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Die invloed van koöperatiewe leer as onderrigstrategie op die houding van Graad 8-wiskundeleerders teenoor probleemoplossing en op hul prestasie in wiskunde / Sarita van der LithVan der Lith, Sarita January 2014 (has links)
Die navorsing is onderneem om die invloed van koöperatiewe leer as „n onderrigstrategie op Graad 8 wiskundeleerders se houding teenoor probleemoplossing en hul prestasie in wiskunde te bepaal. Die doelstellings van die empiriese ondersoek was:
- om die houding van Graad 8 leerders teenoor wiskunde en teenoor probleemoplossing in wiskunde te ondersoek;
- om die invloed van koöperatiewe leer as onderrigstrategie op die houding van graad 8 wiskunde-leerders teenoor wiskunde en teenoor probleemoplossing in wiskunde te ondersoek; en
- om die invloed van koöperatiewe leer as onderrigstrategie op die prestasie van Graad 8 leerders in wiskunde te ondersoek.
Deur middel van „n literatuurstudie as onderrig-leerraamwerk, is die aard van skoolwiskunde; benaderings ten opsigte van die leer van skoolwiskunde, naamlik die behavioristiese-, die kognitiewe- en die konstruktiwistiese leerbenaderings; die rol van probleemoplossing in die onderrig en leer van skoolwiskunde; asook die houding van leerders teenoor wiskunde en teenoor probleemoplossing in wiskunde, bespreek. Na aanleiding van die gebruik van direkte- en indirekte onderrigstrategieë, is die volgende elemente van koöperatiewe leer (indirekte onderrigstrategie) beklemtoon: individuele verantwoordelikheid, interpersoonlike sosiale vaardighede, positiewe persoonlike interaksie, groepvordering en positiewe interafhanklikheid. Koöperatiewe leermetodes en die implementering van koöperatiewe leer in die wiskundeklaskamer is vervolgens bespreek, asook leerders se houding teenoor koöperatiewe leer.
Vir die empiriese ondersoek is „n opeenvolgende verklarende gekombineerde navorsingsmetode-ontwerp gebruik, wat bestaan het uit die insameling en ontleding van kwantitatiewe- en kwalitatiewe data in opeenvolgende fases. „n Voor-eksperimentele evaluering (voortoets) is gedoen om die eksperimentele en kontrolegroepe te vergelyk ten opsigte van hul houding teenoor wiskunde en teenoor probleemoplossing in wiskunde deur die gebruik van „n aangepaste houdingsvraelys (ATMI), asook ten opsigte van leerders se wiskundeprestasie. Die intervensie (koöperatiewe leer as onderrigstrategie) is vervolgens vir „n tydperk van sestien weke op die eksperimentele groep toegepas. Die aangepaste
houdingsvraelys (ATMI) is ook tydens „n na-eksperimentele evaluering (natoets) vir beide (kontrole- en eksperimentele) groepe gebruik, asook vir die vergelyking van genoemde groepe se wiskundeprestasie. Die kwalitatiewe ondersoek is uitgevoer deur individuele gestruktureerde taakgebaseerde onderhoude met geselekteerde deelnemers van die eksperimentele groep te voer. Inligting oor leerders se houding en ervaring ten opsigte van probleemoplossing in wiskunde, hul houding teenoor koöperatiewe leer, asook hul probleemoplossingsvaardighede, is met behulp van die onderhoude bekom.
Uit die resultate van die empiriese navorsing is bevind dat koöperatiewe leer as onderrigstrategie geen beduidende invloed op Graad 8 leerders se houding teenoor wiskunde en teenoor probleemoplossing in wiskunde gehad het nie. Die gebruik van koöperatiewe leer as onderrigstrategie daarenteen, het „n beduidende toename in Graad 8 leerders se prestasie in wiskunde tot gevolg gehad. / MEd (Mathematics Education), North-West University, Potchefstroom Campus, 2015
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Die invloed van koöperatiewe leer as onderrigstrategie op die houding van Graad 8-wiskundeleerders teenoor probleemoplossing en op hul prestasie in wiskunde / Sarita van der LithVan der Lith, Sarita January 2014 (has links)
Die navorsing is onderneem om die invloed van koöperatiewe leer as „n onderrigstrategie op Graad 8 wiskundeleerders se houding teenoor probleemoplossing en hul prestasie in wiskunde te bepaal. Die doelstellings van die empiriese ondersoek was:
- om die houding van Graad 8 leerders teenoor wiskunde en teenoor probleemoplossing in wiskunde te ondersoek;
- om die invloed van koöperatiewe leer as onderrigstrategie op die houding van graad 8 wiskunde-leerders teenoor wiskunde en teenoor probleemoplossing in wiskunde te ondersoek; en
- om die invloed van koöperatiewe leer as onderrigstrategie op die prestasie van Graad 8 leerders in wiskunde te ondersoek.
