Biological activities of medicinal plants traditionally used to treat Septicaemia in the Eastern Cape, South Africa
- Authors: Chinyama, Robert Fred
- Date: 2009
- Subjects: Materia medica, Vegetable -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10119 , http://hdl.handle.net/10948/1274 , Materia medica, Vegetable -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape
- Description: Over the past 25 years, there has been a resurgence of worldwide scientific research in the fields of ethnopharmacology. The Western world has acknowledged the continued use of traditional medicines by the majority of third world countries, and the need for novel drug development. Hence, much of the pharmaceutical research in recent years has focused on the ethnobotanical approach to drug discovery (Light et al., 2005). In South Africa, as in most developing parts of the world, traditional herbal medicine still forms the backbone of rural healthcare. The government health services in South Africa provide only western medical care although the majority of the population consult traditional healers for some or all of their healthcare needs (McGaw et al., 2005). Medicinal plants like Harpephyllum caffrum are used as blood purifiers or emetics (Watt and Breyer-Brandwijk, 1962), and also for treating acne and eczema. The antimicrobial activity of this plant can be used to treat septicaemia, which is ranked the sixth leading cause of death among neonates and the eighth leading cause of death for infants through the first year of life (Heron, 2007). In this study, the plants investigated for antimicrobial activity were Harpephyllum caffrum, Hermannia cuneifolia, Chironia baccifera, Rhigozum obovatum, Felicia muricata and Pentzia incana. These plants were tested against ATTC (American Type Culture Collection) strains and microorganisms isolated from clinical isolates of patients suffering from septicaemia. The assay methods used included the agar diffusion method using the Mast multipoint inoculator, the microtitre dilution method were used to determine the minimum inhibitory concentration, thin layer chromatography fingerprints accompanied by bioautographic assay were used to detect the inhibition of bacterial growth by active compounds separated from plant extracts and the Ames test was required to assess the possibility of bacterial mutagenesis upon the exposure to plant extracts which can lead to carcinogenicity. In agar diffusion method, extracts of Harpephyllum caffrum inhibited nine strains of Candida albicans, three species of Acinetobacter and four strains of E.faecalis. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus and three strains of Staphylococcus aureus. Extracts of Chironia baccifera inhibited one strain of Acinetobacter and five strains of E.faecalis. Extracts of plants Rhigozum obovatum, Felicia muricata, and Pentzia incana showed no antimicrobial activity. In the microtitre dilution method used to determine the minimum inhibitory concentration (MIC), the results were different from the agar diffusion method. More activity was observed. Extracts of Harpephyllum caffrum inhibited three strains of E.coli, six strains of S.aureus, three species of Acinetobacter and one strain of Klebsiella pneumonia. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus, three strains of S.aureus, two strains of K.oxytoca and one species of Acinetobacter. Extracts of Chironia baccifera inhibited three strains of S.aureus, one strain of MRSA, one species of Acinetobacter and one strain of S.haemolyticus. The MIC values ranged from 0.049 to 6.25mg/ml. Using the thin layer chromatography fingerprints, bioautography showed the presence of various inhibitory chemical compounds. Methanol and acetone extracts of Harpephyllum caffrum, separated very well and showed various inhibition zones on exposure to Candida albicans, Enterococcus faecalis and Staphylococcus aureus. The different inhibition zones were recorded as Rf In the Ames test (Maron and Ames, 1983) the methanol and acetone extracts of Harpephyllum caffrum and Hermannia cuneifolia were negative which means they were devoid of any mutagenic properties. Methanol extracts of Harpephyllum caffrum showed similar results in the Ames assay as reported by Verschaeve and Van Staden (2008). values ranging from 0.25 to 0.95. The zones indicate the different inhibiting chemical compounds present in the plant. Petroleum ether, ethyl acetate, chloroform and formic acid were the solvents used in the assay in the ratio 8:7:5:1, respectively. Establishing the antimicrobial activity of these plants contribute to the systematic scientific investigation of indigenous South African medicinal plants.
- Full Text:
- Date Issued: 2009
- Authors: Chinyama, Robert Fred
- Date: 2009
- Subjects: Materia medica, Vegetable -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10119 , http://hdl.handle.net/10948/1274 , Materia medica, Vegetable -- South Africa -- Eastern Cape , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Herbs -- Therapeutic use -- South Africa -- Eastern Cape
- Description: Over the past 25 years, there has been a resurgence of worldwide scientific research in the fields of ethnopharmacology. The Western world has acknowledged the continued use of traditional medicines by the majority of third world countries, and the need for novel drug development. Hence, much of the pharmaceutical research in recent years has focused on the ethnobotanical approach to drug discovery (Light et al., 2005). In South Africa, as in most developing parts of the world, traditional herbal medicine still forms the backbone of rural healthcare. The government health services in South Africa provide only western medical care although the majority of the population consult traditional healers for some or all of their healthcare needs (McGaw et al., 2005). Medicinal plants like Harpephyllum caffrum are used as blood purifiers or emetics (Watt and Breyer-Brandwijk, 1962), and also for treating acne and eczema. The antimicrobial activity of this plant can be used to treat septicaemia, which is ranked the sixth leading cause of death among neonates and the eighth leading cause of death for infants through the first year of life (Heron, 2007). In this study, the plants investigated for antimicrobial activity were Harpephyllum caffrum, Hermannia cuneifolia, Chironia baccifera, Rhigozum obovatum, Felicia muricata and Pentzia incana. These plants were tested against ATTC (American Type Culture Collection) strains and microorganisms isolated from clinical isolates of patients suffering from septicaemia. The assay methods used included the agar diffusion method using the Mast multipoint inoculator, the microtitre dilution method were used to determine the minimum inhibitory concentration, thin layer chromatography fingerprints accompanied by bioautographic assay were used to detect the inhibition of bacterial growth by active compounds separated from plant extracts and the Ames test was required to assess the possibility of bacterial mutagenesis upon the exposure to plant extracts which can lead to carcinogenicity. In agar diffusion method, extracts of Harpephyllum caffrum inhibited nine strains of Candida albicans, three species of Acinetobacter and four strains of E.faecalis. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus and three strains of Staphylococcus aureus. Extracts of Chironia baccifera inhibited one strain of Acinetobacter and five strains of E.faecalis. Extracts of plants Rhigozum obovatum, Felicia muricata, and Pentzia incana showed no antimicrobial activity. In the microtitre dilution method used to determine the minimum inhibitory concentration (MIC), the results were different from the agar diffusion method. More activity was observed. Extracts of Harpephyllum caffrum inhibited three strains of E.coli, six strains of S.aureus, three species of Acinetobacter and one strain of Klebsiella pneumonia. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus, three strains of S.aureus, two strains of K.oxytoca and one species of Acinetobacter. Extracts of Chironia baccifera inhibited three strains of S.aureus, one strain of MRSA, one species of Acinetobacter and one strain of S.haemolyticus. The MIC values ranged from 0.049 to 6.25mg/ml. Using the thin layer chromatography fingerprints, bioautography showed the presence of various inhibitory chemical compounds. Methanol and acetone extracts of Harpephyllum caffrum, separated very well and showed various inhibition zones on exposure to Candida albicans, Enterococcus faecalis and Staphylococcus aureus. The different inhibition zones were recorded as Rf In the Ames test (Maron and Ames, 1983) the methanol and acetone extracts of Harpephyllum caffrum and Hermannia cuneifolia were negative which means they were devoid of any mutagenic properties. Methanol extracts of Harpephyllum caffrum showed similar results in the Ames assay as reported by Verschaeve and Van Staden (2008). values ranging from 0.25 to 0.95. The zones indicate the different inhibiting chemical compounds present in the plant. Petroleum ether, ethyl acetate, chloroform and formic acid were the solvents used in the assay in the ratio 8:7:5:1, respectively. Establishing the antimicrobial activity of these plants contribute to the systematic scientific investigation of indigenous South African medicinal plants.
- Full Text:
- Date Issued: 2009
Breaking down subtle and implicit racial divides in higher education institutions : an educational management perspective
- Toni, Mademoiselle Noluthando
- Authors: Toni, Mademoiselle Noluthando
- Date: 2009
- Subjects: Racism in higher education -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9529 , http://hdl.handle.net/10948/876 , Racism in higher education -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth
- Description: This thesis examined the manifestations of the various forms of racism in a South African institution of higher learning, the Nelson Mandela Metropolitan University (NMMU). The study further attempted to confront racism from the perspective of finding ways in which human relations of a diversified higher education population could be improved. As the issue at hand in this study relates to racism, critical race theory (CRT) was explored in an attempt to understand different perceptions and ways of dealing with racial inequality. CRT recognizes the complexities of racism and the construction of race as a way of justifying political, economic and social inequality (Stovall, 2006:247). This understanding played a role in making sense of perceived racial discrimination which is also connected to gender, age and social class. CRT conceptual tools, such as stories and counter stories featured strongly in the data collection process. Understanding the relationships of power, race and racism, as advocated by CRT, was vital in the process of analyzing data, reporting on the findings, and the proposed recommendations. The empirical data and literature provided insight in the design of a ‘Wheel of Humanity’ which serves as a succinct portrayal of ideas that can work in nurturing acceptable, to better, human relations. The study revealed that Meta-stereotypes influenced the perceptions of racist attitudes, behaviours and practices. As much as overt forms of racism were reported as minimal, subtle and implicit forms still exist, and are aggravated by the ‘culture of power’ that is taken for granted. The success of initiatives designed for the purposes of going beyond race, and adopting a humane approach in instilling the principles of ubuntu, depends on changing attitudes and preconceived ideas.
- Full Text:
- Date Issued: 2009
- Authors: Toni, Mademoiselle Noluthando
- Date: 2009
- Subjects: Racism in higher education -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9529 , http://hdl.handle.net/10948/876 , Racism in higher education -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth
- Description: This thesis examined the manifestations of the various forms of racism in a South African institution of higher learning, the Nelson Mandela Metropolitan University (NMMU). The study further attempted to confront racism from the perspective of finding ways in which human relations of a diversified higher education population could be improved. As the issue at hand in this study relates to racism, critical race theory (CRT) was explored in an attempt to understand different perceptions and ways of dealing with racial inequality. CRT recognizes the complexities of racism and the construction of race as a way of justifying political, economic and social inequality (Stovall, 2006:247). This understanding played a role in making sense of perceived racial discrimination which is also connected to gender, age and social class. CRT conceptual tools, such as stories and counter stories featured strongly in the data collection process. Understanding the relationships of power, race and racism, as advocated by CRT, was vital in the process of analyzing data, reporting on the findings, and the proposed recommendations. The empirical data and literature provided insight in the design of a ‘Wheel of Humanity’ which serves as a succinct portrayal of ideas that can work in nurturing acceptable, to better, human relations. The study revealed that Meta-stereotypes influenced the perceptions of racist attitudes, behaviours and practices. As much as overt forms of racism were reported as minimal, subtle and implicit forms still exist, and are aggravated by the ‘culture of power’ that is taken for granted. The success of initiatives designed for the purposes of going beyond race, and adopting a humane approach in instilling the principles of ubuntu, depends on changing attitudes and preconceived ideas.
