Text in Afrikaans / By ontbinding van 'n huwelik buite gemeenskap van goed beskik die hof oor 'n diskresionere bevoegdheid om 'n herverdeling van bates van die onderskeie boedels te gelas. Die voorvereiste, naamlik 'n bydrae tot die instandhouding of vergroting van die boedel van die ander en die uitleg van die bewoording van die wet bring egter mee dat die hof se diskresie om 'n billike herverdeling te beveel ingekort is. Bydrae behoort op gelyke vlak tesarne met al die relevante faktore 'n rol te speel. Huwelikswangedrag behoort 'n beperkte rol te speel by herverdelingsbevele. In sekere gevalle sal dit egter onbillik wees om skuld as faktor te ignoreer. Die skuld van die party teen wie die verdeling gevra word behoort nie 'n rol te speel nie. Sekere wetswysiginge is nodig ten einde die doel van die wet, naamlik bereiking van geregtigheid tussen die partye, te bewerkstellig. / On dissolution of a maniage out of commwrity of property the court has discretionary power to order a distribution of the assets of the different estates. The precondition, namely a contribution to the maintenance or increase of the estate of the other, and the interpretation of the words of the act, however, results in a curtailment of the court's discretion to order a just and equitable distribution. Contribution should play a role on the same level as all the other relevant factors. Misconduct should play a restricted role in a redistribution order. However, in certain cases it would be inequitable to ignore misconduct as a factor. The misconduct of the party against whom the redistribution is sought should not play a role. Certain amendments of the act are necessary to achieve the aim of the act, namely the attaining of equity between the parties. / Private Law / LL. M.

A two-dimensional hydrodynamic numerical model is extended and applied to simulate the interaction between stellar winds and the interstellar medium (ISM). In particular, the stellar wind evolution of O- and B-type stars is calculated. First, the evolution of a stellar wind into the ambient interstellar medium and also a more dense molecular cloud are considered for the case of no relative motion between the star and the interstellar medium. This interaction results in a cavity being blown into the ISM. Of importance in this work is the boundary radius (astropause) of the stellar wind and also the location where the outflow speed decreases from supersonic to subsonic speeds, called the termination shock. Different parameters like ISM density, outflow speed and mass-loss rate were varied to study the effect these have on the computed astropause (AP) and termination shock (TS) radii. The evolution of these structures is presented up to a simulation time of 1 My. However, stars are not stationary relative to the ISM, and the evolution of stellar winds into the interstellar medium including relative motion is also considered. It is shown that the positions of the TS and AP are dependent on the mass-loss rate and stellar wind outflow speed of the star and the interstellar medium density and relative speed. When these massive stars reach the end of their life, they end their life in a supernova explosion. The explosion results in a blast wave moving outward, called the forward shock (FS) and a reverse shock (RS) also forms which moves inward. Previous work done by Ferreira and de Jager (2008) to simulate supernova remnant (SNR) evolution, was only done for the case of evolution into the undisturbed ISM (no cavity). In this work, the evolution of SNR is simulated taking also into account the pre-existing cavity blown out by the stellar winds of these massive stars. The results of this study showed that the evolution of the SNR is definitely influenced by the presence of a stellar wind cavity even if the cavity is only a few pc in extent. / Thesis (MSc (Space Physics))--North-West University, Potchefstroom Campus, 2011.

A two-dimensional hydrodynamic numerical model is extended and applied to simulate the interaction between stellar winds and the interstellar medium (ISM). In particular, the stellar wind evolution of O- and B-type stars is calculated. First, the evolution of a stellar wind into the ambient interstellar medium and also a more dense molecular cloud are considered for the case of no relative motion between the star and the interstellar medium. This interaction results in a cavity being blown into the ISM. Of importance in this work is the boundary radius (astropause) of the stellar wind and also the location where the outflow speed decreases from supersonic to subsonic speeds, called the termination shock. Different parameters like ISM density, outflow speed and mass-loss rate were varied to study the effect these have on the computed astropause (AP) and termination shock (TS) radii. The evolution of these structures is presented up to a simulation time of 1 My. However, stars are not stationary relative to the ISM, and the evolution of stellar winds into the interstellar medium including relative motion is also considered. It is shown that the positions of the TS and AP are dependent on the mass-loss rate and stellar wind outflow speed of the star and the interstellar medium density and relative speed. When these massive stars reach the end of their life, they end their life in a supernova explosion. The explosion results in a blast wave moving outward, called the forward shock (FS) and a reverse shock (RS) also forms which moves inward. Previous work done by Ferreira and de Jager (2008) to simulate supernova remnant (SNR) evolution, was only done for the case of evolution into the undisturbed ISM (no cavity). In this work, the evolution of SNR is simulated taking also into account the pre-existing cavity blown out by the stellar winds of these massive stars. The results of this study showed that the evolution of the SNR is definitely influenced by the presence of a stellar wind cavity even if the cavity is only a few pc in extent. / Thesis (MSc (Space Physics))--North-West University, Potchefstroom Campus, 2011.

