A geographical analysis of nutrition in the Eastern Cape and Ciskei
- Authors: Fincham, Robert John
- Date: 1985
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4812 , http://hdl.handle.net/10962/d1004905
- Description: From preface: The primary aim of the thesis is to make an anthropometric assessment of levels of nutrition of black pre-school children in selected communities of the Eastern Cape and Ciskei. The communities are those of black labourers and their families on white-owned commercial farms in the Dias Divisional Council area of the Eastern Cape; a rural community of an area of Ciskei known as the Amatola Basin; and Tsweletsl'lele, a 'closer settlement' or resettlement area in Ciskei. A pilot survey of school entrants in the Albany magisterial district also sheds light on the nutrition of children in the small towns, such as Grahamstown, of the Eastern Cape. Through an analysis of nutritional conditions in these disparate communities, it should be possible to begin to establish the geographical variation of nutrition in the region. Black communities in the metropolitan area of Port Elizabeth are not considered in the thesis, but on-going surveillance in the city, by the author, will elucidate nutritional conditions there. In achieving the primary aim of the thesis, attention will be focussed on inter-community rather than intra-community variation in nutrition. Nutrition may vary within communities (intra-community variation), for example, within different parts of the Dias Divisional Council area. While such variation is 1 ikely to be minimal, as will be discussed in the presentation of results in chapter 6, section A(l), it is in itself important, and present research endeavours within the surveillance programme are being geared to explore this dimension of nutritional variation more fully. Inter-community variation in nutrition provides, however, a more than sufficient focus for the thesis. A secondary aim of the thesis is to explore the relationship between nutritional status and socio-economic conditions prevailing in the surveyed communities. The secondary aim makes it possible to obtain a better understanding of the processes whi ch infl uence the geographical pattern of nutrition. A consideration of socio-economic conditions, both within the communities and within the Eastern Cape and Ciskei as a whole, also provides a context in which the nutrition results can be assessed. The third aim of the thesis is to assess possible applications of the survey results to policy formulation, thereby providing an applied dimension to the work.
- Full Text:
- Date Issued: 1985
- Authors: Fincham, Robert John
- Date: 1985
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4812 , http://hdl.handle.net/10962/d1004905
- Description: From preface: The primary aim of the thesis is to make an anthropometric assessment of levels of nutrition of black pre-school children in selected communities of the Eastern Cape and Ciskei. The communities are those of black labourers and their families on white-owned commercial farms in the Dias Divisional Council area of the Eastern Cape; a rural community of an area of Ciskei known as the Amatola Basin; and Tsweletsl'lele, a 'closer settlement' or resettlement area in Ciskei. A pilot survey of school entrants in the Albany magisterial district also sheds light on the nutrition of children in the small towns, such as Grahamstown, of the Eastern Cape. Through an analysis of nutritional conditions in these disparate communities, it should be possible to begin to establish the geographical variation of nutrition in the region. Black communities in the metropolitan area of Port Elizabeth are not considered in the thesis, but on-going surveillance in the city, by the author, will elucidate nutritional conditions there. In achieving the primary aim of the thesis, attention will be focussed on inter-community rather than intra-community variation in nutrition. Nutrition may vary within communities (intra-community variation), for example, within different parts of the Dias Divisional Council area. While such variation is 1 ikely to be minimal, as will be discussed in the presentation of results in chapter 6, section A(l), it is in itself important, and present research endeavours within the surveillance programme are being geared to explore this dimension of nutritional variation more fully. Inter-community variation in nutrition provides, however, a more than sufficient focus for the thesis. A secondary aim of the thesis is to explore the relationship between nutritional status and socio-economic conditions prevailing in the surveyed communities. The secondary aim makes it possible to obtain a better understanding of the processes whi ch infl uence the geographical pattern of nutrition. A consideration of socio-economic conditions, both within the communities and within the Eastern Cape and Ciskei as a whole, also provides a context in which the nutrition results can be assessed. The third aim of the thesis is to assess possible applications of the survey results to policy formulation, thereby providing an applied dimension to the work.
- Full Text:
- Date Issued: 1985
A global ionospheric F2 region peak electron density model using neural networks and extended geophysically relevant inputs
- Authors: Oyeyemi, Elijah Oyedola
- Date: 2006
- Subjects: Neural networks (Computer science) Ionospheric electron density Ionosphere Ionosphere -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5470 , http://hdl.handle.net/10962/d1005255
- Description: This thesis presents my research on the development of a neural network (NN) based global empirical model of the ionospheric F2 region peak electron density using extended geophysically relevant inputs. The main principle behind this approach has been to utilize parameters other than simple geographic co-ordinates, on which the F2 peak electron density is known to depend, and to exploit the technique of NNs, thereby establishing and modeling the non-linear dynamic processes (both in space and time)associated with the F2 region electron density on a global scale. Four different models have been developed in this work. These are the foF2 NN model, M(3000)F2 NN model, short-term forecasting foF2 NN, and a near-real time foF2 NN model. Data used in the training of the NNs were obtained from the worldwide ionosonde stations spanning the period 1964 to 1986 based on availability, which included all periods of calm and disturbed magnetic activity. Common input parameters used in the training of all 4 models are day number (day of the year, DN), Universal Time (UT), a 2 month running mean of the sunspot number (R2), a 2 day running mean of the 3-hour planetary magnetic index ap (A16), solar zenith angle (CHI), geographic latitude (q), magnetic dip angle (I), angle of magnetic declination (D), angle of meridian relative to subsolar point (M). For the short-term and near-real time foF2 models, additional input parameters related to recent past observations of foF2 itself were included in the training of the NNs. The results of the foF2 NN model and M(3000)F2 NN model presented in this work, which compare favourably with the IRI (International Reference Ionosphere) model successfully demonstrate the potential of NNs for spatial and temporal modeling of the ionospheric parameters foF2 and M(3000)F2 globally. The results obtained from the short-term foF2 NN model and nearreal time foF2 NN model reveal that, in addition to the temporal and spatial input variables, short-term forecasting of foF2 is much improved by including past observations of foF2 itself. Results obtained from the near-real time foF2 NN model also reveal that there exists a correlation between measured foF2 values at different locations across the globe. Again, comparisons of the foF2 NN model and M(3000)F2 NN model predictions with that of the IRI model predictions and observed values at some selected high latitude stations, suggest that the NN technique can successfully be employed to model the complex irregularities associated with the high latitude regions. Based on the results obtained in this research and the comparison made with the IRI model (URSI and CCIR coefficients), these results justify consideration of the NN technique for the prediction of global ionospheric parameters. I believe that, after consideration by the IRI community, these models will prove to be valuable to both the high frequency (HF) communication and worldwide ionospheric communities.
- Full Text:
- Date Issued: 2006
- Authors: Oyeyemi, Elijah Oyedola
- Date: 2006
- Subjects: Neural networks (Computer science) Ionospheric electron density Ionosphere Ionosphere -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5470 , http://hdl.handle.net/10962/d1005255
- Description: This thesis presents my research on the development of a neural network (NN) based global empirical model of the ionospheric F2 region peak electron density using extended geophysically relevant inputs. The main principle behind this approach has been to utilize parameters other than simple geographic co-ordinates, on which the F2 peak electron density is known to depend, and to exploit the technique of NNs, thereby establishing and modeling the non-linear dynamic processes (both in space and time)associated with the F2 region electron density on a global scale. Four different models have been developed in this work. These are the foF2 NN model, M(3000)F2 NN model, short-term forecasting foF2 NN, and a near-real time foF2 NN model. Data used in the training of the NNs were obtained from the worldwide ionosonde stations spanning the period 1964 to 1986 based on availability, which included all periods of calm and disturbed magnetic activity. Common input parameters used in the training of all 4 models are day number (day of the year, DN), Universal Time (UT), a 2 month running mean of the sunspot number (R2), a 2 day running mean of the 3-hour planetary magnetic index ap (A16), solar zenith angle (CHI), geographic latitude (q), magnetic dip angle (I), angle of magnetic declination (D), angle of meridian relative to subsolar point (M). For the short-term and near-real time foF2 models, additional input parameters related to recent past observations of foF2 itself were included in the training of the NNs. The results of the foF2 NN model and M(3000)F2 NN model presented in this work, which compare favourably with the IRI (International Reference Ionosphere) model successfully demonstrate the potential of NNs for spatial and temporal modeling of the ionospheric parameters foF2 and M(3000)F2 globally. The results obtained from the short-term foF2 NN model and nearreal time foF2 NN model reveal that, in addition to the temporal and spatial input variables, short-term forecasting of foF2 is much improved by including past observations of foF2 itself. Results obtained from the near-real time foF2 NN model also reveal that there exists a correlation between measured foF2 values at different locations across the globe. Again, comparisons of the foF2 NN model and M(3000)F2 NN model predictions with that of the IRI model predictions and observed values at some selected high latitude stations, suggest that the NN technique can successfully be employed to model the complex irregularities associated with the high latitude regions. Based on the results obtained in this research and the comparison made with the IRI model (URSI and CCIR coefficients), these results justify consideration of the NN technique for the prediction of global ionospheric parameters. I believe that, after consideration by the IRI community, these models will prove to be valuable to both the high frequency (HF) communication and worldwide ionospheric communities.
- Full Text:
- Date Issued: 2006
A high school guidance programme aimed at the primary prevention of sexual abuse of children as part of a national strategy for the prevention of child sexual abuse in South Africa
- Authors: McGregor, Dale
- Date: 1994
- Subjects: Child abuse -- South Africa -- Prevention Educational counseling -- Keiskammahoek Educational counseling -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1553 , http://hdl.handle.net/10962/d1003435
- Description: The sexual abuse of children has become recognised as a major problem affecting children in most, if not all, countries of the world. The prevention of such abuse has, in the last decade, become an issue of international significance. In South Africa, prevention efforts are mainly informal ad hoc strategies initiated by individuals or organisations. As such they suffer from being short-lived and often isolated. Prevention efforts fall into the general categories of primary, secondary and tertiary prevention. Primary prevention focuses on preventing abuse from occurring at all. There are two main aspects to this type of prevention. The first aims at teaching children to protect themselves. The second aims at preventing the development of a disposition to abuse. This study set out to suggest and justify the adoption of a national strategy appropriate to the South African situation, including an overview of what can be done through the schooling system. This strategy will provide a framework and context for individual efforts, and hopefully stimulate new programmes. In addition, a detailed prevention programme for implementation in the secondary school, through the medium of the subject Guidance, was developed. This programme addressed itself mainly to that primary aspect of prevention concerned with preventing people from developing a disposition to abuse. The programme consists of lesson plans, teacher's notes and worksheet materials for pupils.