Deur middel van „n literatuurstudie as onderrig-leerraamwerk, is die aard van skoolwiskunde; benaderings ten opsigte van die leer van skoolwiskunde, naamlik die behavioristiese-, die kognitiewe- en die konstruktiwistiese leerbenaderings; die rol van probleemoplossing in die onderrig en leer van skoolwiskunde; asook die houding van leerders teenoor wiskunde en teenoor probleemoplossing in wiskunde, bespreek. Na aanleiding van die gebruik van direkte- en indirekte onderrigstrategieë, is die volgende elemente van koöperatiewe leer (indirekte onderrigstrategie) beklemtoon: individuele verantwoordelikheid, interpersoonlike sosiale vaardighede, positiewe persoonlike interaksie, groepvordering en positiewe interafhanklikheid. Koöperatiewe leermetodes en die implementering van koöperatiewe leer in die wiskundeklaskamer is vervolgens bespreek, asook leerders se houding teenoor koöperatiewe leer.
Vir die empiriese ondersoek is „n opeenvolgende verklarende gekombineerde navorsingsmetode-ontwerp gebruik, wat bestaan het uit die insameling en ontleding van kwantitatiewe- en kwalitatiewe data in opeenvolgende fases. „n Voor-eksperimentele evaluering (voortoets) is gedoen om die eksperimentele en kontrolegroepe te vergelyk ten opsigte van hul houding teenoor wiskunde en teenoor probleemoplossing in wiskunde deur die gebruik van „n aangepaste houdingsvraelys (ATMI), asook ten opsigte van leerders se wiskundeprestasie. Die intervensie (koöperatiewe leer as onderrigstrategie) is vervolgens vir „n tydperk van sestien weke op die eksperimentele groep toegepas. Die aangepaste
houdingsvraelys (ATMI) is ook tydens „n na-eksperimentele evaluering (natoets) vir beide (kontrole- en eksperimentele) groepe gebruik, asook vir die vergelyking van genoemde groepe se wiskundeprestasie. Die kwalitatiewe ondersoek is uitgevoer deur individuele gestruktureerde taakgebaseerde onderhoude met geselekteerde deelnemers van die eksperimentele groep te voer. Inligting oor leerders se houding en ervaring ten opsigte van probleemoplossing in wiskunde, hul houding teenoor koöperatiewe leer, asook hul probleemoplossingsvaardighede, is met behulp van die onderhoude bekom.
Uit die resultate van die empiriese navorsing is bevind dat koöperatiewe leer as onderrigstrategie geen beduidende invloed op Graad 8 leerders se houding teenoor wiskunde en teenoor probleemoplossing in wiskunde gehad het nie. Die gebruik van koöperatiewe leer as onderrigstrategie daarenteen, het „n beduidende toename in Graad 8 leerders se prestasie in wiskunde tot gevolg gehad. / MEd (Mathematics Education), North-West University, Potchefstroom Campus, 2015
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Psigologiese veranderlikes wat 'n rol speel by akademiese prestasie van eerstejaarstudente aan die PU vir CHO / Tania van ZijlVan Zijl, Tania January 1999 (has links)
The aim of this investigation was to determine the effect of the psychological
variables on the academic performance of first year students at the University of
Potchefstroom.
The reason that research in this field is important is that it can address the
negative influence that the high failure rate of the first year students have on the
community, the economy, and the severe financial and personal strain.
Academic performance is the product of various inter-related factors. It is
however difficult to get a representative model of all these factors. This is
because academic performance, especially at university level, is an extremely
complex and multi-facetted system. These factors need to be examined in
conjunction with one another.
A clear definition of the criteria used for academic performance evaluation is
essential. A distinction is made between first year students that are successful in
their studies as opposed to those that are not. A successful first year student is
defined as a student who is credited with a pass mark in all the subjects required
for that year of study, for the course taken. An unsuccessful first year student is a
student that fails 50% or more of the subjects required for his I her course in that
year, thus forcing the student to prolong the duration of the total study period by
at least one year.
A literature survey was done, in an attempt to identify and discuss some of the
factors that influence academic performance. Various researchers' opinion on
these factors were highlighted. The variables were grouped under the following
headings: biographic, socio-economic, cognitive, personality, and academic
factors.
