The economics of greening the Grahamstown National Arts Festival in South Africa
- Dobson, Blaise, Snowball, Jeanette D
- Authors: Dobson, Blaise , Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71445 , vital:29851 , https://hdl.handle.net/10520/EJC132010
- Description: The article analyses the broad history underpinning the notion of sustainable development and its context within the events industry in South Africa. It explores the willingness of festival-goers to pay for a hypothetical recycling programme to reduce the negative externalities of the Festival. Results show that festival-goers were, on average, willing to pay an additional R2.30 per "green" ticket to fund the proposed programme. A statistical regression was used to explore the determinants of willing-to-pay. If applied to all tickets, the total willing-to-pay amount far exceeded the actual cost of the recycling programme.
- Full Text: false
- Date Issued: 2012
- Authors: Dobson, Blaise , Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71445 , vital:29851 , https://hdl.handle.net/10520/EJC132010
- Description: The article analyses the broad history underpinning the notion of sustainable development and its context within the events industry in South Africa. It explores the willingness of festival-goers to pay for a hypothetical recycling programme to reduce the negative externalities of the Festival. Results show that festival-goers were, on average, willing to pay an additional R2.30 per "green" ticket to fund the proposed programme. A statistical regression was used to explore the determinants of willing-to-pay. If applied to all tickets, the total willing-to-pay amount far exceeded the actual cost of the recycling programme.
- Full Text: false
- Date Issued: 2012
The economics of suicide in South Africa
- Authors: Botha, Ferdi
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396168 , vital:69155 , xlink:href="https://doi.org/10.1111/j.1813-6982.2012.01336.x"
- Description: This study investigates the economics of suicide in South Africa using the Mortality and Causes of Death data from death notification as well as regional economic data for the 2006-2008 period. Using an inflation rate that varies by month and across province of residence as a proxy for economic performance, the results indicate a negative relationship between inflation and suicide, suggesting that suicides are countercyclical. When controlling for month and province fixed effects, however, the inflation coefficient, albeit remaining negative, is no longer significant, except in the female sample. Suicide is more prevalent among younger individuals, while the greatest proportion of suicide is seen among men. Suicides also exhibit a strong seasonal variation, with peaks in spring and summer, with December having the highest suicide prevalence. The overall results indicate a negative but insignificant relationship between economic performance and suicide in South Africa, with socio-economic differences and individual characteristics accounting for most of the variation in suicide.
- Full Text:
- Date Issued: 2012
- Authors: Botha, Ferdi
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396168 , vital:69155 , xlink:href="https://doi.org/10.1111/j.1813-6982.2012.01336.x"
- Description: This study investigates the economics of suicide in South Africa using the Mortality and Causes of Death data from death notification as well as regional economic data for the 2006-2008 period. Using an inflation rate that varies by month and across province of residence as a proxy for economic performance, the results indicate a negative relationship between inflation and suicide, suggesting that suicides are countercyclical. When controlling for month and province fixed effects, however, the inflation coefficient, albeit remaining negative, is no longer significant, except in the female sample. Suicide is more prevalent among younger individuals, while the greatest proportion of suicide is seen among men. Suicides also exhibit a strong seasonal variation, with peaks in spring and summer, with December having the highest suicide prevalence. The overall results indicate a negative but insignificant relationship between economic performance and suicide in South Africa, with socio-economic differences and individual characteristics accounting for most of the variation in suicide.
- Full Text:
- Date Issued: 2012
The effect of a guided enquiry based learning approach on mechanical engineering students' understanding of thermodynamics
- Authors: Louw, Christoffel
- Date: 2012
- Subjects: Thermodynamics -- Mechanical engineering -- Students
- Language: English
- Type: Thesis , Doctoral , D Ed
- Identifier: vital:18474 , http://hdl.handle.net/11260/d1011523
- Description: Personal experiences of almost 17 years as an academic in engineering education in South Africa indicate that with the current teaching methods which are in use, course outcomes as required by the South African Qualification Authority (SAQA) are not achieved in learning Thermodynamics 2 (MTHE 2). The purpose of this research was to investigate alternative methods of teaching and learning MTHE 2 which would assist to improve the students’ academic performance. The population for this research was students registered for National Diploma Mechanical Engineering and the accessible population was 40 students registered for MTHE 2 from Walter Sisulu University, Chiselhurst campus. Out of these 40 students, 20 voluntarily agreed to be the sample. The theoretical framework for this study was social constructivism. Social constructivism states that learning is an active process and the process of knowledge construction occurs in a socio-cultural context where the student and environment actively interact. The student involves himself/herself and does neither remain nor be allowed to remain just as a passive observer. This was an action research where students were exposed to Guided Enquiry Based Learning (GEBL) in groups. From a social constructivists approach to learning, GEBL was used to engage students in social groups during the teaching-learning process with specific focus on selected academic discipline. All ethical considerations applicable to a study of the present nature were adhered to and in addition, signed informed consent forms were obtained from participants prior to the study. Students were given an introduction to the concepts and principles as per the pre-set syllabus for MTHE 2 and this was followed by problem solving sessions in which they were divided into four groups of five students each. The students were given a guided enquiry- and work-based example with an additional list of questions on each module of the syllabus. They had to select the most relevant questions from the list to analyse and develop a solution for each problem. The lecturers’ role was that of a facilitator who assisted each group with problems which the group encountered. This approach engaged students more actively in the learning process and placed more responsibility on them for their own progress in learning. This process also created an atmosphere for interaction with peers and assisted them to develop interpersonal and group communication skills. Key performance indicators were developed to measure the extent to which these outcomes were achieved. The researcher made use of an instrument structured in terms of Likert-type scale in order to objectively assess the extent of achievement. Data collected from the pilot study done in 2009 indicated that GEBL improved the students’ understanding of course content and problem analysis. Quantitative data were collected by means of standard assessment i.e. semester tests, an oral test, final examination and a KPI instrument. The KPIs were formulated to measure the extent to which the outcomes for MTHE 2 had been achieved. Qualitative data were collected through 30-minute interviews, using an open-ended interview schedule, with each member of the sample. The interviews were done by a person who qualified both as an ‘insider and outsider’ in order to minimize the risk of bias and to maintain rigour in the research. In order to qualify as an ‘insider and outsider’, one ought to be as an insider: (a) from the same ethnic group, (b) qualified in Mechanical Engineering with Thermodynamics as a major course, (c) had no power disposition e.g. a former student or a laboratory assistant (excluding staff members within the mechanical engineering department) and as an outsider, one who was not part of the GEBL process. The quantitative scores from the assessments were analysed with Predictive Analysis Software (PASW) to determine the extent to which interventions had assisted student performance. The qualitative data from the interviews were analysed with N-Vivo to reveal the impact of GEBL on student learning and understanding of MTHE 2. The results indicated that with GEBL, the students’ overall scores improved from the first assessment score of 46% written on half of the first module to the final assessment score of 55% written on all seven modules. Students could handle larger volumes of work and still obtain a higher percentage. GEBL assisted students’ in recalling factual MTHE 2 concepts, understanding of MTHE 2 concepts, principles and applications. GEBL also enhanced students’ ability to communicate procedures and processes related to MTHE 2. KPIs formulated to measure the extent to which the outcomes were met in terms of student achievement indicated a 57% achievement thereof. The KPIs developed gave a percentage achievement of the specified outcomes for MTHE 2 with GEBL. Theses KPIs can be used in future to measure the effectiveness of different teaching and learning methods in terms of achieving the outcomes. It is therefore recommended that GEBL be introduced into other engineering courses also to assist students in understanding course content and in achieving the course outcomes.
- Full Text:
- Date Issued: 2012
- Authors: Louw, Christoffel
- Date: 2012
- Subjects: Thermodynamics -- Mechanical engineering -- Students
- Language: English
- Type: Thesis , Doctoral , D Ed
- Identifier: vital:18474 , http://hdl.handle.net/11260/d1011523
- Description: Personal experiences of almost 17 years as an academic in engineering education in South Africa indicate that with the current teaching methods which are in use, course outcomes as required by the South African Qualification Authority (SAQA) are not achieved in learning Thermodynamics 2 (MTHE 2). The purpose of this research was to investigate alternative methods of teaching and learning MTHE 2 which would assist to improve the students’ academic performance. The population for this research was students registered for National Diploma Mechanical Engineering and the accessible population was 40 students registered for MTHE 2 from Walter Sisulu University, Chiselhurst campus. Out of these 40 students, 20 voluntarily agreed to be the sample. The theoretical framework for this study was social constructivism. Social constructivism states that learning is an active process and the process of knowledge construction occurs in a socio-cultural context where the student and environment actively interact. The student involves himself/herself and does neither remain nor be allowed to remain just as a passive observer. This was an action research where students were exposed to Guided Enquiry Based Learning (GEBL) in groups. From a social constructivists approach to learning, GEBL was used to engage students in social groups during the teaching-learning process with specific focus on selected academic discipline. All ethical considerations applicable to a study of the present nature were adhered to and in addition, signed informed consent forms were obtained from participants prior to the study. Students were given an introduction to the concepts and principles as per the pre-set syllabus for MTHE 2 and this was followed by problem solving sessions in which they were divided into four groups of five students each. The students were given a guided enquiry- and work-based example with an additional list of questions on each module of the syllabus. They had to select the most relevant questions from the list to analyse and develop a solution for each problem. The lecturers’ role was that of a facilitator who assisted each group with problems which the group encountered. This approach engaged students more actively in the learning process and placed more responsibility on them for their own progress in learning. This process also created an atmosphere for interaction with peers and assisted them to develop interpersonal and group communication skills. Key performance indicators were developed to measure the extent to which these outcomes were achieved. The researcher made use of an instrument structured in terms of Likert-type scale in order to objectively assess the extent of achievement. Data collected from the pilot study done in 2009 indicated that GEBL improved the students’ understanding of course content and problem analysis. Quantitative data were collected by means of standard assessment i.e. semester tests, an oral test, final examination and a KPI instrument. The KPIs were formulated to measure the extent to which the outcomes for MTHE 2 had been achieved. Qualitative data were collected through 30-minute interviews, using an open-ended interview schedule, with each member of the sample. The interviews were done by a person who qualified both as an ‘insider and outsider’ in order to minimize the risk of bias and to maintain rigour in the research. In order to qualify as an ‘insider and outsider’, one ought to be as an insider: (a) from the same ethnic group, (b) qualified in Mechanical Engineering with Thermodynamics as a major course, (c) had no power disposition e.g. a former student or a laboratory assistant (excluding staff members within the mechanical engineering department) and as an outsider, one who was not part of the GEBL process. The quantitative scores from the assessments were analysed with Predictive Analysis Software (PASW) to determine the extent to which interventions had assisted student performance. The qualitative data from the interviews were analysed with N-Vivo to reveal the impact of GEBL on student learning and understanding of MTHE 2. The results indicated that with GEBL, the students’ overall scores improved from the first assessment score of 46% written on half of the first module to the final assessment score of 55% written on all seven modules. Students could handle larger volumes of work and still obtain a higher percentage. GEBL assisted students’ in recalling factual MTHE 2 concepts, understanding of MTHE 2 concepts, principles and applications. GEBL also enhanced students’ ability to communicate procedures and processes related to MTHE 2. KPIs formulated to measure the extent to which the outcomes were met in terms of student achievement indicated a 57% achievement thereof. The KPIs developed gave a percentage achievement of the specified outcomes for MTHE 2 with GEBL. Theses KPIs can be used in future to measure the effectiveness of different teaching and learning methods in terms of achieving the outcomes. It is therefore recommended that GEBL be introduced into other engineering courses also to assist students in understanding course content and in achieving the course outcomes.