- Full Text:
- Date Issued: 1994
- Authors: McGregor, Dale
- Date: 1994
- Subjects: Child abuse -- South Africa -- Prevention Educational counseling -- Keiskammahoek Educational counseling -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1553 , http://hdl.handle.net/10962/d1003435
- Description: The sexual abuse of children has become recognised as a major problem affecting children in most, if not all, countries of the world. The prevention of such abuse has, in the last decade, become an issue of international significance. In South Africa, prevention efforts are mainly informal ad hoc strategies initiated by individuals or organisations. As such they suffer from being short-lived and often isolated. Prevention efforts fall into the general categories of primary, secondary and tertiary prevention. Primary prevention focuses on preventing abuse from occurring at all. There are two main aspects to this type of prevention. The first aims at teaching children to protect themselves. The second aims at preventing the development of a disposition to abuse. This study set out to suggest and justify the adoption of a national strategy appropriate to the South African situation, including an overview of what can be done through the schooling system. This strategy will provide a framework and context for individual efforts, and hopefully stimulate new programmes. In addition, a detailed prevention programme for implementation in the secondary school, through the medium of the subject Guidance, was developed. This programme addressed itself mainly to that primary aspect of prevention concerned with preventing people from developing a disposition to abuse. The programme consists of lesson plans, teacher's notes and worksheet materials for pupils.
- Full Text:
- Date Issued: 1994
A historic-hermeneutic critique of luthiery with specific reference to selected South African guiter builders
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
A historical analysis of the impact of the 1966 Ugandan constitutional crisis on Buganda’s monarchy
- Authors: Musisi, Fred
- Date: 2017
- Subjects: Uganda -- Politics and government -- 1962-1971 Uganda -- History Buganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20703 , vital:29377
- Description: 1966 was a particularly tumultuous year in the East African country of Uganda. After an era of relative peace and stability, the country was plagued by a range of tragedies that resulted in a constitutional crisis after the 24 May attack on the palace of the King of Buganda. This was the first time in Uganda's short history that the state had deliberately and systematically turned its guns on its own people. As a point of departure the study advances that existing historical analyses on the crisis lack detail. Consequently, the core of the study was to provide a more focused detailed and multi-faceted historical account of the 1966 crisis on the Buganda’s monarchy. The study yielded insights into the political and socio-economic impacts of the 1966 political turmoil on the people of Buganda. Using the historical method to inform the research design; the study employed an archival history methodology to examine how both the colonial legacy and the internal dynamics of the Ugandan society combined to lead to a serious and dramatic conflict between the kingdom of Buganda and State of Uganda. Furthermore, the study demonstrates that the political turmoil left an indelible scar on the Kingdom of Buganda. The study offers clarity on why and how the crisis occurred and contributes a better understanding of the ‘grey area’ of knowledge and insights into what the abolition of the Kingdom meant to the Baganda.
- Full Text:
- Date Issued: 2017
- Authors: Musisi, Fred
- Date: 2017
- Subjects: Uganda -- Politics and government -- 1962-1971 Uganda -- History Buganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20703 , vital:29377
- Description: 1966 was a particularly tumultuous year in the East African country of Uganda. After an era of relative peace and stability, the country was plagued by a range of tragedies that resulted in a constitutional crisis after the 24 May attack on the palace of the King of Buganda. This was the first time in Uganda's short history that the state had deliberately and systematically turned its guns on its own people. As a point of departure the study advances that existing historical analyses on the crisis lack detail. Consequently, the core of the study was to provide a more focused detailed and multi-faceted historical account of the 1966 crisis on the Buganda’s monarchy. The study yielded insights into the political and socio-economic impacts of the 1966 political turmoil on the people of Buganda. Using the historical method to inform the research design; the study employed an archival history methodology to examine how both the colonial legacy and the internal dynamics of the Ugandan society combined to lead to a serious and dramatic conflict between the kingdom of Buganda and State of Uganda. Furthermore, the study demonstrates that the political turmoil left an indelible scar on the Kingdom of Buganda. The study offers clarity on why and how the crisis occurred and contributes a better understanding of the ‘grey area’ of knowledge and insights into what the abolition of the Kingdom meant to the Baganda.
- Full Text:
- Date Issued: 2017
A historical study of John Graham Lake and South African/United States pentecostalism
- Authors: Burpeau, Kemp Pendleton
- Date: 2002
- Subjects: Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2587 , http://hdl.handle.net/10962/d1006484 , Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Description: American minister John Graham Lake (1870-1935) was a pivotal participant in an era of profound religious and political transition. Surprisingly, Lake's often provocative life had previously been largely neglected as a field of academic inquiry. In the U.S. Lake associated with key Holiness, Wesleyan and Apostolic Faith charismatics like John Alexander Dowie of the Zion City, Illinois Utopia, Charles Parham of the Topeka Revival and William Seymour of the Azusa Street Revival. Lake served as an important intermediary between Parham's often reactionary, white orientation that was unreceptive to an enthusiastic black liturgy and Seymour's expansive African-American egalitarianism expressed through exuberant spirit manifestations. Lake's South African ministry was shaped by his middle class white business background, Azusa Street message and American perspectives. He brought together the faith healing movement inspired by Dutch Reformed minister Andrew Murray, P. Ie Roux's black and white Zion charismatic adherents affiliated with Dowie and the new U.S. Pentecostalism of Parham and Seymour. Lake's African-American influenced Pentecostalism was compatible with indigenous African worship. His emphasis on the spiritual needs of the disempowered found a receptive audience in talented black evangelists Elias Letwaba and Edward Lion. Even though acquainted with Mohandas Gandhi, Lake did not undertake a South African social gospel-type civil protest against societal injustice. In fact, Lake's participation with Afrikaner politicians like Louis Botha in fashioning a segregationist land use law was most troubling. Lake was ambivalent about racial integration. His belief in an egalitarian status for all Christians, his Populist/Progressive ethics and his enthusiastic promotion of women's rights were complicated by his advocacy, or at least tolerance, of some disparate racial treatment in his Apostolic Faith Mission and South African society at large. Lake's paternalism and notion of Westem cultural superiority conflicted with his love of all persons. Lake's otherworldly prioritization of individual spiritualism over a socioeconomic agenda usually stymied activism. His uncharacteristic use of nonviolent protest to protect faith healing formed a remarkable contrast with his reluctance to actively campaign against unequal racial treatment in Africa and America. Historiographical perspectives on Lake range from the saintly pioneer charismatic missionary to the Elmer Gantry type charlatan acting only for personal benefit. Lake was a unique personality with his flamboyant rhetoric, strong convictions and feelings of personal worth. His distinctive Jesus as healing and suffering God theology evidenced both consistency with precedent as well as creative anticipation. Shortcomings resulting from his preference to address social concerns on an individual spiritual rather than societal level, his liberties with truth and his bad business judgments resulting in litigation. Nevertheless, Lake's life demonstrated that a gifted but imperfect instrument could accomplish a meaningful ministry. , Adobe Acrobat Pro 9.5.4 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Burpeau, Kemp Pendleton
- Date: 2002
- Subjects: Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2587 , http://hdl.handle.net/10962/d1006484 , Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Description: American minister John Graham Lake (1870-1935) was a pivotal participant in an era of profound religious and political transition. Surprisingly, Lake's often provocative life had previously been largely neglected as a field of academic inquiry. In the U.S. Lake associated with key Holiness, Wesleyan and Apostolic Faith charismatics like John Alexander Dowie of the Zion City, Illinois Utopia, Charles Parham of the Topeka Revival and William Seymour of the Azusa Street Revival. Lake served as an important intermediary between Parham's often reactionary, white orientation that was unreceptive to an enthusiastic black liturgy and Seymour's expansive African-American egalitarianism expressed through exuberant spirit manifestations. Lake's South African ministry was shaped by his middle class white business background, Azusa Street message and American perspectives. He brought together the faith healing movement inspired by Dutch Reformed minister Andrew Murray, P. Ie Roux's black and white Zion charismatic adherents affiliated with Dowie and the new U.S. Pentecostalism of Parham and Seymour. Lake's African-American influenced Pentecostalism was compatible with indigenous African worship. His emphasis on the spiritual needs of the disempowered found a receptive audience in talented black evangelists Elias Letwaba and Edward Lion. Even though acquainted with Mohandas Gandhi, Lake did not undertake a South African social gospel-type civil protest against societal injustice. In fact, Lake's participation with Afrikaner politicians like Louis Botha in fashioning a segregationist land use law was most troubling. Lake was ambivalent about racial integration. His belief in an egalitarian status for all Christians, his Populist/Progressive ethics and his enthusiastic promotion of women's rights were complicated by his advocacy, or at least tolerance, of some disparate racial treatment in his Apostolic Faith Mission and South African society at large. Lake's paternalism and notion of Westem cultural superiority conflicted with his love of all persons. Lake's otherworldly prioritization of individual spiritualism over a socioeconomic agenda usually stymied activism. His uncharacteristic use of nonviolent protest to protect faith healing formed a remarkable contrast with his reluctance to actively campaign against unequal racial treatment in Africa and America. Historiographical perspectives on Lake range from the saintly pioneer charismatic missionary to the Elmer Gantry type charlatan acting only for personal benefit. Lake was a unique personality with his flamboyant rhetoric, strong convictions and feelings of personal worth. His distinctive Jesus as healing and suffering God theology evidenced both consistency with precedent as well as creative anticipation. Shortcomings resulting from his preference to address social concerns on an individual spiritual rather than societal level, his liberties with truth and his bad business judgments resulting in litigation. Nevertheless, Lake's life demonstrated that a gifted but imperfect instrument could accomplish a meaningful ministry. , Adobe Acrobat Pro 9.5.4 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
A historico-theological study of Pentecostalism as a phenomenon within a South African community
- Authors: Pillay, Gerald J
- Date: 1985
- Subjects: Pentecostalism -- South Africa Pentecostal churches -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1222 , http://hdl.handle.net/10962/d1001552
- Description: Preface: An attempt is made in this thesis to document the history of Pentecostalism among Indians in South Africa and to study and evaluate its religious character and main theological tenets. Obviously the peculiar socio-political situation of the Indians in South Africa has influenced the character of Indian Pentecostalism, which has in turn been able to address itself to the critical, cultural and religious disjunctions within this community. Hence an investigation of the dynamic tensions that obtain between crises in the Indian community and Pentecostalism will not only clarify the course of its history but will also explain its theological emphases. However, several studies on Pentecostalism in other communities have concentrated on the sociological dimension almost exclusively and many have even concluded that Pentecostalism is the spontaneous result of psychosocial; economic or cultural upheavals . This kind of reductionism has been largely the result of the uncritical use of 'functional-type' theories postulated by sociologists of religion. Indian Pentecostalism, while it has to be examined within the complex context of the South African community, cannot as we shall show, be adequately explained by any of the prevailing 'functional-type' theories because these theories reduce religion to a sociological function. Since the functional theory has the effect of limiting the perspective on religion to such an extent that the basis of religion, that is, the relation between the individual and faith, is either belittled or ignored, it has been jettisoned in this thesis for an approach free of any deliberately formulated 'theoretical framework'. However, it is necessary to critically examine some of the more popular 'functional-type' theories and the way they have been applied to the study of the Pentecostal movement here and elsewhere, so that by exposing the shortcomings of their application and the contradictions inherent in their assumptions, the approach adopted in this thesis could be clarified.