The following empirical tests were used: Senior Aptitude Test (SAT), the Ninteen
Field Interest Inventory (19-FII), the Personal, Home, Social and Formal
Relations Questionnaire (PHSF) and the Survey of Study Habits and Attitudes
(SSHA). The study population consisted of academically successful and
unsuccessful first year students that started their studies in 1998 at the University
of Potchefstroom. The population included diversity in terms of faculty, race and
gender. Detailed statistics were used to correlate the variables by means of
graphs for each assessment technique. Statistical variance is shown in tabular
form. Psychological differences between men and women are highlighted, as
well as differences between race groups and faculties. The empirical study
shows that there definitely are psychological factors that play a role in academic
performance. A correlation between intelligence, personality, career interests,
study habits and attitude, and the academic performance of the student is shown.
From the literature, and on grounds of the empirical study done, it can be shown
that psychological variables do influence the academic performance of the
student, and that there is a correlation between the variables and academic
performance. / Thesis (M.A.)--Potchefstroom University for Christian Higher Education, 2000
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Psigologiese veranderlikes wat 'n rol speel by akademiese prestasie van eerstejaarstudente aan die PU vir CHO / Tania van ZijlVan Zijl, Tania January 1999 (has links)
The aim of this investigation was to determine the effect of the psychological
variables on the academic performance of first year students at the University of
Potchefstroom.
The reason that research in this field is important is that it can address the
negative influence that the high failure rate of the first year students have on the
community, the economy, and the severe financial and personal strain.
Academic performance is the product of various inter-related factors. It is
however difficult to get a representative model of all these factors. This is
because academic performance, especially at university level, is an extremely
complex and multi-facetted system. These factors need to be examined in
conjunction with one another.
A clear definition of the criteria used for academic performance evaluation is
essential. A distinction is made between first year students that are successful in
their studies as opposed to those that are not. A successful first year student is
defined as a student who is credited with a pass mark in all the subjects required
for that year of study, for the course taken. An unsuccessful first year student is a
student that fails 50% or more of the subjects required for his I her course in that
year, thus forcing the student to prolong the duration of the total study period by
at least one year.
A literature survey was done, in an attempt to identify and discuss some of the
factors that influence academic performance. Various researchers' opinion on
these factors were highlighted. The variables were grouped under the following
headings: biographic, socio-economic, cognitive, personality, and academic
factors.
The following empirical tests were used: Senior Aptitude Test (SAT), the Ninteen
Field Interest Inventory (19-FII), the Personal, Home, Social and Formal
Relations Questionnaire (PHSF) and the Survey of Study Habits and Attitudes
(SSHA). The study population consisted of academically successful and
unsuccessful first year students that started their studies in 1998 at the University
of Potchefstroom. The population included diversity in terms of faculty, race and
gender. Detailed statistics were used to correlate the variables by means of
graphs for each assessment technique. Statistical variance is shown in tabular
form. Psychological differences between men and women are highlighted, as
well as differences between race groups and faculties. The empirical study
shows that there definitely are psychological factors that play a role in academic
performance. A correlation between intelligence, personality, career interests,
study habits and attitude, and the academic performance of the student is shown.
From the literature, and on grounds of the empirical study done, it can be shown
that psychological variables do influence the academic performance of the
student, and that there is a correlation between the variables and academic
performance. / Thesis (M.A.)--Potchefstroom University for Christian Higher Education, 2000
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The implementation of selected technologies to enhance the restoration of indigenous tree species in the deforested riparian areas in the Mapungubwe National Park, South Africa : a case study / Yolandi ElsEls, Yolandi January 2010 (has links)
Stretches of forest along the Limpopo and Shashe Rivers have been classified as a unique forest type
in the vegetation of South Africa and are considered as being "critically endangered" by the South
African Biodiversity Institute. Roughly 400 hectares of this riverine forest area inside the western
section of the Mapungubwe National Park (MNP), a UNESCO World Heritage site, were deforested
and therefore degraded due to previous agricultural cultivation practices. Given the extent of forest
degradation that has occurred, the restoration of this area by means of the re–vegetation of indigenous
trees to its former composition is one of the objectives of the MNP's management plan. The successful
establishment of tree seedlings, especially in semi–arid systems, is however presented with a wide
range of constraints and limiting conditions, which often result in very high mortality rates during
restoration projects. An experimental exclosure, as identified by South African National Parks
(SANParks), was therefore fenced off inside the degraded old lands to act as a demonstration site for
the restoration of indigenous trees.