- Full Text:
- Date Issued: 2012
The effect of an agency-based HIV/AIDS education programme on the knowledge and attitudes of undergraduate students at WSU
- Authors: Wopula, Luvuyo David
- Date: 2012
- Subjects: HIV/AIDS -- Educational programme -- Students
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:18451 , http://hdl.handle.net/11260/d1007757
- Description: The aim of this study was to investigate the effects of an agency-based HIV/AIDS Education programme on knowledge and attitudes of undergraduate students at the Walter Sisulu University (WSU) in South Africa. Participants were divided into experimental and control groups. A questionnaire was designed, validated and used to assess knowledge and attitudes of students towards HIV/AIDS who went through the HIV/AIDS education programme (HAEP) and those who did not. The questions were derived and based on basic HIV/AIDS information as part of the 'Alternative National Curriculum on Responsibility' (AANCHOR) programme used by first year WSU staff which was used in the United States of America. The study findings indicate that knowledge and attitudes of the students improved after the intervention. After the intervention, the t-test showed that students‟ attitudes on HIV/AIDS were found to be significant (p=0.045) when comparing the pre- experimental and intervention groups. However, the study also found that some participants displayed ignorance on the knowledge of HIV/AIDS and its effects. For example, some students believe that mosquitoes can spread HIV/AIDS. On the basis of findings the researcher recommends that all first year students should be expose to WSU HAEP because it is a necessity for empowerment with social, self- dependent skills (against HIV/AIDS) and self efficacy. Key words: HIV/AIDS, knowledge, attitudes, Education programme, students.
- Full Text:
- Date Issued: 2012
- Authors: Wopula, Luvuyo David
- Date: 2012
- Subjects: HIV/AIDS -- Educational programme -- Students
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:18451 , http://hdl.handle.net/11260/d1007757
- Description: The aim of this study was to investigate the effects of an agency-based HIV/AIDS Education programme on knowledge and attitudes of undergraduate students at the Walter Sisulu University (WSU) in South Africa. Participants were divided into experimental and control groups. A questionnaire was designed, validated and used to assess knowledge and attitudes of students towards HIV/AIDS who went through the HIV/AIDS education programme (HAEP) and those who did not. The questions were derived and based on basic HIV/AIDS information as part of the 'Alternative National Curriculum on Responsibility' (AANCHOR) programme used by first year WSU staff which was used in the United States of America. The study findings indicate that knowledge and attitudes of the students improved after the intervention. After the intervention, the t-test showed that students‟ attitudes on HIV/AIDS were found to be significant (p=0.045) when comparing the pre- experimental and intervention groups. However, the study also found that some participants displayed ignorance on the knowledge of HIV/AIDS and its effects. For example, some students believe that mosquitoes can spread HIV/AIDS. On the basis of findings the researcher recommends that all first year students should be expose to WSU HAEP because it is a necessity for empowerment with social, self- dependent skills (against HIV/AIDS) and self efficacy. Key words: HIV/AIDS, knowledge, attitudes, Education programme, students.
- Full Text:
- Date Issued: 2012
The effect of collective efficacy on the introdution of a new curriculum by mathematics teachers
- Authors: Hendricks, Winston Willie
- Date: 2012
- Subjects: Curriculum change -- South Africa , Education -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9508 , http://hdl.handle.net/10948/d1008589 , Curriculum change -- South Africa , Education -- South Africa
- Description: The introduction of curriculum changes in mathematics has brought about challenges for both mathematics teachers and learners in South African schools. Apart from introducing new curriculum content to learners, teachers cope with factors which impact upon their collective efficacy (the sum total of the self-perceptions of all the teachers in a particular school regarding the conduciveness of effective teaching, learning and assessment processes) and on the teacher self-efficacy of mathematics teachers (the personal self-perceptions of mathematics teachers to execute their mandates effectively in the teaching, learning and assessment of mathematics ) which consequently lead to mathematics learners developing better concepts in mathematics. This study focuses on the impact of collective efficacy on the implementation of the New Curriculum Statement (NCS) for mathematics teachers, teaching in schools situated in previously disadvantaged communities. It is within the context of the constraints that these schools face, not only the socio-economic barriers, but also the willingness of all the teachers to develop a culture of teaching and learning, and the consequent impact it has on the effective teaching, learning and assessment of mathematics in the classrooms of these schools, that the effect of efficacious/non-efficacious teachers in these schools is investigated. A mixed method approach by using quantitative data (generated from questionnaires) and qualitative data (generated from interviews) probe the primary research question, which aims to investigate the effect of collective efficacy on the introduction of a new curriculum by mathematics teachers. The sub-questions probe the specific efficacy relations relating to the primary research question in terms of the perceptions and perspectives of all the teachers about their respective sample schools, how these perceptions and perspectives influence mathematics teachers in the manner they perceive their control over the teaching, learning and assessment processes in the mathematics classroom, and the consequent impact it has on mathematics learners developing better concepts and ultimately achieving better academic results in mathematics.
- Full Text:
- Date Issued: 2012
- Authors: Hendricks, Winston Willie
- Date: 2012
- Subjects: Curriculum change -- South Africa , Education -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9508 , http://hdl.handle.net/10948/d1008589 , Curriculum change -- South Africa , Education -- South Africa
- Description: The introduction of curriculum changes in mathematics has brought about challenges for both mathematics teachers and learners in South African schools. Apart from introducing new curriculum content to learners, teachers cope with factors which impact upon their collective efficacy (the sum total of the self-perceptions of all the teachers in a particular school regarding the conduciveness of effective teaching, learning and assessment processes) and on the teacher self-efficacy of mathematics teachers (the personal self-perceptions of mathematics teachers to execute their mandates effectively in the teaching, learning and assessment of mathematics ) which consequently lead to mathematics learners developing better concepts in mathematics. This study focuses on the impact of collective efficacy on the implementation of the New Curriculum Statement (NCS) for mathematics teachers, teaching in schools situated in previously disadvantaged communities. It is within the context of the constraints that these schools face, not only the socio-economic barriers, but also the willingness of all the teachers to develop a culture of teaching and learning, and the consequent impact it has on the effective teaching, learning and assessment of mathematics in the classrooms of these schools, that the effect of efficacious/non-efficacious teachers in these schools is investigated. A mixed method approach by using quantitative data (generated from questionnaires) and qualitative data (generated from interviews) probe the primary research question, which aims to investigate the effect of collective efficacy on the introduction of a new curriculum by mathematics teachers. The sub-questions probe the specific efficacy relations relating to the primary research question in terms of the perceptions and perspectives of all the teachers about their respective sample schools, how these perceptions and perspectives influence mathematics teachers in the manner they perceive their control over the teaching, learning and assessment processes in the mathematics classroom, and the consequent impact it has on mathematics learners developing better concepts and ultimately achieving better academic results in mathematics.
- Full Text:
- Date Issued: 2012
The effect of dietary fish oil replacement with soybean oil on growth and health of dusky kob, Argyrosomus japonicus (Pisces: Sciaenidae)
- Authors: Rossetti, Nani Adami
- Date: 2012
- Subjects: Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5272 , http://hdl.handle.net/10962/d1005116 , Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Description: Lipids are essential components for fish because they contain fatty acids that are vital for regular growth and health. Fish oil is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential fatty acids for carnivorous fish, and therefore this product has traditionally been used as the main source of lipids in fish feeds. However, with declining fisheries resources worldwide and the rapid expansion of the aquaculture industry pressuring this finite resource, such ingredients are becoming less available and more expensive. It is therefore necessary to explore the utilization of ingredients that are sustainable and competitive alternatives to fish oil in marine finfish feeds. This work investigated the effects of the substitution of fish oil with soybean oil on the growth performance, feed efficiency, fatty acid composition of the liver tissue and some health parameters in juvenile dusky kob, Argyrosomus japonicus; an increasingly popular sciaenid marine aquaculture species in South Africa. Six diets (18 % total lipid and 46 % protein) with increasing percentage substitution of fish oil with soybean oil (1, 14, 28, 42, 56 and 70 %) were fed to juvenile kob. After 84 days of feeding these diets to the fish, no significant differences in fish length and weight between treatments were observed. However, there was a significant trend of a decrease in specific growth rate, ranging from (± standard error) 0.87 ± 0.06 to 0.72 ± 0.04 % body weight day⁻¹, and condition factor, ranging from 1.59 ± 0.03 to 1.54 ± 0.02, with increasing vegetable oil replacement in the diets between days 56 and 84. There were no differences in red blood cell count, haematocrit and haemoglobin concentration after 206 days of feeding. However, visceral fat index (VFI) increased significantly from 1.08 ± 0.17 % for fish fed diets with 28 % soybean oil, to 2.24 ± 0.15 % for fish fed diets with 70 % soybean oil. Similarly, hepatosomatic index (HSI) increased significantly from 0.84 ± 0.08 % to 1.80 ± 0.12 % in the control diet and the 56 % soybean oil diet, respectively. After 206 days of feeding, fish fed diets with 42 to 70 % soybean oil showed greater number of lipid vacuoles in the liver, which were also larger in size, and hepatocytes nuclei were displaced to the cell periphery. The fatty acid composition of the liver tissue strongly corresponded to the fatty acid composition of the diets. Linoleic acid accumulated in the liver of the fish fed increasing soybean oil in the diets. In contrast, EPA and DHA decreased from 13.63 to 1.97 %, and 14.34 to 3.28 %, respectively, in the liver tissue of fish fed diets with increasing soybean oil content; consequently the n-3/n-6 ratio was also significantly reduced with inclusion of vegetable oil in the diets. The trend of decreasing growth rate with increasing oil replacement towards the end of the trial corresponds with increases in VFI, HSI, as well as the fatty acid accumulation and lipid vacuoles in the liver. This suggests that dusky kob is less able to metabolise soybean oil at increased substitution levels which would account for the poorer growth at higher levels. The dependence of fish on dietary marine oil decreased significantly with each inclusion of soybean oil in the diets. Nonetheless, the calculations based on the nutrient ratio presented positive outcomes for all treatments, that is, values of marine oil dependency ratio were below one for all treatments. It is concluded that soybean oil can replace fish oil in formulated diets for dusky kob up to a level of 28 % of total dietary lipids, as evidenced by the good growth and feed efficiency, and no apparent negative health effects observed up to this level.
