -- Sources.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1260 , http://hdl.handle.net/10962/d1012293
- Description: The Prayer Book of the Church of England reached South Africa as a part of the establishment of the British Administration at the Cape. In its new environment it obviously required some revision. The Book of 1662 reflected the political and social conditions of its time. lt was designed for a Church not immediately concerned with missionary work amongst heathen peoples but directly established under the Crown. The circumstances of a Church in the colonies, particularly when the colonies became self-governing, required some modernisation of language, some omission and adaptation of old prayers and some addition of new ones. Yet the Church appears to have been wary of attempting anything more than this, and it was especially reluctant to make any revision which might imply a doctrinal change. The consecration prayer in the liturgy -'our incomparable liturgy' - was particularly sacrosanct by virtue of long use and the accretion of sentimental associations. Revision of this part of the book would naturally be slow and hesitant and this is the revision with which we are concerned - the most interesting and important part of the history of the South African Prayer Book. Chapter 1, p. 6.
- Full Text:
- Date Issued: 1958
- Authors: Hinchliff, Peter Bingham
- Date: 1958
- Subjects: Church of the Province of South Africa. Book of common prayer -- History -- Sources Eucharistic prayers Eucharistic prayers -- Anglican Communion Anglican Communion -- Liturgy -- History -- Sources Anglican Communion -- South Africa -- Liturgy -- History -- Sources.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1260 , http://hdl.handle.net/10962/d1012293
- Description: The Prayer Book of the Church of England reached South Africa as a part of the establishment of the British Administration at the Cape. In its new environment it obviously required some revision. The Book of 1662 reflected the political and social conditions of its time. lt was designed for a Church not immediately concerned with missionary work amongst heathen peoples but directly established under the Crown. The circumstances of a Church in the colonies, particularly when the colonies became self-governing, required some modernisation of language, some omission and adaptation of old prayers and some addition of new ones. Yet the Church appears to have been wary of attempting anything more than this, and it was especially reluctant to make any revision which might imply a doctrinal change. The consecration prayer in the liturgy -'our incomparable liturgy' - was particularly sacrosanct by virtue of long use and the accretion of sentimental associations. Revision of this part of the book would naturally be slow and hesitant and this is the revision with which we are concerned - the most interesting and important part of the history of the South African Prayer Book. Chapter 1, p. 6.
- Full Text:
- Date Issued: 1958
The participatory development and implementation of a facilitator’s manual for the promotion of exclusive breastfeeding
- Authors: Katsinde, Shingirai Miranda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/4201 , vital:20632
- Description: Background: Breastfeeding is a common practice, but exclusive breastfeeding for the first six months is no longer a cultural norm in the majority of South African communities. Identification of facilitating and constraining factors which affect breastfeeding and exclusive breastfeeding practices is thus important. The promotion of exclusive breastfeeding is essential for improved infant health and development, especially if it takes into consideration the broader cultural and socio-economic aspects influencing these practices. This study follows up on an initial project conducted in Glenmore and Ndwayana, two rural communities in the Eastern Cape, South Africa. The current study aimed at working with community care workers who are associated with two community based organisations, who work within three communities, Glenmore, Ndwayana and Grahamstown. The study objectives were to identify the factors that influence the adoption of exclusive breastfeeding in the communities researched, to conduct workshops with the community workers on exclusive breastfeeding practices, as well as to develop and implement a facilitator’s manual for the promotion of exclusive breastfeeding. Method: Using the community based participatory research approach and the PEN-3 theoretical framework to guide the research process, individual semi-structured interviews were conducted with 14 community care workers to identify the factors that affect breastfeeding and exclusive breastfeeding. Through participatory involvement and a cyclical research process, a facilitator’s manual on breastfeeding was developed, which was used during the workshops in the training of community care workers on breastfeeding and exclusive breastfeeding practices. A pre and post intervention knowledge questionnaire was given to the community care workers to complete before and after the workshops. The facilitator’s manual was modified based on 14 months of consistent interaction with the community care workers, who provided feedback on improving the content as well as on how to enhance the cultural appropriateness of the facilitator’s manual during guided focus group discussions. Readability testing also guided further modification of the facilitator’s manual. Results:The major findings confirmed that exclusive breastfeeding for six months was no longer a common practice in these three communities. Factors affecting breastfeeding and exclusive breastfeeding were classified as perceptions (knowledge attitudes and beliefs), enablers (resources and facilities) and nurturers (people), in accordance with the PEN-3 model thematic categories. The knowledge questionnaire, semi-structured interview results, and data from the workshops showed that the community care workers were not sufficiently equipped with information on breastfeeding and exclusive breastfeeding. The facilitator’s manual development and modification was made possible by inputs from the community care workers and the community based organisation liaisons. A culturally appropriate, community specific facilitator’s manual for the promotion of breastfeeding and exclusive breastfeeding was produced. Conclusion: The factors affecting breastfeeding and exclusive breastfeeding were identified. These factors were useful in facilitating discussions on how to improve breastfeeding and exclusive breastfeeding practices in the communities researched. The facilitator’s manual and the workshops were useful in equipping community care workers with knowledge on breastfeeding and exclusive breastfeeding. The involvement of community based organisations will assist to ensure sustainability of breastfeeding promotion by community care workers by adopting the facilitator’s manual as part of their women and child development programmes.
- Full Text:
- Date Issued: 2016
- Authors: Katsinde, Shingirai Miranda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/4201 , vital:20632
- Description: Background: Breastfeeding is a common practice, but exclusive breastfeeding for the first six months is no longer a cultural norm in the majority of South African communities. Identification of facilitating and constraining factors which affect breastfeeding and exclusive breastfeeding practices is thus important. The promotion of exclusive breastfeeding is essential for improved infant health and development, especially if it takes into consideration the broader cultural and socio-economic aspects influencing these practices. This study follows up on an initial project conducted in Glenmore and Ndwayana, two rural communities in the Eastern Cape, South Africa. The current study aimed at working with community care workers who are associated with two community based organisations, who work within three communities, Glenmore, Ndwayana and Grahamstown. The study objectives were to identify the factors that influence the adoption of exclusive breastfeeding in the communities researched, to conduct workshops with the community workers on exclusive breastfeeding practices, as well as to develop and implement a facilitator’s manual for the promotion of exclusive breastfeeding. Method: Using the community based participatory research approach and the PEN-3 theoretical framework to guide the research process, individual semi-structured interviews were conducted with 14 community care workers to identify the factors that affect breastfeeding and exclusive breastfeeding. Through participatory involvement and a cyclical research process, a facilitator’s manual on breastfeeding was developed, which was used during the workshops in the training of community care workers on breastfeeding and exclusive breastfeeding practices. A pre and post intervention knowledge questionnaire was given to the community care workers to complete before and after the workshops. The facilitator’s manual was modified based on 14 months of consistent interaction with the community care workers, who provided feedback on improving the content as well as on how to enhance the cultural appropriateness of the facilitator’s manual during guided focus group discussions. Readability testing also guided further modification of the facilitator’s manual. Results:The major findings confirmed that exclusive breastfeeding for six months was no longer a common practice in these three communities. Factors affecting breastfeeding and exclusive breastfeeding were classified as perceptions (knowledge attitudes and beliefs), enablers (resources and facilities) and nurturers (people), in accordance with the PEN-3 model thematic categories. The knowledge questionnaire, semi-structured interview results, and data from the workshops showed that the community care workers were not sufficiently equipped with information on breastfeeding and exclusive breastfeeding. The facilitator’s manual development and modification was made possible by inputs from the community care workers and the community based organisation liaisons. A culturally appropriate, community specific facilitator’s manual for the promotion of breastfeeding and exclusive breastfeeding was produced. Conclusion: The factors affecting breastfeeding and exclusive breastfeeding were identified. These factors were useful in facilitating discussions on how to improve breastfeeding and exclusive breastfeeding practices in the communities researched. The facilitator’s manual and the workshops were useful in equipping community care workers with knowledge on breastfeeding and exclusive breastfeeding. The involvement of community based organisations will assist to ensure sustainability of breastfeeding promotion by community care workers by adopting the facilitator’s manual as part of their women and child development programmes.