- Full Text:
- Date Issued: 2009
Causes and consequences of the shortage of electrical artisans at Eskom
- Authors: Toni, Thami
- Date: 2009
- Subjects: Underemployment , Manpower
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8730 , http://hdl.handle.net/10948/864 , Underemployment , Manpower
- Description: The aim of this research was to examine the causes and consequences of the shortage of electrical artisans at Eskom, using the Southern Region as a case study. Eskom used to be one of the leading public enterprises in the training of artisans to fulfil its own demand as well as to meet industry demand. This research reveals that this is no longer the case. Eskom Southern Region, a sub-division of Eskom Holdings, employs about 1700 employees. More than three quarters of these employees are employed in departments that utilise mostly electrical artisans. Natural attrition and the curtailment on the number of employees indentured and trained as electrical artisans has presented the Eskom Southern Region with a skills acquisition and retention challenge. Against this background, the study sought to discover how far Eskom Southern Region implements training and development interventions and recruitment and retention strategies in response to skill shortages. The study is based on a review of literature on skill shortages, a questionnaire opinion survey on skill shortages completed by employees at Eskom Southern Region, document study, and interviews with relevant stakeholders. The empirical study confirmed the findings of the research and skills shortages were identified for particular positions employing electrical artisans. The results show worsening skill shortages and hard-to-fill vacancies. The study proposes recommendations that encompass strategic responses, workplace-based strategies, and training-based strategies to address the shortage of electrical artisans.
- Full Text:
- Date Issued: 2009
- Authors: Toni, Thami
- Date: 2009
- Subjects: Underemployment , Manpower
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8730 , http://hdl.handle.net/10948/864 , Underemployment , Manpower
- Description: The aim of this research was to examine the causes and consequences of the shortage of electrical artisans at Eskom, using the Southern Region as a case study. Eskom used to be one of the leading public enterprises in the training of artisans to fulfil its own demand as well as to meet industry demand. This research reveals that this is no longer the case. Eskom Southern Region, a sub-division of Eskom Holdings, employs about 1700 employees. More than three quarters of these employees are employed in departments that utilise mostly electrical artisans. Natural attrition and the curtailment on the number of employees indentured and trained as electrical artisans has presented the Eskom Southern Region with a skills acquisition and retention challenge. Against this background, the study sought to discover how far Eskom Southern Region implements training and development interventions and recruitment and retention strategies in response to skill shortages. The study is based on a review of literature on skill shortages, a questionnaire opinion survey on skill shortages completed by employees at Eskom Southern Region, document study, and interviews with relevant stakeholders. The empirical study confirmed the findings of the research and skills shortages were identified for particular positions employing electrical artisans. The results show worsening skill shortages and hard-to-fill vacancies. The study proposes recommendations that encompass strategic responses, workplace-based strategies, and training-based strategies to address the shortage of electrical artisans.
- Full Text:
- Date Issued: 2009
Celebrity endorsements of branded apparel and its role in printed advertising
- Authors: Liu, Ziyu
- Date: 2009
- Subjects: Advertising -- Brand name products , Brand name products , Endorsements in advertising
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9363 , http://hdl.handle.net/10948/1178 , Advertising -- Brand name products , Brand name products , Endorsements in advertising
- Description: Purchasing is an important concept in the life of students. The decision whether to purchase branded apparel is hence a very important one. The 21st century student is less loyal and more demanding when choosing branded apparel. Marketers should understand how students evaluate celebrity endorsers when they appear in printed advertising and respond accordingly. The objective of the research is to find out how celebrity endorsed print advertisements affect Nelson Mandela Metropolitan University (NMMU) students’ purchase behaviour. The results of this study could assist marketers in improving the quality of their advertising and to more accurately meet the needs of this dynamic student market. A literature review was conducted to provide an understanding of the consumer purchasing behaviour and the role celebrity endorser played in printed advertisements. The empirical study was designed to assess the impact of the use of celebrity endorsements of printed advertisements targeted at NMMU students. The empirical findings showed that both male and female students indicated that the use of celebrity endorsers get their attention and created interest, and make advertisements more memorable. Males were more influenced than ii females. Moreover, both groups indicated that for a desired or familiar product, celebrity endorsers did not easily change their purchase decisions. It was also found that the use of pictures, colours and wording featured in the advertisements are important to students. The study proposes that marketers should continue to focus on effective marketing communications and establish whether a celebrity should be used. The correct selection of a celebrity endorser can help to create greater consumer persuasion.
- Full Text:
- Date Issued: 2009
- Authors: Liu, Ziyu
- Date: 2009
- Subjects: Advertising -- Brand name products , Brand name products , Endorsements in advertising
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9363 , http://hdl.handle.net/10948/1178 , Advertising -- Brand name products , Brand name products , Endorsements in advertising
- Description: Purchasing is an important concept in the life of students. The decision whether to purchase branded apparel is hence a very important one. The 21st century student is less loyal and more demanding when choosing branded apparel. Marketers should understand how students evaluate celebrity endorsers when they appear in printed advertising and respond accordingly. The objective of the research is to find out how celebrity endorsed print advertisements affect Nelson Mandela Metropolitan University (NMMU) students’ purchase behaviour. The results of this study could assist marketers in improving the quality of their advertising and to more accurately meet the needs of this dynamic student market. A literature review was conducted to provide an understanding of the consumer purchasing behaviour and the role celebrity endorser played in printed advertisements. The empirical study was designed to assess the impact of the use of celebrity endorsements of printed advertisements targeted at NMMU students. The empirical findings showed that both male and female students indicated that the use of celebrity endorsers get their attention and created interest, and make advertisements more memorable. Males were more influenced than ii females. Moreover, both groups indicated that for a desired or familiar product, celebrity endorsers did not easily change their purchase decisions. It was also found that the use of pictures, colours and wording featured in the advertisements are important to students. The study proposes that marketers should continue to focus on effective marketing communications and establish whether a celebrity should be used. The correct selection of a celebrity endorser can help to create greater consumer persuasion.
- Full Text:
- Date Issued: 2009
Challenges faced by female managers in schools within the Nelson Mandela Metropole
- Authors: Paulsen, Shareen Erica
- Date: 2009
- Subjects: Women school principals , Women -- Education , Feminism and education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9528 , http://hdl.handle.net/10948/897 , Women school principals , Women -- Education , Feminism and education
- Description: This study seeks to identify and examine the challenges that female principals experience. Women are slowly climbing the promotional ladder within education, yet they experience many challenges. The fact that society has the perception that women are mothers and caregivers does not make the advancement of females easy. Although the GETT report (1996) made recommendations to ensure equality in education females are still vastly under-represented in managerial positions in education. The study was conducted from a feminine perspective. It is a qualitative case study and individual interviews, a focus group interview, observation and field notes were used to collect data. A total of three females were included in the study. Participants were purposefully selected. Two of the participants are from disadvantaged schools while the third one is an ex-Model C principal. A consent form was sent to all the participants, covering all ethical issues of voluntary participation, confidentiality and anonymity. The main question was the challenges faced by female managers in education. Having spent time with each of the principals the data in the form of field notes and transcripts were analysed. It was found that the three principals experienced similar challenges. Their responses did not always reflect what the literature said regarding the challenges. All three principals felt that more formal support structures from the DoE is needed. They mentioned that the following could be implemented to ensure that they are more effective and better prepared to face these challenges: Workshops; Mentoring and Networking; Financial Assistance; and, Capacity Building.
- Full Text:
- Date Issued: 2009
- Authors: Paulsen, Shareen Erica
- Date: 2009
- Subjects: Women school principals , Women -- Education , Feminism and education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9528 , http://hdl.handle.net/10948/897 , Women school principals , Women -- Education , Feminism and education
- Description: This study seeks to identify and examine the challenges that female principals experience. Women are slowly climbing the promotional ladder within education, yet they experience many challenges. The fact that society has the perception that women are mothers and caregivers does not make the advancement of females easy. Although the GETT report (1996) made recommendations to ensure equality in education females are still vastly under-represented in managerial positions in education. The study was conducted from a feminine perspective. It is a qualitative case study and individual interviews, a focus group interview, observation and field notes were used to collect data. A total of three females were included in the study. Participants were purposefully selected. Two of the participants are from disadvantaged schools while the third one is an ex-Model C principal. A consent form was sent to all the participants, covering all ethical issues of voluntary participation, confidentiality and anonymity. The main question was the challenges faced by female managers in education. Having spent time with each of the principals the data in the form of field notes and transcripts were analysed. It was found that the three principals experienced similar challenges. Their responses did not always reflect what the literature said regarding the challenges. All three principals felt that more formal support structures from the DoE is needed. They mentioned that the following could be implemented to ensure that they are more effective and better prepared to face these challenges: Workshops; Mentoring and Networking; Financial Assistance; and, Capacity Building.
- Full Text:
- Date Issued: 2009
Chang liver cell line as a model for Type II Diabetes in the liver and possible reversal of this condition by an indigenous medicinal plant
- Authors: Williams, Saralene Iona
- Date: 2009
- Subjects: Diabetes -- Alternative treatment , Medicinal plants , Traditional medicine , Liver -- Diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10339 , http://hdl.handle.net/10948/d1016179
- Description: The incidence of Type 2 Diabetes Mellittus (T2DM) is increasing world wide. In Africa the limited access to health care and the insidious course of the disease lead to more severe illness and diabetic complications. There is a need to find alternative approaches to treatment and prevention that address the problems and needs of Africa. Sutherlandia frutescens (S.frutescens) is a traditional herbal plant with known anti-diabetic properties, the precise mechanism of action of S.frutescens is not known. In order to develop new approaches for treatment and prevention of T2DM the pathophysiology of T2DM must be understood. T2DM is the final outcome of a multi-organ disease characterized by early defects in muscle, adipocytes, hepatocytes and pancreatic β-cells. In this study the role of the liver was investigated because of its central role in glucose and lipid metabolism. It is hard to differentiate between all the influences in an in vivo model, so the aim of this study was to develop an in vitro model of T2DM in Chang liver cells and to determine if S.frutescens can reverse the state of insulin resistance in this model. Different culture media conditions were screened to identify a method that can be used as the T2DM model in Chang liver cells. Serum free medium (MCBD-201) supplemented with human diabetic serum, (2.5%-10%), high insulin concentrations (0.1μM-1μM), high fructose concentrations (1-10mM). and a combination of high insulin and high fructose was used for this screening. Chang liver cells cultured in MCBD-201 medium supplemented with 1mM fructose and 0.1μM insulin showed reduced glucose uptake and increased lipid accumulation. The effect of two S.frutescens extracts, two anti-diabetic drugs, metformin and ciglitazone, and a hypolipidemic drug ciprofibrate were determined and shown to increase glucose uptake and reduce lipid accumulation. It was postulated that exposing the cells to excess nutrients in the form of high fructose would stimulate the cells to become adipogenic and accumulate lipids, which would interfere with the glucose uptake and induce insulin resistance. Gene expression of PPARγ, PPARα, and SREBP-1 transcription factors regulating lipid metabolism was determined in Chang liver cells cultured in insulin resistance inducing medium over a 48 hour time course. The expression of PPARγ, known to stimulate adipogenesis was increased after 6, 24 and 48 hours of exposure (P(H1)<0.0001). The expression of PPARα, known to stimulate β-oxidation expression, was significantly decreased after 24 hours of exposure (P(H1)<0.0001). The presence of the plant extracts in the insulin resistance inducing media protect against this increase in adipogenesis and decrease in β-oxidation after 48 hours of exposure by increasing PPARα expression and decreasing PPARγ expression. A PCR Array was performed which identified 32 more potential molecular targets of S.frutescens. Five of the 32 targets identified with the PCR Array were validated using qRT-PCR. These genes play a role in lipid and glucose metabolism and protection against oxidative stress and inflammation. In summary a cellular model of insulin resistace in hepatocytes has been established and the capacity of S.frutescens to reverse this process has been demonstrated by acting as a dual PPARγ/α agonist. New genes have been identified in the development of insulin resistance and as targets of S.frutescens.