- Full Text:
- Date Issued: 2012
- Authors: Rossetti, Nani Adami
- Date: 2012
- Subjects: Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5272 , http://hdl.handle.net/10962/d1005116 , Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Description: Lipids are essential components for fish because they contain fatty acids that are vital for regular growth and health. Fish oil is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential fatty acids for carnivorous fish, and therefore this product has traditionally been used as the main source of lipids in fish feeds. However, with declining fisheries resources worldwide and the rapid expansion of the aquaculture industry pressuring this finite resource, such ingredients are becoming less available and more expensive. It is therefore necessary to explore the utilization of ingredients that are sustainable and competitive alternatives to fish oil in marine finfish feeds. This work investigated the effects of the substitution of fish oil with soybean oil on the growth performance, feed efficiency, fatty acid composition of the liver tissue and some health parameters in juvenile dusky kob, Argyrosomus japonicus; an increasingly popular sciaenid marine aquaculture species in South Africa. Six diets (18 % total lipid and 46 % protein) with increasing percentage substitution of fish oil with soybean oil (1, 14, 28, 42, 56 and 70 %) were fed to juvenile kob. After 84 days of feeding these diets to the fish, no significant differences in fish length and weight between treatments were observed. However, there was a significant trend of a decrease in specific growth rate, ranging from (± standard error) 0.87 ± 0.06 to 0.72 ± 0.04 % body weight day⁻¹, and condition factor, ranging from 1.59 ± 0.03 to 1.54 ± 0.02, with increasing vegetable oil replacement in the diets between days 56 and 84. There were no differences in red blood cell count, haematocrit and haemoglobin concentration after 206 days of feeding. However, visceral fat index (VFI) increased significantly from 1.08 ± 0.17 % for fish fed diets with 28 % soybean oil, to 2.24 ± 0.15 % for fish fed diets with 70 % soybean oil. Similarly, hepatosomatic index (HSI) increased significantly from 0.84 ± 0.08 % to 1.80 ± 0.12 % in the control diet and the 56 % soybean oil diet, respectively. After 206 days of feeding, fish fed diets with 42 to 70 % soybean oil showed greater number of lipid vacuoles in the liver, which were also larger in size, and hepatocytes nuclei were displaced to the cell periphery. The fatty acid composition of the liver tissue strongly corresponded to the fatty acid composition of the diets. Linoleic acid accumulated in the liver of the fish fed increasing soybean oil in the diets. In contrast, EPA and DHA decreased from 13.63 to 1.97 %, and 14.34 to 3.28 %, respectively, in the liver tissue of fish fed diets with increasing soybean oil content; consequently the n-3/n-6 ratio was also significantly reduced with inclusion of vegetable oil in the diets. The trend of decreasing growth rate with increasing oil replacement towards the end of the trial corresponds with increases in VFI, HSI, as well as the fatty acid accumulation and lipid vacuoles in the liver. This suggests that dusky kob is less able to metabolise soybean oil at increased substitution levels which would account for the poorer growth at higher levels. The dependence of fish on dietary marine oil decreased significantly with each inclusion of soybean oil in the diets. Nonetheless, the calculations based on the nutrient ratio presented positive outcomes for all treatments, that is, values of marine oil dependency ratio were below one for all treatments. It is concluded that soybean oil can replace fish oil in formulated diets for dusky kob up to a level of 28 % of total dietary lipids, as evidenced by the good growth and feed efficiency, and no apparent negative health effects observed up to this level.
- Full Text:
- Date Issued: 2012
The effect of foreign direct investment on economic growth: evidence from South Africa
- Authors: Mazenda, Adrino
- Date: 2012
- Subjects: International Monetary Fund , Investments, Foreign -- South Africa , Economic development -- South Africa , International finance , Finance -- Developing countries
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11462 , http://hdl.handle.net/10353/d1007027 , International Monetary Fund , Investments, Foreign -- South Africa , Economic development -- South Africa , International finance , Finance -- Developing countries
- Description: Foreign direct investment amongst other mechanisms provides capital inflow meant to stimulate economic growth. Apart from promoting economic growth, FDI can also lead to increase in employment, technology, technical knowhow and managerial skills. South Africa has implemented various policy initiatives in attempts to attract foreign investment. This study investigates on the effect of foreign direct investment on economic growth, with particular reference to the South African economy. The period of study is from 1980 to 2010. The study begins by reviewing literature on economic growth and foreign direct investment. South Africa’s macroeconomic background is examined to determine the trends in FDI inflows and economic growth. An empirical model linking theoretical and empirical literature on the effect of FDI on economic growth is estimated using the Johansen cointegration and VECM framework. Variables specified in the methodology include real gross domestic product (RGDP), foreign direct investment (FDI), domestic investment (INVE), real exchange rate (REXCH) and foreign marketable debt (DEBT). The long run results showed that FDI, REXCH and DEBT have a negative impact on growth. INVE has a positive impact on growth. Short run results indicated that there is no strong pressure on RGDP to restore long-run equilibrium whenever there is a disturbance. The short run lag of FDI was found to exert a positive impact on growth. The impulse response and variance decomposition analysis complemented the long and short-run findings. Shocks on REXCH, and DEBT generated a negative response on RGDP. The shocks were not significantly different from zero and were transitory. Results from the variance decomposition analysis revealed that the fundamentals explain some, but not all, of the variations of RGDP. For the fifth year forecast error variance RGDP explains the largest component of the variation followed by INVE, REXCH, FDI and DEBT. After a period of ten years, the influence of RGDP and INVE declines, whereas REXCH, FDI and DEBT increase. Conclusions and policy recommendations were made using these results.
- Full Text:
- Date Issued: 2012
- Authors: Mazenda, Adrino
- Date: 2012
- Subjects: International Monetary Fund , Investments, Foreign -- South Africa , Economic development -- South Africa , International finance , Finance -- Developing countries
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11462 , http://hdl.handle.net/10353/d1007027 , International Monetary Fund , Investments, Foreign -- South Africa , Economic development -- South Africa , International finance , Finance -- Developing countries
- Description: Foreign direct investment amongst other mechanisms provides capital inflow meant to stimulate economic growth. Apart from promoting economic growth, FDI can also lead to increase in employment, technology, technical knowhow and managerial skills. South Africa has implemented various policy initiatives in attempts to attract foreign investment. This study investigates on the effect of foreign direct investment on economic growth, with particular reference to the South African economy. The period of study is from 1980 to 2010. The study begins by reviewing literature on economic growth and foreign direct investment. South Africa’s macroeconomic background is examined to determine the trends in FDI inflows and economic growth. An empirical model linking theoretical and empirical literature on the effect of FDI on economic growth is estimated using the Johansen cointegration and VECM framework. Variables specified in the methodology include real gross domestic product (RGDP), foreign direct investment (FDI), domestic investment (INVE), real exchange rate (REXCH) and foreign marketable debt (DEBT). The long run results showed that FDI, REXCH and DEBT have a negative impact on growth. INVE has a positive impact on growth. Short run results indicated that there is no strong pressure on RGDP to restore long-run equilibrium whenever there is a disturbance. The short run lag of FDI was found to exert a positive impact on growth. The impulse response and variance decomposition analysis complemented the long and short-run findings. Shocks on REXCH, and DEBT generated a negative response on RGDP. The shocks were not significantly different from zero and were transitory. Results from the variance decomposition analysis revealed that the fundamentals explain some, but not all, of the variations of RGDP. For the fifth year forecast error variance RGDP explains the largest component of the variation followed by INVE, REXCH, FDI and DEBT. After a period of ten years, the influence of RGDP and INVE declines, whereas REXCH, FDI and DEBT increase. Conclusions and policy recommendations were made using these results.
- Full Text:
- Date Issued: 2012
The effect of harvesting approaches on fruit yield, embelin concentration and regrowth dynamics of the forest shrub, Embelia tsjeriam-cottam, in central India
- Pandey, Ashok K, Shackleton, Charlie M
- Authors: Pandey, Ashok K , Shackleton, Charlie M
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181094 , vital:43698 , xlink:href="https://doi.org/10.1016/j.foreco.2011.11.015"
- Description: Embelia tsjeriam-cottam Roem and Schult A. DC. (Myrsinaceae), popularly known as Vaividang, is a vulnerable forest species because of the high demand of fruits for medicinal purposes. It is in great demand in ayurveda and the pharmaceutical industry (>100 t/yr), which has imposed tremendous pressure on some natural populations. The fruits contain embelin (a benzoquinone derivative), which has wide clinical applications. Considering the importance, growing use and decreasing populations in some areas of its natural habitat, a study on development of sustainable harvesting practices of E. tsjeriam-cottam fruits was conducted in Chhattisgarh, in central India. Experiments were laid out in Dhamtari, Marvahi and Bilaspur forest divisions of the state covering both protected and open forests in a randomized design with three replications. At each site, quadrats of 40 × 20 m were laid out to study the effect of two fruit harvesting methods and four harvesting intensities on fruit yield, and regeneration of the species. Fruits were analyzed for their embelin content by HPLC method. This study is the first to experimentally assess the consequences of harvesting of E. tsjeriam-cottam fruits from India. It was found that up to 70% fruits could be hand plucked at the right time of maturity (December) to obtain quality produce without impacting the current population size. Since every year is not a good fruiting year, it is difficult to develop universal harvest regime for sustainable management of E. tsjeriam-cottam. The embelin content increased as fruits ripened, ranging from 1.01% to 5.63%. The adoption of sustainable harvesting practices will be helpful in sustainable management of E. tsjeriam-cottam and also provide income and livelihood opportunities to rural people on a sustainable basis.
- Full Text:
- Date Issued: 2012
- Authors: Pandey, Ashok K , Shackleton, Charlie M
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181094 , vital:43698 , xlink:href="https://doi.org/10.1016/j.foreco.2011.11.015"
- Description: Embelia tsjeriam-cottam Roem and Schult A. DC. (Myrsinaceae), popularly known as Vaividang, is a vulnerable forest species because of the high demand of fruits for medicinal purposes. It is in great demand in ayurveda and the pharmaceutical industry (>100 t/yr), which has imposed tremendous pressure on some natural populations. The fruits contain embelin (a benzoquinone derivative), which has wide clinical applications. Considering the importance, growing use and decreasing populations in some areas of its natural habitat, a study on development of sustainable harvesting practices of E. tsjeriam-cottam fruits was conducted in Chhattisgarh, in central India. Experiments were laid out in Dhamtari, Marvahi and Bilaspur forest divisions of the state covering both protected and open forests in a randomized design with three replications. At each site, quadrats of 40 × 20 m were laid out to study the effect of two fruit harvesting methods and four harvesting intensities on fruit yield, and regeneration of the species. Fruits were analyzed for their embelin content by HPLC method. This study is the first to experimentally assess the consequences of harvesting of E. tsjeriam-cottam fruits from India. It was found that up to 70% fruits could be hand plucked at the right time of maturity (December) to obtain quality produce without impacting the current population size. Since every year is not a good fruiting year, it is difficult to develop universal harvest regime for sustainable management of E. tsjeriam-cottam. The embelin content increased as fruits ripened, ranging from 1.01% to 5.63%. The adoption of sustainable harvesting practices will be helpful in sustainable management of E. tsjeriam-cottam and also provide income and livelihood opportunities to rural people on a sustainable basis.