- Full Text:
- Date Issued: 2016
Introducing a multi-cultural dimension into the study of literature at secondary school level
- Authors: Vogel, Sonja
- Date: 1996
- Subjects: English literature -- Study and teaching (Secondary) -- South Africa Multicultural education -- South Africa Culture in literature Ethnicity in literature
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1584 , http://hdl.handle.net/10962/d1003466
- Description: The first aim of teaching English literature has always been for the student to gain enjoyment from, and acquire skill in, reading. Further goals point to the affective development of pupils involving such qualities as critical thinking and expressing views, empathetic understanding of other people, moral awareness and increased self-knowledge and self-understanding. These are indeed laudable aims, but examiners have always had difficulties in examining them adequately to satisfy the critics. Teachers often doubt that they achieve such lofty aims. These very aims have the sceptics sneering at the discipline because such qualities cannot be measured and the pupil's worth for the workplace cannot be satisfactorily assessed. This has resulted in the merit of the study of literature being questioned and usually found wanting. Therefore, on the one hand, this research looks for a method of studying literature which will ensure that the study will be neccesary and desirable today and into the foreseeable future. On the other hand, the socio-political changes in South Africa, particularly since 1992, have offered a possible area of research to complement the first. During the past few years, South Africans have been forced to recognise the fact that a multitude of different races and people live and work together more closely in this country and yet they know nothing, or very little, of one another. Thus this research also investigates the addition of a cultural component to literature study to help young people gain empathetic understanding of different cultures and of their own cultures as well, to be able to live together in harmony. With this approach, pupils may conceivably be educated through literature, to become well-adjusted, critical, effective adults so that they may play their role as citizens and shapers of their increasingly complex, multi-cultural society. Because of the context of literature study, in which this personal growth takes place, the aims identified above may be measured and assessed to suit both the sceptics and the devotees of literature study.
- Full Text:
- Date Issued: 1996
- Authors: Vogel, Sonja
- Date: 1996
- Subjects: English literature -- Study and teaching (Secondary) -- South Africa Multicultural education -- South Africa Culture in literature Ethnicity in literature
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1584 , http://hdl.handle.net/10962/d1003466
- Description: The first aim of teaching English literature has always been for the student to gain enjoyment from, and acquire skill in, reading. Further goals point to the affective development of pupils involving such qualities as critical thinking and expressing views, empathetic understanding of other people, moral awareness and increased self-knowledge and self-understanding. These are indeed laudable aims, but examiners have always had difficulties in examining them adequately to satisfy the critics. Teachers often doubt that they achieve such lofty aims. These very aims have the sceptics sneering at the discipline because such qualities cannot be measured and the pupil's worth for the workplace cannot be satisfactorily assessed. This has resulted in the merit of the study of literature being questioned and usually found wanting. Therefore, on the one hand, this research looks for a method of studying literature which will ensure that the study will be neccesary and desirable today and into the foreseeable future. On the other hand, the socio-political changes in South Africa, particularly since 1992, have offered a possible area of research to complement the first. During the past few years, South Africans have been forced to recognise the fact that a multitude of different races and people live and work together more closely in this country and yet they know nothing, or very little, of one another. Thus this research also investigates the addition of a cultural component to literature study to help young people gain empathetic understanding of different cultures and of their own cultures as well, to be able to live together in harmony. With this approach, pupils may conceivably be educated through literature, to become well-adjusted, critical, effective adults so that they may play their role as citizens and shapers of their increasingly complex, multi-cultural society. Because of the context of literature study, in which this personal growth takes place, the aims identified above may be measured and assessed to suit both the sceptics and the devotees of literature study.
- Full Text:
- Date Issued: 1996
An investigation of an innovative teaching approach to explore how Grade 11 Physical Science learners make sense of the topic light
- Mutikisha, Nghidixumo Jeremia
- Authors: Mutikisha, Nghidixumo Jeremia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/8055 , vital:21340
- Description: In the Namibian education curriculum the topic light is offered in Grade 7 Natural Science and Health Education (NSHE) and in Grades 10, 11 and 12 Physical Science. The Namibian junior secondary certificate (JSC) Examiners’ reports for 2011 to 2013 indicate that more than 50% of learners have been performing poorly on questions on the topic light particularly on the questions related to the properties of light. Similarly, the Namibian senior secondary certificate ordinary (NSSCO) level Examiners’ reports for2011 to 2013indicate that many learners struggled to answer questions related to reflection and refraction of light. These results triggered my interest to investigate how Grade 11Physical Science learners make sense of the topic light based on their conceptions, experiences, prior knowledge as well as looking into factors that enable or constrain them in making sense of the topic light. This research was a case study of one secondary school in Namibian urban area. It was carried out with 22 Grade 11 Physical Science learners through a designed ASEI-PDSI (Activities, Students, Experiment, Improvisation-Plan, Do, See, Improve) teaching intervention to explore how they make sense of the topic light. Underpinned by an interpretive paradigm, the study tried to explore how learners make sense of the topic light through ASEI-PDSI teaching approach. Within the interpretive paradigm, a mixed method case study approach was adopted. In the context of this study the quan→QUAL design was applied. The study was informed by constructivism consisting of both cognitive and social constructivism as a theoretical framework looking into learners’ sense making, prior knowledge and social interaction as well as knowledge construction. Convenience and purposive sampling were used to select those 22 grade 11 Physical Science learners. The data were generated using tests (pre-test and post-test), questionnaires, stimulated recall interviews, lesson observations and video-stimulated recall interviews. Triangulation of data was employed to ensure validity and trustworthiness of the research findings. Prior the commencement of the study, informed consents were obtained in writing from the Director of Ohangwena Directorate of Education, school principal, Grade 11Physical Science teacher, learners as well as from the parents of the learners involved in the study. The findings of the study revealed that there was a positive shift in learners’ sense making as it was reflected by the learners’ post-test scores in comparison to the pre-test scores. The post test scores were higher than the pre-test scores. The study thus recommends for the adoption of an ASEI teaching approach to be used during science lessons in schools in Namibia for better academic improvement.
- Full Text:
- Date Issued: 2017
- Authors: Mutikisha, Nghidixumo Jeremia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/8055 , vital:21340
- Description: In the Namibian education curriculum the topic light is offered in Grade 7 Natural Science and Health Education (NSHE) and in Grades 10, 11 and 12 Physical Science. The Namibian junior secondary certificate (JSC) Examiners’ reports for 2011 to 2013 indicate that more than 50% of learners have been performing poorly on questions on the topic light particularly on the questions related to the properties of light. Similarly, the Namibian senior secondary certificate ordinary (NSSCO) level Examiners’ reports for2011 to 2013indicate that many learners struggled to answer questions related to reflection and refraction of light. These results triggered my interest to investigate how Grade 11Physical Science learners make sense of the topic light based on their conceptions, experiences, prior knowledge as well as looking into factors that enable or constrain them in making sense of the topic light. This research was a case study of one secondary school in Namibian urban area. It was carried out with 22 Grade 11 Physical Science learners through a designed ASEI-PDSI (Activities, Students, Experiment, Improvisation-Plan, Do, See, Improve) teaching intervention to explore how they make sense of the topic light. Underpinned by an interpretive paradigm, the study tried to explore how learners make sense of the topic light through ASEI-PDSI teaching approach. Within the interpretive paradigm, a mixed method case study approach was adopted. In the context of this study the quan→QUAL design was applied. The study was informed by constructivism consisting of both cognitive and social constructivism as a theoretical framework looking into learners’ sense making, prior knowledge and social interaction as well as knowledge construction. Convenience and purposive sampling were used to select those 22 grade 11 Physical Science learners. The data were generated using tests (pre-test and post-test), questionnaires, stimulated recall interviews, lesson observations and video-stimulated recall interviews. Triangulation of data was employed to ensure validity and trustworthiness of the research findings. Prior the commencement of the study, informed consents were obtained in writing from the Director of Ohangwena Directorate of Education, school principal, Grade 11Physical Science teacher, learners as well as from the parents of the learners involved in the study. The findings of the study revealed that there was a positive shift in learners’ sense making as it was reflected by the learners’ post-test scores in comparison to the pre-test scores. The post test scores were higher than the pre-test scores. The study thus recommends for the adoption of an ASEI teaching approach to be used during science lessons in schools in Namibia for better academic improvement.