- Full Text:
- Date Issued: 2009
- Authors: Williams, Saralene Iona
- Date: 2009
- Subjects: Diabetes -- Alternative treatment , Medicinal plants , Traditional medicine , Liver -- Diseases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10339 , http://hdl.handle.net/10948/d1016179
- Description: The incidence of Type 2 Diabetes Mellittus (T2DM) is increasing world wide. In Africa the limited access to health care and the insidious course of the disease lead to more severe illness and diabetic complications. There is a need to find alternative approaches to treatment and prevention that address the problems and needs of Africa. Sutherlandia frutescens (S.frutescens) is a traditional herbal plant with known anti-diabetic properties, the precise mechanism of action of S.frutescens is not known. In order to develop new approaches for treatment and prevention of T2DM the pathophysiology of T2DM must be understood. T2DM is the final outcome of a multi-organ disease characterized by early defects in muscle, adipocytes, hepatocytes and pancreatic β-cells. In this study the role of the liver was investigated because of its central role in glucose and lipid metabolism. It is hard to differentiate between all the influences in an in vivo model, so the aim of this study was to develop an in vitro model of T2DM in Chang liver cells and to determine if S.frutescens can reverse the state of insulin resistance in this model. Different culture media conditions were screened to identify a method that can be used as the T2DM model in Chang liver cells. Serum free medium (MCBD-201) supplemented with human diabetic serum, (2.5%-10%), high insulin concentrations (0.1μM-1μM), high fructose concentrations (1-10mM). and a combination of high insulin and high fructose was used for this screening. Chang liver cells cultured in MCBD-201 medium supplemented with 1mM fructose and 0.1μM insulin showed reduced glucose uptake and increased lipid accumulation. The effect of two S.frutescens extracts, two anti-diabetic drugs, metformin and ciglitazone, and a hypolipidemic drug ciprofibrate were determined and shown to increase glucose uptake and reduce lipid accumulation. It was postulated that exposing the cells to excess nutrients in the form of high fructose would stimulate the cells to become adipogenic and accumulate lipids, which would interfere with the glucose uptake and induce insulin resistance. Gene expression of PPARγ, PPARα, and SREBP-1 transcription factors regulating lipid metabolism was determined in Chang liver cells cultured in insulin resistance inducing medium over a 48 hour time course. The expression of PPARγ, known to stimulate adipogenesis was increased after 6, 24 and 48 hours of exposure (P(H1)<0.0001). The expression of PPARα, known to stimulate β-oxidation expression, was significantly decreased after 24 hours of exposure (P(H1)<0.0001). The presence of the plant extracts in the insulin resistance inducing media protect against this increase in adipogenesis and decrease in β-oxidation after 48 hours of exposure by increasing PPARα expression and decreasing PPARγ expression. A PCR Array was performed which identified 32 more potential molecular targets of S.frutescens. Five of the 32 targets identified with the PCR Array were validated using qRT-PCR. These genes play a role in lipid and glucose metabolism and protection against oxidative stress and inflammation. In summary a cellular model of insulin resistace in hepatocytes has been established and the capacity of S.frutescens to reverse this process has been demonstrated by acting as a dual PPARγ/α agonist. New genes have been identified in the development of insulin resistance and as targets of S.frutescens.
- Full Text:
- Date Issued: 2009
Characterization of hydrogen and helium implanted silicon carbide
- Authors: O'Connell, Jacques Herman
- Date: 2009
- Subjects: Silicon carbide , Hydrogen , Helium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10539 , http://hdl.handle.net/10948/979 , Silicon carbide , Hydrogen , Helium
- Description: This dissertation focuses on the characterization of hydrogen implanted 3C-SiC and helium implanted 6H-SiC and the interaction of silver and palladium with the SiC. The main technique used for the analysis of the implanted SiC was transmission electron microscopy (TEM), although scanning electron microscopy (SEM) and nanoindentation hardness testing were also used. Both H and He implantations were done at an ion energy of 100 keV and the total dose for both species was 1017 ions/cm2. Specimens were annealed at 1000 °C for 20 min in an inert atmosphere. The observed depth of ion damage agreed closely with that predicted by TRIM 2008. The damaged region in the He implanted specimens had a high density of small bubbles but no cracks were observed. Severe cracking was observed along the damaged region in the H implanted specimens. A second phase hexagonal (4H-SiC) was detected in two grains in the 3C-SiC and some grown in voids were also observed. The wettability of SiC by a 2:1 by volume mixture of Ag and Pd is extremely low but is significantly increased through the addition of Si to the mixture. The Si containing metal mixture was found to migrate along the grain boundaries of polycrystalline 3CSiC while sealing the point of entry. Pd attacks SiC and severe etching was observed on the surface of 6H-SiC. An epitaxially orientated Pd2Si inclusion was observed in the 6H-SiC. No effect of implantation damage on the interaction of Pd and Ag with SiC was observed. Pd etched the surface of the He implanted 6H-SiC down through the damaged region with no evidence of implantation damage left after 67 hours of annealing and thus no conclusions could be drawn. The metal mixture interacted with the non implanted surface of the H implanted 3C-SiC after dissolving the Si substrate and therefore the effect of the ion damage on the interaction could not be investigated. Nanoindentation hardness measurements showed a marked increase in hardness of He implanted 6H-SiC annealed for 20 min at 1000 °C over that of as implanted and virgin material. There was also a large decrease in hardness corresponding to the depth of the ion damage.
- Full Text:
- Date Issued: 2009
- Authors: O'Connell, Jacques Herman
- Date: 2009
- Subjects: Silicon carbide , Hydrogen , Helium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10539 , http://hdl.handle.net/10948/979 , Silicon carbide , Hydrogen , Helium
- Description: This dissertation focuses on the characterization of hydrogen implanted 3C-SiC and helium implanted 6H-SiC and the interaction of silver and palladium with the SiC. The main technique used for the analysis of the implanted SiC was transmission electron microscopy (TEM), although scanning electron microscopy (SEM) and nanoindentation hardness testing were also used. Both H and He implantations were done at an ion energy of 100 keV and the total dose for both species was 1017 ions/cm2. Specimens were annealed at 1000 °C for 20 min in an inert atmosphere. The observed depth of ion damage agreed closely with that predicted by TRIM 2008. The damaged region in the He implanted specimens had a high density of small bubbles but no cracks were observed. Severe cracking was observed along the damaged region in the H implanted specimens. A second phase hexagonal (4H-SiC) was detected in two grains in the 3C-SiC and some grown in voids were also observed. The wettability of SiC by a 2:1 by volume mixture of Ag and Pd is extremely low but is significantly increased through the addition of Si to the mixture. The Si containing metal mixture was found to migrate along the grain boundaries of polycrystalline 3CSiC while sealing the point of entry. Pd attacks SiC and severe etching was observed on the surface of 6H-SiC. An epitaxially orientated Pd2Si inclusion was observed in the 6H-SiC. No effect of implantation damage on the interaction of Pd and Ag with SiC was observed. Pd etched the surface of the He implanted 6H-SiC down through the damaged region with no evidence of implantation damage left after 67 hours of annealing and thus no conclusions could be drawn. The metal mixture interacted with the non implanted surface of the H implanted 3C-SiC after dissolving the Si substrate and therefore the effect of the ion damage on the interaction could not be investigated. Nanoindentation hardness measurements showed a marked increase in hardness of He implanted 6H-SiC annealed for 20 min at 1000 °C over that of as implanted and virgin material. There was also a large decrease in hardness corresponding to the depth of the ion damage.
- Full Text:
- Date Issued: 2009
Citizen participation, decentralization and inclusive development : a survey on citizen participation and decentralization in South Africa with specific reference to the Eastern Cape c.2005
- Authors: Robino, Carolina
- Date: 2009
- Subjects: Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9084 , http://hdl.handle.net/10948/875 , Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Description: Contemporary debates about development confer a prominent role to citizen participation and decentralization. Growing scepticism about the efficacy of narrowly conceived measures add pressure to reform development both theoretically and in practical terms. There is a greater understanding that ‘traditional’ development approaches and policies need to be reformulated and decentralization and citizen participation have been proposed as remedies to previous development failures. It is frequently argued that citizen participation will improve the efficiency and efficacy of public services. Citizen participation is meant to render local government more accountable and to contribute to deepening democracy, by reinforcing representative democratic institutions with participatory forms. At the same time, decentralization reforms have been proposed as a response to the failures of highly centralized states. From a political perspective, it is argued, decentralization reforms can help the central state gain legitimacy and have been seen as a strategy for maintaining political stability. It has been repeatedly suggested that physical proximity makes it easier for citizens to hold local officials accountable for their performance. From an economic perspective, decentralization can improve the match between the mix of services provided by the public sector and the preferences of the local population. It has also been noted that people are more willing to pay for services that respond to their priorities and that increased competition between local governments generates spaces for more creative responses adapted to local needs. But then, can decentralization and citizen participation live up to the faith and expectations that they have inspired? I argue that the literature commonly over-emphasises the role of citizen participation and decentralization in development and what these processes and reforms can achieve. Much of the evidence is anecdotal in nature and tends to neglect the specific contexts in which these processes take place. Also largely ignored are political economy considerations and a critical exploration of the relationship between these two key words. At best, when their interrelationships are addressed decentralization and citizen participation are conceived as based on a symbiotic relationship. I suggest, however, that the relationship between these two processes is not as straightforward as most of the literature assumes. The meanings of these two key words in current development lexicon are explored and critically assessed. I argue that whether or not the rising prominence of these two words actually means the emergence of a new development agenda is a moot point. It critically depends on the understandings of these ambiguous terms. The thesis adopts a political economy approach. Combined with this is an awareness of the broader historical and socio-economic context in which citizen participation and decentralization take place. The thesis applies these ideas triangulating diverse research methods and data sources. It combines a literature review and documentary analysis, a survey conducted with municipal authorities and civil society organizations in the Eastern Cape as well as structured interviews with Ward councillors and with key informants. From a theoretical perspective, the study lays a foundation for understanding the relationship between development policies outcomes and the nature of citizen participation and decentralization in developing countries. This, in turn, provides a basis from which citizen participation and decentralization in South Africa can be assessed and understood. The thesis presents evidence from a case study of the Eastern Cape, South Africa. By revealing how different dimensions of decentralization and citizen participation operate and intersect, the findings demonstrate, that contrary to common knowledge, citizen participation and decentralization are frequently at odds. Moreover, contrary to frequent statements, the research also shows that opening new spaces for participation in decentralized local governance can result in fewer changes and disappointing results at best, undermining the transformative potential of the concepts of participation and decentralization.