A pilot study conducted in 2006, involved the transplantation of selected indigenous tree species with
the aim of evaluating suitable re–vegetation technologies. The research contained in this dissertation
was also conducted inside the experimental exclosure, where recommendations derived from the pilot
study were evaluated, including the assessment of new re–vegetation technologies to enhance the
establishment of the indigenous trees. This study was therefore a follow–up project which involved
both field– and greenhouse trials. Seedlings of the following species were either transplanted into the
experimental exclosure (field trial) or cultivated inside a controlled environment in the greenhouse at
the North–West University: Acacia xanthophloea Benth. (fever tree), Berchemia discolor (Klotzsch)
Hemsl. (brown–ivory), Combretum imberbe Wawra (leadwood), Faidherbia albida (Delile) A. Chev.
(ana tree), Philenoptera violacea (Klotzsch) Schrire (apple–leaf), Salvadora australis Schweick.
(narrow–leaved mustard tree) and Xanthocercis zambesiaca (Baker) Dumaz–le–Grand (nyala tree).
During the follow–up study the effects of various enhancement treatments were tested regarding the
survival, growth and physiological performance of seedlings in both the field– and greenhouse trials.
The enhancement treatments consisted of the addition of compost and indigenous arbuscular
mycorrhizal fungi (AMF). In addition, seedlings transplanted during the pilot study, which did not
include enhancement treatments, were also monitored for establishment and growth. The potential use
of established Acacia tortilis Hayne trees to facilitate growth and establishment and to act as "nursing
plants", was also assessed. In addition, various pre–sowing treatments were also applied to seeds of
selected tree species in the greenhouse to assess the germination rate.
The survivorship and growth of seedlings in both the field– and greenhouse trial were determined by
using three growth parameters, namely "stem diameter at the base", "stem diameter 30 cm from the base", and "height of the tree in its natural growth form". Chlorophyll fluorescence induction (JIP test)
was measured on seedlings in both trials, using the multi–parametric expression, namely performance
index (PIABS), as a measure of the overall vitality of the plants of each species–treatment combination.
Physical and chemical analyses were carried out on the soil inside the experimental exclosure. Basic
descriptive statistics were used to analyse seedling survival and germination rates, and a two–way
analysis of variance (ANOVA) was used to determine the statistical significant effects of the various
enhancement treatments on diameter growth in each species (p < 0.05). Fluorescence data were
processed using the Biolyzer software and significant effects in each species were determined using
the Student's t–test (p < 0.05). Multivariate data ordinations using the CANOCO package were used to
determine the differences in soil types inside the experimental exclosure.
Moisture stress due to transplantation shock, competition with dense grass cover and herbivory,
resulted in an overall 55.8% seedling survival rate and negative stem diameter growth for transplanted
seedlings in the field. In comparison, seedlings cultivated in the greenhouse had much higher survival
rates and showed positive stem diameter growth. Most species in the greenhouse showed higher
growth rates and significantly higher vitality values when planted with enhancement treatments. The
responses of transplanted seedlings to the enhancement treatments were very species–specific in the
field trials. Based on these results, it was concluded that the enhancement treatments were beneficial
with regard to the establishment and growth of most of the species. The beneficial effect was however
cancelled out by the various abiotic and biotic factors encountered in the natural environment.
Seedlings transplanted in the understory of established pioneer A. tortilis trees had much lower
survival rates as the extensive root system of A. tortilis most likely out–competed the transplanted
seedlings for moisture and nutrients. Many seedlings were also predated by insects or small mammals
which reduced the growing potential. The germination trials recorded the highest germination rates for
most species when germinated in the compost–containing treatments. These trials also indicated that
all of the investigated species showed higher survival rates when pre–sowing treatments, such as
soaking, mechanical scarification and removing the seed from fruit, were applied. Various
recommendations emphasising long–term monitoring, proper maintenance and after–care of future
restoration efforts are made. These include experimental layout of exclosure plots and pretransplantation
treatments of seedlings while cultivated in the nursery. During this study, the
experimental exclosure was also used as a demonstration site for training and capacity building for
SANParks personnel and students from academic institutions. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
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Socio–demographic characteristics and antecedents associated with the career uncertainty of university students / H. BothaBotha, Hannchen January 2011 (has links)
The changing work environment has caused individuals to revise and change their career decisions. This creates career uncertainty, which has become a widespread problem, particularly for students. When this problem is not addressed, it leads to career indecision, or less optimal choices which could influence career opportunities and quality of life. Career indecision could impact on organisations, resulting in problems such as person–job adjustment, lack of engagement and burnout. Although research on career uncertainty is available internationally, there is limited research on career uncertainty and its antecedents in the South African context. Career uncertainty can have short– and long–term effects on the individual. This study therefore contributes toward the gap in research on the antecedents of career uncertainty. Given that career uncertainty is a problem that individuals are constantly confronted with, it is important that the antecedents of this be investigated.