- Full Text:
- Date Issued: 2017
The design of an urban agriculture centre for Port Elizabeth
- Authors: Marinus, Sheree Anne
- Date: 2016
- Subjects: Urban agriculture -- South Africa -- Port Elizabeth City planning -- South Africa -- Port Elizabeth , Sustainable development -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/18919 , vital:28749
- Description: This dissertation is based on the design of an Urban Agriculture Centre situated within the urban fabric of Port Elizabeth, South Africa. The treatise evolves out of issues pertaining to actual problems. Deforestation, desertification, floods, drought, population growth and pollution, only to name a few, are issues that play a crucial role in the survival of humanity and other ecosystems. After extensive research, it was identified that traditional farms are unsustainable, inefficient and causes great damage to the environment. Current farming methods will not be able to produce enough food for the growing population. Traditional farming relies on the climate and particular seasons to produce crops. At the rate that the population is growing, traditional farmers will not be able to keep up. Traditional farms use hectares and hectares of land - this is the one major disadvantage, as there is only a certain amount of arable land in the country. The treatise diagnosed this problem, and proposes that farming should move into the urban areas, where the majority of the population subsists. New generation farming techniques allows for agriculture to take place within the urban fabric. The agriculture technique that will be used in this treatise is hydroponics. The treatise addresses urban issues such as sprawl and wasted space within urban areas. For this reason, the treatise adopts a derelict industrial heritage building, within the Central Business District of Port Elizabeth, as the building that will be utilized by the proposed urban farm. The treatise has chosen the Old Premier Mill Building in Port Elizabeth as a suitable candidate for the proposed project. The building is over one hundred years old, and possesses unique heritage value. Using an existing building is a sustainable option, but for obvious reasons the treatise will be challenged to preserve the heritage value of the old Premier Mill building. The concept of an urban farm/vertical farm is perceived as a highly technical building, due to its nature, which demands a ‘high-tech’ aesthetic. The treatise challenges this contrast: designing a highly technical building while trying to preserve a structure of high heritage value. Part one of this dissertation sets the groundwork for the treatise and discusses the different aspects the of the project that will influence the design. Part two sets the foundation for all the aspects that will inform the treatise concerning the proposed project. The knowledge gathered in these two sections will be applied in part three of this dissertation.
- Full Text:
- Date Issued: 2016
- Authors: Marinus, Sheree Anne
- Date: 2016
- Subjects: Urban agriculture -- South Africa -- Port Elizabeth City planning -- South Africa -- Port Elizabeth , Sustainable development -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/18919 , vital:28749
- Description: This dissertation is based on the design of an Urban Agriculture Centre situated within the urban fabric of Port Elizabeth, South Africa. The treatise evolves out of issues pertaining to actual problems. Deforestation, desertification, floods, drought, population growth and pollution, only to name a few, are issues that play a crucial role in the survival of humanity and other ecosystems. After extensive research, it was identified that traditional farms are unsustainable, inefficient and causes great damage to the environment. Current farming methods will not be able to produce enough food for the growing population. Traditional farming relies on the climate and particular seasons to produce crops. At the rate that the population is growing, traditional farmers will not be able to keep up. Traditional farms use hectares and hectares of land - this is the one major disadvantage, as there is only a certain amount of arable land in the country. The treatise diagnosed this problem, and proposes that farming should move into the urban areas, where the majority of the population subsists. New generation farming techniques allows for agriculture to take place within the urban fabric. The agriculture technique that will be used in this treatise is hydroponics. The treatise addresses urban issues such as sprawl and wasted space within urban areas. For this reason, the treatise adopts a derelict industrial heritage building, within the Central Business District of Port Elizabeth, as the building that will be utilized by the proposed urban farm. The treatise has chosen the Old Premier Mill Building in Port Elizabeth as a suitable candidate for the proposed project. The building is over one hundred years old, and possesses unique heritage value. Using an existing building is a sustainable option, but for obvious reasons the treatise will be challenged to preserve the heritage value of the old Premier Mill building. The concept of an urban farm/vertical farm is perceived as a highly technical building, due to its nature, which demands a ‘high-tech’ aesthetic. The treatise challenges this contrast: designing a highly technical building while trying to preserve a structure of high heritage value. Part one of this dissertation sets the groundwork for the treatise and discusses the different aspects the of the project that will influence the design. Part two sets the foundation for all the aspects that will inform the treatise concerning the proposed project. The knowledge gathered in these two sections will be applied in part three of this dissertation.
- Full Text:
- Date Issued: 2016
The evaluation of indomethacin and theophylline oral controlled/modified-release dosage forms in vitro-in vivo correlations
- Tandt, Ludo Alfons Germaan Luc
- Authors: Tandt, Ludo Alfons Germaan Luc
- Date: 1992
- Subjects: Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3794 , http://hdl.handle.net/10962/d1003272 , Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Description: Over the past few decades many researchers have investigated the utility of in vitro - in vivo correlations for the assessment of dosage forms. These investigations are, however, dependent on reproducible dissolution data and well conducted biostudies in order to establish meaningful and robust correlations. Despite the fact that the establishment of such correlations is perhaps idealistic, considerable interest has still been shown in this area of research. Various Controlled/Modified Release Dosage Forms (CMRD's) of theophylline, a weakly basic drug, and indomethacin, a weakly acidic drug, were assessed in order to establish in vitro - in vivo correlations. Dissolution rate studies were carried out using either the USP basket or paddle apparatus. The dissolution rate studies were conducted in a range of dissolution media of varying pH. Bioavailability studies were conducted on the dosage forms used by the Biopharmaceutics Research Institute at Rhodes University. The results of these biostudies were kindly made available for use in this research project. Type A correlations were established using a mathematical simulation process whereby expected in vivo responses are simulated and compared to actual profiles obtained for the dosage forms. In order to perform the simulations the dissolution rate profiles were stripped and using linear regression and the methods of residuals the dissolution rate order and the relevant dissolution rates were obtained. The results of the s imulations indicated that the in vivo serum concentration-time curves could be accurately predicted for the theophylline dosage forms but to a lesser extent, for the indomethacin formulations. The dissolution rate studies indicated that the paddle method is a suitable method for dissolution rate studies of theophylline CMRD's, although it appeared that the optimum pH of the dissolution medium was formulation dependent. Dissolution rate studies conducted on indomethacin formulations indicated that the USP specified basket method for extended-release indomethacin formulations was not able to distinguish between two formulations which exhibited different in vivo profiles. The conversion to the paddle method was, however, able to highlight the differences between these formulations. The use of three dimensional topographs to depict dissolution rate profiles was demonstrated for formulations of both theophylline and indomethacin. The topographs enabled the successful differentiation between bioinequivalent formulations. The dissolution rate profiles were also fitted to the Wei bull equation and the parameters obtained from this were compared to the Weibull parameters obtained from the in vivo absorption plots obtained using the Wagner-Nelson method. The results indicated that the Weibull function was suitable to describe both the in vivo and in vitro data. The following recommendations for the preformulation dissolution studies of weakly acidic and weakly basic drugs are proposed. The dissolution rate studies of weakly acid drugs, such as indomethacin, should be carried out over a range of pH utilising the paddle apparatus. Three dimensional topographs based on the dissolution data should be constructed and used as a comparative tool for different formulations. Based on these comparisons the appropriate formulation can then be selected for a pilot scale in vivo bioavailability study. The dissolution rate studies of weakly basic drugs, such as theophylline, should be carried out over a range of pH utilising the paddle apparatus. The dissolution data should then be used to simulate the expected in vivo profile and on this basis the appropriate formulation selected for a pilot scale bioavailability study. The above approach to the preformulation studies of new CMRO's would allow for the more careful selection of new dosage forms and could thus eliminate costly and unnecessary bioavailability studies performed on inferior formulations.