- Full Text:
- Date Issued: 2012
The effect of moringa oleifera leaf meal on growth perfomance, gut integrity, bone strenght, quality and oxidative stability of meat from broiler chickens
- Authors: Nkukwana, Tobela T
- Date: 2012
- Subjects: Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11820 , http://hdl.handle.net/10353/d1006835 , Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Description: This study was designed was to determine the effects of additive supplementation of Moringa oleifera leaf meal on growth performance, digestibility, digestive organ size, intestinal integrity, bone ash content and bone breaking strength, as well as meat yield and quality of broiler chickens. A total of 2400 day-old unsexed Cobb-500 broiler chicks were randomly allocated to 5 treatment groups: T1, positive control, 668 g/ton Salinomycin and 500 g/ton Albac; T2, T3 and T4 contained graded levels of MOLM at 1 percent, 3 percent and 5 percent of dry matter (DM) intake, respectively; and T5, a negative control (0 percent additives) in a complete randomized design experiment. Except for week one, FI and FCR was highest (P < 0.05) in T4 birds; while T1 birds had the highest FI in the period of 22 to 27d (P < 0.05). Throughout the production period, birds supplemented with MOLM had the highest BW (P < 0.05) than the birds fed the control diets. Feed intake (FI) and feed conversion ratio (FCR) among treatments was highest (P < 0.05) in T4 birds during the period of 8 to 14 d; and was highest (P < 0.05) for T1 birds in the period of 22 to 27d. Protein efficiency ratio (PER) and energy utilization efficiency (EEU) ratios were statistically significant among treatments (P < 0.05). However, dietary treatments had no effect (P > 0.05) on the weights of the heart, liver, spleen, or the gizzard, although the bursa for T2 birds was the lightest (P < 0.05); while gizzard erosion score was highest in T2 birds. All of the nutrients measured, except for fat, had negative intercepts that were significantly different (P < 0.05) from zero, indicating the presence of endogenous fecal losses. Tibiae length (TL) was highest in T2. The dried defatted weight (DW) was heaviest (P < 0.05) for T3 (11.20 ± 0.347) and T5 (11.08 ± 0.328). A positive correlation (r = 0.667; P < 0.01) between TW and DW was observed. There were no dietary effects on bone breaking strength (BBS), but T1 tibiae had highest resistance to breaking force (T1 > T4 > T3 > T2 > T5). Calcium was highest (P < 0.05) in T1; and lowest inT2 and T5. Phosphorus levels were lowest (P < 0.05) in T1; and highest (P < 0.05) in T5 compared. The highest Ca: P ratio was obtained in T4 (P < 0.05); while the ash percent was highest (P < 0.05) in T1. Drip loss increased as L* values increased; and a negative correlation was observed between L* and pH. On D1, C18: 0 and C22 in T2, while C15:0 was highest in T4. On D1, C20:2, C20:3n6 and C22:6n3 were highest in T2 (P < 0.05); T4 had the highest C18:3n6 (P < 0.05), while C20:2 was highest in T5 (P < 0.05). The P/S ratio on D1 was highest in T4; while n-6/n-3 was highest in T1; and n-3 was highest in T3. On D8, the n-3 was highest in T1 (P < 0.05). Results of the current study show that supplementation of M. oleifera leaf at additive levels of up to 5 percent of the bird’s DMI does have the potential to influence the bird performance without any detrimental effects on nutrient utilization, bird health, bone strength and/or meat quality, which can be concluded that MOLM enhanced the bird’s genetic potential for optimal productivity.
- Full Text:
- Date Issued: 2012
- Authors: Nkukwana, Tobela T
- Date: 2012
- Subjects: Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11820 , http://hdl.handle.net/10353/d1006835 , Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Description: This study was designed was to determine the effects of additive supplementation of Moringa oleifera leaf meal on growth performance, digestibility, digestive organ size, intestinal integrity, bone ash content and bone breaking strength, as well as meat yield and quality of broiler chickens. A total of 2400 day-old unsexed Cobb-500 broiler chicks were randomly allocated to 5 treatment groups: T1, positive control, 668 g/ton Salinomycin and 500 g/ton Albac; T2, T3 and T4 contained graded levels of MOLM at 1 percent, 3 percent and 5 percent of dry matter (DM) intake, respectively; and T5, a negative control (0 percent additives) in a complete randomized design experiment. Except for week one, FI and FCR was highest (P < 0.05) in T4 birds; while T1 birds had the highest FI in the period of 22 to 27d (P < 0.05). Throughout the production period, birds supplemented with MOLM had the highest BW (P < 0.05) than the birds fed the control diets. Feed intake (FI) and feed conversion ratio (FCR) among treatments was highest (P < 0.05) in T4 birds during the period of 8 to 14 d; and was highest (P < 0.05) for T1 birds in the period of 22 to 27d. Protein efficiency ratio (PER) and energy utilization efficiency (EEU) ratios were statistically significant among treatments (P < 0.05). However, dietary treatments had no effect (P > 0.05) on the weights of the heart, liver, spleen, or the gizzard, although the bursa for T2 birds was the lightest (P < 0.05); while gizzard erosion score was highest in T2 birds. All of the nutrients measured, except for fat, had negative intercepts that were significantly different (P < 0.05) from zero, indicating the presence of endogenous fecal losses. Tibiae length (TL) was highest in T2. The dried defatted weight (DW) was heaviest (P < 0.05) for T3 (11.20 ± 0.347) and T5 (11.08 ± 0.328). A positive correlation (r = 0.667; P < 0.01) between TW and DW was observed. There were no dietary effects on bone breaking strength (BBS), but T1 tibiae had highest resistance to breaking force (T1 > T4 > T3 > T2 > T5). Calcium was highest (P < 0.05) in T1; and lowest inT2 and T5. Phosphorus levels were lowest (P < 0.05) in T1; and highest (P < 0.05) in T5 compared. The highest Ca: P ratio was obtained in T4 (P < 0.05); while the ash percent was highest (P < 0.05) in T1. Drip loss increased as L* values increased; and a negative correlation was observed between L* and pH. On D1, C18: 0 and C22 in T2, while C15:0 was highest in T4. On D1, C20:2, C20:3n6 and C22:6n3 were highest in T2 (P < 0.05); T4 had the highest C18:3n6 (P < 0.05), while C20:2 was highest in T5 (P < 0.05). The P/S ratio on D1 was highest in T4; while n-6/n-3 was highest in T1; and n-3 was highest in T3. On D8, the n-3 was highest in T1 (P < 0.05). Results of the current study show that supplementation of M. oleifera leaf at additive levels of up to 5 percent of the bird’s DMI does have the potential to influence the bird performance without any detrimental effects on nutrient utilization, bird health, bone strength and/or meat quality, which can be concluded that MOLM enhanced the bird’s genetic potential for optimal productivity.
- Full Text:
- Date Issued: 2012
The effect of South African labour legislation on refugees and migrants
- Authors: Swartz, Natasha Schantal
- Date: 2012
- Subjects: Labor laws and legislation -- South Africa , Refugees -- South Africa , Foreign workers -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10289 , http://hdl.handle.net/10948/d1019921
- Description: Since South Africa was declared a democratic country, the number of refugees fleeing to South Africa has increased. While it is understandable that refugees would flee to a country with a Constitution that protects the rights of everyone within its territory, this influx of refugees and migrants also puts a strain on the South African economy. One of the main problems associated with refugees and migrants in this country is their illegal status. Failure to obtain legal status in the country can be attributed to their own negligence to attend to the Refugee Reception Office, upon their arrival in the country. On the other hand, the South African government also fails foreigners in that the service provided at the Refugee Reception Offices is not up to the standard promised in the legislation. A further problem associated with refugees and migrants in the country is that they are competing with South Africans for jobs that are already scarce in the country. A foreigners need to earn a living is the driving force behind entering the employment market, and often illegally. Where refugees and migrants do not have the required work permits, their employment is prohibited in terms of the Immigration Act 13 of 2002 and they are thus illegal workers. Until recently, South Africa has followed the same policy as other international countries. Illegal workers did not have access to the protection provided by our labour legislation, by virtue of the illegality of their employment contracts. This position was changed by the Discovery Health case where the courts focused more on the existence of an employment relationship as oppose to an employment contract.
- Full Text:
- Date Issued: 2012
- Authors: Swartz, Natasha Schantal
- Date: 2012
- Subjects: Labor laws and legislation -- South Africa , Refugees -- South Africa , Foreign workers -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10289 , http://hdl.handle.net/10948/d1019921
- Description: Since South Africa was declared a democratic country, the number of refugees fleeing to South Africa has increased. While it is understandable that refugees would flee to a country with a Constitution that protects the rights of everyone within its territory, this influx of refugees and migrants also puts a strain on the South African economy. One of the main problems associated with refugees and migrants in this country is their illegal status. Failure to obtain legal status in the country can be attributed to their own negligence to attend to the Refugee Reception Office, upon their arrival in the country. On the other hand, the South African government also fails foreigners in that the service provided at the Refugee Reception Offices is not up to the standard promised in the legislation. A further problem associated with refugees and migrants in the country is that they are competing with South Africans for jobs that are already scarce in the country. A foreigners need to earn a living is the driving force behind entering the employment market, and often illegally. Where refugees and migrants do not have the required work permits, their employment is prohibited in terms of the Immigration Act 13 of 2002 and they are thus illegal workers. Until recently, South Africa has followed the same policy as other international countries. Illegal workers did not have access to the protection provided by our labour legislation, by virtue of the illegality of their employment contracts. This position was changed by the Discovery Health case where the courts focused more on the existence of an employment relationship as oppose to an employment contract.