- Full Text:
- Date Issued: 2009
- Authors: Robino, Carolina
- Date: 2009
- Subjects: Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9084 , http://hdl.handle.net/10948/875 , Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Description: Contemporary debates about development confer a prominent role to citizen participation and decentralization. Growing scepticism about the efficacy of narrowly conceived measures add pressure to reform development both theoretically and in practical terms. There is a greater understanding that ‘traditional’ development approaches and policies need to be reformulated and decentralization and citizen participation have been proposed as remedies to previous development failures. It is frequently argued that citizen participation will improve the efficiency and efficacy of public services. Citizen participation is meant to render local government more accountable and to contribute to deepening democracy, by reinforcing representative democratic institutions with participatory forms. At the same time, decentralization reforms have been proposed as a response to the failures of highly centralized states. From a political perspective, it is argued, decentralization reforms can help the central state gain legitimacy and have been seen as a strategy for maintaining political stability. It has been repeatedly suggested that physical proximity makes it easier for citizens to hold local officials accountable for their performance. From an economic perspective, decentralization can improve the match between the mix of services provided by the public sector and the preferences of the local population. It has also been noted that people are more willing to pay for services that respond to their priorities and that increased competition between local governments generates spaces for more creative responses adapted to local needs. But then, can decentralization and citizen participation live up to the faith and expectations that they have inspired? I argue that the literature commonly over-emphasises the role of citizen participation and decentralization in development and what these processes and reforms can achieve. Much of the evidence is anecdotal in nature and tends to neglect the specific contexts in which these processes take place. Also largely ignored are political economy considerations and a critical exploration of the relationship between these two key words. At best, when their interrelationships are addressed decentralization and citizen participation are conceived as based on a symbiotic relationship. I suggest, however, that the relationship between these two processes is not as straightforward as most of the literature assumes. The meanings of these two key words in current development lexicon are explored and critically assessed. I argue that whether or not the rising prominence of these two words actually means the emergence of a new development agenda is a moot point. It critically depends on the understandings of these ambiguous terms. The thesis adopts a political economy approach. Combined with this is an awareness of the broader historical and socio-economic context in which citizen participation and decentralization take place. The thesis applies these ideas triangulating diverse research methods and data sources. It combines a literature review and documentary analysis, a survey conducted with municipal authorities and civil society organizations in the Eastern Cape as well as structured interviews with Ward councillors and with key informants. From a theoretical perspective, the study lays a foundation for understanding the relationship between development policies outcomes and the nature of citizen participation and decentralization in developing countries. This, in turn, provides a basis from which citizen participation and decentralization in South Africa can be assessed and understood. The thesis presents evidence from a case study of the Eastern Cape, South Africa. By revealing how different dimensions of decentralization and citizen participation operate and intersect, the findings demonstrate, that contrary to common knowledge, citizen participation and decentralization are frequently at odds. Moreover, contrary to frequent statements, the research also shows that opening new spaces for participation in decentralized local governance can result in fewer changes and disappointing results at best, undermining the transformative potential of the concepts of participation and decentralization.
- Full Text:
- Date Issued: 2009
Civil engineering components for a conceptual elevated light rail transit model with reference to Nelson Mandela Bay
- Authors: Zang, Jin
- Date: 2009
- Subjects: Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9593 , http://hdl.handle.net/10948/769 , Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Description: The increase of motor vehicles, especially in cities, cause transport problems of traffic congestion, vehicle accidents, air pollution and a lack of public spaces. The increasing number of motor vehicles consumes huge amounts of finite petrol energy and emits large amounts of gases that are harmful to the atmosphere and the natural environment. Therefore, the current road transport network is not a sustainable form of public transport for the future. In order to seek a suitable transportation mode, the Infrastructure and Engineering Business Unit of the Nelson Mandela Bay Municipality (NMBM) did some feasibility studies about light rail transit (LRT) from 1984 to 1988. The NMBM-report (1988: 8) concluded that a LRT system would provide the most suitable and primary mode to serve Nelson Mandela Bay (NMB). Although LRT was regarded as the most suitable primary mode of transport at that time (1988), further studies that were reported in 2006 recommended an alternative public transportation system. This research refers to these studies done for the NMB area and other studies and reports for other areas, but focus on the identification of the most suitable civil engineering components for a conceptual elevated light rail transit (ELRT) model. Electrical driven LRT systems have advantages over internal-combustion driven vehicles in terms of environmental protection. Traditional LRT systems are at ground level and are integrated with the existing road network. Some successful LRT systems indicate that the success of LRT systems is mainly dependent on integration with the existing road network. However, the integration of road transport systems with LRT systems cause increased congestion and accidents. An ELRT system can solve these problems. Bangkok has already built an ELRT system to solve its severe traffic congestion. 4 In order to develop a conceptual ELRT model, this research aimed to determine the most suitable civil engineering components for a conceptual ELRT model, including: (i) the most suitable type of bridge foundation; (ii) the most suitable type bridge girder; (iii) the most suitable type of sleeper; and (iv) whether the track should be a ballasted or non-ballasted type. The grounded theory approach was adopted to build up sets of data from which the most suitable components could be selected. In addition, design analyses were done of the various types of components to determine their suitability for a conceptual ELRT model. Experienced engineers and experts were also consulted to identify the most suitable components. After analyses and selection of the most suitable components, outstanding experts were approached to evaluate the components that showed up as the most suitable through the research. The research results indicated that bored and cast-in-place piles, a double-cell trapezoidal segmental box girder, and twin-block sleepers on a non-ballasted sleeper bed are the most suitable civil engineering components.
- Full Text:
- Date Issued: 2009
- Authors: Zang, Jin
- Date: 2009
- Subjects: Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9593 , http://hdl.handle.net/10948/769 , Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Description: The increase of motor vehicles, especially in cities, cause transport problems of traffic congestion, vehicle accidents, air pollution and a lack of public spaces. The increasing number of motor vehicles consumes huge amounts of finite petrol energy and emits large amounts of gases that are harmful to the atmosphere and the natural environment. Therefore, the current road transport network is not a sustainable form of public transport for the future. In order to seek a suitable transportation mode, the Infrastructure and Engineering Business Unit of the Nelson Mandela Bay Municipality (NMBM) did some feasibility studies about light rail transit (LRT) from 1984 to 1988. The NMBM-report (1988: 8) concluded that a LRT system would provide the most suitable and primary mode to serve Nelson Mandela Bay (NMB). Although LRT was regarded as the most suitable primary mode of transport at that time (1988), further studies that were reported in 2006 recommended an alternative public transportation system. This research refers to these studies done for the NMB area and other studies and reports for other areas, but focus on the identification of the most suitable civil engineering components for a conceptual elevated light rail transit (ELRT) model. Electrical driven LRT systems have advantages over internal-combustion driven vehicles in terms of environmental protection. Traditional LRT systems are at ground level and are integrated with the existing road network. Some successful LRT systems indicate that the success of LRT systems is mainly dependent on integration with the existing road network. However, the integration of road transport systems with LRT systems cause increased congestion and accidents. An ELRT system can solve these problems. Bangkok has already built an ELRT system to solve its severe traffic congestion. 4 In order to develop a conceptual ELRT model, this research aimed to determine the most suitable civil engineering components for a conceptual ELRT model, including: (i) the most suitable type of bridge foundation; (ii) the most suitable type bridge girder; (iii) the most suitable type of sleeper; and (iv) whether the track should be a ballasted or non-ballasted type. The grounded theory approach was adopted to build up sets of data from which the most suitable components could be selected. In addition, design analyses were done of the various types of components to determine their suitability for a conceptual ELRT model. Experienced engineers and experts were also consulted to identify the most suitable components. After analyses and selection of the most suitable components, outstanding experts were approached to evaluate the components that showed up as the most suitable through the research. The research results indicated that bored and cast-in-place piles, a double-cell trapezoidal segmental box girder, and twin-block sleepers on a non-ballasted sleeper bed are the most suitable civil engineering components.
- Full Text:
- Date Issued: 2009
Civil liability of an employer for injuries on duty
- Authors: Brandt, Denver Charles
- Date: 2009
- Subjects: Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10195 , http://hdl.handle.net/10948/1042 , Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Description: The workplace has evolved dramatically in the past decades. Technology has improved, innovative ways of utilising nuclear power have been developed, new chemicals have been introduced to the market and the adverse effects of other chemicals on both human health and safety and the environment have been discovered. This has influenced the nature of the workplace itself. While employees enjoy a common law right to a safe working environment and health and safety, state intervention currently provides restricted claims to an employee who has sustained injuries or contracted occupational diseases. This thesis explores the effect of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 which deprives an employee of its common law right to institute civil action against an employer for an injury sustained or disease contracted during the course and scope of employment. Furthermore, this thesis also explores the marriage between the Occupational Health and Safety Act 89 of 1993 and the Compensation for Occupational Injuries and Diseases Act 130 of 1993 as well as the position of ‘employee’ and ‘employer’ insofar as the scope and application of these two acts are concerned with specific reference to the position of labour broker employees. The use of indemnity clauses and its validity in South Africa will also be explored and discussed. This thesis also dedicates a chapter to the leading case authority of Jooste v Score Supermarket Trading (Pty) Ltd and its effect insofar as the enforcement and application of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 is concerned. It is impossible to mention all the changes in the workplace that have occurred in the recent years, and this discussion therefore focuses on the current position of employees who have been deprived of their common law right to institute delictual action for damages resulting from an injury sustained while on duty as well as the impact of the current restrictive claims available to them. Alterations to existing approaches are also proposed to resurrect the common law right of employees to institute action against their employers. , Abstract
- Full Text:
- Date Issued: 2009
- Authors: Brandt, Denver Charles
- Date: 2009
- Subjects: Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10195 , http://hdl.handle.net/10948/1042 , Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Description: The workplace has evolved dramatically in the past decades. Technology has improved, innovative ways of utilising nuclear power have been developed, new chemicals have been introduced to the market and the adverse effects of other chemicals on both human health and safety and the environment have been discovered. This has influenced the nature of the workplace itself. While employees enjoy a common law right to a safe working environment and health and safety, state intervention currently provides restricted claims to an employee who has sustained injuries or contracted occupational diseases. This thesis explores the effect of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 which deprives an employee of its common law right to institute civil action against an employer for an injury sustained or disease contracted during the course and scope of employment. Furthermore, this thesis also explores the marriage between the Occupational Health and Safety Act 89 of 1993 and the Compensation for Occupational Injuries and Diseases Act 130 of 1993 as well as the position of ‘employee’ and ‘employer’ insofar as the scope and application of these two acts are concerned with specific reference to the position of labour broker employees. The use of indemnity clauses and its validity in South Africa will also be explored and discussed. This thesis also dedicates a chapter to the leading case authority of Jooste v Score Supermarket Trading (Pty) Ltd and its effect insofar as the enforcement and application of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 is concerned. It is impossible to mention all the changes in the workplace that have occurred in the recent years, and this discussion therefore focuses on the current position of employees who have been deprived of their common law right to institute delictual action for damages resulting from an injury sustained while on duty as well as the impact of the current restrictive claims available to them. Alterations to existing approaches are also proposed to resurrect the common law right of employees to institute action against their employers. , Abstract
- Full Text:
- Date Issued: 2009
Comparing the development of a sample of South African pre-school boys and girls utilizing the Griffiths Mental Development Scales-extended revised
- Authors: Jakins, Tamarin Ashlea
- Date: 2009
- Subjects: Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9904 , http://hdl.handle.net/10948/990 , Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Description: Both children and adults share a common, culturally distinct view of what it means to be male or female. These gender stereotypes are pervasive in society and daily social interactions, and influence all aspects of gender development (Golombok & Fivush, 1994). The inherent physical differences of boys and girls may have triggered the speculation and accompanying myths surrounding the existence of gender differences in childhood development. Many people believe that boys and girls follow a different developmental path that lead to gender differences in intellectual ability. An up-to-date and integrative review of theory and research on gender indicates two opposing perspectives on the topic, with substantial information supporting each view. However, this is the first study to examine and compare a sample of South African pre-school boys and girls from a truly holistic developmental perspective on the recently released Griffiths Mental Development Scales-Extended Revised (GMDS-ER). Developmental theorists have emphasized the profound impact early childhood development has on subsequent development, as it shapes the course of an individual’s life. Contemporary cognitive developmental theories, such as Demetriou’s (2000; 2004) developmental model of cognitive development, advance that child development does not progress in a fixed and predictable manner. Instead, Demetriou proposes that development occurs in a wave-like fashion, where the processes and functions of the various levels of the mind may be at differing points in their cycle of development. When one function progresses to a higher level, it unlocks the possibility for another function to advance to a different point in its cycle (Demetriou et al., 2002). As the significance of understanding the process of early childhood development more fully increases, so does the need to establish with more confidence the value and role of developmental assessment in the early identification of problems. The overall purpose of this study was to generate comparative information regarding the general development of a sample of 5- and 6-year-old South African pre-school boys and girls. Specifically, the study aimed to explore and describe the developmental profiles of pre-school boys and girls within the abovementioned age group with respect to their overall performance on the GMDS-ER as well as their performance on the six Subscales. Then, the mean General Quotients (GQ) and developmental profiles of the pre-school boys and girls obtained on the GMDS-ER were compared. An exploratory-descriptive quantitative research method was used. The sample (N = 64) was selected through a combination of non-probability, purposive and convenience xiii sampling. Within this framework, a between-subjects design in which matching was used to control extraneous variables, was employed. Data was analysed using descriptive statistics and independent sample t-tests to compare the GQs of the gender groups. A Hotellings T2 was used to compare the Subscale profiles. No significant gender differences were found when comparing the overall developmental and Subscale profiles of the boys and girls on the GMDS-ER. However, certain interesting trends did emerge from a review of the findings when compared to the literature review and previous studies. The information generated from this study has contributed to our knowledge base of the performance of South African children on the recently released GMDS-ER.