- Full Text:
- Date Issued: 1985
- Authors: Pillay, Gerald J
- Date: 1985
- Subjects: Pentecostalism -- South Africa Pentecostal churches -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1222 , http://hdl.handle.net/10962/d1001552
- Description: Preface: An attempt is made in this thesis to document the history of Pentecostalism among Indians in South Africa and to study and evaluate its religious character and main theological tenets. Obviously the peculiar socio-political situation of the Indians in South Africa has influenced the character of Indian Pentecostalism, which has in turn been able to address itself to the critical, cultural and religious disjunctions within this community. Hence an investigation of the dynamic tensions that obtain between crises in the Indian community and Pentecostalism will not only clarify the course of its history but will also explain its theological emphases. However, several studies on Pentecostalism in other communities have concentrated on the sociological dimension almost exclusively and many have even concluded that Pentecostalism is the spontaneous result of psychosocial; economic or cultural upheavals . This kind of reductionism has been largely the result of the uncritical use of 'functional-type' theories postulated by sociologists of religion. Indian Pentecostalism, while it has to be examined within the complex context of the South African community, cannot as we shall show, be adequately explained by any of the prevailing 'functional-type' theories because these theories reduce religion to a sociological function. Since the functional theory has the effect of limiting the perspective on religion to such an extent that the basis of religion, that is, the relation between the individual and faith, is either belittled or ignored, it has been jettisoned in this thesis for an approach free of any deliberately formulated 'theoretical framework'. However, it is necessary to critically examine some of the more popular 'functional-type' theories and the way they have been applied to the study of the Pentecostal movement here and elsewhere, so that by exposing the shortcomings of their application and the contradictions inherent in their assumptions, the approach adopted in this thesis could be clarified.
- Full Text:
- Date Issued: 1985
A history of the direct taxation of the African people of Kenya, 1895-1973
- Authors: Tarus, Isaac Kipsang
- Date: 2005
- Subjects: Mau Mau -- History Taxation -- Kenya Tax collection -- Kenya Fiscal policy -- Kenya Kenya -- Economic policy Kenya -- History -- 1895-1963
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2561 , http://hdl.handle.net/10962/d1002414
- Description: This study examines the origin, the manifestation and impact of the direct taxation of Africans in Kenya. While the state had several reasons for imposing taxation on Africans, the basic factor weighed on the need for a definitive source of revenue. For most of the colonial period, this aggregated to about 37½ percent of the total revenues. The thesis shows how taxes were collected from Africans, how this led to participation in the cash economy and how they continually resisted and evaded such taxation. Tax collection was synonymous with colonialism and this was manifested through the central role of chiefs, who used taxes and force to coerce Africans into migrant wage labour. Through taxation policies, legislation and African resourcefulness, migrant wage labour served the needs of a colonial capitalist settler economy. In this way, the colonial state revealed its capacity for dominance, power and exploitation. Evidence has been adduced to show that African taxation was an important factor in Kenya’s administrative, political and economic development. The policy of African taxation, land loss and poor working conditions are remembered as having interfered with African mechanisms for accumulating wealth. One of the main objections of the payment of taxes was the manner of its collection. Those unable to pay were imprisoned or detained while many took to instant flight at the sight of the tax collector. The thesis shows that in spite of all these harsh tax collection methods, peasants remained largely resilient and industrious. The Mau Mau movement was the culmination of various peasant grievances in which the colonial state used steep taxation as a counter-insurgency measure. Kenya’s independence in 1963, however, never altered the predatory nature of the state. Subtle, opportunistic and overt ways continued to be used to extract taxes from the peasants and the working class. It was not until 1973 that the much-hated colonial poll tax that had been renamed as graduated poll tax was abolished and replaced by indirect taxation. Finally, taxation like other colonial legacies has endured and has become one of the most important sources of revenue for the government to manage its fiscal policies.
- Full Text:
- Date Issued: 2005
- Authors: Tarus, Isaac Kipsang
- Date: 2005
- Subjects: Mau Mau -- History Taxation -- Kenya Tax collection -- Kenya Fiscal policy -- Kenya Kenya -- Economic policy Kenya -- History -- 1895-1963
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2561 , http://hdl.handle.net/10962/d1002414
- Description: This study examines the origin, the manifestation and impact of the direct taxation of Africans in Kenya. While the state had several reasons for imposing taxation on Africans, the basic factor weighed on the need for a definitive source of revenue. For most of the colonial period, this aggregated to about 37½ percent of the total revenues. The thesis shows how taxes were collected from Africans, how this led to participation in the cash economy and how they continually resisted and evaded such taxation. Tax collection was synonymous with colonialism and this was manifested through the central role of chiefs, who used taxes and force to coerce Africans into migrant wage labour. Through taxation policies, legislation and African resourcefulness, migrant wage labour served the needs of a colonial capitalist settler economy. In this way, the colonial state revealed its capacity for dominance, power and exploitation. Evidence has been adduced to show that African taxation was an important factor in Kenya’s administrative, political and economic development. The policy of African taxation, land loss and poor working conditions are remembered as having interfered with African mechanisms for accumulating wealth. One of the main objections of the payment of taxes was the manner of its collection. Those unable to pay were imprisoned or detained while many took to instant flight at the sight of the tax collector. The thesis shows that in spite of all these harsh tax collection methods, peasants remained largely resilient and industrious. The Mau Mau movement was the culmination of various peasant grievances in which the colonial state used steep taxation as a counter-insurgency measure. Kenya’s independence in 1963, however, never altered the predatory nature of the state. Subtle, opportunistic and overt ways continued to be used to extract taxes from the peasants and the working class. It was not until 1973 that the much-hated colonial poll tax that had been renamed as graduated poll tax was abolished and replaced by indirect taxation. Finally, taxation like other colonial legacies has endured and has become one of the most important sources of revenue for the government to manage its fiscal policies.
- Full Text:
- Date Issued: 2005
A history of the Grahamstown Teachers’ Training College 1894-1975
- Authors: Kelly, Leonard Eric
- Date: 2017
- Subjects: Grahamstown Teachers' Training College , Teachers -- Training of -- South Africa -- Makhanda -- History , Universities and colleges -- South Africa -- Makhanda -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7903 , vital:21322
- Description: In the Cape Colony, and then in South Africa generally, the twentieth century was to see the emergence, growth, and final closure of teacher training colleges. South Africa was one of the few Anglophone countries on the African Continent which, in 2003, did not have a separate and dedicated system of Teacher Education Colleges.1 From the 1920s on, there was a spirited debate over whether primary school teacher training was better achieved in the training college or the university. The publication of the National Education Amendment Act (No 73 of 1969) finally placed all teacher training, primary/elementary and secondary, within University Faculties of Education. The present study investigates the history of the Grahamstown Teacher Training College (GTTC) which was officially recognised in 1894 for the training of young white women. The GTTC was an independent college, founded and owned by an Anglican Religious Community for women, the Community of the Resurrection of Our Lord (CR), but it was also an Aided College of the Cape Education Department. As an Aided College, the GTTC was subject to Government Inspection annually, and the students wrote the official examinations set by the Department of Education. The College was run entirely by women and existed for 81 years. The emphasis in the college was on the practical professional training offered. The focus was on the ‘complete’ education of the student, rather than merely on the content of the curriculum. This study shows that the GTTC more than earned its reputation of being one of the finest training colleges in South Africa and that it was indeed a unique educational development. A feature of particular note was that the college was a trail-blazer, a pioneer in the field of education practices. It was the first college to introduce class music and class singing, the first to employ a physical education teacher, to have a full-time librarian and elocutionist, and it was at the GTTC that the assignment method of study was introduced. All these factors are highlighted in the course of this study.
- Full Text:
- Date Issued: 2017
- Authors: Kelly, Leonard Eric
- Date: 2017
- Subjects: Grahamstown Teachers' Training College , Teachers -- Training of -- South Africa -- Makhanda -- History , Universities and colleges -- South Africa -- Makhanda -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7903 , vital:21322
- Description: In the Cape Colony, and then in South Africa generally, the twentieth century was to see the emergence, growth, and final closure of teacher training colleges. South Africa was one of the few Anglophone countries on the African Continent which, in 2003, did not have a separate and dedicated system of Teacher Education Colleges.1 From the 1920s on, there was a spirited debate over whether primary school teacher training was better achieved in the training college or the university. The publication of the National Education Amendment Act (No 73 of 1969) finally placed all teacher training, primary/elementary and secondary, within University Faculties of Education. The present study investigates the history of the Grahamstown Teacher Training College (GTTC) which was officially recognised in 1894 for the training of young white women. The GTTC was an independent college, founded and owned by an Anglican Religious Community for women, the Community of the Resurrection of Our Lord (CR), but it was also an Aided College of the Cape Education Department. As an Aided College, the GTTC was subject to Government Inspection annually, and the students wrote the official examinations set by the Department of Education. The College was run entirely by women and existed for 81 years. The emphasis in the college was on the practical professional training offered. The focus was on the ‘complete’ education of the student, rather than merely on the content of the curriculum. This study shows that the GTTC more than earned its reputation of being one of the finest training colleges in South Africa and that it was indeed a unique educational development. A feature of particular note was that the college was a trail-blazer, a pioneer in the field of education practices. It was the first college to introduce class music and class singing, the first to employ a physical education teacher, to have a full-time librarian and elocutionist, and it was at the GTTC that the assignment method of study was introduced. All these factors are highlighted in the course of this study.