The objectives of this study were to 1) conceptualise the antecedents of career uncertainty according to the literature; 2) determine if socio–demographic characteristics (gender, career guidance, help from parents, help from other individuals and work experience) are significant predictors of career uncertainty; 3) determine if personality characteristics (self–esteem, self–efficacy and neuroticism) are significant predictors of career uncertainty; 4) determine if career decision–making difficulties are significant predictors of career uncertainty; 5) determine if student burnout and student engagement are significant predictors of career uncertainty; and 6) determine if academic performance is a significant predictor of career uncertainty.
A non–probability quota sample (N = 782) was used to investigate antecedents of career uncertainty in a sample of university students. Career uncertainty was measured by one item The changing work environment has caused individuals to revise and change their career decisions. This creates career uncertainty, which has become a widespread problem, particularly for students. When this problem is not addressed, it leads to career indecision, or less optimal choices which could influence career opportunities and quality of life. Career indecision could impact on organisations, resulting in problems such as person–job adjustment, lack of engagement and burnout. Although research on career uncertainty is available internationally, there is limited research on career uncertainty and its antecedents in the South African context. Career uncertainty can have short– and long–term effects on the individual. This study therefore contributes toward the gap in research on the antecedents of career uncertainty. Given that career uncertainty is a problem that individuals are constantly confronted with, it is important that the antecedents of this be investigated.
The objectives of this study were to 1) conceptualise the antecedents of career uncertainty according to the literature; 2) determine if socio–demographic characteristics (gender, career guidance, help from parents, help from other individuals and work experience) are significant predictors of career uncertainty; 3) determine if personality characteristics (self–esteem, self–efficacy and neuroticism) are significant predictors of career uncertainty; 4) determine if career decision–making difficulties are significant predictors of career uncertainty; 5) determine if student burnout and student engagement are significant predictors of career uncertainty; and 6) determine if academic performance is a significant predictor of career uncertainty.
A non–probability quota sample (N = 782) was used to investigate antecedents of career uncertainty in a sample of university students. Career uncertainty was measured by one item consisting of four categories: I am very sure; I know exactly what career I will pursue (n = 228), I am fairly sure what career I will pursue (n = 416), I am not sure at all which career I will pursue (n = 135) and I do not plan to follow a career (n = 3). For the objective of the study, categories one and two were grouped together with participants who were fairly certain which career they would follow, while participants in category three represented participants who were uncertain. Category four was not included as only three participants within that category answered. In total, 644 students were (fairly) certain, while 135 were uncertain. These two groups were enclosed as a dependent variable in the logistic regression.
The results of this study showed that work experience influences career uncertainty to some extent. This is supported by previous research. Furthermore, it was found that self–esteem also influences career uncertainty to some degree. However, these two variables were only significant in the first steps of the logistic regression. Furthermore, the results showed that career decision–making difficulties share a significant relationship with career uncertainty. The study also found that significant antecedents of career uncertainty include: a lack of information about the decision–making process; a lack of information about occupations; inconsistent information due to internal conflict; a lack of information about ways of obtaining information; and inconsistent information due to external conflict. In conclusion, exhaustion, cynicism and dedication were also found to be significant antecedents of career uncertainty. Based on these results, this study suggests that student burnout and student engagement influence an individual’s level of career uncertainty.
Recommendations were made for practice as well as for future research. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2012.
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Iron status, anthropometric status and cognitive performance of black African school children aged 6–11 years in the Klerksdorp area / Taljaard CTaljaard, Christine January 1900 (has links)
AIM
Poor iron status and under–nutrition among children are of concern not only in South Africa but worldwide. Both independent and combined associations between poor iron status, under–nutrition and cognitive development and function have been investigated. This mini–dissertation investigated possible associations between iron status indicators, anthropometric nutritional status and cognitive performance in the Beverage Fortified with Micronutrients (BeForMi) study population (black South African children aged 6–11 years in the North–West province of South Africa).
METHODS
The study was cross–sectional and based on the BeForMi study baseline data. Primary school children (n = 414) with the highest serum transferrin receptor (STR) and zinc protoporphyrin (ZnPP) levels were included. Anthropometric z–scores - BMI–for–age (BAZ), height–for–age (HAZ), and weight–for–age (WAZ) - and iron status indicators - haemoglobin (Hb), serum ferritin (SF), STR and ZnPP - were determined. The Kaufman Assessment Battery for Children, Second edition (KABC–II) was used to generate cognitive scores.