- Full Text:
- Date Issued: 1992
- Authors: Tandt, Ludo Alfons Germaan Luc
- Date: 1992
- Subjects: Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3794 , http://hdl.handle.net/10962/d1003272 , Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Description: Over the past few decades many researchers have investigated the utility of in vitro - in vivo correlations for the assessment of dosage forms. These investigations are, however, dependent on reproducible dissolution data and well conducted biostudies in order to establish meaningful and robust correlations. Despite the fact that the establishment of such correlations is perhaps idealistic, considerable interest has still been shown in this area of research. Various Controlled/Modified Release Dosage Forms (CMRD's) of theophylline, a weakly basic drug, and indomethacin, a weakly acidic drug, were assessed in order to establish in vitro - in vivo correlations. Dissolution rate studies were carried out using either the USP basket or paddle apparatus. The dissolution rate studies were conducted in a range of dissolution media of varying pH. Bioavailability studies were conducted on the dosage forms used by the Biopharmaceutics Research Institute at Rhodes University. The results of these biostudies were kindly made available for use in this research project. Type A correlations were established using a mathematical simulation process whereby expected in vivo responses are simulated and compared to actual profiles obtained for the dosage forms. In order to perform the simulations the dissolution rate profiles were stripped and using linear regression and the methods of residuals the dissolution rate order and the relevant dissolution rates were obtained. The results of the s imulations indicated that the in vivo serum concentration-time curves could be accurately predicted for the theophylline dosage forms but to a lesser extent, for the indomethacin formulations. The dissolution rate studies indicated that the paddle method is a suitable method for dissolution rate studies of theophylline CMRD's, although it appeared that the optimum pH of the dissolution medium was formulation dependent. Dissolution rate studies conducted on indomethacin formulations indicated that the USP specified basket method for extended-release indomethacin formulations was not able to distinguish between two formulations which exhibited different in vivo profiles. The conversion to the paddle method was, however, able to highlight the differences between these formulations. The use of three dimensional topographs to depict dissolution rate profiles was demonstrated for formulations of both theophylline and indomethacin. The topographs enabled the successful differentiation between bioinequivalent formulations. The dissolution rate profiles were also fitted to the Wei bull equation and the parameters obtained from this were compared to the Weibull parameters obtained from the in vivo absorption plots obtained using the Wagner-Nelson method. The results indicated that the Weibull function was suitable to describe both the in vivo and in vitro data. The following recommendations for the preformulation dissolution studies of weakly acidic and weakly basic drugs are proposed. The dissolution rate studies of weakly acid drugs, such as indomethacin, should be carried out over a range of pH utilising the paddle apparatus. Three dimensional topographs based on the dissolution data should be constructed and used as a comparative tool for different formulations. Based on these comparisons the appropriate formulation can then be selected for a pilot scale in vivo bioavailability study. The dissolution rate studies of weakly basic drugs, such as theophylline, should be carried out over a range of pH utilising the paddle apparatus. The dissolution data should then be used to simulate the expected in vivo profile and on this basis the appropriate formulation selected for a pilot scale bioavailability study. The above approach to the preformulation studies of new CMRO's would allow for the more careful selection of new dosage forms and could thus eliminate costly and unnecessary bioavailability studies performed on inferior formulations.
- Full Text:
- Date Issued: 1992
Antidiabetic and toxicological properties of Dianthus thunbergii (Caryophyllaceae) roots and Hypoxis argentea (Hypoxidaceae) corms
- Authors: Akinrinde, Akinleye Stephen
- Date: 2017
- Subjects: Medicinal plants--South Africa--Eastern Cape Traditional medicine--South Africa--Eastern Cape Diabetics--Alternative treatment--South Africa
- Language: English
- Type: Thesis , Doctoral , Biochemistry
- Identifier: http://hdl.handle.net/10353/16036 , vital:40606
- Description: Diabetes mellitus is a chronic metabolic disorder primarily characterized by elevated blood glucose levels. Its rapidly increasing prevalence as a major non-communicable disease is now a growing concern for both developed and developing countries. The development of safe, cost-effective and pharmacologically-effective medications continues to a major challenge of antidiabetic management. Since most conventional antidiabetic drugs are costly and present with numerous adverse effects, alternatives are increasingly being sought from natural sources, most notably medicinal plants, as viable approaches to tackling the scourge of this disease. In the Eastern Cape Province of South Africa, the roots of Dianthus thunbergii and corms of Hypoxis argentea are frequently used traditionally for the treatment of diabetes mellitus, although no scientific evidence exists to validate their effectiveness for diabetes management. The studies conducted in the resent research were, therefore, aimed at investigating the antidiabetic and toxicological properties of these plants, in an attempt to providing data towards validating their use in traditional management of diabetes mellitus. Aqueous and ethanol extracts of the underground parts of D. thunbergii and H. argentea were initially subjected to analysis of their phytochemical composition, relative to standard compounds, and the nature of their in-vitro antioxidant activities using standard spectrophotometric methods. The potentials of these extracts for cytotoxicity and/or cell proliferation were evaluated using MTT assay in HepG2 cells and Crystal violet assay in INS-1 cells. These activities were further examined in INS-1 cells using live cell fluorescence imaging techniques. To evaluate the antidiabetic properties of the extracts, they were screened for their inhibitory effects on the activities of different enzymes including α-amylase, α-glucosidase, porcine pancreatic lipase, Dipeptidyl peptidase IV (DPP-IV), collagenase and the drug metabolizing enzyme, CYP3A4, while also assessing their effects on protein glycation using in- vitro visible and fluorescence spectrophotometric approaches. Cell culture procedures were carried out to evaluate the effects of the extracts on glucose utilization in HepG2 cells and L6 myotubes; nitric oxide production in RAW 264.7 macrophages; glucose metabolism in INS-1 cells, as well as triglyceride accumulation in 3T3-L1 pre-adipocytes. Furthermore, identification of compounds present in the aqueous and ethanol extracts was carried out by Liquid chromatography- Mass spectrometry (LC-MS), while volatile oils extracted from fresh and dried parts of the two plants by hydrodistillation were also analyzed by Gas chromatography-Mass spectrometry (GC-MS). The ethanol extracts of both D. thunbergii and H. argentea contained higher amounts of total phenols, flavonoids, tannins, proanthocyanidins and alkaloids, when compared with the aqueous extracts. This finding was in direct correlation with the antioxidant activities of the extracts, with the ethanol extracts of both plants demonstrating stronger scavenging activities against hydrogen peroxide, nitric oxide, ABTS and DPPH radicals, while also exhibiting higher ferric reducing antioxidant potentials, when compared with the aqueous extracts, and in some cases, the standard antioxidants, Vitamin C, butylated hydroxytoluene and rutin. The aqueous extracts of D. thunbergii exhibited the highest toxicity in HepG2 cells with IC50 < 50 μg/ml, while also producing a concentration-dependent reduction in the viability of INS-1 cells up to 41.81percent at 50 μg/ml. Both extracts of H. argentea, however, did not produce any significant toxicity in these cells. Fluorescence imaging of live INS-1 cells using Hoechst and propidium iodide staining revealed stimulation of cell proliferation by H. argentea, while the cytotoxicity of D. thunbergii was further confirmed. H. argentea caused stimulation of glucose uptake in HepG2 cells up to 119.58 percent at 100 μg/ml and as much as 116.96 percent in L6 myotubes at 50 μg/ml, without showing toxicity to these cells. D. thunbergii produced 18.39 percent increase in L6 glucose uptake above untreated control; although its effect on HepG2 glucose uptake was irrelevant as significant toxicity was produced in these cells. H. argentea produced a concentration-dependent reduction in nitric oxide production in RAW macrophages, although not as effectively as the positive control, aminoguanidine. Again, the toxicity of D. thunbergii to this cell line precludes the relevance of nitric oxide inhibition as an antidiabetic mechanism for this plant. D. thunbergii produced a concentration-dependent increase in 3T3-L1 triglyceride accumulation, as measured by Oil red O staining, compared to untreated cells, while H. argentea exerted no significant alterations in pre- adipocyte differentiation. Generally, the two plants produced weak inhibition of the activities of the various enzymes measured, suggesting that this mechanism may not play a major role in the activities of these plants as possible antidiabetic agents. GC-MS analysis revealed major differences in the volatile oil composition between fresh and dried plant parts for both plants. Most notably, total terpenoid content of D. thunbergii oils reduced significantly from 77.17 percent in the fresh root oil to 47.58 percent in the dried root oil. Total terpenoid content was much lower in H. argentea oils, but similarly reduced from 10.58 percent in the fresh corm oil to 4.00 percent in the dried corm oil. LC-MS analysis enabled the tentative identification of compounds including phenolic glycosides, flavonoids, alkaloids, terpenoids saponins and sapogenins, many of which have been reported in literature to exert bioactivities relevant to the ones elucidated in the present study. Overall, H. argentea exhibited antidiabetic properties that may be mediated by its stimulation of glucose uptake in HepG2 and L6 cells; stimulation of proliferation in INS-1 cells; lack of stimulation of 3T3-L1 triglyceride accumulation and a tendency to reduce nitric oxide production in RAW macrophages. These activities suggest that H. argentea has promise for further investigations as an antidiabetic agent. On the contrary, D. thunbergii exhibited significant toxicity to HepG2 cells, INS-1 cells and RAW macrophages. Its cytotoxicity at the concentrations investigated in the present studies raises significant concerns about any potential antidiabetic applications for this plant.