Occupational risk management can be a catalyst in generating superior returns for all stakeholders on a sustainable basis. A number of companies in South Africa have implemented Cardinal Rules of Safety adopted from international companies to ensure the safety of their employees. The purpose of this study was to measure the impact of the cardinal rules on employee safety behaviour implemented at power stations in Mpumalanga. The empirical study was done by using a questionnaire as measuring instrument. The questionnaire was developed from a literature review and contains questions and items relevant to the initial research problem. The questionnaire comprised of five–point Likert scale type questions.The convenience sampling method was applied identifying 90 participants at three different power stations in Mpumalanga taking part in the study. Statistical analysis was performed by the Statistical Consulting Service of the North–West University using SPSS. Cronbach’s alpha co–efficients was used to determine the reliability of the factors. Descriptive statistics (Mean, standard, deviation, were used in the compiling of the profile of the results. While Spearman’s rho correlation coefficient was calculated to identify practically significant associations between variables and factors The research findings suggest that there is practical significant correlation between the factors that were measured. The opinion given by respondents suggests that cardinal rules of safety were implemented, given all the necessary support by management and enforced throughout the organisation. / Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2012.

Compromised calcium homeostasis in the central nervous system (CNS) is implicated as a major contributor in the pathology of neurodegeneration. Dysregulation of Ca2+ homeostasis initiates downstream Ca2+–dependent events that lead to apoptotic and/or necrotic cell death. Increases in the intracellular free calcium concentration ([Ca2+]i) may be the result of Ca2+ influx from the extracellular environment or Ca2+ release from intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Influx from the extracellular environment is controlled predominantly by voltage gated calcium channels (VGCC), such as L–type calcium channels (LTCC) and ionotropic glutamate receptors, such as the N–methyl–D–aspartate (NMDA) receptors. Ca2+ release from the ER occurs through the inositol–1,4,5–triphosphate receptors (IP3Rs) or ryanodine receptors (RyRs) via IP3–induced or Ca2+–induced mechanisms. Mitigation of Ca2+ overload through these Ca2+ channels offers an opportunity for pharmacological interventions that may protect against neuronal death. In the present study the ability of a novel series of polycyclic compounds, both the pentacycloundecylamines and triquinylamines, to regulate calcium influx through LTCC was evaluated in PC12 cells using calcium imaging with Fura–2/AM in a fluorescence microplate reader. We were also able for the first time to determine IC50 values for these compounds as LTCC blockers. In addition, selected compounds were evaluated for their ability to offer protection in apoptosis–identifying assays such as the lactate dehydrogenase release assay (LDH–assay), trypan blue staining assay and immunohistochemistry utilizing the Annexin V–FITC stain for apoptosis. We were also able to obtain single crystal structures for the tricyclo[6.3.0.02,6]undecane–4,9–dien–3,11–dione (9) and tricyclo[6.3.0.02,6]undecane–3,11–dione (10) scaffolds as well as a derivative, N–(3–methoxybenzyl)–3,11–azatricyclo[6.3.0.02,6]undecane (14f). We also evaluated the possibility that the polycyclic compounds might be able to modulate Ca2+ flux through intracellular Ca2+ channels. Computational methods were utilized to accurately predicted IC50 values and develop a QSAR model with marginal error. The linear regression model delivered r2 = 0.83, which indicated a favorable correlation between the predicted and experimental IC50 values. This model could thus serve as valuable predictor for future structural design and optimization efforts. Data obtained from the crystallographic analysis confirmed the NMR–data based structural assignments done for these compounds in previous studies. Obtaining structural information gave valuable insight into the differences in size and geometric constrains, which are key features for the LTCC activity of these compounds. vii In conclusion, we found that all of the compounds evaluated were able to attenuate Ca2+ influx through the LTCC, with some compounds having IC50 values comparable with known LTCC blockers such as nimodipine. Representative compounds were evaluated for their ability to afford protection against apoptosis induced by 200 ?M H2O2. With the exception of compound 14c (the most potent LTCC blocker in the series, IC50 = 0.398 ?M), most compounds were able to afford protection at two or more concentrations evaluated. Compound 14c displayed inherent toxicity at the highest concentrations evaluated (100 ?M). We concluded that compounds representing both types of structures (pentacycloudecylamines and triquinylamines) have the ability to attenuate excessive Ca2+ influx through the LTCC. In general the aza–pentacycloundecylamines (8a–c) were the most potent LTCC blocker which also had the ability to offer protection in the cell viability assays. However, NGP1–01 (7a) had the most favorable pharmacological profile overall with good activity as an LTCC blocker (IC50 = 86 ?M) and the ability to significantly attenuate cell death in the cell viability assays, exhibiting no toxicity. In addition to their ability to modulate Ca2+ influx from the extracellular environment, these compounds also displayed the ability to modulate Ca2+ flux through intracellular Ca2+ channels. The mechanisms by which they act on intracellular Ca2+ channels still remains unclear, but from this preliminary study it would appear that these compounds are able to partially inhibiting Ca2+–ATPase activity whilst possibly simultaneously inhibiting the IP3R. In the absence of extracellular Ca2+ these compounds showed the ability in inhibit voltage–induced Ca2+ release (VICaR), possibly by modulating the gating charge of the voltage sensor being the dihydropyridine receptors. In future studies it might be worthwhile to do an expanded QSAR study and evaluate the aza–pentacycloundecylamines. To clarify the mechanisms by which the polycyclic compounds interact with intracellular Ca2+ channels we should examine the direct interaction with the individual Ca2+ channels independently. The polycyclic compounds evaluated in this study demonstrate potential as multifunctional drugs due to their ability to broadly regulate calcium homeostasis through multiple pathways of Ca2+ entry. This may prove to be more effective in diseases where perturbed Ca2+ homeostasis have devastating effects eventually leading to excitotoxicity and cell death. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.