RESULTS
Fourteen percent of children were underweight (WAZ <= 2 SDs), 12.8% stunted (HAZ <= 2 SDs) and 8.4% wasted (BAZ <= 2 SDs). Of the children, 7.1% were anaemic (Hb < 11.5 g/dL), 13% iron depleted (Hb < 11.5 g/dL and SF < 12 ug/L) and 2.7% had iron deficiency anaemia (Hb < 11.5 g/dL and SF < 12 ug/L). Low iron stores (SF < 12 ug/L) were observed in 15.7% of the children. Positive correlations were found between SF and WAZ (r = 0.1, p = 0.047), Hb and HAZ (r = 0.13, p = 0.007) and WAZ (r = 0.13, p = 0.009). Positive correlations with small effect sizes were observed between some cognitive scores and z–scores (p < 0.05, r–value range 0.10 – 0.24). Negative correlations with small effect sizes were observed for the subtests Triangles and Rover (both subtests on simultaneous processing) with Hb (p = 0.008, r = –0.13) and SF (p = 0.04, r = –0.1) respectively. Higher HAZ, WAZ and education level of the head of household were all significantly associated with the likelihood that a child would fall within the upper quartile of Hb values in our study group (p = 0.036, p = 0.032 and p = 0.036 respectively).
CONCLUSION
The results suggested that under–nutrition was positively associated with poor iron status and lower cognitive scores in this study population. Further research, investigating specific effects of poor iron status at different stages of growth and the relationship with cognitive function later in life may help explain the negative correlations observed between current iron status indicators and cognitive scores. / Thesis (M.Sc (Dietetics))--North-West University, Potchefstroom Campus, 2011.
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The implementation of selected technologies to enhance the restoration of indigenous tree species in the deforested riparian areas in the Mapungubwe National Park, South Africa : a case study / Yolandi ElsEls, Yolandi January 2010 (has links)
Stretches of forest along the Limpopo and Shashe Rivers have been classified as a unique forest type
in the vegetation of South Africa and are considered as being "critically endangered" by the South
African Biodiversity Institute. Roughly 400 hectares of this riverine forest area inside the western
section of the Mapungubwe National Park (MNP), a UNESCO World Heritage site, were deforested
and therefore degraded due to previous agricultural cultivation practices. Given the extent of forest
degradation that has occurred, the restoration of this area by means of the re–vegetation of indigenous
trees to its former composition is one of the objectives of the MNP's management plan. The successful
establishment of tree seedlings, especially in semi–arid systems, is however presented with a wide
range of constraints and limiting conditions, which often result in very high mortality rates during
restoration projects. An experimental exclosure, as identified by South African National Parks
(SANParks), was therefore fenced off inside the degraded old lands to act as a demonstration site for
the restoration of indigenous trees.
A pilot study conducted in 2006, involved the transplantation of selected indigenous tree species with
the aim of evaluating suitable re–vegetation technologies. The research contained in this dissertation
was also conducted inside the experimental exclosure, where recommendations derived from the pilot
study were evaluated, including the assessment of new re–vegetation technologies to enhance the
establishment of the indigenous trees. This study was therefore a follow–up project which involved
both field– and greenhouse trials. Seedlings of the following species were either transplanted into the
experimental exclosure (field trial) or cultivated inside a controlled environment in the greenhouse at
the North–West University: Acacia xanthophloea Benth. (fever tree), Berchemia discolor (Klotzsch)
Hemsl. (brown–ivory), Combretum imberbe Wawra (leadwood), Faidherbia albida (Delile) A. Chev.
(ana tree), Philenoptera violacea (Klotzsch) Schrire (apple–leaf), Salvadora australis Schweick.
(narrow–leaved mustard tree) and Xanthocercis zambesiaca (Baker) Dumaz–le–Grand (nyala tree).
During the follow–up study the effects of various enhancement treatments were tested regarding the
survival, growth and physiological performance of seedlings in both the field– and greenhouse trials.
The enhancement treatments consisted of the addition of compost and indigenous arbuscular
mycorrhizal fungi (AMF). In addition, seedlings transplanted during the pilot study, which did not
include enhancement treatments, were also monitored for establishment and growth. The potential use
of established Acacia tortilis Hayne trees to facilitate growth and establishment and to act as "nursing
plants", was also assessed. In addition, various pre–sowing treatments were also applied to seeds of
selected tree species in the greenhouse to assess the germination rate.