- Full Text:
- Date Issued: 2012
The effect of strategic project leadership elements on successful strategic management implementation
- Authors: Nel, Nevin Narhan
- Date: 2012
- Subjects: Strategic management , Project management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8819 , http://hdl.handle.net/10948/d1018931
- Description: Executives and managers are required to develop the required competencies to ensure the long term success of their organisations. In the competitive and dynamic business environment organisations are faced with, strategic management and planning has gained momentum as a management science which aids managers and executives in circumventing the challenges that such a dynamic environment can present. Strategic management and planning is, however, of no consequence unless the strategic plan is deployed and implemented in an organisation and the implemented plan is evaluated in action. Many organisations find the process of strategy implementation much more of a challenge than the process of strategy formulation. Consequently, many of these organisations have utilised project management to assist in the strategic management implementation process. The competitive and dynamic business environment also requires organisations to constantly develop and execute more innovative business strategies to remain competitive. In order to do this, many organisations have started to explore the alignment between business strategy and project management strategy. Various commentators note that successful implementation of strategy is challenging, especially considering the 70 per cent execution failure rate. It is further noted that organisations only realise 60 per cent of the potential value of their intended strategies due to failures in planning and implementation. Consequently, projects are often chosen as vehicles to implement these business strategies. The primary objective of this research is to improve the implementation of strategic management initiatives within organisations. This was achieved by investigating whether Shenhar’s strategic project leadership elements (i.e. organisational structure, process definition, implementation metrics, implementation tools and organisational culture) have an impact on the successful implementation of strategic management initiatives. The study also aims to investigate whether age, gender, race, designation, education, industry experience and tenure at Eskom Telecommunications, have an impact on the perception of the following variables under investigation: Implementation metrics; Implementation tools; Organisational structure; Organisational culture; Process definition; and Strategic management implementation. If the correlation between strategic management implementation and Shenhar’s strategic project leadership elements is established, it would assist organisations in the implementation of successful strategic management initiatives, by aiding an understanding of how these independent variables affect the implementation process. Improved implementation of strategic management initiatives would assist management teams in organisations to overcome the unique challenges that change in an organisation’s internal and external environment cause. The scope of this study was limited to be conducted in Eskom Telecommunications only. The study is concluded with a number of recommendations that Eskom Telecommunications could implement to improve strategic management implementation and a synopsis of this study’s contribution to theory is provided, in addition to recommendations for future research.
- Full Text:
- Date Issued: 2012
- Authors: Nel, Nevin Narhan
- Date: 2012
- Subjects: Strategic management , Project management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8819 , http://hdl.handle.net/10948/d1018931
- Description: Executives and managers are required to develop the required competencies to ensure the long term success of their organisations. In the competitive and dynamic business environment organisations are faced with, strategic management and planning has gained momentum as a management science which aids managers and executives in circumventing the challenges that such a dynamic environment can present. Strategic management and planning is, however, of no consequence unless the strategic plan is deployed and implemented in an organisation and the implemented plan is evaluated in action. Many organisations find the process of strategy implementation much more of a challenge than the process of strategy formulation. Consequently, many of these organisations have utilised project management to assist in the strategic management implementation process. The competitive and dynamic business environment also requires organisations to constantly develop and execute more innovative business strategies to remain competitive. In order to do this, many organisations have started to explore the alignment between business strategy and project management strategy. Various commentators note that successful implementation of strategy is challenging, especially considering the 70 per cent execution failure rate. It is further noted that organisations only realise 60 per cent of the potential value of their intended strategies due to failures in planning and implementation. Consequently, projects are often chosen as vehicles to implement these business strategies. The primary objective of this research is to improve the implementation of strategic management initiatives within organisations. This was achieved by investigating whether Shenhar’s strategic project leadership elements (i.e. organisational structure, process definition, implementation metrics, implementation tools and organisational culture) have an impact on the successful implementation of strategic management initiatives. The study also aims to investigate whether age, gender, race, designation, education, industry experience and tenure at Eskom Telecommunications, have an impact on the perception of the following variables under investigation: Implementation metrics; Implementation tools; Organisational structure; Organisational culture; Process definition; and Strategic management implementation. If the correlation between strategic management implementation and Shenhar’s strategic project leadership elements is established, it would assist organisations in the implementation of successful strategic management initiatives, by aiding an understanding of how these independent variables affect the implementation process. Improved implementation of strategic management initiatives would assist management teams in organisations to overcome the unique challenges that change in an organisation’s internal and external environment cause. The scope of this study was limited to be conducted in Eskom Telecommunications only. The study is concluded with a number of recommendations that Eskom Telecommunications could implement to improve strategic management implementation and a synopsis of this study’s contribution to theory is provided, in addition to recommendations for future research.
- Full Text:
- Date Issued: 2012
The effectiveness of agricultural extension as perceived by small scale farm holders
- Authors: Olufayo, Ayowumi Motunrayo
- Date: 2012
- Subjects: Agricultural extension work -- South Africa , Agriculture -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10592 , http://hdl.handle.net/10948/d1019765
- Description: Empirical studies have suggested that agricultural extension can increase agricultural productivity. However, the increase in productivity is dependent on a number of issues. As a result, this particular study was conducted among farmers in order to examine the relationship between the provision of extension services and increased productivity in a regional context. The perceptions of vegetable home gardeners resident in the Nelson Mandela Metropolitan area, who participated in the Siyazondla Homestead Production Programme, formed the source of the primary data. The views of these farmers were analysed to determine how extension services affected their performance. The findings revealed that the farmers have a good perception of the extension services, although this negatively correlates with their level of performance. In addition, the data indicate that farmers who had a poor perception of extension services tend to achieve high production while those with a good impression of services had a poor performance. It was however observed that level of education, farming experience and exposure to print media influenced the responses that were captured in the study.
- Full Text:
- Date Issued: 2012
- Authors: Olufayo, Ayowumi Motunrayo
- Date: 2012
- Subjects: Agricultural extension work -- South Africa , Agriculture -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10592 , http://hdl.handle.net/10948/d1019765
- Description: Empirical studies have suggested that agricultural extension can increase agricultural productivity. However, the increase in productivity is dependent on a number of issues. As a result, this particular study was conducted among farmers in order to examine the relationship between the provision of extension services and increased productivity in a regional context. The perceptions of vegetable home gardeners resident in the Nelson Mandela Metropolitan area, who participated in the Siyazondla Homestead Production Programme, formed the source of the primary data. The views of these farmers were analysed to determine how extension services affected their performance. The findings revealed that the farmers have a good perception of the extension services, although this negatively correlates with their level of performance. In addition, the data indicate that farmers who had a poor perception of extension services tend to achieve high production while those with a good impression of services had a poor performance. It was however observed that level of education, farming experience and exposure to print media influenced the responses that were captured in the study.
- Full Text:
- Date Issued: 2012
The effectiveness of internal newsletters: case study of Transnet Freight Rail's platform
- Matshoba, Thembekile Phillinah
- Authors: Matshoba, Thembekile Phillinah
- Date: 2012
- Subjects: Newsletters , Business communication
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8420 , http://hdl.handle.net/10948/d1015672
- Description: The research is based on a case study of an internal newsletter, Platform. The objective was to obtain more information about Transnet Freight Rail employees‘ thoughts on its effectiveness and the effectiveness of internal newsletters by using Platform as an example. The treatise explored the perceptions of employees and Transnet in terms of the effectiveness of the internal newsletter as a communication tool as well as their attitudes towards the newsletter as an information disseminating medium. A mixed methods approach was used for analysis in this study. The first methodological paradigm took an interpretivist approach, focusing primarily on analysing the content of the newsletter. The second methodological design was based on the positivistic theory approach and utilised a survey by questionnaire. One hundred and twenty (120) questionnaires were issued to Transnet Freight Rail employees representing the three regions: Central Region, Eastern Region & Western Region and the Head Office of which 120 (100 percent) were received back by the deadline. Of these respondents 56 (46,66 percent) said that they find Platform very relevant as an internal newsletter. A further finding was that 68,33 percent of the respondents said Platform should stay as it is. About 58,33 percent of the respondents took 30 minutes to an hour to read the newsletter with ratings of 72,5 percent interested in communication from management, 65 percent in financial performance, 60 percent in news about people and 59,16 percent in departmental information. The main types of information required are about updates on business performance and safety news. The content of six editions of the newsletter was analysed. The newsletter editions used were from the latest one published counting backwards. The content of the newsletter varies in each edition and depends on the theme. There are similar themes that come up with every edition such as safety. The style of writing used is simple to ensure maximum understanding.
- Full Text:
- Date Issued: 2012
- Authors: Matshoba, Thembekile Phillinah
- Date: 2012
- Subjects: Newsletters , Business communication
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8420 , http://hdl.handle.net/10948/d1015672
- Description: The research is based on a case study of an internal newsletter, Platform. The objective was to obtain more information about Transnet Freight Rail employees‘ thoughts on its effectiveness and the effectiveness of internal newsletters by using Platform as an example. The treatise explored the perceptions of employees and Transnet in terms of the effectiveness of the internal newsletter as a communication tool as well as their attitudes towards the newsletter as an information disseminating medium. A mixed methods approach was used for analysis in this study. The first methodological paradigm took an interpretivist approach, focusing primarily on analysing the content of the newsletter. The second methodological design was based on the positivistic theory approach and utilised a survey by questionnaire. One hundred and twenty (120) questionnaires were issued to Transnet Freight Rail employees representing the three regions: Central Region, Eastern Region & Western Region and the Head Office of which 120 (100 percent) were received back by the deadline. Of these respondents 56 (46,66 percent) said that they find Platform very relevant as an internal newsletter. A further finding was that 68,33 percent of the respondents said Platform should stay as it is. About 58,33 percent of the respondents took 30 minutes to an hour to read the newsletter with ratings of 72,5 percent interested in communication from management, 65 percent in financial performance, 60 percent in news about people and 59,16 percent in departmental information. The main types of information required are about updates on business performance and safety news. The content of six editions of the newsletter was analysed. The newsletter editions used were from the latest one published counting backwards. The content of the newsletter varies in each edition and depends on the theme. There are similar themes that come up with every edition such as safety. The style of writing used is simple to ensure maximum understanding.
- Full Text:
- Date Issued: 2012
The effectiveness of school management: conflict management skills as a missing link in selected schools in Gauteng
- Authors: Msila, Vuyisile
- Date: 2012
- Subjects: Conflict management -- South Africa -- Gauteng , School management and organization -- South Africa -- Gauteng , Educational leadership -- South Africa -- Gauteng
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8288 , http://hdl.handle.net/10948/d1018647
- Description: Growing research in educational leadership and management shows that there are many factors that have an impact on the running of effective schools. Many people are now aware of the importance of the school management‟s role in guiding successful schools. This quantitative study was conducted in Gauteng where 100 school managers responded to a questionnaire which probed them about their conflict management and competence skills. The participants responded to a 40 item Likert scale instrument. Each of the items had five alternatives to choose from. The results demonstrate that many teachers were never trained in conflict management skills and that they also find it hard to resolve disputes in their schools. Furthermore, a majority of the participants attributed the dysfunctionality and lack of teacher commitment to the pervading unresolved conflicts in their schools. There was also consensus that intractable conflict adversely affects the culture of learning and teaching in schools. Among the recommendations highlighted at the end are to ensure that prospective school managers are empowered with conflict management skills before assuming their positions.