- Full Text:
- Date Issued: 2009
- Authors: Jakins, Tamarin Ashlea
- Date: 2009
- Subjects: Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9904 , http://hdl.handle.net/10948/990 , Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Description: Both children and adults share a common, culturally distinct view of what it means to be male or female. These gender stereotypes are pervasive in society and daily social interactions, and influence all aspects of gender development (Golombok & Fivush, 1994). The inherent physical differences of boys and girls may have triggered the speculation and accompanying myths surrounding the existence of gender differences in childhood development. Many people believe that boys and girls follow a different developmental path that lead to gender differences in intellectual ability. An up-to-date and integrative review of theory and research on gender indicates two opposing perspectives on the topic, with substantial information supporting each view. However, this is the first study to examine and compare a sample of South African pre-school boys and girls from a truly holistic developmental perspective on the recently released Griffiths Mental Development Scales-Extended Revised (GMDS-ER). Developmental theorists have emphasized the profound impact early childhood development has on subsequent development, as it shapes the course of an individual’s life. Contemporary cognitive developmental theories, such as Demetriou’s (2000; 2004) developmental model of cognitive development, advance that child development does not progress in a fixed and predictable manner. Instead, Demetriou proposes that development occurs in a wave-like fashion, where the processes and functions of the various levels of the mind may be at differing points in their cycle of development. When one function progresses to a higher level, it unlocks the possibility for another function to advance to a different point in its cycle (Demetriou et al., 2002). As the significance of understanding the process of early childhood development more fully increases, so does the need to establish with more confidence the value and role of developmental assessment in the early identification of problems. The overall purpose of this study was to generate comparative information regarding the general development of a sample of 5- and 6-year-old South African pre-school boys and girls. Specifically, the study aimed to explore and describe the developmental profiles of pre-school boys and girls within the abovementioned age group with respect to their overall performance on the GMDS-ER as well as their performance on the six Subscales. Then, the mean General Quotients (GQ) and developmental profiles of the pre-school boys and girls obtained on the GMDS-ER were compared. An exploratory-descriptive quantitative research method was used. The sample (N = 64) was selected through a combination of non-probability, purposive and convenience xiii sampling. Within this framework, a between-subjects design in which matching was used to control extraneous variables, was employed. Data was analysed using descriptive statistics and independent sample t-tests to compare the GQs of the gender groups. A Hotellings T2 was used to compare the Subscale profiles. No significant gender differences were found when comparing the overall developmental and Subscale profiles of the boys and girls on the GMDS-ER. However, certain interesting trends did emerge from a review of the findings when compared to the literature review and previous studies. The information generated from this study has contributed to our knowledge base of the performance of South African children on the recently released GMDS-ER.
- Full Text:
- Date Issued: 2009
Compensation for polarization mode dispersion and nonlinear birefringence in a multichannel optical fibre system
- Authors: Waswa, David Wafula
- Date: 2009
- Subjects: Fiber optics , Nonlinear optics , Polarization (Light)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10375 , http://hdl.handle.net/10948/885 , Fiber optics , Nonlinear optics , Polarization (Light)
- Description: Polarization mode dispersion (PMD) is stochastic in nature and continues evolving in an unpredictable manner according to the changing environment. Nonlinear birefringence in multichannel systems alters the polarization states of the bits, so that they vary from one bit to the next in a way that is difficult to predict. These are the two major signal-impairment effects that are inherent in optical fibre transmission links which can seriously degrade network performance. It is therefore extremely challenging to compensate for both linear and nonlinear birefringence in multichannel systems. The purpose of this thesis is to investigate the interaction between PMD and nonlinear induced birefringence in a fibre with consideration of mode coupling. A sound knowledge of this interaction is necessary in designing a linear and nonlinear polarization mode dispersion compensator for WDM systems, as was successfully carried out in this study. The investigation shows that the effect of nonlinear birefringence alone depolarizes the signal, while in high PMD links where polarization mode coupling is high, the nonlinear birefringence effect couples with second-order PMD such that it may reduce the penalty and improve the signal DOP. Further investigation shows that when nonlinear birefringence becomes significant, asymmetry arises between the two principal axes of the fibre, such that it is only one axis which experiences the effect of nonlinear birefringence. It is found out that along this vii axis, there exists a critical point in pump power where the nonlinear birefringence cancels PMD in the link and improves the signal. An adaptive compensator to cancel PMD and nonlinear birefringence was designed based on feedforward DOP-monitoring signal. The compensator was tested both at laboratory level and on the Telkom buried fibre link and found to be functioning as intended. It was able to adaptively track and compensate PMD in the link in less than a second. The compensator was able to cancel PMD in the link up to a maximum of 30 ps. The compensator improved the DOP of the worst signal by more than 100 percent.
- Full Text:
- Date Issued: 2009
- Authors: Waswa, David Wafula
- Date: 2009
- Subjects: Fiber optics , Nonlinear optics , Polarization (Light)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10375 , http://hdl.handle.net/10948/885 , Fiber optics , Nonlinear optics , Polarization (Light)
- Description: Polarization mode dispersion (PMD) is stochastic in nature and continues evolving in an unpredictable manner according to the changing environment. Nonlinear birefringence in multichannel systems alters the polarization states of the bits, so that they vary from one bit to the next in a way that is difficult to predict. These are the two major signal-impairment effects that are inherent in optical fibre transmission links which can seriously degrade network performance. It is therefore extremely challenging to compensate for both linear and nonlinear birefringence in multichannel systems. The purpose of this thesis is to investigate the interaction between PMD and nonlinear induced birefringence in a fibre with consideration of mode coupling. A sound knowledge of this interaction is necessary in designing a linear and nonlinear polarization mode dispersion compensator for WDM systems, as was successfully carried out in this study. The investigation shows that the effect of nonlinear birefringence alone depolarizes the signal, while in high PMD links where polarization mode coupling is high, the nonlinear birefringence effect couples with second-order PMD such that it may reduce the penalty and improve the signal DOP. Further investigation shows that when nonlinear birefringence becomes significant, asymmetry arises between the two principal axes of the fibre, such that it is only one axis which experiences the effect of nonlinear birefringence. It is found out that along this vii axis, there exists a critical point in pump power where the nonlinear birefringence cancels PMD in the link and improves the signal. An adaptive compensator to cancel PMD and nonlinear birefringence was designed based on feedforward DOP-monitoring signal. The compensator was tested both at laboratory level and on the Telkom buried fibre link and found to be functioning as intended. It was able to adaptively track and compensate PMD in the link in less than a second. The compensator was able to cancel PMD in the link up to a maximum of 30 ps. The compensator improved the DOP of the worst signal by more than 100 percent.
- Full Text:
- Date Issued: 2009
Complexes of the ReO³⁺/Re(CO)₃cores with multidentate N,O-Donor chelates
- Authors: Potgieter, Kim Carey
- Date: 2009
- Subjects: Rhenium , Schiff bases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10387 , http://hdl.handle.net/10948/1225 , Rhenium , Schiff bases
- Description: This study investigates the coordination modes of multidentate N,O-donor ligands toward the [ReVO]3+ and fac-[ReI(CO)3]+ cores. The reactions of trans-[ReOX3(PPh3)2] (X = Cl, Br) with 4-aminoantipyrine (H2pap) were studied, and the complexes cis-[ReX2(pap)(H2pap)(PPh3)](ReO4) were isolated. The X-ray crystal structures show that both complexes display a distorted octahedral geometry around the central rhenium atom, and are mirror images of each other. The ligand pap is coordinated monodentately through the doubly deprotonated amino nitrogen as an imide, and H2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. The attempted synthesis of the potentially hexadentate Schiff base ligand 1,2-bis(2-{(Z)- [(2-hydroxyphenyl)imido]methyl}phenoxy)benzene from the condensation reaction of 2- (2-((2-aminophenoxy)methyl)benzyloxy)benzenamine and salicylaldehyde produced the zwitterion derivative (H2ono) of 2-{(Z)-[2-(hydroxyphenyl)imino]methyl}phenol. The tridentate Schiff bases (Z)-2-(2-aminobenzylideneamino)phenol (H3onn) and (Z)-2-(2- (methylthio)benzylideneamino)phenol (Hons) were prepared in a similar manner. The reaction of H2ono with trans-[ReOBr3(PPh3)2] surprisingly led to the isolation of the rhenium(III) complex [ReBr(PPh3)2(ono)], in which ono acts as a dianionic tridentate ligand. The reaction of H3onn with trans-[ReOBr3(PPh3)2] produced the imidorhenium(V) complex salt [ReBr(PPh3)2(onn)]Br, in which onn is coordinated as a trianionic tridentate imidoiminophenolate. The reaction of Hons with [Re(CO)5Br] led to the further decomposition of the Hons ligand, and the rhenium(I) product fac- [Re(CO)3(ons)(Hno)] (Hno = 2-aminophenol) was isolated, with ons coordinated as a monoanionic bidentate chelate (with a free SCH3 group), and Hno present as a neutral monodentate ligand with coordination through the amino nitrogen atom. Abstract Nelson Mandela Metropolitan University vi The reactions of the potentially hexadentate ligand N,N’-{ethane-1,2- diylbis[nitrilomethylidenebenzene-1,2-diyl]}bis(2-aminobenzeneimine) (H2ted) with rhenium(V) starting materials resulted in the decomposition of the H2ted molecule to give different coordinated multidentate ligands coordinated to the rhenium(V) centers. In the reaction of H2ted with trans-[ReOBr3(PPh3)2] in ethanol, the highly unusual ‘3+3’ complex cation [Re(tnn)(Htnn)]Br2 was isolated, in which tnn is coordinated as a tridentate imido-imino-amine, and Htnn is present as a tridentate monoanionic amidoimino- amine chelate (H2tnn = N-(2-aminophenylmethylidene)ethane-1,2-diamine). With trans-[ReO2(py)4]Cl as starting material, the neutral complex [ReO(dne)] was found, in which the tetradentate chelate dne acts as a triamido-imine. The reaction of cis- [ReO2I(PPh3)2] with H2ted led to the formation of the monocationic complex salt [ReO(ane)]PF6, with ane acting as a tetradentate dianionic diamidodiimine (H2ane = N,N’-bis[(2-aminophenyl)methylidene] ethane-1,2-diamine). The seven-coordinate rhenium(III) complex cation [Re(dhp)(PPh3)2]+ (H2dhp = 2,6-bis(2- hydroxyphenyliminomethyl)pyridine) was isolated as the iodide salt from the reaction of cis-[ReO2I(PPh3)2] with H2dhp in ethanol and as the perrhenate salt from the reaction of trans-[ReOBr3(PPh3)2] with H2dhp in methanol. Both products result from a disproportionation reaction with perrhenate also being produced in the process. The complex fac-[Re(CO)3(H2dhp)Br] was prepared from [Re(CO)5Br] and H2dhp in toluene, where the H2dhp ligand acts as a neutral bidentate NN-donor chelate. The metal is coordinated to three carbonyl donors in a facial orientation, to a neutral imino nitrogen, a pyridinic nitrogen and a bromide.