- Full Text:
- Date Issued: 2017
A history of the growth and development of the Seventh-Day Adventist Church in Southern Africa, 1920-1960
- Thompson, Ronald Charles Lloyd
- Authors: Thompson, Ronald Charles Lloyd
- Date: 1979
- Subjects: Seventh-Day Adventists -- South Africa -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1231 , http://hdl.handle.net/10962/d1007294
- Description: From Introduction: The most natural divisions of time for this historical survey of the growth and development of the Seventh-day Adventist Church in Southern Africa fall into three periods: (1) from 1920, when the African Division of Seventh-day Adventists was organized, to 1931, when it was reorganized under the name Southern African Division; (2) from 1931 to 1945, covering the period years of the Great Depression and Second world War; (3) from 1946 to 1960, the post-war. Attention is given in Chapter I to a certain phase of church development because the church had emerged at the highest level of Adventist organization, i.e. a Division. Although the first group of Adventists adopted the simplest form of organization in 1892 known as the South African Conference, the church was small and little known. The church at Division level therefore embarked on a programme of orientation and adaptation to gain recognition and make itself known everywhere. Closely allied to this was organization. Chapter II defines the organization of the church and explains how it was financed. The history of its organization and reorganization is also traced. Chapters III and IV deal with an era of expansion during the twenties in the establishment of missions, medical missions and training institutions, while new mission fields were entered and old mission fields were further developed. Chapters V and VI continue to trace the development of missions, mission fields, medical missions, and training institutions together with important changes in the medical and educational work. Further reorganization and new developments in the European church and African church are also outlined. The great emphasis on expansion and the development of institutions finally reached a point whereby "institutionalism" overtook "evangelism". Chapter VII discusses this problem and what was done to try and arrest it. Thus the history of the church is brought to an interesting turning point and climax in Part Two. Chapter VIII breaks from the common run of growth and development in missions, medical missions and institutions and traces the development of the principles and practice of the Adventist Church. The Southern African Division set itself the objective of full maturity in the establishment of a self-supporting, self-governing and self- propagating church in Africa. The history of these principles are covered together with the principles governing the reception of government grants-in-aid. Chapter IX deals with the analysis and development of the three-fold ministry of teaching, preaching and healing. These chapters in Part Three do not constitute a conclusion but simply give further insights in the growth and development of the church .
- Full Text:
- Date Issued: 1979
- Authors: Thompson, Ronald Charles Lloyd
- Date: 1979
- Subjects: Seventh-Day Adventists -- South Africa -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1231 , http://hdl.handle.net/10962/d1007294
- Description: From Introduction: The most natural divisions of time for this historical survey of the growth and development of the Seventh-day Adventist Church in Southern Africa fall into three periods: (1) from 1920, when the African Division of Seventh-day Adventists was organized, to 1931, when it was reorganized under the name Southern African Division; (2) from 1931 to 1945, covering the period years of the Great Depression and Second world War; (3) from 1946 to 1960, the post-war. Attention is given in Chapter I to a certain phase of church development because the church had emerged at the highest level of Adventist organization, i.e. a Division. Although the first group of Adventists adopted the simplest form of organization in 1892 known as the South African Conference, the church was small and little known. The church at Division level therefore embarked on a programme of orientation and adaptation to gain recognition and make itself known everywhere. Closely allied to this was organization. Chapter II defines the organization of the church and explains how it was financed. The history of its organization and reorganization is also traced. Chapters III and IV deal with an era of expansion during the twenties in the establishment of missions, medical missions and training institutions, while new mission fields were entered and old mission fields were further developed. Chapters V and VI continue to trace the development of missions, mission fields, medical missions, and training institutions together with important changes in the medical and educational work. Further reorganization and new developments in the European church and African church are also outlined. The great emphasis on expansion and the development of institutions finally reached a point whereby "institutionalism" overtook "evangelism". Chapter VII discusses this problem and what was done to try and arrest it. Thus the history of the church is brought to an interesting turning point and climax in Part Two. Chapter VIII breaks from the common run of growth and development in missions, medical missions and institutions and traces the development of the principles and practice of the Adventist Church. The Southern African Division set itself the objective of full maturity in the establishment of a self-supporting, self-governing and self- propagating church in Africa. The history of these principles are covered together with the principles governing the reception of government grants-in-aid. Chapter IX deals with the analysis and development of the three-fold ministry of teaching, preaching and healing. These chapters in Part Three do not constitute a conclusion but simply give further insights in the growth and development of the church .
- Full Text:
- Date Issued: 1979
A history of the South African police in Port Elizabeth, 1913-1956
- Authors: Watson, Kelvin Innes
- Date: 2000
- Subjects: Police -- South Africa -- Eastern Cape South African Police -- South Africa -- Port Elizabeth -- History Police -- South Africa -- Port Elizabeth -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2570 , http://hdl.handle.net/10962/d1002423
- Description: This thesis investigates the policing activities of the South African Police (SAP) in Port Elizabeth from the formation of the SAP in 1913 to the creation of two separate police districts in the city in 1956. It begins with the recruitment and training of police personnel, outlining the difficulty in obtaining sufficient white recruits for most of the period while at the same time stressing the ease with which the Force was able to obtain black recruits. The preponderance of Afrikaner policemen serving in Port Elizabeth from the 1920s onwards is made clear, as is the para-military nature of the SAP, which was maintained and reinforced as a result of training methods and the process of socialisation. As state servants, police personnel were expected to serve loyally and obediently a state becoming increasingly repressive towards its black citizens. Generally inadequate conditions of service remained the norm throughout the period yet the SAP’s commitment to the state never wavered, bar one isolated, short-lived incidence. The administration and functioning of policing in Port Elizabeth is explored by focussing on specific organisational features pertinent to the city and the changes wrought by the police hierarchy to deal with the city’s demographic and spatial expansion. The SAP tended to employ three different forms of policing in the city as a result of its apartheid-driven agenda which compelled it to differentiate between the various population groups in terms of maintaining law and order. The privileged white community experienced routine, civil policing whereas the black community was policed largely in a socially and politically oppressive manner; this was in line with government policy. On the whole, however, the more brutal and sinister nature of policing was yet to come to the fore although this thesis does point towards the increasingly repressive nature of policing in South Africa during the apartheid era.
- Full Text:
- Date Issued: 2000
- Authors: Watson, Kelvin Innes
- Date: 2000
- Subjects: Police -- South Africa -- Eastern Cape South African Police -- South Africa -- Port Elizabeth -- History Police -- South Africa -- Port Elizabeth -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2570 , http://hdl.handle.net/10962/d1002423
- Description: This thesis investigates the policing activities of the South African Police (SAP) in Port Elizabeth from the formation of the SAP in 1913 to the creation of two separate police districts in the city in 1956. It begins with the recruitment and training of police personnel, outlining the difficulty in obtaining sufficient white recruits for most of the period while at the same time stressing the ease with which the Force was able to obtain black recruits. The preponderance of Afrikaner policemen serving in Port Elizabeth from the 1920s onwards is made clear, as is the para-military nature of the SAP, which was maintained and reinforced as a result of training methods and the process of socialisation. As state servants, police personnel were expected to serve loyally and obediently a state becoming increasingly repressive towards its black citizens. Generally inadequate conditions of service remained the norm throughout the period yet the SAP’s commitment to the state never wavered, bar one isolated, short-lived incidence. The administration and functioning of policing in Port Elizabeth is explored by focussing on specific organisational features pertinent to the city and the changes wrought by the police hierarchy to deal with the city’s demographic and spatial expansion. The SAP tended to employ three different forms of policing in the city as a result of its apartheid-driven agenda which compelled it to differentiate between the various population groups in terms of maintaining law and order. The privileged white community experienced routine, civil policing whereas the black community was policed largely in a socially and politically oppressive manner; this was in line with government policy. On the whole, however, the more brutal and sinister nature of policing was yet to come to the fore although this thesis does point towards the increasingly repressive nature of policing in South Africa during the apartheid era.
- Full Text:
- Date Issued: 2000
A history of the Thembu and their relationship with the Cape, 1850-1900
- Authors: Wagenaar, E J C
- Date: 1989
- Subjects: Tembu (African people) -- History Missions -- South Africa -- Cape of Good Hope South Africa -- History -- Frontier Wars, 1811-1878 Cape of Good Hope (South Africa) -- Politics and government Land tenure -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2569 , http://hdl.handle.net/10962/d1002422
- Description: Present day Thembuland is situated roughly between the Mthatha and Kei rivers. It lies within the south-western portion of the political unit which has been known since 1976 as the Republic of Transkei. It comprises the territories formerly known as Emigrant Thembuland (now the districts of Cala and Cofimvaba) and Thembuland Proper, i.e. the districts of Mqanduli, Umtata, Engcobo and Bomvanaland. We have evidence that Thembu people had already settled in Thembu land Proper, at the Mbashe river, by the beginning of the 17th century. Pioneering clans many have entered the territory at a much earlier date. In the 1830's some clans broke away from the Mbashe settlement, and moved to the region of present day Queenstown. In 1853 their lands were included in the so-called Tambookie Location, which in 1871 became the district of Glen Grey. Emigrant Thembuland came into existence in 1865 when four chiefs from Glen Grey accepted Sir Philip Wodehouse's offer to settle on the lands across the White Kei whence the Xhosa chief Sarhili had been expelled in 1857. This thesis deals with the history of the people who lived in these territories between 1850 and 1900.