- Full Text:
- Date Issued: 2017
- Authors: Akinrinde, Akinleye Stephen
- Date: 2017
- Subjects: Medicinal plants--South Africa--Eastern Cape Traditional medicine--South Africa--Eastern Cape Diabetics--Alternative treatment--South Africa
- Language: English
- Type: Thesis , Doctoral , Biochemistry
- Identifier: http://hdl.handle.net/10353/16036 , vital:40606
- Description: Diabetes mellitus is a chronic metabolic disorder primarily characterized by elevated blood glucose levels. Its rapidly increasing prevalence as a major non-communicable disease is now a growing concern for both developed and developing countries. The development of safe, cost-effective and pharmacologically-effective medications continues to a major challenge of antidiabetic management. Since most conventional antidiabetic drugs are costly and present with numerous adverse effects, alternatives are increasingly being sought from natural sources, most notably medicinal plants, as viable approaches to tackling the scourge of this disease. In the Eastern Cape Province of South Africa, the roots of Dianthus thunbergii and corms of Hypoxis argentea are frequently used traditionally for the treatment of diabetes mellitus, although no scientific evidence exists to validate their effectiveness for diabetes management. The studies conducted in the resent research were, therefore, aimed at investigating the antidiabetic and toxicological properties of these plants, in an attempt to providing data towards validating their use in traditional management of diabetes mellitus. Aqueous and ethanol extracts of the underground parts of D. thunbergii and H. argentea were initially subjected to analysis of their phytochemical composition, relative to standard compounds, and the nature of their in-vitro antioxidant activities using standard spectrophotometric methods. The potentials of these extracts for cytotoxicity and/or cell proliferation were evaluated using MTT assay in HepG2 cells and Crystal violet assay in INS-1 cells. These activities were further examined in INS-1 cells using live cell fluorescence imaging techniques. To evaluate the antidiabetic properties of the extracts, they were screened for their inhibitory effects on the activities of different enzymes including α-amylase, α-glucosidase, porcine pancreatic lipase, Dipeptidyl peptidase IV (DPP-IV), collagenase and the drug metabolizing enzyme, CYP3A4, while also assessing their effects on protein glycation using in- vitro visible and fluorescence spectrophotometric approaches. Cell culture procedures were carried out to evaluate the effects of the extracts on glucose utilization in HepG2 cells and L6 myotubes; nitric oxide production in RAW 264.7 macrophages; glucose metabolism in INS-1 cells, as well as triglyceride accumulation in 3T3-L1 pre-adipocytes. Furthermore, identification of compounds present in the aqueous and ethanol extracts was carried out by Liquid chromatography- Mass spectrometry (LC-MS), while volatile oils extracted from fresh and dried parts of the two plants by hydrodistillation were also analyzed by Gas chromatography-Mass spectrometry (GC-MS). The ethanol extracts of both D. thunbergii and H. argentea contained higher amounts of total phenols, flavonoids, tannins, proanthocyanidins and alkaloids, when compared with the aqueous extracts. This finding was in direct correlation with the antioxidant activities of the extracts, with the ethanol extracts of both plants demonstrating stronger scavenging activities against hydrogen peroxide, nitric oxide, ABTS and DPPH radicals, while also exhibiting higher ferric reducing antioxidant potentials, when compared with the aqueous extracts, and in some cases, the standard antioxidants, Vitamin C, butylated hydroxytoluene and rutin. The aqueous extracts of D. thunbergii exhibited the highest toxicity in HepG2 cells with IC50 < 50 μg/ml, while also producing a concentration-dependent reduction in the viability of INS-1 cells up to 41.81percent at 50 μg/ml. Both extracts of H. argentea, however, did not produce any significant toxicity in these cells. Fluorescence imaging of live INS-1 cells using Hoechst and propidium iodide staining revealed stimulation of cell proliferation by H. argentea, while the cytotoxicity of D. thunbergii was further confirmed. H. argentea caused stimulation of glucose uptake in HepG2 cells up to 119.58 percent at 100 μg/ml and as much as 116.96 percent in L6 myotubes at 50 μg/ml, without showing toxicity to these cells. D. thunbergii produced 18.39 percent increase in L6 glucose uptake above untreated control; although its effect on HepG2 glucose uptake was irrelevant as significant toxicity was produced in these cells. H. argentea produced a concentration-dependent reduction in nitric oxide production in RAW macrophages, although not as effectively as the positive control, aminoguanidine. Again, the toxicity of D. thunbergii to this cell line precludes the relevance of nitric oxide inhibition as an antidiabetic mechanism for this plant. D. thunbergii produced a concentration-dependent increase in 3T3-L1 triglyceride accumulation, as measured by Oil red O staining, compared to untreated cells, while H. argentea exerted no significant alterations in pre- adipocyte differentiation. Generally, the two plants produced weak inhibition of the activities of the various enzymes measured, suggesting that this mechanism may not play a major role in the activities of these plants as possible antidiabetic agents. GC-MS analysis revealed major differences in the volatile oil composition between fresh and dried plant parts for both plants. Most notably, total terpenoid content of D. thunbergii oils reduced significantly from 77.17 percent in the fresh root oil to 47.58 percent in the dried root oil. Total terpenoid content was much lower in H. argentea oils, but similarly reduced from 10.58 percent in the fresh corm oil to 4.00 percent in the dried corm oil. LC-MS analysis enabled the tentative identification of compounds including phenolic glycosides, flavonoids, alkaloids, terpenoids saponins and sapogenins, many of which have been reported in literature to exert bioactivities relevant to the ones elucidated in the present study. Overall, H. argentea exhibited antidiabetic properties that may be mediated by its stimulation of glucose uptake in HepG2 and L6 cells; stimulation of proliferation in INS-1 cells; lack of stimulation of 3T3-L1 triglyceride accumulation and a tendency to reduce nitric oxide production in RAW macrophages. These activities suggest that H. argentea has promise for further investigations as an antidiabetic agent. On the contrary, D. thunbergii exhibited significant toxicity to HepG2 cells, INS-1 cells and RAW macrophages. Its cytotoxicity at the concentrations investigated in the present studies raises significant concerns about any potential antidiabetic applications for this plant.
- Full Text:
- Date Issued: 2017
Phthalocyanine-nanoparticle conjugates for photodynamic therapy of cancer and phototransformation of organic pollutants
- Authors: Khoza, Phindile Brenda
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Photochemotherapy , Cancer -- Chemotherapy , Zinc oxide , Photocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4538 , http://hdl.handle.net/10962/d1017918
- Description: The synthesis and extensive spectroscopical characterization of novel phthalocyanines are reported. The new compounds were characterized by elemental analysis, FT-IR, ¹HNMR, mass spectrometry and UV–Vis spectroscopy. The new phthalocyanines showed remarkable photophysicochemical behaviour. The novel phthalocyanines were then conjugated to nanoparticles, silver and ZnO. The coupling of the novel Pcs to nanoparticles was through covalent bonding and ligand exchange. These conjugates were supported onto electrospun polystyrene fibers and chitosan microbeads for use as photocatalysts. The efficiency of the immobilized Pcs and Pc-nanoparticles was assessed by the phototrasfromation of organic pollutants, methyl orange and Rhodamine 6G as model dyes. Upon conjugating phthalocyanines to nanoparticles, there was a great increase in the rate of photodegradation of the model dyes. The photodynamic activity of the novel phthalocyanines upon conjugating to nanoparticles and selected targeting agents is also reported. The targeting agents employed in this study are folic acid and polylysine. Conjugating the phthalocyanines to folic acid or polylysine improved the solubility of the phthalocyanines in aqueous media. The potency of the conjugates was investigated on breast (MCF-7), prostate and melanoma cancer cell lines. The phthalocyanines showed no toxicity in the absence of light. However, upon illumination, a concentration dependent cellular decrease was observed.