- Full Text:
- Date Issued: 2009
- Authors: Potgieter, Kim Carey
- Date: 2009
- Subjects: Rhenium , Schiff bases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10387 , http://hdl.handle.net/10948/1225 , Rhenium , Schiff bases
- Description: This study investigates the coordination modes of multidentate N,O-donor ligands toward the [ReVO]3+ and fac-[ReI(CO)3]+ cores. The reactions of trans-[ReOX3(PPh3)2] (X = Cl, Br) with 4-aminoantipyrine (H2pap) were studied, and the complexes cis-[ReX2(pap)(H2pap)(PPh3)](ReO4) were isolated. The X-ray crystal structures show that both complexes display a distorted octahedral geometry around the central rhenium atom, and are mirror images of each other. The ligand pap is coordinated monodentately through the doubly deprotonated amino nitrogen as an imide, and H2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. The attempted synthesis of the potentially hexadentate Schiff base ligand 1,2-bis(2-{(Z)- [(2-hydroxyphenyl)imido]methyl}phenoxy)benzene from the condensation reaction of 2- (2-((2-aminophenoxy)methyl)benzyloxy)benzenamine and salicylaldehyde produced the zwitterion derivative (H2ono) of 2-{(Z)-[2-(hydroxyphenyl)imino]methyl}phenol. The tridentate Schiff bases (Z)-2-(2-aminobenzylideneamino)phenol (H3onn) and (Z)-2-(2- (methylthio)benzylideneamino)phenol (Hons) were prepared in a similar manner. The reaction of H2ono with trans-[ReOBr3(PPh3)2] surprisingly led to the isolation of the rhenium(III) complex [ReBr(PPh3)2(ono)], in which ono acts as a dianionic tridentate ligand. The reaction of H3onn with trans-[ReOBr3(PPh3)2] produced the imidorhenium(V) complex salt [ReBr(PPh3)2(onn)]Br, in which onn is coordinated as a trianionic tridentate imidoiminophenolate. The reaction of Hons with [Re(CO)5Br] led to the further decomposition of the Hons ligand, and the rhenium(I) product fac- [Re(CO)3(ons)(Hno)] (Hno = 2-aminophenol) was isolated, with ons coordinated as a monoanionic bidentate chelate (with a free SCH3 group), and Hno present as a neutral monodentate ligand with coordination through the amino nitrogen atom. Abstract Nelson Mandela Metropolitan University vi The reactions of the potentially hexadentate ligand N,N’-{ethane-1,2- diylbis[nitrilomethylidenebenzene-1,2-diyl]}bis(2-aminobenzeneimine) (H2ted) with rhenium(V) starting materials resulted in the decomposition of the H2ted molecule to give different coordinated multidentate ligands coordinated to the rhenium(V) centers. In the reaction of H2ted with trans-[ReOBr3(PPh3)2] in ethanol, the highly unusual ‘3+3’ complex cation [Re(tnn)(Htnn)]Br2 was isolated, in which tnn is coordinated as a tridentate imido-imino-amine, and Htnn is present as a tridentate monoanionic amidoimino- amine chelate (H2tnn = N-(2-aminophenylmethylidene)ethane-1,2-diamine). With trans-[ReO2(py)4]Cl as starting material, the neutral complex [ReO(dne)] was found, in which the tetradentate chelate dne acts as a triamido-imine. The reaction of cis- [ReO2I(PPh3)2] with H2ted led to the formation of the monocationic complex salt [ReO(ane)]PF6, with ane acting as a tetradentate dianionic diamidodiimine (H2ane = N,N’-bis[(2-aminophenyl)methylidene] ethane-1,2-diamine). The seven-coordinate rhenium(III) complex cation [Re(dhp)(PPh3)2]+ (H2dhp = 2,6-bis(2- hydroxyphenyliminomethyl)pyridine) was isolated as the iodide salt from the reaction of cis-[ReO2I(PPh3)2] with H2dhp in ethanol and as the perrhenate salt from the reaction of trans-[ReOBr3(PPh3)2] with H2dhp in methanol. Both products result from a disproportionation reaction with perrhenate also being produced in the process. The complex fac-[Re(CO)3(H2dhp)Br] was prepared from [Re(CO)5Br] and H2dhp in toluene, where the H2dhp ligand acts as a neutral bidentate NN-donor chelate. The metal is coordinated to three carbonyl donors in a facial orientation, to a neutral imino nitrogen, a pyridinic nitrogen and a bromide.
- Full Text:
- Date Issued: 2009
Coping strategies of African women middle managers in the manufacturing industry
- Authors: Mayeko, Ncedisa
- Date: 2009
- Subjects: Women executives -- South Africa , Stress management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9901 , http://hdl.handle.net/10948/1071 , Women executives -- South Africa , Stress management
- Description: African women in South Africa have for decades, if not centuries, been marginalized in the workplace. With the dawn of the new South Africa came Affirmative Action and subsequently, the Employment Equity Act. These policies offered African women opportunities to enter the workplace. The review of the literature shows that the psychological functioning of African women managers has received minimal research attention. In addition, the literature review on coping focused on the individual and communal coping strategies which indicated that individual and systemic strategies have been neglected in both the theories of coping and extant empirical literature. The current study addresses this through the conceptualisation of coping from a systemic perspective. The current study aimed to explore and describe the coping strategies of African women middle managers in the manufacturing industry in the Nelson Mandela Metropolitan area. The study was conducted within a qualitative research paradigm and took the form of exploratory research. Non-probability snowball sampling was utilized to identify participants for the study. The sample consisted of three African women managers who held middle management positions in the manufacturing industry in the Nelson Mandela metropolitan area. Semi-structured interviewing was utilised to collect the data. In order to analyse the data, Tesch’s (1990) qualitative analysis steps were utilised. The study showed that African women middle managers relied on individual strategies such as assertiveness, spirituality and, positive attitude to cope. These individual strategies were not used in isolation, as the participants relied on various subsystems within which they were embedded to cope with the demands they faced.
- Full Text:
- Date Issued: 2009
- Authors: Mayeko, Ncedisa
- Date: 2009
- Subjects: Women executives -- South Africa , Stress management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9901 , http://hdl.handle.net/10948/1071 , Women executives -- South Africa , Stress management
- Description: African women in South Africa have for decades, if not centuries, been marginalized in the workplace. With the dawn of the new South Africa came Affirmative Action and subsequently, the Employment Equity Act. These policies offered African women opportunities to enter the workplace. The review of the literature shows that the psychological functioning of African women managers has received minimal research attention. In addition, the literature review on coping focused on the individual and communal coping strategies which indicated that individual and systemic strategies have been neglected in both the theories of coping and extant empirical literature. The current study addresses this through the conceptualisation of coping from a systemic perspective. The current study aimed to explore and describe the coping strategies of African women middle managers in the manufacturing industry in the Nelson Mandela Metropolitan area. The study was conducted within a qualitative research paradigm and took the form of exploratory research. Non-probability snowball sampling was utilized to identify participants for the study. The sample consisted of three African women managers who held middle management positions in the manufacturing industry in the Nelson Mandela metropolitan area. Semi-structured interviewing was utilised to collect the data. In order to analyse the data, Tesch’s (1990) qualitative analysis steps were utilised. The study showed that African women middle managers relied on individual strategies such as assertiveness, spirituality and, positive attitude to cope. These individual strategies were not used in isolation, as the participants relied on various subsystems within which they were embedded to cope with the demands they faced.
- Full Text:
- Date Issued: 2009
Corruption and its effects on the development of the construction industry in Malawi
- Chiocha, Charles Injess Martin
- Authors: Chiocha, Charles Injess Martin
- Date: 2009
- Subjects: Contruction industry -- Corrupt practices -- Malawi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9692 , http://hdl.handle.net/10948/933 , Contruction industry -- Corrupt practices -- Malawi
- Description: The purpose of this study was to investigate corruption and its effects on the development of the construction industry in Malawi. The major causes were identified and probable solutions as well as preventive measures suggested for all stakeholders in the construction industry in Malawi and neighbouring countries to follow in order to combat bribery and corruption. This treatise consisted of a literature review for the causes of bribery, fraud and corruption, effects of corruption on the construction industry, preventive measures, probable solutions to corruption and a descriptive survey involving responses from building and civil engineering contractors, the built environment professionals, home owners, developers, public works officers amongst others from the construction industry in Malawi. According to the literature study, the construction industry is one of the most corrupt industries in the world, which is a huge concern and threat both to governments, investors and humanity at large. This must be addressed by all the official players in the construction industry, from the innovator of a project to the tradesmen employed on that site. The research showed that all players in the construction industry are aware of the impact of corruption on the development of the construction industry in Malawi. Furthermore, there is room for improvement as far as prevention, reduction and elimination of corruption is concerned.
- Full Text:
- Date Issued: 2009
- Authors: Chiocha, Charles Injess Martin
- Date: 2009
- Subjects: Contruction industry -- Corrupt practices -- Malawi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9692 , http://hdl.handle.net/10948/933 , Contruction industry -- Corrupt practices -- Malawi
- Description: The purpose of this study was to investigate corruption and its effects on the development of the construction industry in Malawi. The major causes were identified and probable solutions as well as preventive measures suggested for all stakeholders in the construction industry in Malawi and neighbouring countries to follow in order to combat bribery and corruption. This treatise consisted of a literature review for the causes of bribery, fraud and corruption, effects of corruption on the construction industry, preventive measures, probable solutions to corruption and a descriptive survey involving responses from building and civil engineering contractors, the built environment professionals, home owners, developers, public works officers amongst others from the construction industry in Malawi. According to the literature study, the construction industry is one of the most corrupt industries in the world, which is a huge concern and threat both to governments, investors and humanity at large. This must be addressed by all the official players in the construction industry, from the innovator of a project to the tradesmen employed on that site. The research showed that all players in the construction industry are aware of the impact of corruption on the development of the construction industry in Malawi. Furthermore, there is room for improvement as far as prevention, reduction and elimination of corruption is concerned.