- Full Text:
- Date Issued: 2012
- Authors: Msila, Vuyisile
- Date: 2012
- Subjects: Conflict management -- South Africa -- Gauteng , School management and organization -- South Africa -- Gauteng , Educational leadership -- South Africa -- Gauteng
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8288 , http://hdl.handle.net/10948/d1018647
- Description: Growing research in educational leadership and management shows that there are many factors that have an impact on the running of effective schools. Many people are now aware of the importance of the school management‟s role in guiding successful schools. This quantitative study was conducted in Gauteng where 100 school managers responded to a questionnaire which probed them about their conflict management and competence skills. The participants responded to a 40 item Likert scale instrument. Each of the items had five alternatives to choose from. The results demonstrate that many teachers were never trained in conflict management skills and that they also find it hard to resolve disputes in their schools. Furthermore, a majority of the participants attributed the dysfunctionality and lack of teacher commitment to the pervading unresolved conflicts in their schools. There was also consensus that intractable conflict adversely affects the culture of learning and teaching in schools. Among the recommendations highlighted at the end are to ensure that prospective school managers are empowered with conflict management skills before assuming their positions.
- Full Text:
- Date Issued: 2012
The effectiveness of selected Quaker Peace Centre training workshops in the Western Cape
- Dywili, Mlungiseleli Vincent
- Authors: Dywili, Mlungiseleli Vincent
- Date: 2012
- Subjects: Peace , Conflict management -- South Africa -- Western Cape , Reconciliation
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8264 , http://hdl.handle.net/10948/d1013254
- Description: Several Alternatives to Violence Project (AVP) training workshops have been established to help transform correctional institutions worldwide. There is no evidence of any research on AVP conducted in the context of South African Schools to date. This research therefore aims to evaluate AVP training by the Quaker Peace Centre at five high schools on the Cape Flats. Taking a qualitative approach, the study provides a literary contextualization of the problem of violence in South African schools as well as the history of AVP programmes in South Africa and abroad. In respect of his data collection, the researcher used both evaluation forms submitted at the completion of training events, as well as a purpose-designed questionnaire, mailed to a convenience sample of 635 past participants in the training. The results of the study indicate that the AVP workshops have had an impact on the lives of the participants, and there is an acknowledgement of feelings of empowerment experienced by recipients, which enables sound recommendations to be made.
- Full Text:
- Date Issued: 2012
- Authors: Dywili, Mlungiseleli Vincent
- Date: 2012
- Subjects: Peace , Conflict management -- South Africa -- Western Cape , Reconciliation
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8264 , http://hdl.handle.net/10948/d1013254
- Description: Several Alternatives to Violence Project (AVP) training workshops have been established to help transform correctional institutions worldwide. There is no evidence of any research on AVP conducted in the context of South African Schools to date. This research therefore aims to evaluate AVP training by the Quaker Peace Centre at five high schools on the Cape Flats. Taking a qualitative approach, the study provides a literary contextualization of the problem of violence in South African schools as well as the history of AVP programmes in South Africa and abroad. In respect of his data collection, the researcher used both evaluation forms submitted at the completion of training events, as well as a purpose-designed questionnaire, mailed to a convenience sample of 635 past participants in the training. The results of the study indicate that the AVP workshops have had an impact on the lives of the participants, and there is an acknowledgement of feelings of empowerment experienced by recipients, which enables sound recommendations to be made.
- Full Text:
- Date Issued: 2012
The effectiveness of the integrated quality management system to improve the performance of educators in the East London District
- Authors: Blayi, Mcebisi
- Date: 2012
- Subjects: Total quality management in education , Total quality management -- South Africa -- Eastern Cape , Teachers -- Quality -- South Africa --Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9452 , http://hdl.handle.net/10948/d1014634
- Description: This study aimed to evaluate the effectiveness of the Integrated Quality Management System (IQMS) in improving the performance of educators. While literature exists on IQMS as a performance management system for educators in South Africa, no research examines it as a Performance Improvement (PI) system. Given the gap in the literature, this study aimed to answer the question: How effective is the IQMS in improving the performance of educators? The IQMS policy mandates the District Office to design and implement Performance Improvement interventions. This study investigated the effectiveness of the IQMS as a PI system with specific reference to the interventions designed and implemented by the East London District of Education. The introduction of the IQMS marked a paradigm shift from the inspectorate system. It introduced a democratic system of teacher evaluation. It put consultative structures in place and allowed educators to make their voices heard during the evaluation process through pre-evaluation meetings and feedback. The IQMS is a standards based system of evaluation. As such it is morphed with the use of rating scores and rubrics to identify the performance gap, which is followed by the development and implementation of intervention strategies to close the gap. The concept of Performance Improvement (PI) which is the process of identifying and analyzing individual performance gaps, planning for future performance improvement, designing and implementing interventions to close performance gaps, comes into play. This study was conducted using qualitative research methods. Data from questionnaires and the interviews were triangulated with information from a review of policy documents from the Department of Basic Education, pertinent documents from the East London District of Education and sampled high schools in Mdantsane. The Post Level 1 Educators are primary stakeholders in this study, and the School Principals and Education Specialists are secondary stakeholders. In this qualitative study, forty-two high school Post Level 1 (PL1) educators provided responses to an open-ended questionnaire. Six PL1 educators were interviewed. Three high school principals and three education specialists provided responses to open-ended questionnaires. Pertinent documents were surveyed. Qualitative responses were categorized and analyzed into themes and sub-themes. The findings of the current study indicate that the IQMS in its current form did not impact positively on the Performance Improvement of educators. Five specific findings emerged from this study: Educators have not embraced IQMS as a Performance Improvement system; The twofold purpose of the IQMS: development and salary progression renders it ineffective in improving the performance of educators; The logical framework for the implementation of the IQMS is not adhered to; The implementation of the IQMS is not monitored; The IQMS has no impact on learner attainment. This study also documents other positive areas in the implementation of the IQMS. This study has implications and recommendations for further research, practice and provides valuable information to the Department of Basic Education and the teacher unions in the Education Labour Relations Council as they review the IQMS and in implementing future teacher performance evaluation policies.
- Full Text:
- Date Issued: 2012
- Authors: Blayi, Mcebisi
- Date: 2012
- Subjects: Total quality management in education , Total quality management -- South Africa -- Eastern Cape , Teachers -- Quality -- South Africa --Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9452 , http://hdl.handle.net/10948/d1014634
- Description: This study aimed to evaluate the effectiveness of the Integrated Quality Management System (IQMS) in improving the performance of educators. While literature exists on IQMS as a performance management system for educators in South Africa, no research examines it as a Performance Improvement (PI) system. Given the gap in the literature, this study aimed to answer the question: How effective is the IQMS in improving the performance of educators? The IQMS policy mandates the District Office to design and implement Performance Improvement interventions. This study investigated the effectiveness of the IQMS as a PI system with specific reference to the interventions designed and implemented by the East London District of Education. The introduction of the IQMS marked a paradigm shift from the inspectorate system. It introduced a democratic system of teacher evaluation. It put consultative structures in place and allowed educators to make their voices heard during the evaluation process through pre-evaluation meetings and feedback. The IQMS is a standards based system of evaluation. As such it is morphed with the use of rating scores and rubrics to identify the performance gap, which is followed by the development and implementation of intervention strategies to close the gap. The concept of Performance Improvement (PI) which is the process of identifying and analyzing individual performance gaps, planning for future performance improvement, designing and implementing interventions to close performance gaps, comes into play. This study was conducted using qualitative research methods. Data from questionnaires and the interviews were triangulated with information from a review of policy documents from the Department of Basic Education, pertinent documents from the East London District of Education and sampled high schools in Mdantsane. The Post Level 1 Educators are primary stakeholders in this study, and the School Principals and Education Specialists are secondary stakeholders. In this qualitative study, forty-two high school Post Level 1 (PL1) educators provided responses to an open-ended questionnaire. Six PL1 educators were interviewed. Three high school principals and three education specialists provided responses to open-ended questionnaires. Pertinent documents were surveyed. Qualitative responses were categorized and analyzed into themes and sub-themes. The findings of the current study indicate that the IQMS in its current form did not impact positively on the Performance Improvement of educators. Five specific findings emerged from this study: Educators have not embraced IQMS as a Performance Improvement system; The twofold purpose of the IQMS: development and salary progression renders it ineffective in improving the performance of educators; The logical framework for the implementation of the IQMS is not adhered to; The implementation of the IQMS is not monitored; The IQMS has no impact on learner attainment. This study also documents other positive areas in the implementation of the IQMS. This study has implications and recommendations for further research, practice and provides valuable information to the Department of Basic Education and the teacher unions in the Education Labour Relations Council as they review the IQMS and in implementing future teacher performance evaluation policies.
- Full Text:
- Date Issued: 2012
The effects of climate change on the realisation of the right to adequate food in Kenya
- Khayundi, Francis Mapati Bulimo
- Authors: Khayundi, Francis Mapati Bulimo
- Date: 2012
- Subjects: Climatic changes -- Social aspects -- Research -- Kenya , Right to food -- Research -- Kenya , Human rights -- Research -- Kenya , Food security -- Research -- Kenya , Food law and legislation -- Kenya
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3675 , http://hdl.handle.net/10962/d1003190 , Climatic changes -- Social aspects -- Research -- Kenya , Right to food -- Research -- Kenya , Human rights -- Research -- Kenya , Food security -- Research -- Kenya , Food law and legislation -- Kenya
- Description: This thesis examines the interplay between the effects of climate change and human rights. It seeks to interrogate the contribution of human rights in addressing the effects of climate change on the enjoyment of the right to food in Kenya. Climate change has been recognised as a human rights issue. Despite this acknowledgement, many states are yet to deal with climate change as a growing threat to the realisation of human rights. The situation is made worse by the glacial pace in securing a binding legal agreement to tackle climate change. The thesis also reveals that despite their seemingly disparate and disconnected nature, both the human rights and climate change regimes seek to achieve the same goal albeit in different ways. The thesis argues that a considerable portion of the Kenyan population has not been able to enjoy the right to food as a result of droughts and floods. It adopts the view that, with the effects of climate change being evident, the frequency and magnitude of droughts and floods has increased with far reaching consequences on the right to food. Measures by the Kenyan government to address the food situation have always been knee jerk and inadequate in nature. This is despite the fact that Kenya is a signatory to a number of human rights instruments that deal with the right to food. With the promulgation of a new Constitution with a justiciable right to food, there is a need for the Kenyan government to meet its human rights obligations. This thesis concludes by suggesting ways in which the right to food can be applied in order to address some of the effects of climate change. It argues that by adopting a human rights approach to the right to food, the State will have to adopt measures that take into consideration the impacts of climate change. Furthermore, the State is under an obligation to engage in activities that will not contribute to climate change and negatively affect the right.