- Full Text:
- Date Issued: 1989
- Authors: Wagenaar, E J C
- Date: 1989
- Subjects: Tembu (African people) -- History Missions -- South Africa -- Cape of Good Hope South Africa -- History -- Frontier Wars, 1811-1878 Cape of Good Hope (South Africa) -- Politics and government Land tenure -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2569 , http://hdl.handle.net/10962/d1002422
- Description: Present day Thembuland is situated roughly between the Mthatha and Kei rivers. It lies within the south-western portion of the political unit which has been known since 1976 as the Republic of Transkei. It comprises the territories formerly known as Emigrant Thembuland (now the districts of Cala and Cofimvaba) and Thembuland Proper, i.e. the districts of Mqanduli, Umtata, Engcobo and Bomvanaland. We have evidence that Thembu people had already settled in Thembu land Proper, at the Mbashe river, by the beginning of the 17th century. Pioneering clans many have entered the territory at a much earlier date. In the 1830's some clans broke away from the Mbashe settlement, and moved to the region of present day Queenstown. In 1853 their lands were included in the so-called Tambookie Location, which in 1871 became the district of Glen Grey. Emigrant Thembuland came into existence in 1865 when four chiefs from Glen Grey accepted Sir Philip Wodehouse's offer to settle on the lands across the White Kei whence the Xhosa chief Sarhili had been expelled in 1857. This thesis deals with the history of the people who lived in these territories between 1850 and 1900.
- Full Text:
- Date Issued: 1989
A holistic approach in understanding the effects of dietary protein sources on the growth and reproductive development of farmed abalone, Haliotis midae
- Wu, Yu
- Authors: Wu, Yu
- Date: 2020
- Subjects: Abalones -- Nutrition , Abalones -- Reproduction , Abalones -- Growth , Abalone culture , Haliotis midae -- Nutrition , Haliotis midae -- Reproduction , Haliotis midae -- Growth , Haliotis midae fisheries
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167719 , vital:41506
- Description: The combination of fishmeal and soya in the formulated feed of farmed South African abalone, Haliotis midae, not only improved abalone growth, but also the sustainability of the compound diets by reducing the reliance on fishmeal. However, the presence of soya produced larger gonads compared to those of abalone fed kelp or single-source protein diets. There is an increasing drive to control sexual maturation and reduce undesirable spawning events in farmed abalone. However, the reasons for the reported effects of soya inclusion on the reproductive development of farmed H. midae remain unresolved. The aim of this research was to use a combination of techniques to contribute to the understanding of the relationship between growth, reproductive and nutritional physiology of farmed H. midae fed diets of varying protein sources. These techniques included stable isotope analysis (SIA), fatty acid analysis, gonad histological assessments and haemolymph sexsteroid hormone analysis. The objectives were to examine the allocation of protein and nutritional components to somatic and reproductive tissues. This study also included the first attempt to investigate the role that sex steroid hormones play during gametogenesis. Abalone (40 – 50 g abalone-1) were fed one of four diets: either a single-source protein-based diet, i.e., (1) fishmeal-only (FM) or (2) soya-only (S), or a combination diet of (3) fishmeal-soya (FM S) or (4) fishmeal-sunflower meal (FM SM). Sampling occurred in 45-day intervals over one year. Dietary protein source had an effect on the growth of abalone, with enhancements in growth linked to the combination of fishmeal and a plant-protein source. The fishmeal ingredient was the most utilised protein source throughout the temporal changes in protein allocation into somatic and reproductive tissue, followed by soya and then sunflower meal. The mean whole- body mass of abalone was significantly influenced by an interaction between time and dietary treatment, with average whole-body mass changing differently over time between treatments (RM-ANOVA, F(24, 96) = 2.13, p = 0.005). Overall, abalone that were fed FM S had higher mean whole-body mass values than abalone that were fed the single-protein based diets, while abalone that were fed FM SM were similar to animals from all dietary treatments (RMANOVA, F(3, 12) = 5.75, p = 0.01). Male abalone had significantly higher gonad bulk index (GBI) values compared to females (RM-ANOVA, F(1, 24) = 49.03, p < 0.001) and this was independent of dietary treatment. Within each sex, female abalone fed the FM S diet (15.92 ± 1.88 mm3 g-1) had significantly higher GBI values than abalone fed S (9.76 ± 1.08 mm3 g-1), while abalone fed FM (11.96 ± 1.71 mm3 g-1) and FM SM (11.90 ± 0.80 mm3 g-1) were similar to abalone from all other dietary treatments (Tukey’s HSD, p < 0.05). Male abalone fed the FM S (21.59 ± 2.10 mm3 g-1) and FM SM diet (19.30 ± 2.63 mm3 g-1) had similar GBI values and they were significantly higher than in abalone fed the S diet (14.74 ± 1.27 mm3 g-1), while abalone fed FM S had significantly higher GBI values than abalone that consumed the FM diet (15.08 ±1.63mm3 g-1) ( Tukey’s HSD, p < 0.05). Although sunflower meal was poorly utilised, it produced similar overall growth to abalone that were fed the FM S diets. Yet, feed conversion ratio values were significantly lower for abalone fed FM S (1.30 ± 0.13) compared to those in the other three treatments, with ratios ranging from 1.65 – 1.72 over the one-year. The fatty acid compositions of the somatic and gonadal tissues were similar between treatments (PERMANOVA, p = 0.21), while fatty acid composition was influenced by sampling day, tissue type and abalone sex (PERMANOVA, p < 0.05). The essential fatty acids (EFAs) eicosadienoic acid and a-linolenic acid were present in abalone tissue, but they were not detected in the diets, suggesting the important role that an alternate food source (e.g. farmed abalone also had access to diatoms) may have played and the ability that H. midae may have in converting long-chain polyunsaturated fatty acids from C18 precursors. A change in the abundance of EFAs in the gonad tissue during highest and lowest GBI values suggested that arachidonic, eicosapentaenoic, g-linolenic and linoleic acid were important in females, while eicosapentaenoic, eicosadienoic and a-linolenic acid were important for male reproductive development. Dietary protein sources had an effect on the frequency distribution of maturity stages, where females that were fed FM S produced more ripe gonads and more males that were fed FM SM contained testes that showed signs of ripeness over the one-year study. Although dietary protein influenced the sex steroid concentrations in females and males, exhibiting fluctuations throughout the one-year period, no distinct pattern linked to gametogenesis were observed. The results from this study illustrate: (1) the importance of conducting laboratory studies when implementing SIA and mixing models in aquaculture nutrition; (2) conducting nutritional studies on mature, grow-out abalone; and (3) assessing the importance of naturally occurring diatoms in their diet and their contribution to growth and reproduction. The novel contribution of this research towards abalone nutritional physiology, the implications of these findings to industry as well as potential considerations for future studies were addressed.
- Full Text:
- Date Issued: 2020
- Authors: Wu, Yu
- Date: 2020
- Subjects: Abalones -- Nutrition , Abalones -- Reproduction , Abalones -- Growth , Abalone culture , Haliotis midae -- Nutrition , Haliotis midae -- Reproduction , Haliotis midae -- Growth , Haliotis midae fisheries
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167719 , vital:41506
- Description: The combination of fishmeal and soya in the formulated feed of farmed South African abalone, Haliotis midae, not only improved abalone growth, but also the sustainability of the compound diets by reducing the reliance on fishmeal. However, the presence of soya produced larger gonads compared to those of abalone fed kelp or single-source protein diets. There is an increasing drive to control sexual maturation and reduce undesirable spawning events in farmed abalone. However, the reasons for the reported effects of soya inclusion on the reproductive development of farmed H. midae remain unresolved. The aim of this research was to use a combination of techniques to contribute to the understanding of the relationship between growth, reproductive and nutritional physiology of farmed H. midae fed diets of varying protein sources. These techniques included stable isotope analysis (SIA), fatty acid analysis, gonad histological assessments and haemolymph sexsteroid hormone analysis. The objectives were to examine the allocation of protein and nutritional components to somatic and reproductive tissues. This study also included the first attempt to investigate the role that sex steroid hormones play during gametogenesis. Abalone (40 – 50 g abalone-1) were fed one of four diets: either a single-source protein-based diet, i.e., (1) fishmeal-only (FM) or (2) soya-only (S), or a combination diet of (3) fishmeal-soya (FM S) or (4) fishmeal-sunflower meal (FM SM). Sampling occurred in 45-day intervals over one year. Dietary protein source had an effect on the growth of abalone, with enhancements in growth linked to the combination of fishmeal and a plant-protein source. The fishmeal ingredient was the most utilised protein source throughout the temporal changes in protein allocation into somatic and reproductive tissue, followed by soya and then sunflower meal. The mean whole- body mass of abalone was significantly influenced by an interaction between time and dietary treatment, with average whole-body mass changing differently over time between treatments (RM-ANOVA, F(24, 96) = 2.13, p = 0.005). Overall, abalone that were fed FM S had higher mean whole-body mass values than abalone that were fed the single-protein based diets, while abalone that were fed FM SM were similar to animals from all dietary treatments (RMANOVA, F(3, 12) = 5.75, p = 0.01). Male abalone had significantly higher gonad bulk index (GBI) values compared to females (RM-ANOVA, F(1, 24) = 49.03, p < 0.001) and this was independent of dietary treatment. Within each sex, female abalone fed the FM S diet (15.92 ± 1.88 mm3 g-1) had significantly higher GBI values than abalone fed S (9.76 ± 1.08 mm3 g-1), while abalone fed FM (11.96 ± 1.71 mm3 g-1) and FM SM (11.90 ± 0.80 mm3 g-1) were similar to abalone from all other dietary treatments (Tukey’s HSD, p < 0.05). Male abalone fed the FM S (21.59 ± 2.10 mm3 g-1) and FM SM diet (19.30 ± 2.63 mm3 g-1) had similar GBI values and they were significantly higher than in abalone fed the S diet (14.74 ± 1.27 mm3 g-1), while abalone fed FM S had significantly higher GBI values than abalone that consumed the FM diet (15.08 ±1.63mm3 g-1) ( Tukey’s HSD, p < 0.05). Although sunflower meal was poorly utilised, it produced similar overall growth to abalone that were fed the FM S diets. Yet, feed conversion ratio values were significantly lower for abalone fed FM S (1.30 ± 0.13) compared to those in the other three treatments, with ratios ranging from 1.65 – 1.72 over the one-year. The fatty acid compositions of the somatic and gonadal tissues were similar between treatments (PERMANOVA, p = 0.21), while fatty acid composition was influenced by sampling day, tissue type and abalone sex (PERMANOVA, p < 0.05). The essential fatty acids (EFAs) eicosadienoic acid and a-linolenic acid were present in abalone tissue, but they were not detected in the diets, suggesting the important role that an alternate food source (e.g. farmed abalone also had access to diatoms) may have played and the ability that H. midae may have in converting long-chain polyunsaturated fatty acids from C18 precursors. A change in the abundance of EFAs in the gonad tissue during highest and lowest GBI values suggested that arachidonic, eicosapentaenoic, g-linolenic and linoleic acid were important in females, while eicosapentaenoic, eicosadienoic and a-linolenic acid were important for male reproductive development. Dietary protein sources had an effect on the frequency distribution of maturity stages, where females that were fed FM S produced more ripe gonads and more males that were fed FM SM contained testes that showed signs of ripeness over the one-year study. Although dietary protein influenced the sex steroid concentrations in females and males, exhibiting fluctuations throughout the one-year period, no distinct pattern linked to gametogenesis were observed. The results from this study illustrate: (1) the importance of conducting laboratory studies when implementing SIA and mixing models in aquaculture nutrition; (2) conducting nutritional studies on mature, grow-out abalone; and (3) assessing the importance of naturally occurring diatoms in their diet and their contribution to growth and reproduction. The novel contribution of this research towards abalone nutritional physiology, the implications of these findings to industry as well as potential considerations for future studies were addressed.