- Full Text:
- Date Issued: 2009
Cost and reward as motivating factors in distributed collaborative learning assignments : a grounded theory analasis
- Van Niekerk, Johanna Cornelia
- Authors: Van Niekerk, Johanna Cornelia
- Date: 2009
- Subjects: Group work in education -- South Africa , Team learning approach in education -- South Africa , Education -- Experimental methods
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9764 , http://hdl.handle.net/10948/1103 , Group work in education -- South Africa , Team learning approach in education -- South Africa , Education -- Experimental methods
- Description: The objective of this research study was to obtain a better understanding of the factors that affect lecturer and student participation in distributed collaborative learning assignments (DCLAs). A substantial number of courses worldwide have included DCLAs in their curricula in an attempt to teach students virtual communication and teaming skills, and to allow distributed students to learn course content collaboratively in a virtual environment. The execution and management of these assignments have proven to be more challenging that expected. Several attempts reported on in the literature had to be abandoned when cost exceeded the rewards for both lecturers and students. In a fouryear cyclical action research project carried out at the PETech (Port Elizabeth Technikon, currently part of the Nelson Mandela Metropolitan University, South Africa), ICT students at several of the PETech campuses were required to complete a DCLA in virtual teams. This project also had to be terminated when it was realised that virtual team learning was minimal and the time investment unacceptably high. For the research study reported on in this thesis the data collected during the four “preresearch” cycles and the experiences reported in the literature were analysed. The lessons learnt were applied to a new additional DCLA cycle which formed part of an ICT course, although this execution still showed room for improvement. A second additional cycle was then executed which had a high participation rate and was overwhelmingly labelled by the participating students as a valuable and enjoyable learning experience. Analysis of the factors affecting participation in DCLAs shows that they are numerous and tightly interlinked, and that each factor is able to take on a wide range of values. This complicates descriptive reporting as each of the DCLAs was unique with unique outcomes and would have to be reported as such in order to iii ABSTRACT iv gain an understanding of the factors. Hence, a level of abstraction was needed, which was accomplished by applying the traditional Glaserian grounded theory method to the data collected during the four “preresearch” and the two additional cycles, and from the literature on the topic. The outcome is a perceived costs and rewards (PCR) theory for participation in DCLAs. As participation is crucial for the learning experience of each student as well as his/her team members in an action learning environment, deciding on participation by continually calculating the costs versus rewards became the focal point of the theory. To the best of the author’s knowledge this research study makes a theoretical contribution to the existing body of ICT educational knowledge in the form of a perceived costs and rewards theory for DCLA participation and a practical contribution in that it provides a theory that can be used to explain, understand, interpret and predict participation in DCLAs. This research study provides guidance for future research in both of these areas.
- Full Text:
- Date Issued: 2009
- Authors: Van Niekerk, Johanna Cornelia
- Date: 2009
- Subjects: Group work in education -- South Africa , Team learning approach in education -- South Africa , Education -- Experimental methods
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9764 , http://hdl.handle.net/10948/1103 , Group work in education -- South Africa , Team learning approach in education -- South Africa , Education -- Experimental methods
- Description: The objective of this research study was to obtain a better understanding of the factors that affect lecturer and student participation in distributed collaborative learning assignments (DCLAs). A substantial number of courses worldwide have included DCLAs in their curricula in an attempt to teach students virtual communication and teaming skills, and to allow distributed students to learn course content collaboratively in a virtual environment. The execution and management of these assignments have proven to be more challenging that expected. Several attempts reported on in the literature had to be abandoned when cost exceeded the rewards for both lecturers and students. In a fouryear cyclical action research project carried out at the PETech (Port Elizabeth Technikon, currently part of the Nelson Mandela Metropolitan University, South Africa), ICT students at several of the PETech campuses were required to complete a DCLA in virtual teams. This project also had to be terminated when it was realised that virtual team learning was minimal and the time investment unacceptably high. For the research study reported on in this thesis the data collected during the four “preresearch” cycles and the experiences reported in the literature were analysed. The lessons learnt were applied to a new additional DCLA cycle which formed part of an ICT course, although this execution still showed room for improvement. A second additional cycle was then executed which had a high participation rate and was overwhelmingly labelled by the participating students as a valuable and enjoyable learning experience. Analysis of the factors affecting participation in DCLAs shows that they are numerous and tightly interlinked, and that each factor is able to take on a wide range of values. This complicates descriptive reporting as each of the DCLAs was unique with unique outcomes and would have to be reported as such in order to iii ABSTRACT iv gain an understanding of the factors. Hence, a level of abstraction was needed, which was accomplished by applying the traditional Glaserian grounded theory method to the data collected during the four “preresearch” and the two additional cycles, and from the literature on the topic. The outcome is a perceived costs and rewards (PCR) theory for participation in DCLAs. As participation is crucial for the learning experience of each student as well as his/her team members in an action learning environment, deciding on participation by continually calculating the costs versus rewards became the focal point of the theory. To the best of the author’s knowledge this research study makes a theoretical contribution to the existing body of ICT educational knowledge in the form of a perceived costs and rewards theory for DCLA participation and a practical contribution in that it provides a theory that can be used to explain, understand, interpret and predict participation in DCLAs. This research study provides guidance for future research in both of these areas.
- Full Text:
- Date Issued: 2009
Critical analysis of the 2007 public service strike and its impact on the evolution of formalised collective bargaining in South Africa
- Authors: Bhe, Vuyisile
- Date: 2009
- Subjects: Collective bargaining -- South Africa , Dispute resolution (Law) -- South Africa , Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Industrial relations -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10192 , http://hdl.handle.net/10948/1043 , Collective bargaining -- South Africa , Dispute resolution (Law) -- South Africa , Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Industrial relations -- South Africa
- Description: Section 213 of the Labour Relations Act defines ’strike’ as the partial or complete concerted refusal to work, or the retardation or obstruction of work, by persons who are or have been employed by the same employer or by different employers, for the purpose of remedying a grievance or resolving a dispute in respect of any matter of mutual interest between the employer and employee, and any reference to “work” this definition includes overtime work, whether it is voluntary or compulsory. According to Mcllroy: “As long as our society is divided between those who own and control the means of production and those who only have the ability to work, strikes will be inevitable because they are the ultimate means workers have of protecting themselves.” 1 The Constitutional Court justified the exclusion of a constitutional right to lock out and the inclusion of a constitutional right to strike by indicating that the right to strike is not equivalent to a right to lock out and is essential for workplace democracy. 2 The right to strike is essential to bolster collective bargaining and thereby to give employees the power to bargain effectively with employers. The employers on the According to the Constitutional Court employers enjoy greater social and economic power compared to individual workers and may exercise a wide range of power against workers through a range of weapons, such as dismissal, the employment of alternative or replacement labour, the unilateral implementation of new terms and conditions of employment, and the exclusion of workers from the workplace. To combat this and have a say in the workplace, the Constitutional Court held that “employees need to act in concert to provide them collectively with sufficient power to bargain effectively with employers and exercise collective power primarily through the mechanism of strike action”. The importance of the right to strike in creating workplace democracy is also reflected in a number of Labour Court and Labour Appeal Court judgments. other hand have economic strength that is used to bargain effectively. That is why the strike enjoys constitutional protection, whereas the lock-out does not. , Abstract
- Full Text:
- Date Issued: 2009
- Authors: Bhe, Vuyisile
- Date: 2009
- Subjects: Collective bargaining -- South Africa , Dispute resolution (Law) -- South Africa , Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Industrial relations -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10192 , http://hdl.handle.net/10948/1043 , Collective bargaining -- South Africa , Dispute resolution (Law) -- South Africa , Strikes and lockouts -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Industrial relations -- South Africa
- Description: Section 213 of the Labour Relations Act defines ’strike’ as the partial or complete concerted refusal to work, or the retardation or obstruction of work, by persons who are or have been employed by the same employer or by different employers, for the purpose of remedying a grievance or resolving a dispute in respect of any matter of mutual interest between the employer and employee, and any reference to “work” this definition includes overtime work, whether it is voluntary or compulsory. According to Mcllroy: “As long as our society is divided between those who own and control the means of production and those who only have the ability to work, strikes will be inevitable because they are the ultimate means workers have of protecting themselves.” 1 The Constitutional Court justified the exclusion of a constitutional right to lock out and the inclusion of a constitutional right to strike by indicating that the right to strike is not equivalent to a right to lock out and is essential for workplace democracy. 2 The right to strike is essential to bolster collective bargaining and thereby to give employees the power to bargain effectively with employers. The employers on the According to the Constitutional Court employers enjoy greater social and economic power compared to individual workers and may exercise a wide range of power against workers through a range of weapons, such as dismissal, the employment of alternative or replacement labour, the unilateral implementation of new terms and conditions of employment, and the exclusion of workers from the workplace. To combat this and have a say in the workplace, the Constitutional Court held that “employees need to act in concert to provide them collectively with sufficient power to bargain effectively with employers and exercise collective power primarily through the mechanism of strike action”. The importance of the right to strike in creating workplace democracy is also reflected in a number of Labour Court and Labour Appeal Court judgments. other hand have economic strength that is used to bargain effectively. That is why the strike enjoys constitutional protection, whereas the lock-out does not. , Abstract
- Full Text:
- Date Issued: 2009
Curiosity, exploration, and strategies for dealing with uncertainty amongst psychologists-in-training
- Authors: Gerber, Ora
- Date: 2009
- Subjects: Psychologists -- Training of -- South Africa , Psychology -- Study and teaching , Uncertainty -- Psychological aspects , Positive psychology -- South Africa , Risk-taking (Psychology) -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9883 , http://hdl.handle.net/10948/1238 , Psychologists -- Training of -- South Africa , Psychology -- Study and teaching , Uncertainty -- Psychological aspects , Positive psychology -- South Africa , Risk-taking (Psychology) -- South Africa
- Description: By adopting a positive psychology framework, the aim of this study was to explore and describe the level of curiosity and exploration amongst psychologists-in-training, and how they dealt with uncertainty in the context of their professional development. A mixed-method exploratory-descriptive research design was employed to collect the quantitative data by means of the Curiosity and Exploratory Inventory. The qualitative data were collected using semistructured interviews to explore how psychologists-in-training have dealt with uncertainty. Purposive-availability sampling was used to select the participants at three South African universities. A total number of 50 participants completed the CEI and six participants were interviewed. The data were analysed using mixed-method data analysis. It was found that participants had moderate-to-high levels of curiosity and exploration, with higher levels of exploration than absorption. The majority of participants reported that they actively sought as much information as they could and frequently looked for new opportunities to grow as persons. The strategies used by the selected group of participants to deal with uncertainty included: reliance on clinical supervision; consultation with peers; self-enhancement; reliance on theory; learning from practical experience; using certain cognitive appraisals; and self-care. Certain conclusions and recommendations were made based on the findings of the study.