- Full Text:
- Date Issued: 2012
- Authors: Khayundi, Francis Mapati Bulimo
- Date: 2012
- Subjects: Climatic changes -- Social aspects -- Research -- Kenya , Right to food -- Research -- Kenya , Human rights -- Research -- Kenya , Food security -- Research -- Kenya , Food law and legislation -- Kenya
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3675 , http://hdl.handle.net/10962/d1003190 , Climatic changes -- Social aspects -- Research -- Kenya , Right to food -- Research -- Kenya , Human rights -- Research -- Kenya , Food security -- Research -- Kenya , Food law and legislation -- Kenya
- Description: This thesis examines the interplay between the effects of climate change and human rights. It seeks to interrogate the contribution of human rights in addressing the effects of climate change on the enjoyment of the right to food in Kenya. Climate change has been recognised as a human rights issue. Despite this acknowledgement, many states are yet to deal with climate change as a growing threat to the realisation of human rights. The situation is made worse by the glacial pace in securing a binding legal agreement to tackle climate change. The thesis also reveals that despite their seemingly disparate and disconnected nature, both the human rights and climate change regimes seek to achieve the same goal albeit in different ways. The thesis argues that a considerable portion of the Kenyan population has not been able to enjoy the right to food as a result of droughts and floods. It adopts the view that, with the effects of climate change being evident, the frequency and magnitude of droughts and floods has increased with far reaching consequences on the right to food. Measures by the Kenyan government to address the food situation have always been knee jerk and inadequate in nature. This is despite the fact that Kenya is a signatory to a number of human rights instruments that deal with the right to food. With the promulgation of a new Constitution with a justiciable right to food, there is a need for the Kenyan government to meet its human rights obligations. This thesis concludes by suggesting ways in which the right to food can be applied in order to address some of the effects of climate change. It argues that by adopting a human rights approach to the right to food, the State will have to adopt measures that take into consideration the impacts of climate change. Furthermore, the State is under an obligation to engage in activities that will not contribute to climate change and negatively affect the right.
- Full Text:
- Date Issued: 2012
The effects of real exchange rate misalignment on economic growth: a case study of Kenya
- Authors: Ndavi, Theresa Watwii
- Date: 2012
- Subjects: Foreign exchange rate , Foreign exchange market , Economic development
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8985 , http://hdl.handle.net/10948/d1008109 , Foreign exchange rate , Foreign exchange market , Economic development
- Description: This paper investigates the effects of real exchange rate misalignment (REM) on economic growth in Kenya over the period 1964-2009. The real exchange rate misalignment is defined as the difference between the equilibrium exchange rate and the actual real exchange rate (RER). The equilibrium real exchange rate was obtained by using the purchasing power parity (PPP) approach. To this effect, the study examined the existence or absence of the cointegration between the REM and economic growth, using the autoregressive distributed lag (ARDL) bounds testing approach. The ARDL approach is employed to determine both the long-run and short-run dynamics of the model. The results suggest that no long-run relationship exists between economic growth and the REM in Kenya. The short-run model is then estimated, using the OLS (ordinary least squares) method. From this model, it is determined that trade openness has a positive impact on economic growth, while foreign aid has a negative impact on economic growth; and both are considered empirically significant. The inflation rate and REM both negatively impact economic growth, but are empirically insignificant. All variables corroborate the a priori expectations.
- Full Text:
- Date Issued: 2012
- Authors: Ndavi, Theresa Watwii
- Date: 2012
- Subjects: Foreign exchange rate , Foreign exchange market , Economic development
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8985 , http://hdl.handle.net/10948/d1008109 , Foreign exchange rate , Foreign exchange market , Economic development
- Description: This paper investigates the effects of real exchange rate misalignment (REM) on economic growth in Kenya over the period 1964-2009. The real exchange rate misalignment is defined as the difference between the equilibrium exchange rate and the actual real exchange rate (RER). The equilibrium real exchange rate was obtained by using the purchasing power parity (PPP) approach. To this effect, the study examined the existence or absence of the cointegration between the REM and economic growth, using the autoregressive distributed lag (ARDL) bounds testing approach. The ARDL approach is employed to determine both the long-run and short-run dynamics of the model. The results suggest that no long-run relationship exists between economic growth and the REM in Kenya. The short-run model is then estimated, using the OLS (ordinary least squares) method. From this model, it is determined that trade openness has a positive impact on economic growth, while foreign aid has a negative impact on economic growth; and both are considered empirically significant. The inflation rate and REM both negatively impact economic growth, but are empirically insignificant. All variables corroborate the a priori expectations.
- Full Text:
- Date Issued: 2012
The effects of salinity and inundation on salt marsh plants in the context of climate change
- Authors: Tabot, Pascal Tabi
- Date: 2012
- Subjects: Salt marsh plants -- Climatic factors , Plant ecophysiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10637 , http://hdl.handle.net/10948/d1019919
- Description: Ecophysiology studies are needed to predict plant responses in relation to climate change. Variations in salinity and inundation are expected to influence the survival and distribution of salt marsh. The following species were chosen to study as they occur in most South African salt marshes and are representative of different tidal ranges; namely Triglochin buchenaui (lower intertidal), Bassia diffusa (upper intertidal succulent) and Limonium linifolium (upper intertidal non-succulent). To simulate climate change conditions as predicted for South Africa, a 3 x 5 controlled experiment of three inundation levels (tidal, submerged and drought) and five salinity levels (0, 8, 18, 35, 45 ppt) was conducted for each species. This resulted in 15 treatments per species. Plant responses were measured over a three month period. Triglochin buchenaui showed significant variation in height (7.57 ± 0.5 to 29 ± 1.55 cm, p < 0.005, DF = 55) with optimum growth at 0 ppt under tidal conditions; leaf area increments and relative growth rates which decreased with increasing salinity under all inundation states. There was almost a cessation of growth under submergence which reduces the plant’s regeneration potential under these conditions. Proline accumulation (1.84 ± 0.23 to 3.36 ± 0.38 mg l-1), response of photosynthetic pigments and electrolyte leakage (8.17 ± 0.80 to 38.36 ± 7.42 percent) were fundamental to osmotic and membrane response regulation. Plants survived in all inundation states at salinity up to 45 ppt, but the optimum range was 0 to 18 ppt, and best water state was the tidal condition. Viable rhizomes were produced under drought conditions. Bassia diffusa (Thunb.) Kuntze plants under submergence died within one month, irrespective of the salinity. Optimum growth occurred in plants of the tidal treatment at 18 ppt, and reduced with increased salinity and drought conditions. Plants in the tidal treatments were more succulent than the drought-treated plants. There was reduced leaf mass and high anthocyanin concentrations in drought-treated plants and these effects increased with salinity. Soil and leaf water potential were positively correlated with anthocyanin concentration in leaves and stems, suggesting anthocyanin accumulated in response to drought and could be an adaptation to lower the plant’s water potential under drought conditions. A shift of anthocyanin from leaves to stems was found in drought-treated plants, and this possibly enables the maximization of photosynthesis in leaves, to complement its role in osmotic balance and photo-protection. Growth of Limonium linifolium showed that the plant was tolerant to a wide range of salinity under both tidal and drought conditions, but was susceptible to complete submergence, with high membrane damage even in tidal-treated plants. Plants died within 2 weeks of complete submergence. Results further indicated that L. linifolium tolerates extreme drought by accumulating large quantities of proline and oxalic acid, which consequently lowers its water potential for uptake of soil water of high salinity. Excess salts were excreted through salt glands. This is an important adaptation for a plant that thrives in a highly variable saline habitat Further investigation of submergence effects on upper intertidal species using B. diffusa showed three key stages in the response. A drop in chlorophyll a+b within 6 hours (4.2 ± 0.2 to 2.4 ± 0.3 mg l-1) with a corresponding increase in carotenoid concentration (0.6 ± 0.1 mg l-1) indicated an immediate response to submergence. Oxalic acid concentration was highest on Day 4 (13.6 mM) as opposed to control levels, indicative of its role in submergence tolerance, thus Day 4 may be the peak of positive acclimation. The third phase was marked by a sharp increase in electrolyte leakage to 47.5 ± 2.6 percent on Day 10, from 9.4 ± 1.4 percent on Day 7, with a corresponding decrease in total dissolved solutes between Days 7 and 10. Results suggest that oxalic acid accumulates under submergence possibly as a stabilizing osmolyte. The threshold for tolerance of the species under submergence is 7 days with membrane damage thereafter. Bassia diffusa would not survive prolonged submergence (> 7 days) but could survive submergence of short duration (< 7 days) through continuous underwater photosynthesis, accumulation of osmolytes such as oxalic acid and carotenoid, and maintenance of relative water content and succulence within control levels. When considered together, results showed that the two upper intertidal species were sensitive to waterlogging and would not survive complete submergence, whereas the lower intertidal species could in addition to its natural range, thrive in conditions typical of the upper intertidal range, namely prolonged dry conditions and high sediment salinity. These results have important implications for the future management of salt marshes under predicted climate change conditions. In permanently open South African estuaries, a landward migration of salt marsh will be possible if coastal squeeze is limited and the rate of landward recruitment is on par with sea level rise. In this case salt marsh species would retain their current zonation while shifting inland. Increased sea storms and saltwater intrusion could lead to high salinity concentration in the sediment and significantly reduce growth of salt-sensitive plants. In estuaries that are temporarily open to the sea, reduced freshwater inflow will result in an increase in mouth closure, high water levels, prolonged submergence, and consequently die back of salt marsh vegetation. On the other hand increased abstraction and drought would result in low water levels and high sediment salinity which would decrease growth and survival of salt marsh. This research has provided new knowledge on the ecophysiology of salt marsh plants which can be used to predict the responses of plants to climate change.