The survivorship and growth of seedlings in both the field– and greenhouse trial were determined by
using three growth parameters, namely "stem diameter at the base", "stem diameter 30 cm from the base", and "height of the tree in its natural growth form". Chlorophyll fluorescence induction (JIP test)
was measured on seedlings in both trials, using the multi–parametric expression, namely performance
index (PIABS), as a measure of the overall vitality of the plants of each species–treatment combination.
Physical and chemical analyses were carried out on the soil inside the experimental exclosure. Basic
descriptive statistics were used to analyse seedling survival and germination rates, and a two–way
analysis of variance (ANOVA) was used to determine the statistical significant effects of the various
enhancement treatments on diameter growth in each species (p < 0.05). Fluorescence data were
processed using the Biolyzer software and significant effects in each species were determined using
the Student's t–test (p < 0.05). Multivariate data ordinations using the CANOCO package were used to
determine the differences in soil types inside the experimental exclosure.
Moisture stress due to transplantation shock, competition with dense grass cover and herbivory,
resulted in an overall 55.8% seedling survival rate and negative stem diameter growth for transplanted
seedlings in the field. In comparison, seedlings cultivated in the greenhouse had much higher survival
rates and showed positive stem diameter growth. Most species in the greenhouse showed higher
growth rates and significantly higher vitality values when planted with enhancement treatments. The
responses of transplanted seedlings to the enhancement treatments were very species–specific in the
field trials. Based on these results, it was concluded that the enhancement treatments were beneficial
with regard to the establishment and growth of most of the species. The beneficial effect was however
cancelled out by the various abiotic and biotic factors encountered in the natural environment.
Seedlings transplanted in the understory of established pioneer A. tortilis trees had much lower
survival rates as the extensive root system of A. tortilis most likely out–competed the transplanted
seedlings for moisture and nutrients. Many seedlings were also predated by insects or small mammals
which reduced the growing potential. The germination trials recorded the highest germination rates for
most species when germinated in the compost–containing treatments. These trials also indicated that
all of the investigated species showed higher survival rates when pre–sowing treatments, such as
soaking, mechanical scarification and removing the seed from fruit, were applied. Various
recommendations emphasising long–term monitoring, proper maintenance and after–care of future
restoration efforts are made. These include experimental layout of exclosure plots and pretransplantation
treatments of seedlings while cultivated in the nursery. During this study, the
experimental exclosure was also used as a demonstration site for training and capacity building for
SANParks personnel and students from academic institutions. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
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Socio–demographic characteristics and antecedents associated with the career uncertainty of university students / H. BothaBotha, Hannchen January 2011 (has links)
The changing work environment has caused individuals to revise and change their career decisions. This creates career uncertainty, which has become a widespread problem, particularly for students. When this problem is not addressed, it leads to career indecision, or less optimal choices which could influence career opportunities and quality of life. Career indecision could impact on organisations, resulting in problems such as person–job adjustment, lack of engagement and burnout. Although research on career uncertainty is available internationally, there is limited research on career uncertainty and its antecedents in the South African context. Career uncertainty can have short– and long–term effects on the individual. This study therefore contributes toward the gap in research on the antecedents of career uncertainty. Given that career uncertainty is a problem that individuals are constantly confronted with, it is important that the antecedents of this be investigated.
The objectives of this study were to 1) conceptualise the antecedents of career uncertainty according to the literature; 2) determine if socio–demographic characteristics (gender, career guidance, help from parents, help from other individuals and work experience) are significant predictors of career uncertainty; 3) determine if personality characteristics (self–esteem, self–efficacy and neuroticism) are significant predictors of career uncertainty; 4) determine if career decision–making difficulties are significant predictors of career uncertainty; 5) determine if student burnout and student engagement are significant predictors of career uncertainty; and 6) determine if academic performance is a significant predictor of career uncertainty.
A non–probability quota sample (N = 782) was used to investigate antecedents of career uncertainty in a sample of university students. Career uncertainty was measured by one item The changing work environment has caused individuals to revise and change their career decisions. This creates career uncertainty, which has become a widespread problem, particularly for students. When this problem is not addressed, it leads to career indecision, or less optimal choices which could influence career opportunities and quality of life. Career indecision could impact on organisations, resulting in problems such as person–job adjustment, lack of engagement and burnout. Although research on career uncertainty is available internationally, there is limited research on career uncertainty and its antecedents in the South African context. Career uncertainty can have short– and long–term effects on the individual. This study therefore contributes toward the gap in research on the antecedents of career uncertainty. Given that career uncertainty is a problem that individuals are constantly confronted with, it is important that the antecedents of this be investigated.