- Full Text:
- Date Issued: 2020
A holistic healthcare model for higher education campus health services
- Authors: Ricks, Esmeralda Jennifer
- Date: 2008
- Subjects: College students -- Health and hygiene -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: vital:10038 , http://hdl.handle.net/10948/666 , College students -- Health and hygiene -- South Africa -- Eastern Cape
- Description: Most students are adolescents and young adults, a group characterized by a new-found sense of independence, experimentation with sex and sometimes drugs and a feeling of invincibility (Gayle, Richard, Keeling, Garcia-Tunon, Kilbourne, Narkunas, Ingram, rogers and Curran, 1990:1538). These behavioural, developmental and environmental issues may contribute to premature morbidity, mortality and reduced quality of life for university students (Patrick et al., 1992:260). The ages of staff on the other hand range from young adults to retirement age. The types of health problems that exist among staff who use the campus health service include First Aid treatment on site for injuries on duty and more chronic health problems such as, for example, hypertension and diabetes mellitus. To date there is very little evidence as to whether or not the healthcare needs of students and staff are being met comprehensively or whether the practitioners rendering the service are knowledgeable and complying with the PHC norms and standards developed by the department of Health’s Quality Assurance Directorate. The lack of such empirical data can contribute to misconceptions and hamper the management of public health problems experienced in SA, for example sexually transmitted infections and the transmission of HIV. Thus the purpose of this research was to develop a model that would assist registered nurses employed at a higher education campus health service in the Western Region of the Eastern Cape Province to render a healthcare service relevant to the healthcare needs of the students and staff on campus.
- Full Text:
- Date Issued: 2008
- Authors: Ricks, Esmeralda Jennifer
- Date: 2008
- Subjects: College students -- Health and hygiene -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: vital:10038 , http://hdl.handle.net/10948/666 , College students -- Health and hygiene -- South Africa -- Eastern Cape
- Description: Most students are adolescents and young adults, a group characterized by a new-found sense of independence, experimentation with sex and sometimes drugs and a feeling of invincibility (Gayle, Richard, Keeling, Garcia-Tunon, Kilbourne, Narkunas, Ingram, rogers and Curran, 1990:1538). These behavioural, developmental and environmental issues may contribute to premature morbidity, mortality and reduced quality of life for university students (Patrick et al., 1992:260). The ages of staff on the other hand range from young adults to retirement age. The types of health problems that exist among staff who use the campus health service include First Aid treatment on site for injuries on duty and more chronic health problems such as, for example, hypertension and diabetes mellitus. To date there is very little evidence as to whether or not the healthcare needs of students and staff are being met comprehensively or whether the practitioners rendering the service are knowledgeable and complying with the PHC norms and standards developed by the department of Health’s Quality Assurance Directorate. The lack of such empirical data can contribute to misconceptions and hamper the management of public health problems experienced in SA, for example sexually transmitted infections and the transmission of HIV. Thus the purpose of this research was to develop a model that would assist registered nurses employed at a higher education campus health service in the Western Region of the Eastern Cape Province to render a healthcare service relevant to the healthcare needs of the students and staff on campus.
- Full Text:
- Date Issued: 2008
A holistic investigation of amateur batters performance responses to a century protocol: a focused cognitive perspective
- Authors: Goble, David
- Date: 2017
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket players -- Physiology , Cricket players -- Health and hygiene , Cognition -- Testing , Neurophysiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/40725 , vital:25020
- Description: No cognitive study has implemented an exercise modality that requires both physical effort and cognitive control, therefore, the effects of such exercise are unknown. Additionally, no studies have investigated how prolonged batting impacts cognitive functioning nor how physical responses and cognitive functioning are related while batting. At intensities of 6070 percent heart rate maximum, acute and prolonged bouts of physical activity have been shown to improve cognitive functioning. At higher intensities, the beneficial effects are minimal and in some cases performance is impaired. Therefore, the aim of this investigation was to determine how prolonged intermittent batting (a task that requires high muscular and cardiovascular loads but also continuous cognitive control) affects cognitive, physiological, physical and biophysical responses in amateur batters. Further aims included to test the reliability of the method employed in assessing these responses. To answer this question, the investigation was separated into three studies: phase 1 (a large-scale pilot) and phase 2 and 3 (a repeated measures test-retest hypothesis). In each phase, batters completed the 30 over BATEX simulation, which replicated the demands of scoring a one-day international century. To establish physiological, physical and perceptual strain; heart rate, sprint times and perceived exertion data were collected each over. Changes in body mass over time were compared to determine the effects of fluid loss on cognitive performance. Before, during and after the simulation, psychomotor function, visual attention, working memory, visual learning and memory as well as executive functions were assessed (CogState brief test battery). During cognitive assessments, heart rate and heart rate variability parameters were sampled so that autonomic modulation of the heart could be determined. The methodological differences between phase 1 and phase 2 and 3, were (respectively); the frequency of cognitive assessments (five vs. three), the samples used (15 schoolboy vs. 16 academy batters), hydration protocols (250ml of Energade vs. water ad libitum) and a singular change in a physical dependent variable (batting accuracy vs. vertical jump). In schoolboy and academy batters, the prolonged batting simulation placed significant strain on the cardiovascular and muscular subsystems; increasing heart rate (p<0.01), decreasing body mass (p<0.01) and deteriorating sprint performance (p<0.01) over time. In each sample, batters’ perceived exertion increased significantly (p<0.01) and exertion was highest in the final over of the protocol. Interestingly, the changes in cardiovascular and muscular responses were larger in schoolboy batters. While the cognitive performance decrements over time were not significant in academy batters (p>0.05; d<0.2), the magnitude of impairment in psychomotor function (p>0.05; d = 0.37), visual attention (p>0.05; d = 0.56), working memory (p>0.05; d = 0.61) and executive function (p>0.05; d = 0.58) was larger in schoolboy batters. In both samples, the simulation altered the modulation of heart rate significantly. Heart rate variability decreased linearly with time spent batting (p<0.01; d>0.8). During cognitive assessments, heart rate variability increased with time-on-task, where responses were significantly higher (p<0.05) in the last task of the battery compared to the first. Importantly, the results of the retest phase were the same as in the test phase and only two condition effects were observed; (i) heart rate (retest lower: p<0.04;d = 0.39), (ii) body mass (retest lower: p<0.03;d = 0.09). A task-related condition effect in heart rate variability (PNN30) was also observed (retest higher: p<0.03; d = not calculated). Resultantly, the test-retest reliability of phase 2 and 3 was high. The results indicate that prolonged intermittent batting at an intensity of 64-77 %HRmax impaired cognitive functioning in amateur batters. However, the cardiovascular and muscular strain induced by prolonged intermittent batting and its effects on cognitive functioning are mediated by intrinsic and extrinsic factors (age, training status, playing experience and hydration). Therefore, while prolonged batting has similar effects on cognitive functioning as acute bouts of physical activity, they do not share the same relationship. The author hypothesises that the continuous cognitive component inherent in prolonged batting mitigates the beneficial effects of physical activity, as demonstrated previously. Future research is needed to elucidate this relationship. Additionally, player experience affects the way in which batters regulate performance while batting; which also affects the rate of and magnitude of impairment during batting. Finally, the methodological limitations of this study provide direction for future research into batting.
- Full Text:
- Date Issued: 2017
- Authors: Goble, David
- Date: 2017
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket players -- Physiology , Cricket players -- Health and hygiene , Cognition -- Testing , Neurophysiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/40725 , vital:25020
- Description: No cognitive study has implemented an exercise modality that requires both physical effort and cognitive control, therefore, the effects of such exercise are unknown. Additionally, no studies have investigated how prolonged batting impacts cognitive functioning nor how physical responses and cognitive functioning are related while batting. At intensities of 6070 percent heart rate maximum, acute and prolonged bouts of physical activity have been shown to improve cognitive functioning. At higher intensities, the beneficial effects are minimal and in some cases performance is impaired. Therefore, the aim of this investigation was to determine how prolonged intermittent batting (a task that requires high muscular and cardiovascular loads but also continuous cognitive control) affects cognitive, physiological, physical and biophysical responses in amateur batters. Further aims included to test the reliability of the method employed in assessing these responses. To answer this question, the investigation was separated into three studies: phase 1 (a large-scale pilot) and phase 2 and 3 (a repeated measures test-retest hypothesis). In each phase, batters completed the 30 over BATEX simulation, which replicated the demands of scoring a one-day international century. To establish physiological, physical and perceptual strain; heart rate, sprint times and perceived exertion data were collected each over. Changes in body mass over time were compared to determine the effects of fluid loss on cognitive performance. Before, during and after the simulation, psychomotor function, visual attention, working memory, visual learning and memory as well as executive functions were assessed (CogState brief test battery). During cognitive assessments, heart rate and heart rate variability parameters were sampled so that autonomic modulation of the heart could be determined. The methodological differences between phase 1 and phase 2 and 3, were (respectively); the frequency of cognitive assessments (five vs. three), the samples used (15 schoolboy vs. 16 academy batters), hydration protocols (250ml of Energade vs. water ad libitum) and a singular change in a physical dependent variable (batting accuracy vs. vertical jump). In schoolboy and academy batters, the prolonged batting simulation placed significant strain on the cardiovascular and muscular subsystems; increasing heart rate (p<0.01), decreasing body mass (p<0.01) and deteriorating sprint performance (p<0.01) over time. In each sample, batters’ perceived exertion increased significantly (p<0.01) and exertion was highest in the final over of the protocol. Interestingly, the changes in cardiovascular and muscular responses were larger in schoolboy batters. While the cognitive performance decrements over time were not significant in academy batters (p>0.05; d<0.2), the magnitude of impairment in psychomotor function (p>0.05; d = 0.37), visual attention (p>0.05; d = 0.56), working memory (p>0.05; d = 0.61) and executive function (p>0.05; d = 0.58) was larger in schoolboy batters. In both samples, the simulation altered the modulation of heart rate significantly. Heart rate variability decreased linearly with time spent batting (p<0.01; d>0.8). During cognitive assessments, heart rate variability increased with time-on-task, where responses were significantly higher (p<0.05) in the last task of the battery compared to the first. Importantly, the results of the retest phase were the same as in the test phase and only two condition effects were observed; (i) heart rate (retest lower: p<0.04;d = 0.39), (ii) body mass (retest lower: p<0.03;d = 0.09). A task-related condition effect in heart rate variability (PNN30) was also observed (retest higher: p<0.03; d = not calculated). Resultantly, the test-retest reliability of phase 2 and 3 was high. The results indicate that prolonged intermittent batting at an intensity of 64-77 %HRmax impaired cognitive functioning in amateur batters. However, the cardiovascular and muscular strain induced by prolonged intermittent batting and its effects on cognitive functioning are mediated by intrinsic and extrinsic factors (age, training status, playing experience and hydration). Therefore, while prolonged batting has similar effects on cognitive functioning as acute bouts of physical activity, they do not share the same relationship. The author hypothesises that the continuous cognitive component inherent in prolonged batting mitigates the beneficial effects of physical activity, as demonstrated previously. Future research is needed to elucidate this relationship. Additionally, player experience affects the way in which batters regulate performance while batting; which also affects the rate of and magnitude of impairment during batting. Finally, the methodological limitations of this study provide direction for future research into batting.