- Full Text:
- Date Issued: 2012
- Authors: Tabot, Pascal Tabi
- Date: 2012
- Subjects: Salt marsh plants -- Climatic factors , Plant ecophysiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10637 , http://hdl.handle.net/10948/d1019919
- Description: Ecophysiology studies are needed to predict plant responses in relation to climate change. Variations in salinity and inundation are expected to influence the survival and distribution of salt marsh. The following species were chosen to study as they occur in most South African salt marshes and are representative of different tidal ranges; namely Triglochin buchenaui (lower intertidal), Bassia diffusa (upper intertidal succulent) and Limonium linifolium (upper intertidal non-succulent). To simulate climate change conditions as predicted for South Africa, a 3 x 5 controlled experiment of three inundation levels (tidal, submerged and drought) and five salinity levels (0, 8, 18, 35, 45 ppt) was conducted for each species. This resulted in 15 treatments per species. Plant responses were measured over a three month period. Triglochin buchenaui showed significant variation in height (7.57 ± 0.5 to 29 ± 1.55 cm, p < 0.005, DF = 55) with optimum growth at 0 ppt under tidal conditions; leaf area increments and relative growth rates which decreased with increasing salinity under all inundation states. There was almost a cessation of growth under submergence which reduces the plant’s regeneration potential under these conditions. Proline accumulation (1.84 ± 0.23 to 3.36 ± 0.38 mg l-1), response of photosynthetic pigments and electrolyte leakage (8.17 ± 0.80 to 38.36 ± 7.42 percent) were fundamental to osmotic and membrane response regulation. Plants survived in all inundation states at salinity up to 45 ppt, but the optimum range was 0 to 18 ppt, and best water state was the tidal condition. Viable rhizomes were produced under drought conditions. Bassia diffusa (Thunb.) Kuntze plants under submergence died within one month, irrespective of the salinity. Optimum growth occurred in plants of the tidal treatment at 18 ppt, and reduced with increased salinity and drought conditions. Plants in the tidal treatments were more succulent than the drought-treated plants. There was reduced leaf mass and high anthocyanin concentrations in drought-treated plants and these effects increased with salinity. Soil and leaf water potential were positively correlated with anthocyanin concentration in leaves and stems, suggesting anthocyanin accumulated in response to drought and could be an adaptation to lower the plant’s water potential under drought conditions. A shift of anthocyanin from leaves to stems was found in drought-treated plants, and this possibly enables the maximization of photosynthesis in leaves, to complement its role in osmotic balance and photo-protection. Growth of Limonium linifolium showed that the plant was tolerant to a wide range of salinity under both tidal and drought conditions, but was susceptible to complete submergence, with high membrane damage even in tidal-treated plants. Plants died within 2 weeks of complete submergence. Results further indicated that L. linifolium tolerates extreme drought by accumulating large quantities of proline and oxalic acid, which consequently lowers its water potential for uptake of soil water of high salinity. Excess salts were excreted through salt glands. This is an important adaptation for a plant that thrives in a highly variable saline habitat Further investigation of submergence effects on upper intertidal species using B. diffusa showed three key stages in the response. A drop in chlorophyll a+b within 6 hours (4.2 ± 0.2 to 2.4 ± 0.3 mg l-1) with a corresponding increase in carotenoid concentration (0.6 ± 0.1 mg l-1) indicated an immediate response to submergence. Oxalic acid concentration was highest on Day 4 (13.6 mM) as opposed to control levels, indicative of its role in submergence tolerance, thus Day 4 may be the peak of positive acclimation. The third phase was marked by a sharp increase in electrolyte leakage to 47.5 ± 2.6 percent on Day 10, from 9.4 ± 1.4 percent on Day 7, with a corresponding decrease in total dissolved solutes between Days 7 and 10. Results suggest that oxalic acid accumulates under submergence possibly as a stabilizing osmolyte. The threshold for tolerance of the species under submergence is 7 days with membrane damage thereafter. Bassia diffusa would not survive prolonged submergence (> 7 days) but could survive submergence of short duration (< 7 days) through continuous underwater photosynthesis, accumulation of osmolytes such as oxalic acid and carotenoid, and maintenance of relative water content and succulence within control levels. When considered together, results showed that the two upper intertidal species were sensitive to waterlogging and would not survive complete submergence, whereas the lower intertidal species could in addition to its natural range, thrive in conditions typical of the upper intertidal range, namely prolonged dry conditions and high sediment salinity. These results have important implications for the future management of salt marshes under predicted climate change conditions. In permanently open South African estuaries, a landward migration of salt marsh will be possible if coastal squeeze is limited and the rate of landward recruitment is on par with sea level rise. In this case salt marsh species would retain their current zonation while shifting inland. Increased sea storms and saltwater intrusion could lead to high salinity concentration in the sediment and significantly reduce growth of salt-sensitive plants. In estuaries that are temporarily open to the sea, reduced freshwater inflow will result in an increase in mouth closure, high water levels, prolonged submergence, and consequently die back of salt marsh vegetation. On the other hand increased abstraction and drought would result in low water levels and high sediment salinity which would decrease growth and survival of salt marsh. This research has provided new knowledge on the ecophysiology of salt marsh plants which can be used to predict the responses of plants to climate change.
- Full Text:
- Date Issued: 2012
The effects of sustained attention, workload and task-related fatigue on physiological measures and performance during a tracking task
- Authors: De Gray Birch, Casey
- Date: 2012
- Subjects: Fatigue -- Physiological aspects -- Research , Attention -- Physiological aspects -- Research , Human engineering -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5120 , http://hdl.handle.net/10962/d1005198 , Fatigue -- Physiological aspects -- Research , Attention -- Physiological aspects -- Research , Human engineering -- Research
- Description: Despite extensive research into the concept of mental fatigue there is as yet no “gold standard” definition or measurement technique available. Because of this a large amount of fatigue-related errors are still seen in the workplace. The complexity of the problem lies with the inability to directly measure mental processes as well as the various endogenous and exogenous factors that interact to produce the experienced fatigue. Fatigue has been divided into sleep-related and task-related fatigue; however the task-related aspect is evident both during normal waking hours as well as during periods of sleep deprivation, therefore this aspect is considered important in the understanding of fatigue in general. The concept of task-related fatigue has further been divided into active and passive fatigue states; however differentiation between the two requires careful consideration. Various physiological measures have been employed in an attempt to gain a better understanding of the mechanisms involved in the generation of fatigue, however often studies have produced dissociating results. The current study considered the task-related fatigue elicited by a tracking task requiring sustained attention, in order to evaluate the usefulness of various cardiovascular and oculomotor measures as indicators of fatigue. A secondary aim was to determine whether the behavioural and physiological parameter responses could be used to infer the type of fatigue incurred (i.e. an active versus passive fatigue state) as well as the energetical mechanisms involved during task performance. A simple driving simulator task was used as the main tracking task, requiring constant attention and concentration. This task was performed for approximately two hours. Three experimental groups (consisting of 14 subjects each) were used: a control group that performed the tracking task only, a group that performed a five minute auditory memory span task concurrently with the driving task after every 20 minutes of pure driving, and a group that performed a visual choice reaction task for five minutes following every 20 minute driving period. The secondary tasks were employed in order to evaluate the extent of resource allocation as well as arousal level. Performance measures included various driving performance parameters, as well as secondary task performance. Physiological measures included heart rate frequency (HR) and various time- and frequency-domain heart rate variability (HRV)parameters, pupil dilation, blink frequency and duration, fixations, and saccadic parameters as well as critical flicker fusion frequency (CFFF). The Borg CR-10 scale was used to evaluate subjective fatigue during the task, and the NASA-TLX was completed following the task. A decline in driving performance over time was supplemented by measures such as HR, HRV and pupil dilation indicating an increase in parasympathetic activity (or a reduction in arousal). An increase in blink frequency was considered as a sign of withdrawal of attentional resources over time. Longer and faster saccades were also evident over time, coupled with shorter fixations. With regards to the secondary task influence, the choice RT task did not affect any behavioural or physiological parameters, thereby contesting the active fatigue theory of resource depletion, as well as implying that the increase in demand for the same resources used by the primary task was insufficient to affect the state of the subjects. The increased load elicited by the memory span task improved driving performance and increased measures of HR, HRV, pupil dilation and blink frequency. Some of these measures produced opposite effects to what was expected; an attempt to explain the dissociation of the various physiological parameters was expressed in terms of arousal, effort and resource theories. Overall, the results indicate that the fatigue and/or reduced arousal accompanying a monotonous sustained attention task can, to some degree, be alleviated through intermittent performance of a secondary task engaging mental resources other than the ones used for the primary task. The degree to which such a task is beneficial, however, requires careful consideration as while an immediate increase in arousal and primary task performance is noted, the impact of the task on general attentional resources may be detrimental in the case of reacting should an emergency situation occur.
- Full Text:
- Date Issued: 2012
- Authors: De Gray Birch, Casey
- Date: 2012
- Subjects: Fatigue -- Physiological aspects -- Research , Attention -- Physiological aspects -- Research , Human engineering -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5120 , http://hdl.handle.net/10962/d1005198 , Fatigue -- Physiological aspects -- Research , Attention -- Physiological aspects -- Research , Human engineering -- Research
- Description: Despite extensive research into the concept of mental fatigue there is as yet no “gold standard” definition or measurement technique available. Because of this a large amount of fatigue-related errors are still seen in the workplace. The complexity of the problem lies with the inability to directly measure mental processes as well as the various endogenous and exogenous factors that interact to produce the experienced fatigue. Fatigue has been divided into sleep-related and task-related fatigue; however the task-related aspect is evident both during normal waking hours as well as during periods of sleep deprivation, therefore this aspect is considered important in the understanding of fatigue in general. The concept of task-related fatigue has further been divided into active and passive fatigue states; however differentiation between the two requires careful consideration. Various physiological measures have been employed in an attempt to gain a better understanding of the mechanisms involved in the generation of fatigue, however often studies have produced dissociating results. The current study considered the task-related fatigue elicited by a tracking task requiring sustained attention, in order to evaluate the usefulness of various cardiovascular and oculomotor measures as indicators of fatigue. A secondary aim was to determine whether the behavioural and physiological parameter responses could be used to infer the type of fatigue incurred (i.e. an active versus passive fatigue state) as well as the energetical mechanisms involved during task performance. A simple driving simulator task was used as the main tracking task, requiring constant attention and concentration. This task was performed for approximately two hours. Three experimental groups (consisting of 14 subjects each) were used: a control group that performed the tracking task only, a group that performed a five minute auditory memory span task concurrently with the driving task after every 20 minutes of pure driving, and a group that performed a visual choice reaction task for five minutes following every 20 minute driving period. The secondary tasks were employed in order to evaluate the extent of resource allocation as well as arousal level. Performance measures included various driving performance parameters, as well as secondary task performance. Physiological measures included heart rate frequency (HR) and various time- and frequency-domain heart rate variability (HRV)parameters, pupil dilation, blink frequency and duration, fixations, and saccadic parameters as well as critical flicker fusion frequency (CFFF). The Borg CR-10 scale was used to evaluate subjective fatigue during the task, and the NASA-TLX was completed following the task. A decline in driving performance over time was supplemented by measures such as HR, HRV and pupil dilation indicating an increase in parasympathetic activity (or a reduction in arousal). An increase in blink frequency was considered as a sign of withdrawal of attentional resources over time. Longer and faster saccades were also evident over time, coupled with shorter fixations. With regards to the secondary task influence, the choice RT task did not affect any behavioural or physiological parameters, thereby contesting the active fatigue theory of resource depletion, as well as implying that the increase in demand for the same resources used by the primary task was insufficient to affect the state of the subjects. The increased load elicited by the memory span task improved driving performance and increased measures of HR, HRV, pupil dilation and blink frequency. Some of these measures produced opposite effects to what was expected; an attempt to explain the dissociation of the various physiological parameters was expressed in terms of arousal, effort and resource theories. Overall, the results indicate that the fatigue and/or reduced arousal accompanying a monotonous sustained attention task can, to some degree, be alleviated through intermittent performance of a secondary task engaging mental resources other than the ones used for the primary task. The degree to which such a task is beneficial, however, requires careful consideration as while an immediate increase in arousal and primary task performance is noted, the impact of the task on general attentional resources may be detrimental in the case of reacting should an emergency situation occur.
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- Date Issued: 2012