The objectives of this study were to 1) conceptualise the antecedents of career uncertainty according to the literature; 2) determine if socio–demographic characteristics (gender, career guidance, help from parents, help from other individuals and work experience) are significant predictors of career uncertainty; 3) determine if personality characteristics (self–esteem, self–efficacy and neuroticism) are significant predictors of career uncertainty; 4) determine if career decision–making difficulties are significant predictors of career uncertainty; 5) determine if student burnout and student engagement are significant predictors of career uncertainty; and 6) determine if academic performance is a significant predictor of career uncertainty.
A non–probability quota sample (N = 782) was used to investigate antecedents of career uncertainty in a sample of university students. Career uncertainty was measured by one item consisting of four categories: I am very sure; I know exactly what career I will pursue (n = 228), I am fairly sure what career I will pursue (n = 416), I am not sure at all which career I will pursue (n = 135) and I do not plan to follow a career (n = 3). For the objective of the study, categories one and two were grouped together with participants who were fairly certain which career they would follow, while participants in category three represented participants who were uncertain. Category four was not included as only three participants within that category answered. In total, 644 students were (fairly) certain, while 135 were uncertain. These two groups were enclosed as a dependent variable in the logistic regression.
The results of this study showed that work experience influences career uncertainty to some extent. This is supported by previous research. Furthermore, it was found that self–esteem also influences career uncertainty to some degree. However, these two variables were only significant in the first steps of the logistic regression. Furthermore, the results showed that career decision–making difficulties share a significant relationship with career uncertainty. The study also found that significant antecedents of career uncertainty include: a lack of information about the decision–making process; a lack of information about occupations; inconsistent information due to internal conflict; a lack of information about ways of obtaining information; and inconsistent information due to external conflict. In conclusion, exhaustion, cynicism and dedication were also found to be significant antecedents of career uncertainty. Based on these results, this study suggests that student burnout and student engagement influence an individual’s level of career uncertainty.
Recommendations were made for practice as well as for future research. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2012.
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Iron status, anthropometric status and cognitive performance of black African school children aged 6–11 years in the Klerksdorp area / Taljaard CTaljaard, Christine January 1900 (has links)
AIM
Poor iron status and under–nutrition among children are of concern not only in South Africa but worldwide. Both independent and combined associations between poor iron status, under–nutrition and cognitive development and function have been investigated. This mini–dissertation investigated possible associations between iron status indicators, anthropometric nutritional status and cognitive performance in the Beverage Fortified with Micronutrients (BeForMi) study population (black South African children aged 6–11 years in the North–West province of South Africa).
METHODS
The study was cross–sectional and based on the BeForMi study baseline data. Primary school children (n = 414) with the highest serum transferrin receptor (STR) and zinc protoporphyrin (ZnPP) levels were included. Anthropometric z–scores - BMI–for–age (BAZ), height–for–age (HAZ), and weight–for–age (WAZ) - and iron status indicators - haemoglobin (Hb), serum ferritin (SF), STR and ZnPP - were determined. The Kaufman Assessment Battery for Children, Second edition (KABC–II) was used to generate cognitive scores.
RESULTS
Fourteen percent of children were underweight (WAZ <= 2 SDs), 12.8% stunted (HAZ <= 2 SDs) and 8.4% wasted (BAZ <= 2 SDs). Of the children, 7.1% were anaemic (Hb < 11.5 g/dL), 13% iron depleted (Hb < 11.5 g/dL and SF < 12 ug/L) and 2.7% had iron deficiency anaemia (Hb < 11.5 g/dL and SF < 12 ug/L). Low iron stores (SF < 12 ug/L) were observed in 15.7% of the children. Positive correlations were found between SF and WAZ (r = 0.1, p = 0.047), Hb and HAZ (r = 0.13, p = 0.007) and WAZ (r = 0.13, p = 0.009). Positive correlations with small effect sizes were observed between some cognitive scores and z–scores (p < 0.05, r–value range 0.10 – 0.24). Negative correlations with small effect sizes were observed for the subtests Triangles and Rover (both subtests on simultaneous processing) with Hb (p = 0.008, r = –0.13) and SF (p = 0.04, r = –0.1) respectively. Higher HAZ, WAZ and education level of the head of household were all significantly associated with the likelihood that a child would fall within the upper quartile of Hb values in our study group (p = 0.036, p = 0.032 and p = 0.036 respectively).
CONCLUSION
The results suggested that under–nutrition was positively associated with poor iron status and lower cognitive scores in this study population. Further research, investigating specific effects of poor iron status at different stages of growth and the relationship with cognitive function later in life may help explain the negative correlations observed between current iron status indicators and cognitive scores. / Thesis (M.Sc (Dietetics))--North-West University, Potchefstroom Campus, 2011.
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