- Full Text:
- Date Issued: 2017
A housing affordability and tenure of choice quantum deliverable model in South Africa
- Authors: Kabundu, Emmanuel Kizito
- Date: 2020
- Subjects: Housing -- Prices -- South Africa Housing -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49606 , vital:41740
- Description: The aim of this research was to develop a model that practically determines the tenure of choice and affordability of households in South Africa, which will thus help towards informed decision making by analysts and housing officials. Presently, there is no clear systematic means (except for simplistic ratios) of determining the degree of the effect of changes in the housing market (such as implemented policies) on the tenure of choice and affordability decisions of households. The research set out to improve upon the usage of ratios by basing its analysis on the theoretical underpinnings of both user costs of occupancy and an assumption of endogeneity between tenure of choice and affordability. The research used the general household survey data from Statistics South Africa for the analysis and validation. Generalized joint binary regression (on assumption of endogeneity between tenure of choice and affordability) was used as a check against the user costs of occupancy modelling. An independent market analysis carried out showed that South Africa has consistently faced increasing problems of acute housing shortages and housing affordability. Never the less, apart from subsidy programs, the option to promote renting, coupled with use of innovative building technologies showed promise of significantly alleviating these problems. More living space is especially more vital than ever, amid the current crisis of COVID-19 pademic. Statistical tests indicated strong evidence suggesting that the developed user costs of occupancy model (dynamic tenure model) is reliable at correctly recovering the tenure statuses of the households, with its recovery rates being better than those of the regression model. Both models provided useful unique, but different insights into the housing market and also correctly predicted the behavioural patterns of South African housing markets, such as significantly worsening affordability, and a market that is biased towards home ownership. The analysis also showed that affordability and tenure of choice were significantly affected by locational factors, household characteristics (such as race and age of household head), and most significantly, the age of the household head (which is a proxy to household income). The research successfully met its goal of model building but also recognized the need to merge these two models (dynamic tenure model and the regression model) into one model for more comprehensive housing related analysis. The research also recognized a need to fully operationalize the optimization, Monte Carlo and parallelization modules in order to improve the practical usefulness and effectiveness of the model. The significance of the study is that it it underpins the basis for proper tenure and affordability analysis, by assuming endogeneity between the two (2), and provides a modelling framework based on these criteria, that are useful for meaningful housing market analysis.
- Full Text:
- Date Issued: 2020
- Authors: Kabundu, Emmanuel Kizito
- Date: 2020
- Subjects: Housing -- Prices -- South Africa Housing -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49606 , vital:41740
- Description: The aim of this research was to develop a model that practically determines the tenure of choice and affordability of households in South Africa, which will thus help towards informed decision making by analysts and housing officials. Presently, there is no clear systematic means (except for simplistic ratios) of determining the degree of the effect of changes in the housing market (such as implemented policies) on the tenure of choice and affordability decisions of households. The research set out to improve upon the usage of ratios by basing its analysis on the theoretical underpinnings of both user costs of occupancy and an assumption of endogeneity between tenure of choice and affordability. The research used the general household survey data from Statistics South Africa for the analysis and validation. Generalized joint binary regression (on assumption of endogeneity between tenure of choice and affordability) was used as a check against the user costs of occupancy modelling. An independent market analysis carried out showed that South Africa has consistently faced increasing problems of acute housing shortages and housing affordability. Never the less, apart from subsidy programs, the option to promote renting, coupled with use of innovative building technologies showed promise of significantly alleviating these problems. More living space is especially more vital than ever, amid the current crisis of COVID-19 pademic. Statistical tests indicated strong evidence suggesting that the developed user costs of occupancy model (dynamic tenure model) is reliable at correctly recovering the tenure statuses of the households, with its recovery rates being better than those of the regression model. Both models provided useful unique, but different insights into the housing market and also correctly predicted the behavioural patterns of South African housing markets, such as significantly worsening affordability, and a market that is biased towards home ownership. The analysis also showed that affordability and tenure of choice were significantly affected by locational factors, household characteristics (such as race and age of household head), and most significantly, the age of the household head (which is a proxy to household income). The research successfully met its goal of model building but also recognized the need to merge these two models (dynamic tenure model and the regression model) into one model for more comprehensive housing related analysis. The research also recognized a need to fully operationalize the optimization, Monte Carlo and parallelization modules in order to improve the practical usefulness and effectiveness of the model. The significance of the study is that it it underpins the basis for proper tenure and affordability analysis, by assuming endogeneity between the two (2), and provides a modelling framework based on these criteria, that are useful for meaningful housing market analysis.
- Full Text:
- Date Issued: 2020
A knowledge-oriented, context-sensitive architectural framework for service deployment in marginalized rural communities
- Authors: Thinyane, Mamello P
- Date: 2009
- Subjects: Information technology Expert systems (Computer science) Software architecture User interfaces (Computer systems) Ethnoscience Social networks Rural development Technical assistance -- Developing countries Information networks -- Developing countries
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4599 , http://hdl.handle.net/10962/d1004843
- Description: The notion of a global knowledge society is somewhat of a misnomer due to the fact that large portions of the global community are not participants in this global knowledge society which is driven, shaped by and socio-technically biased towards a small fraction of the global population. Information and Communication Technology (ICT) is culture-sensitive and this is a dynamic that is largely ignored in the majority of ICT for Development (ICT4D) interventions, leading to the technological determinism flaw and ultimately a failure of the undertaken projects. The deployment of ICT solutions, in particular in the context of ICT4D, must be informed by the cultural and socio-technical profile of the deployment environments and solutions themselves must be developed with a focus towards context-sensitivity and ethnocentricity. In this thesis, we investigate the viability of a software architectural framework for the development of ICT solutions that are context-sensitive and ethnocentric1, and so aligned with the cultural and social dynamics within the environment of deployment. The conceptual framework, named PIASK, defines five tiers (presentation, interaction, access, social networking, and knowledge base) which allow for: behavioural completeness of the layer components; a modular and functionally decoupled architecture; and the flexibility to situate and contextualize the developed applications along the dimensions of the User Interface (UI), interaction modalities, usage metaphors, underlying Indigenous Knowledge (IK), and access protocols. We have developed a proof-of-concept service platform, called KnowNet, based on the PIASK architecture. KnowNet is built around the knowledge base layer, which consists of domain ontologies that encapsulate the knowledge in the platform, with an intrinsic flexibility to access secondary knowledge repositories. The domain ontologies constructed (as examples) are for the provisioning of eServices to support societal activities (e.g. commerce, health, agriculture, medicine) within a rural and marginalized area of Dwesa, in the Eastern Cape province of South Africa. The social networking layer allows for situating the platform within the local social systems. Heterogeneity of user profiles and multiplicity of end-user devices are handled through the access and the presentation components, and the service logic is implemented by the interaction components. This services platform validates the PIASK architecture for end-to-end provisioning of multi-modal, heterogeneous, ontology-based services. The development of KnowNet was informed on one hand by the latest trends within service architectures, semantic web technologies and social applications, and on the other hand by the context consideration based on the profile (IK systems dynamics, infrastructure, usability requirements) of the Dwesa community. The realization of the service platform is based on the JADE Multi-Agent System (MAS), and this shows the applicability and adequacy of MAS’s for service deployment in a rural context, at the same time providing key advantages such as platform fault-tolerance, robustness and flexibility. While the context of conceptualization of PIASK and the implementation of KnowNet is that of rurality and of ICT4D, the applicability of the architecture extends to other similarly heterogeneous and context-sensitive domains. KnowNet has been validated for functional and technical adequacy, and we have also undertaken an initial prevalidation for social context sensitivity. We observe that the five tier PIASK architecture provides an adequate framework for developing context-sensitive and ethnocentric software: by functionally separating and making explicit the social networking and access tier components, while still maintaining the traditional separation of presentation, business logic and data components.