- Full Text:
- Date Issued: 2015
- Authors: Khoza, Phindile Brenda
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Photochemotherapy , Cancer -- Chemotherapy , Zinc oxide , Photocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4538 , http://hdl.handle.net/10962/d1017918
- Description: The synthesis and extensive spectroscopical characterization of novel phthalocyanines are reported. The new compounds were characterized by elemental analysis, FT-IR, ¹HNMR, mass spectrometry and UV–Vis spectroscopy. The new phthalocyanines showed remarkable photophysicochemical behaviour. The novel phthalocyanines were then conjugated to nanoparticles, silver and ZnO. The coupling of the novel Pcs to nanoparticles was through covalent bonding and ligand exchange. These conjugates were supported onto electrospun polystyrene fibers and chitosan microbeads for use as photocatalysts. The efficiency of the immobilized Pcs and Pc-nanoparticles was assessed by the phototrasfromation of organic pollutants, methyl orange and Rhodamine 6G as model dyes. Upon conjugating phthalocyanines to nanoparticles, there was a great increase in the rate of photodegradation of the model dyes. The photodynamic activity of the novel phthalocyanines upon conjugating to nanoparticles and selected targeting agents is also reported. The targeting agents employed in this study are folic acid and polylysine. Conjugating the phthalocyanines to folic acid or polylysine improved the solubility of the phthalocyanines in aqueous media. The potency of the conjugates was investigated on breast (MCF-7), prostate and melanoma cancer cell lines. The phthalocyanines showed no toxicity in the absence of light. However, upon illumination, a concentration dependent cellular decrease was observed.
- Full Text:
- Date Issued: 2015
A networking approach to sharing music studio resources
- Authors: Foss, Richard John
- Date: 1996
- Subjects: MIDI (Standard) Computer sound processing Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4659 , http://hdl.handle.net/10962/d1006660
- Description: This thesis investigates the extent to which networking technology can be used to provide remote workstation access to a pool of shared music studio resources. A pilot system is described in which MIDI messages, studio control data, and audio signals flow between the workstations and a studio server. A booking and timing facility avoids contention and allows for accurate reports of studio usage. The operation of the system has been evaluated in terms of its ability to satislY three fundamental goals, namely the remote, shared and centralized access to studio resources. Three essential network configurations have been identified, incorporating a mix of star and bus topologies, and their relative potential for satisfYing the fundamental goals has been highlighted.
- Full Text:
- Date Issued: 1996
- Authors: Foss, Richard John
- Date: 1996
- Subjects: MIDI (Standard) Computer sound processing Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4659 , http://hdl.handle.net/10962/d1006660
- Description: This thesis investigates the extent to which networking technology can be used to provide remote workstation access to a pool of shared music studio resources. A pilot system is described in which MIDI messages, studio control data, and audio signals flow between the workstations and a studio server. A booking and timing facility avoids contention and allows for accurate reports of studio usage. The operation of the system has been evaluated in terms of its ability to satislY three fundamental goals, namely the remote, shared and centralized access to studio resources. Three essential network configurations have been identified, incorporating a mix of star and bus topologies, and their relative potential for satisfYing the fundamental goals has been highlighted.
- Full Text:
- Date Issued: 1996
Assessing the impact of school governance in the Limpopo Department of Education with specific reference to Mankweng and Polokwane circuits
- Authors: Mothapo, Sentshuhleng Jacob
- Date: 2011
- Subjects: School management and organization -- South Africa -- Limpopo , Leadership -- South Africa -- Limpopo , Responsibility -- South Africa -- Limpopo , Teacher effectiveness -- South Africa -- Limpopo , School boards -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Doctoral , PhD (in Public Administration)
- Identifier: vital:11663 , http://hdl.handle.net/10353/d1007096 , School management and organization -- South Africa -- Limpopo , Leadership -- South Africa -- Limpopo , Responsibility -- South Africa -- Limpopo , Teacher effectiveness -- South Africa -- Limpopo , School boards -- South Africa -- Limpopo
- Description: Education has been identified as a priority area by the South African government, in particular by the African National Congress as the ruling party. To this end, huge amounts of money are being spent on education as a service that has been approved by the legislators. Rules and regulations have been promulgated, and among others, the South African Schools Act, Act No. 84 of 1996, has been enacted. Rich research has also been funded with the sole intention of providing quality education to the people. Education of unacceptably poor quality has, however, been the result, as postulated by Peterson and Hassel (1998:55). The above are attested to by the findings that the political tensions emanating from the conduct of the South African Democratic Teachers’ Union and the Professional Educators’ Union, leading to class disruptions and general instability, erode the ethos of accountability on the part of educators and therefore impact negatively on service delivery. Furthermore, the Limpopo Department of Education is not immune to the challenges ranging from the elements of corrupt activities that often surface, teacher attrition which in the main is caused by lack of discipline. Winkler, Modise and Dawber (1998) indicate that teaching has never been easy, and many teachers are leaving their jobs because of the many problems with children in classrooms. Some of the problems cited are children who do not want to learn and learning that is becoming too difficult for the students because they do not want to listen. This study adopted sequential mixed methods namely, quantitative and qualitative research methods which are viewed as complementary rather than opposing approaches. Information was amassed from the subjects through interviews, observation, documentary survey and observation and the information has since been triangulated to validate the facts. All the methodologies employed proved to be useful in this study. The study sought to test the hypothesis “Good governance is informed by strong accountability and future-oriented organisation, continuously steering it towards its mission and vision, and thereby ensuring that the day-to-day management and administration are always linked with the organisation’s values and goals and thus eventually bringing about effectual and accelerated service delivery” to the South African populace without compromise. After empirically testing the hypothesis, showing mixed reaction informed by the findings of the study, five recommendations were made, based on the conclusions arrived at.
- Full Text:
- Date Issued: 2011
- Authors: Mothapo, Sentshuhleng Jacob
- Date: 2011
- Subjects: School management and organization -- South Africa -- Limpopo , Leadership -- South Africa -- Limpopo , Responsibility -- South Africa -- Limpopo , Teacher effectiveness -- South Africa -- Limpopo , School boards -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Doctoral , PhD (in Public Administration)
- Identifier: vital:11663 , http://hdl.handle.net/10353/d1007096 , School management and organization -- South Africa -- Limpopo , Leadership -- South Africa -- Limpopo , Responsibility -- South Africa -- Limpopo , Teacher effectiveness -- South Africa -- Limpopo , School boards -- South Africa -- Limpopo
- Description: Education has been identified as a priority area by the South African government, in particular by the African National Congress as the ruling party. To this end, huge amounts of money are being spent on education as a service that has been approved by the legislators. Rules and regulations have been promulgated, and among others, the South African Schools Act, Act No. 84 of 1996, has been enacted. Rich research has also been funded with the sole intention of providing quality education to the people. Education of unacceptably poor quality has, however, been the result, as postulated by Peterson and Hassel (1998:55). The above are attested to by the findings that the political tensions emanating from the conduct of the South African Democratic Teachers’ Union and the Professional Educators’ Union, leading to class disruptions and general instability, erode the ethos of accountability on the part of educators and therefore impact negatively on service delivery. Furthermore, the Limpopo Department of Education is not immune to the challenges ranging from the elements of corrupt activities that often surface, teacher attrition which in the main is caused by lack of discipline. Winkler, Modise and Dawber (1998) indicate that teaching has never been easy, and many teachers are leaving their jobs because of the many problems with children in classrooms. Some of the problems cited are children who do not want to learn and learning that is becoming too difficult for the students because they do not want to listen. This study adopted sequential mixed methods namely, quantitative and qualitative research methods which are viewed as complementary rather than opposing approaches. Information was amassed from the subjects through interviews, observation, documentary survey and observation and the information has since been triangulated to validate the facts. All the methodologies employed proved to be useful in this study. The study sought to test the hypothesis “Good governance is informed by strong accountability and future-oriented organisation, continuously steering it towards its mission and vision, and thereby ensuring that the day-to-day management and administration are always linked with the organisation’s values and goals and thus eventually bringing about effectual and accelerated service delivery” to the South African populace without compromise. After empirically testing the hypothesis, showing mixed reaction informed by the findings of the study, five recommendations were made, based on the conclusions arrived at.