- Full Text:
- Date Issued: 2009
- Authors: Gerber, Ora
- Date: 2009
- Subjects: Psychologists -- Training of -- South Africa , Psychology -- Study and teaching , Uncertainty -- Psychological aspects , Positive psychology -- South Africa , Risk-taking (Psychology) -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9883 , http://hdl.handle.net/10948/1238 , Psychologists -- Training of -- South Africa , Psychology -- Study and teaching , Uncertainty -- Psychological aspects , Positive psychology -- South Africa , Risk-taking (Psychology) -- South Africa
- Description: By adopting a positive psychology framework, the aim of this study was to explore and describe the level of curiosity and exploration amongst psychologists-in-training, and how they dealt with uncertainty in the context of their professional development. A mixed-method exploratory-descriptive research design was employed to collect the quantitative data by means of the Curiosity and Exploratory Inventory. The qualitative data were collected using semistructured interviews to explore how psychologists-in-training have dealt with uncertainty. Purposive-availability sampling was used to select the participants at three South African universities. A total number of 50 participants completed the CEI and six participants were interviewed. The data were analysed using mixed-method data analysis. It was found that participants had moderate-to-high levels of curiosity and exploration, with higher levels of exploration than absorption. The majority of participants reported that they actively sought as much information as they could and frequently looked for new opportunities to grow as persons. The strategies used by the selected group of participants to deal with uncertainty included: reliance on clinical supervision; consultation with peers; self-enhancement; reliance on theory; learning from practical experience; using certain cognitive appraisals; and self-care. Certain conclusions and recommendations were made based on the findings of the study.
- Full Text:
- Date Issued: 2009
Decision making improvement by effectively utilising activity-based costing and activity-based management tools
- Authors: Palmer, Vivian Julian
- Date: 2009
- Subjects: Decision making , Thought and thinking
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8677 , http://hdl.handle.net/10948/1152 , Decision making , Thought and thinking
- Description: The aim of this study was to suggest ways to effectively utilise Activity-Based Costing and Activity-Based Managment within Eskom Transmission Southern Grid to improve decision making towards improved business and financial performance. The ultimate purpose was to assist managers and staff to implement ABC and ABM effectively for improved business and financial performance. The focus was on the following objective: To suggest ways to effectively utilise ABC & ABM within Eskom Transmission Southern Grid as to improve decision making and business financial performance. Given the selection of management tools available, instruments such as ABC and ABM are usually not implemented alone, but may be supported by one or more approaches. For this reason ABC and ABM are contrasted with several other popular instruments mentioned in the literature. The instruments are: • The value chain; • Continuous improvement; • The theory of constraints; and • Total quality management. Insight will be given to provide managers with more accurate information regarding maintenance for the Grid and tools in identifying critical bottlenecks. By applying the TOC, TQM and continuous improvement strategies, managers will be able to make improved decisions, leading to improved financial performance in the Eskom Transmission Southern Grid. iii The literature study revealed that ABC and ABM prove to be the cornerstone for informed decision making. Since organisations are highly dependent on quality information to make these informed decisions, ABC and ABM reorientate the organisation towards understanding and managing work processes thus impacting financial performance positively. ABC and ABM trace the cost of activities such as engineering and procurement to how maintenance benefits from these activities. The empirical study consisted of a structured questionnaire distributed to a sample population of engineers and managers in Eskom Transmission Southern Grid in Port Elizabeth. It was aimed at gathering information about the use of ABC and ABM within the Grid. Semi-structured interviews were also conducted with financial staff in the Grid and a focus group interview with engineering staff was done. The main findings of the empirical investigation revealed that management and staff lack insight into the use of ABC and ABM and how it can be integrated with existing improvement systems within the organisation. This study is concluded with a number of recommendations. These recommendations address the shortcomings and improvements that can be made to improve the utilisation of ABC and ABM within the organisation. The recommendations address the following: • Ensuring full commitment towards organisational goals and broadening the endorsement of ABC within the organisation; • Highlighting the importance of financial performance throughout the Grid; • Training of Managers, finance staff and engineers is required for proper execution of the ABC system; • Implementers need skills and know-how of the ABC and ABM system ensuring full utilisation; • The main cost drivers are identified, prioritised and efforts channelled into these activities; • Tools such as the Theory Of Constraints and Total Quality Management from the proposed model would assist the Grid in identifying the bottlenecks of a system correctly, thus know explicitly the amount of slack capacity of each activity available during a specific time period.
- Full Text:
- Date Issued: 2009
- Authors: Palmer, Vivian Julian
- Date: 2009
- Subjects: Decision making , Thought and thinking
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8677 , http://hdl.handle.net/10948/1152 , Decision making , Thought and thinking
- Description: The aim of this study was to suggest ways to effectively utilise Activity-Based Costing and Activity-Based Managment within Eskom Transmission Southern Grid to improve decision making towards improved business and financial performance. The ultimate purpose was to assist managers and staff to implement ABC and ABM effectively for improved business and financial performance. The focus was on the following objective: To suggest ways to effectively utilise ABC & ABM within Eskom Transmission Southern Grid as to improve decision making and business financial performance. Given the selection of management tools available, instruments such as ABC and ABM are usually not implemented alone, but may be supported by one or more approaches. For this reason ABC and ABM are contrasted with several other popular instruments mentioned in the literature. The instruments are: • The value chain; • Continuous improvement; • The theory of constraints; and • Total quality management. Insight will be given to provide managers with more accurate information regarding maintenance for the Grid and tools in identifying critical bottlenecks. By applying the TOC, TQM and continuous improvement strategies, managers will be able to make improved decisions, leading to improved financial performance in the Eskom Transmission Southern Grid. iii The literature study revealed that ABC and ABM prove to be the cornerstone for informed decision making. Since organisations are highly dependent on quality information to make these informed decisions, ABC and ABM reorientate the organisation towards understanding and managing work processes thus impacting financial performance positively. ABC and ABM trace the cost of activities such as engineering and procurement to how maintenance benefits from these activities. The empirical study consisted of a structured questionnaire distributed to a sample population of engineers and managers in Eskom Transmission Southern Grid in Port Elizabeth. It was aimed at gathering information about the use of ABC and ABM within the Grid. Semi-structured interviews were also conducted with financial staff in the Grid and a focus group interview with engineering staff was done. The main findings of the empirical investigation revealed that management and staff lack insight into the use of ABC and ABM and how it can be integrated with existing improvement systems within the organisation. This study is concluded with a number of recommendations. These recommendations address the shortcomings and improvements that can be made to improve the utilisation of ABC and ABM within the organisation. The recommendations address the following: • Ensuring full commitment towards organisational goals and broadening the endorsement of ABC within the organisation; • Highlighting the importance of financial performance throughout the Grid; • Training of Managers, finance staff and engineers is required for proper execution of the ABC system; • Implementers need skills and know-how of the ABC and ABM system ensuring full utilisation; • The main cost drivers are identified, prioritised and efforts channelled into these activities; • Tools such as the Theory Of Constraints and Total Quality Management from the proposed model would assist the Grid in identifying the bottlenecks of a system correctly, thus know explicitly the amount of slack capacity of each activity available during a specific time period.
- Full Text:
- Date Issued: 2009
Detecting changes in elephant body condition in relation to resource quality
- Authors: De Klerk, Christelle
- Date: 2009
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10704 , http://hdl.handle.net/10948/939 , Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape
- Description: Elephants, as megaherbivores, are known to have extensive impacts on vegetation, especially in enclosed areas. This raises the issue that elephants in enclosed areas may become limited by resource availability. Resource limitation is generally expressed via density dependence, but elephants, due to their slow demography, may not be affected by initial changes in resource availability. This highlights the need for a more sensitive measure of resource limitation to allow for the detection of energy stress within a population before changes in vital rates occur. This study investigated visual changes in elephant body condition in relation to resource availability in a number of Eastern Cape reserves to assess whether body condition could be used to detect life stages, as well as seasons and sites which may be resource limited. Elephant life stages were divided into energy stressed (newly weaned calves, lactating females, and old females) and non-energy stressed classes (sub-adults and non-lactating females) to determine whether energy stressed life stages were more vulnerable to resource limitation. In the AENP it was found that lactating and old females exhibited significantly poorer body condition than non-energy stressed individuals, but that weaned calves had body conditions similar to non-energy stressed individuals. Comparisons between seasons revealed that all life stages exhibited better condition in winter than summer or spring, with lactating females showing little recovery of condition over time. Seasonal body conditions were correlated with rainfall recorded in the Addo Elephant National Park. Comparisons of elephant body condition between sites (n = 6) revealed that body condition varied across sites, with poorer body condition associated with areas of higher elephant density and low rainfall during the study period. Comparisons with faecal dietary quality data both between sites and seasons indicated that body condition also responded to changes in the availability of protein and neutral detergent fibre (NDF) of plant resources, with higher protein and lower values associated with better condition. Based on condition estimates of elephants occurring in the Addo Main Camp, it was established that this population is experiencing nutritional stress, with energy stressed individuals exhibiting the lowest body conditions. This was supported by dietary quality measures. Our findings suggest that elephant body condition is a good measure for detecting resource limitation, both within populations and between seasons, and that elephant body condition respond to relatively small changes in resource conditions, thus making it an effective measure for the detection of nutritional stress. Additionally, our findings show that energy stressed individuals, particularly lactating and old females are more vulnerable to resource limitation. This demonstrates the importance of monitoring these life stages for the detection of density dependence within populations. Finally, our data suggest that threshold values of faecal dietary quality may exist at which body condition within a population begins to deteriorate, making it possible to determine the condition of a population through values obtained in faecal samples.
- Full Text:
- Date Issued: 2009
- Authors: De Klerk, Christelle
- Date: 2009
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10704 , http://hdl.handle.net/10948/939 , Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape
- Description: Elephants, as megaherbivores, are known to have extensive impacts on vegetation, especially in enclosed areas. This raises the issue that elephants in enclosed areas may become limited by resource availability. Resource limitation is generally expressed via density dependence, but elephants, due to their slow demography, may not be affected by initial changes in resource availability. This highlights the need for a more sensitive measure of resource limitation to allow for the detection of energy stress within a population before changes in vital rates occur. This study investigated visual changes in elephant body condition in relation to resource availability in a number of Eastern Cape reserves to assess whether body condition could be used to detect life stages, as well as seasons and sites which may be resource limited. Elephant life stages were divided into energy stressed (newly weaned calves, lactating females, and old females) and non-energy stressed classes (sub-adults and non-lactating females) to determine whether energy stressed life stages were more vulnerable to resource limitation. In the AENP it was found that lactating and old females exhibited significantly poorer body condition than non-energy stressed individuals, but that weaned calves had body conditions similar to non-energy stressed individuals. Comparisons between seasons revealed that all life stages exhibited better condition in winter than summer or spring, with lactating females showing little recovery of condition over time. Seasonal body conditions were correlated with rainfall recorded in the Addo Elephant National Park. Comparisons of elephant body condition between sites (n = 6) revealed that body condition varied across sites, with poorer body condition associated with areas of higher elephant density and low rainfall during the study period. Comparisons with faecal dietary quality data both between sites and seasons indicated that body condition also responded to changes in the availability of protein and neutral detergent fibre (NDF) of plant resources, with higher protein and lower values associated with better condition. Based on condition estimates of elephants occurring in the Addo Main Camp, it was established that this population is experiencing nutritional stress, with energy stressed individuals exhibiting the lowest body conditions. This was supported by dietary quality measures. Our findings suggest that elephant body condition is a good measure for detecting resource limitation, both within populations and between seasons, and that elephant body condition respond to relatively small changes in resource conditions, thus making it an effective measure for the detection of nutritional stress. Additionally, our findings show that energy stressed individuals, particularly lactating and old females are more vulnerable to resource limitation. This demonstrates the importance of monitoring these life stages for the detection of density dependence within populations. Finally, our data suggest that threshold values of faecal dietary quality may exist at which body condition within a population begins to deteriorate, making it possible to determine the condition of a population through values obtained in faecal samples.
- Full Text:
- Date Issued: 2009