- Full Text:
- Date Issued: 2009
- Authors: Thinyane, Mamello P
- Date: 2009
- Subjects: Information technology Expert systems (Computer science) Software architecture User interfaces (Computer systems) Ethnoscience Social networks Rural development Technical assistance -- Developing countries Information networks -- Developing countries
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4599 , http://hdl.handle.net/10962/d1004843
- Description: The notion of a global knowledge society is somewhat of a misnomer due to the fact that large portions of the global community are not participants in this global knowledge society which is driven, shaped by and socio-technically biased towards a small fraction of the global population. Information and Communication Technology (ICT) is culture-sensitive and this is a dynamic that is largely ignored in the majority of ICT for Development (ICT4D) interventions, leading to the technological determinism flaw and ultimately a failure of the undertaken projects. The deployment of ICT solutions, in particular in the context of ICT4D, must be informed by the cultural and socio-technical profile of the deployment environments and solutions themselves must be developed with a focus towards context-sensitivity and ethnocentricity. In this thesis, we investigate the viability of a software architectural framework for the development of ICT solutions that are context-sensitive and ethnocentric1, and so aligned with the cultural and social dynamics within the environment of deployment. The conceptual framework, named PIASK, defines five tiers (presentation, interaction, access, social networking, and knowledge base) which allow for: behavioural completeness of the layer components; a modular and functionally decoupled architecture; and the flexibility to situate and contextualize the developed applications along the dimensions of the User Interface (UI), interaction modalities, usage metaphors, underlying Indigenous Knowledge (IK), and access protocols. We have developed a proof-of-concept service platform, called KnowNet, based on the PIASK architecture. KnowNet is built around the knowledge base layer, which consists of domain ontologies that encapsulate the knowledge in the platform, with an intrinsic flexibility to access secondary knowledge repositories. The domain ontologies constructed (as examples) are for the provisioning of eServices to support societal activities (e.g. commerce, health, agriculture, medicine) within a rural and marginalized area of Dwesa, in the Eastern Cape province of South Africa. The social networking layer allows for situating the platform within the local social systems. Heterogeneity of user profiles and multiplicity of end-user devices are handled through the access and the presentation components, and the service logic is implemented by the interaction components. This services platform validates the PIASK architecture for end-to-end provisioning of multi-modal, heterogeneous, ontology-based services. The development of KnowNet was informed on one hand by the latest trends within service architectures, semantic web technologies and social applications, and on the other hand by the context consideration based on the profile (IK systems dynamics, infrastructure, usability requirements) of the Dwesa community. The realization of the service platform is based on the JADE Multi-Agent System (MAS), and this shows the applicability and adequacy of MAS’s for service deployment in a rural context, at the same time providing key advantages such as platform fault-tolerance, robustness and flexibility. While the context of conceptualization of PIASK and the implementation of KnowNet is that of rurality and of ICT4D, the applicability of the architecture extends to other similarly heterogeneous and context-sensitive domains. KnowNet has been validated for functional and technical adequacy, and we have also undertaken an initial prevalidation for social context sensitivity. We observe that the five tier PIASK architecture provides an adequate framework for developing context-sensitive and ethnocentric software: by functionally separating and making explicit the social networking and access tier components, while still maintaining the traditional separation of presentation, business logic and data components.
- Full Text:
- Date Issued: 2009
A leadership development model to enhance ethical governance in South Africa
- Authors: Els, Ryno Juan
- Date: 2019
- Subjects: Leadership -- South Africa , Public administration -- Moral and ethical aspects Corporate governance Business ethics -- South Africa Africa Professional ethics Organizational behavior -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/39863 , vital:35489
- Description: From the United States of America’s White House to the Vatican in Vatican City, from Harare, Zimbabwe to the Union buildings in South Africa, to large organisations like Volkswagen, BP and KPMG, leadership failures are prolific. Globalised and local leadership failures and scandals are plagued by narcissistic, toxic, corrupt and dishonest behaviour by heads of state, CEOs and clergy. The effect of executive leadership failures is that they set the tone for a corrupt culture that spirals negatively down to grass-roots level. Unethical leadership in organisations manifests in various ways including misconduct, deception and cheating. Apart from regular exposés of leadership scandals globally, there has been a notable increase in ethical leadership derailments caused by unethical behaviour. The question is why leaders, who are considered to understand value-based morality, engage in unethical behaviour when confronted with the opportunity. In recent, empirical research in behavioural ethics and moral psychology, it was found that morally sound leaders often indulge in unethical behaviour. Unethical leadership behaviour includes misdemeanours in tax returns, overstating performance, inflating business expense accounts, involvement in corruption, counter-productive work behaviour, being morally disengaged and being untruthful during negotiations. Recent research indicates that unethical leadership leads to an increase in poor governance and propels vicious cycles that have a negative impact on human development, economic growth and the environment. This research study includes traditional and contemporary leadership theories that have been evaluated as well as an in-depth discussion of the necessity and importance of ethical governance. An innovative, ethical leadership development model has been designed and aligned with servant, ethical, authentic and integrated leadership styles where spiritual, cultural and emotional intelligences play a significant role in leadership maturity. A fresh perspective on the King IV Report (2016) as an international benchmark together with other authoritative literature and case studies of unethical governance have been discussed to shed light on the latest leadership theories and ethics in the 21st century. The findings of this study have been tested statistically by means of structural equation modelling (SEM). The findings confirmed empirically that accountability, stakeholders’ interests and the regulatory environment need to be implemented by ethical leaders in order to enhance ethical governance. The lack of a practical, outcome-based, leadership development model provided an opportunity to develop an ethical leadership development model that would have a positive impact on ethical governance, thereby contributing to the body of knowledge.
- Full Text:
- Date Issued: 2019
- Authors: Els, Ryno Juan
- Date: 2019
- Subjects: Leadership -- South Africa , Public administration -- Moral and ethical aspects Corporate governance Business ethics -- South Africa Africa Professional ethics Organizational behavior -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/39863 , vital:35489
- Description: From the United States of America’s White House to the Vatican in Vatican City, from Harare, Zimbabwe to the Union buildings in South Africa, to large organisations like Volkswagen, BP and KPMG, leadership failures are prolific. Globalised and local leadership failures and scandals are plagued by narcissistic, toxic, corrupt and dishonest behaviour by heads of state, CEOs and clergy. The effect of executive leadership failures is that they set the tone for a corrupt culture that spirals negatively down to grass-roots level. Unethical leadership in organisations manifests in various ways including misconduct, deception and cheating. Apart from regular exposés of leadership scandals globally, there has been a notable increase in ethical leadership derailments caused by unethical behaviour. The question is why leaders, who are considered to understand value-based morality, engage in unethical behaviour when confronted with the opportunity. In recent, empirical research in behavioural ethics and moral psychology, it was found that morally sound leaders often indulge in unethical behaviour. Unethical leadership behaviour includes misdemeanours in tax returns, overstating performance, inflating business expense accounts, involvement in corruption, counter-productive work behaviour, being morally disengaged and being untruthful during negotiations. Recent research indicates that unethical leadership leads to an increase in poor governance and propels vicious cycles that have a negative impact on human development, economic growth and the environment. This research study includes traditional and contemporary leadership theories that have been evaluated as well as an in-depth discussion of the necessity and importance of ethical governance. An innovative, ethical leadership development model has been designed and aligned with servant, ethical, authentic and integrated leadership styles where spiritual, cultural and emotional intelligences play a significant role in leadership maturity. A fresh perspective on the King IV Report (2016) as an international benchmark together with other authoritative literature and case studies of unethical governance have been discussed to shed light on the latest leadership theories and ethics in the 21st century. The findings of this study have been tested statistically by means of structural equation modelling (SEM). The findings confirmed empirically that accountability, stakeholders’ interests and the regulatory environment need to be implemented by ethical leaders in order to enhance ethical governance. The lack of a practical, outcome-based, leadership development model provided an opportunity to develop an ethical leadership development model that would have a positive impact on ethical governance, thereby contributing to the body of knowledge.
- Full Text:
- Date Issued: 2019
A lean production approach to materials management in the Nigerian construction industry
- Authors: Albert, Idowu
- Date: 2020
- Subjects: Materials management , Lean manufacturing Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46008 , vital:39408
- Description: The Nigerian Construction Industry faces a problem of poor materials management that leads to, among other things, materials waste, poor quality of work, poor materials flow, project delay and cost overrun. Overcoming these challenges, requires the rethinking the current modus operandi of the Nigerian construction industry. One such method that has been espoused as having potential to improve materials management, and associated challenges is ‘lean production’. This research aimed at deciphering the lean approach to production management with a view of extracting its utility in enhancing materials management in the construction industry. The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed. The research activities included a comprehensive review of the related literature and study of selected cases. Abuja, the Federal capital territory of Nigeria was the selected geographical scope of the research. Ten case studies were purposefully selected for the study. The research instrument was a tick box used for direct observation. The study revealed that poor materials management has a negative effect on the materials management plan. Moreover, mixing of waste at the site, negates the effort for identification of materials waste streams, and makes it difficult to account for materials waste, as well as implementing a materials waste management policy on sites. The research also found that poor materials management has a significant effect (high, moderate or low) on materials waste, quality of work, materials flow, productivity, project delay, project profitability and accounting for materials. The research has developed a conceptual model for a lean production approach to materials management based on the results and informed by the theoretical framework. The study has achieved its aim of establishing an understanding of the lean production approach to materials management in the Nigerian construction industry. The study recommends that construction professionals should be well informed on the effects of poor materials management.
- Full Text:
- Date Issued: 2020
- Authors: Albert, Idowu
- Date: 2020
- Subjects: Materials management , Lean manufacturing Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46008 , vital:39408
- Description: The Nigerian Construction Industry faces a problem of poor materials management that leads to, among other things, materials waste, poor quality of work, poor materials flow, project delay and cost overrun. Overcoming these challenges, requires the rethinking the current modus operandi of the Nigerian construction industry. One such method that has been espoused as having potential to improve materials management, and associated challenges is ‘lean production’. This research aimed at deciphering the lean approach to production management with a view of extracting its utility in enhancing materials management in the construction industry. The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed. The research activities included a comprehensive review of the related literature and study of selected cases. Abuja, the Federal capital territory of Nigeria was the selected geographical scope of the research. Ten case studies were purposefully selected for the study. The research instrument was a tick box used for direct observation. The study revealed that poor materials management has a negative effect on the materials management plan. Moreover, mixing of waste at the site, negates the effort for identification of materials waste streams, and makes it difficult to account for materials waste, as well as implementing a materials waste management policy on sites. The research also found that poor materials management has a significant effect (high, moderate or low) on materials waste, quality of work, materials flow, productivity, project delay, project profitability and accounting for materials. The research has developed a conceptual model for a lean production approach to materials management based on the results and informed by the theoretical framework. The study has achieved its aim of establishing an understanding of the lean production approach to materials management in the Nigerian construction industry. The study recommends that construction professionals should be well informed on the effects of poor materials management.
- Full Text:
- Date Issued: 2020
A lignocellulolytic enzyme system for fruit waste degradation : commercial enzyme mixture synergy and bioreactor design
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Date Issued: 2014
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Date Issued: 2014