- Full Text:
- Date Issued: 2011
Pascalʾs Pensées and Baudelaireʾs Les fleurs du mal : a study of the parallels and development of the theme of ʺennuiʺ
- Authors: Hammond, Nicholas Gascoigne
- Date: 1987
- Subjects: Pascal, Blaise, 1623-1662 -- Criticism and interpretation , Pascal, Blaise, 1623-1662 -- Pensées , Baudelaire, Charles, 1821-1867 -- Criticism and interpretation , Baudelaire, Charles, 1821-1867 -- Fleurs du mal
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3562 , http://hdl.handle.net/10962/d1002009
- Description: From Introduction: Upon first reading the writings of both Pascal and Baudelaire, one cannot help being struck by a sensation of awe at the penetrating insight into the human condition possessed by both writers. A further exploration of the realms of Pascalian and Baudelairian thought considerably strengthens this initial reaction into a recognition that both authors were men of equal moral and spiritual intensity. Despite their outward differences, both sought to attain a deep understanding of human nature, but without attempting to offer any excuses on behalf of man. Furthermore, the two writers employ an identical term to describe the condition of humanity: "ennui". Although the word exists in the writings of contemporaries of both Pascal and Baudelaire, no other author makes such full, unique and significant use of ennui. As this thesis will hopefully prove, Baudelaire was indeed directly and positively influenced by Pascal. However, it is not our intention to concentrate upon such an influence; rather, we wish to indicate the parallels and development of the theme of ennui, so central to each man's outlook, in their respective writings. Evidently, it would be beyond the boundaries of this thesis if we were to try to analyse closely the entire creative output of Pascal and Baudelaire; and so, although their other works will act as points of reference, the two books which are generally regarded as their masterpieces will be used as the basis of the unfinished Christian "Apologie" which was projected by Pascal, now known as the Pensées (1670), and Baudelaire’s Les Fleurs du Mal (1857 and 1861)
- Full Text:
- Date Issued: 1987
- Authors: Hammond, Nicholas Gascoigne
- Date: 1987
- Subjects: Pascal, Blaise, 1623-1662 -- Criticism and interpretation , Pascal, Blaise, 1623-1662 -- Pensées , Baudelaire, Charles, 1821-1867 -- Criticism and interpretation , Baudelaire, Charles, 1821-1867 -- Fleurs du mal
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3562 , http://hdl.handle.net/10962/d1002009
- Description: From Introduction: Upon first reading the writings of both Pascal and Baudelaire, one cannot help being struck by a sensation of awe at the penetrating insight into the human condition possessed by both writers. A further exploration of the realms of Pascalian and Baudelairian thought considerably strengthens this initial reaction into a recognition that both authors were men of equal moral and spiritual intensity. Despite their outward differences, both sought to attain a deep understanding of human nature, but without attempting to offer any excuses on behalf of man. Furthermore, the two writers employ an identical term to describe the condition of humanity: "ennui". Although the word exists in the writings of contemporaries of both Pascal and Baudelaire, no other author makes such full, unique and significant use of ennui. As this thesis will hopefully prove, Baudelaire was indeed directly and positively influenced by Pascal. However, it is not our intention to concentrate upon such an influence; rather, we wish to indicate the parallels and development of the theme of ennui, so central to each man's outlook, in their respective writings. Evidently, it would be beyond the boundaries of this thesis if we were to try to analyse closely the entire creative output of Pascal and Baudelaire; and so, although their other works will act as points of reference, the two books which are generally regarded as their masterpieces will be used as the basis of the unfinished Christian "Apologie" which was projected by Pascal, now known as the Pensées (1670), and Baudelaire’s Les Fleurs du Mal (1857 and 1861)
- Full Text:
- Date Issued: 1987
Application of bidentate N,N'-donor extractants in the hydrometallurgical separation of base metals from an acidic sulfate medium
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
- Date Issued: 2013
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
- Date Issued: 2013
The rural-urban interface: the ambiguous nature of informal settlements, with special reference to the Daggafontein settlement in Gauteng
- Authors: Kumalo, Sibongiseni
- Date: 2005
- Subjects: Cities and towns -- South Africa -- Gauteng -- Growth , Squatter settlements -- South Africa -- Gauteng , Urban anthropology -- South Africa -- Gauteng , Rural-urban migration -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2091 , http://hdl.handle.net/10962/d1002654 , Cities and towns -- South Africa -- Gauteng -- Growth , Squatter settlements -- South Africa -- Gauteng , Urban anthropology -- South Africa -- Gauteng , Rural-urban migration -- South Africa
- Description: The thesis is concerned with the rural-urban interface. It questions and argues against the validity of what used to be called the rural-urban divide, and presents the rural-urban interface as a single social field. The research makes use of Daggafontein informal settlement in Gauteng, providing a general socio-economic overview of this settlement by discussing the ways in which people in this settlement make a living. Most of the people come from rural areas and the patterns of their association within the settlement reveal that they associate themselves with people from their own rural homes of origin. Movement between Daggafontein and rural areas show some level of commitment to home areas. Perceptions of the urban-rural interface by people of Daggafontein informal settlement show that these two areas are not necessarily separate from each other, but are part of the same continuum as socio-economic relations continue to straddle the rural and the urban. As people, perceptions and values move in both directions along the rural-urban interface, the classification of the informal settlement becomes highly ambiguous, because it contains both rural and urban elements.
- Full Text:
- Date Issued: 2005
- Authors: Kumalo, Sibongiseni
- Date: 2005
- Subjects: Cities and towns -- South Africa -- Gauteng -- Growth , Squatter settlements -- South Africa -- Gauteng , Urban anthropology -- South Africa -- Gauteng , Rural-urban migration -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2091 , http://hdl.handle.net/10962/d1002654 , Cities and towns -- South Africa -- Gauteng -- Growth , Squatter settlements -- South Africa -- Gauteng , Urban anthropology -- South Africa -- Gauteng , Rural-urban migration -- South Africa
- Description: The thesis is concerned with the rural-urban interface. It questions and argues against the validity of what used to be called the rural-urban divide, and presents the rural-urban interface as a single social field. The research makes use of Daggafontein informal settlement in Gauteng, providing a general socio-economic overview of this settlement by discussing the ways in which people in this settlement make a living. Most of the people come from rural areas and the patterns of their association within the settlement reveal that they associate themselves with people from their own rural homes of origin. Movement between Daggafontein and rural areas show some level of commitment to home areas. Perceptions of the urban-rural interface by people of Daggafontein informal settlement show that these two areas are not necessarily separate from each other, but are part of the same continuum as socio-economic relations continue to straddle the rural and the urban. As people, perceptions and values move in both directions along the rural-urban interface, the classification of the informal settlement becomes highly ambiguous, because it contains both rural and urban elements.
- Full Text:
- Date Issued: 2005
Development of conservation methods for gunnera perpensa l.: an overexploited medicinal plant in the Eastern Cape, South Africa
- Authors: Chigor, Chinyere Blessing
- Date: 2014
- Subjects: Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11311 , http://hdl.handle.net/10353/d1019832 , Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Description: South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa.
- Full Text:
- Date Issued: 2014
- Authors: Chigor, Chinyere Blessing
- Date: 2014
- Subjects: Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11311 , http://hdl.handle.net/10353/d1019832 , Gunnera -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Medical anthropology -- South Africa -- Eastern Cape , Medical policy -- South Africa -- Eastern Cape
- Description: South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa.
- Full Text:
- Date Issued: 2014
Nonlinear optical behavior of lanthanide phthalocyanines and their conjugates with a selection of nanomaterials
- Authors: Sekhosana, Kutloano Edward
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4580 , vital:20695
- Description: This thesis presents novel asymmetrical and symmetrical lanthanide phthalocyanines (Pcs) characterized using a number techniques including proton nuclear magnetic resonance, electron spin resonance, time correlated single photon counting, FTIR spectrometry, MALDI-TOF mass spectrometry, UV-Vis spectrometry, Raman spectroscopy and CHNS elemental analysis. The design of theses lanthanide Pcs takes the form of mononuclear, binuclear, trinuclear, bis- and tris(phthalocyanines). Nanomaterials such as zinc oxide nanoparticles (ZnO NPs), multi-walled carbon nanotubes (MWCNTs) and graphene oxide nanosheets (GONS) (oxidized and reduced) were employed for covalent linkage to mono- and binuclear phthalocyanines as conjugates. Transmission electron microscopy was used to characterize ZnO NPs, MWCNTs and GONS alone and when linked to lanthanide Pcs. Lanthanide Pcs alone and when linked to ZnO NPs, MWCNTs and GONS where embedded in polymers such as poly (methyl methacrylate) (PMMA), poly (bisphenol A carbonate) (PBC) and poly (acrylic acid) (PAA) for thin film preparation. The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction (XRD). Optical limiting properties of lanthanide Pcs alone and as conjugates in solution and when incorporated into polymers were determined by employing a Z-scan technique. It emerged that low symmetry lanthanide Pcs (19, 20 and 21), the blue forms of bis(phthalocyanines) (only in solution; 24 and 28) as well as tris(phthalocyanines) (30 and 31) exhibit low limiting threshold (Ilim) values in solution and thin films (particularly PBC and PAA). The low limiting threshold values make these lanthanide Pcs reliable optical limiters.
- Full Text:
- Date Issued: 2017
- Authors: Sekhosana, Kutloano Edward
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4580 , vital:20695
- Description: This thesis presents novel asymmetrical and symmetrical lanthanide phthalocyanines (Pcs) characterized using a number techniques including proton nuclear magnetic resonance, electron spin resonance, time correlated single photon counting, FTIR spectrometry, MALDI-TOF mass spectrometry, UV-Vis spectrometry, Raman spectroscopy and CHNS elemental analysis. The design of theses lanthanide Pcs takes the form of mononuclear, binuclear, trinuclear, bis- and tris(phthalocyanines). Nanomaterials such as zinc oxide nanoparticles (ZnO NPs), multi-walled carbon nanotubes (MWCNTs) and graphene oxide nanosheets (GONS) (oxidized and reduced) were employed for covalent linkage to mono- and binuclear phthalocyanines as conjugates. Transmission electron microscopy was used to characterize ZnO NPs, MWCNTs and GONS alone and when linked to lanthanide Pcs. Lanthanide Pcs alone and when linked to ZnO NPs, MWCNTs and GONS where embedded in polymers such as poly (methyl methacrylate) (PMMA), poly (bisphenol A carbonate) (PBC) and poly (acrylic acid) (PAA) for thin film preparation. The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction (XRD). Optical limiting properties of lanthanide Pcs alone and as conjugates in solution and when incorporated into polymers were determined by employing a Z-scan technique. It emerged that low symmetry lanthanide Pcs (19, 20 and 21), the blue forms of bis(phthalocyanines) (only in solution; 24 and 28) as well as tris(phthalocyanines) (30 and 31) exhibit low limiting threshold (Ilim) values in solution and thin films (particularly PBC and PAA). The low limiting threshold values make these lanthanide Pcs reliable optical limiters.
- Full Text:
- Date Issued: 2017
In-silico analysis of Plasmodium falciparum Hop protein and its interactions with Hsp70 and Hsp90
- Authors: Clitheroe, Crystal-Leigh
- Date: 2013
- Subjects: Plasmodium falciparum , Heat shock proteins , Molecular chaperones , Homology (Biology) , Protein-protein interactions , Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3896 , http://hdl.handle.net/10962/d1003819 , Plasmodium falciparum , Heat shock proteins , Molecular chaperones , Homology (Biology) , Protein-protein interactions , Malaria -- Chemotherapy
- Description: A lessor understood co-chaperone, the Hsp70/Hsp90 organising protein (Hop), has been found to play an important role in modulating the activity and co-interaction of two essential chaperones; Hsp90 and Hsp70. The best understood aspects of Hop so far indicate that residues in the concave surfaces of the three tetratricopeptide repeat (TPR) domains in the protein bind selectively to the C-terminal motifs of Hsp70 and Hsp90. Recent research suggests that P. falciparum Hop (PfHop), PfHsp90 and PfHsp70 do interact and form complex in the P. falciparum trophozooite and are overexpressed in this infective stage. However, there has been almost no computational research on malarial Hop protein in complex with other malarial Hsps.The current work has focussed on several aspects of the in-silico characterisation of PfHop, including an in-depth multiple sequence alignment and phylogenetic analysis of the protein; which showed that Hop is very well conserved across a wide range of available phyla (four Kingdoms, 60 species). Homology modelling was employed to predict several protein structures for these interactions in P. falciparum, as well as predict structures of the relevant TPR domains of Human Hop (HsHop) in complex with its own Hsp90 and Hsp70 C-terminal peptide partners for comparison. Protein complex interaction analyses indicate that concave TPR sites bound to the C-terminal motifs of partner proteins are very similar in both species, due to the excellent conservation of the TPR domain’s “double carboxylate binding clamp”. Motif analysis was combined with phylogenetic trees and structure mapping in novel ways to attain more information on the evolutionary conservation of important structural and functional sites on Hop. Alternative sites of interaction between Hop TPR2 and Hsp90’s M and C domains are distinctly less well conserved between the two species, but still important to complex formation, making this a likely interaction site for selective drug targeting. Binding and interaction energies for all modelled complexes have been calculated; indicating that all HsHop TPR domains have higher affinities for their respective C-terminal partners than do their P. falciparum counterparts. An alternate motif corresponding to the C-terminal motif of PfHsp70-x (exported to the infected erythrocyte cytosol) in complex with both human and malarial TPR1 and TPR2B domains was analysed, and these studies suggest that the human TPR domains have a higher affinity for this motif than do the respective PfHop TPR domains. This may indicate potential for a cross species protein interaction to take place, as PfHop is not transported to the human erythrocyte cytosol.
- Full Text:
- Date Issued: 2013
- Authors: Clitheroe, Crystal-Leigh
- Date: 2013
- Subjects: Plasmodium falciparum , Heat shock proteins , Molecular chaperones , Homology (Biology) , Protein-protein interactions , Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3896 , http://hdl.handle.net/10962/d1003819 , Plasmodium falciparum , Heat shock proteins , Molecular chaperones , Homology (Biology) , Protein-protein interactions , Malaria -- Chemotherapy
- Description: A lessor understood co-chaperone, the Hsp70/Hsp90 organising protein (Hop), has been found to play an important role in modulating the activity and co-interaction of two essential chaperones; Hsp90 and Hsp70. The best understood aspects of Hop so far indicate that residues in the concave surfaces of the three tetratricopeptide repeat (TPR) domains in the protein bind selectively to the C-terminal motifs of Hsp70 and Hsp90. Recent research suggests that P. falciparum Hop (PfHop), PfHsp90 and PfHsp70 do interact and form complex in the P. falciparum trophozooite and are overexpressed in this infective stage. However, there has been almost no computational research on malarial Hop protein in complex with other malarial Hsps.The current work has focussed on several aspects of the in-silico characterisation of PfHop, including an in-depth multiple sequence alignment and phylogenetic analysis of the protein; which showed that Hop is very well conserved across a wide range of available phyla (four Kingdoms, 60 species). Homology modelling was employed to predict several protein structures for these interactions in P. falciparum, as well as predict structures of the relevant TPR domains of Human Hop (HsHop) in complex with its own Hsp90 and Hsp70 C-terminal peptide partners for comparison. Protein complex interaction analyses indicate that concave TPR sites bound to the C-terminal motifs of partner proteins are very similar in both species, due to the excellent conservation of the TPR domain’s “double carboxylate binding clamp”. Motif analysis was combined with phylogenetic trees and structure mapping in novel ways to attain more information on the evolutionary conservation of important structural and functional sites on Hop. Alternative sites of interaction between Hop TPR2 and Hsp90’s M and C domains are distinctly less well conserved between the two species, but still important to complex formation, making this a likely interaction site for selective drug targeting. Binding and interaction energies for all modelled complexes have been calculated; indicating that all HsHop TPR domains have higher affinities for their respective C-terminal partners than do their P. falciparum counterparts. An alternate motif corresponding to the C-terminal motif of PfHsp70-x (exported to the infected erythrocyte cytosol) in complex with both human and malarial TPR1 and TPR2B domains was analysed, and these studies suggest that the human TPR domains have a higher affinity for this motif than do the respective PfHop TPR domains. This may indicate potential for a cross species protein interaction to take place, as PfHop is not transported to the human erythrocyte cytosol.
- Full Text:
- Date Issued: 2013
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