Occupational risk management can be a catalyst in generating superior returns for all stakeholders on a sustainable basis. A number of companies in South Africa have implemented Cardinal Rules of Safety adopted from international companies to ensure the safety of their employees. The purpose of this study was to measure the impact of the cardinal rules on employee safety behaviour implemented at power stations in Mpumalanga. The empirical study was done by using a questionnaire as measuring instrument. The questionnaire was developed from a literature review and contains questions and items relevant to the initial research problem. The questionnaire comprised of five–point Likert scale type questions.The convenience sampling method was applied identifying 90 participants at three different power stations in Mpumalanga taking part in the study. Statistical analysis was performed by the Statistical Consulting Service of the North–West University using SPSS. Cronbach’s alpha co–efficients was used to determine the reliability of the factors. Descriptive statistics (Mean, standard, deviation, were used in the compiling of the profile of the results. While Spearman’s rho correlation coefficient was calculated to identify practically significant associations between variables and factors The research findings suggest that there is practical significant correlation between the factors that were measured. The opinion given by respondents suggests that cardinal rules of safety were implemented, given all the necessary support by management and enforced throughout the organisation. / Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2012.

Compromised calcium homeostasis in the central nervous system (CNS) is implicated as a major contributor in the pathology of neurodegeneration. Dysregulation of Ca2+ homeostasis initiates downstream Ca2+–dependent events that lead to apoptotic and/or necrotic cell death. Increases in the intracellular free calcium concentration ([Ca2+]i) may be the result of Ca2+ influx from the extracellular environment or Ca2+ release from intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Influx from the extracellular environment is controlled predominantly by voltage gated calcium channels (VGCC), such as L–type calcium channels (LTCC) and ionotropic glutamate receptors, such as the N–methyl–D–aspartate (NMDA) receptors. Ca2+ release from the ER occurs through the inositol–1,4,5–triphosphate receptors (IP3Rs) or ryanodine receptors (RyRs) via IP3–induced or Ca2+–induced mechanisms. Mitigation of Ca2+ overload through these Ca2+ channels offers an opportunity for pharmacological interventions that may protect against neuronal death. In the present study the ability of a novel series of polycyclic compounds, both the pentacycloundecylamines and triquinylamines, to regulate calcium influx through LTCC was evaluated in PC12 cells using calcium imaging with Fura–2/AM in a fluorescence microplate reader. We were also able for the first time to determine IC50 values for these compounds as LTCC blockers. In addition, selected compounds were evaluated for their ability to offer protection in apoptosis–identifying assays such as the lactate dehydrogenase release assay (LDH–assay), trypan blue staining assay and immunohistochemistry utilizing the Annexin V–FITC stain for apoptosis. We were also able to obtain single crystal structures for the tricyclo[6.3.0.02,6]undecane–4,9–dien–3,11–dione (9) and tricyclo[6.3.0.02,6]undecane–3,11–dione (10) scaffolds as well as a derivative, N–(3–methoxybenzyl)–3,11–azatricyclo[6.3.0.02,6]undecane (14f). We also evaluated the possibility that the polycyclic compounds might be able to modulate Ca2+ flux through intracellular Ca2+ channels. Computational methods were utilized to accurately predicted IC50 values and develop a QSAR model with marginal error. The linear regression model delivered r2 = 0.83, which indicated a favorable correlation between the predicted and experimental IC50 values. This model could thus serve as valuable predictor for future structural design and optimization efforts. Data obtained from the crystallographic analysis confirmed the NMR–data based structural assignments done for these compounds in previous studies. Obtaining structural information gave valuable insight into the differences in size and geometric constrains, which are key features for the LTCC activity of these compounds. vii In conclusion, we found that all of the compounds evaluated were able to attenuate Ca2+ influx through the LTCC, with some compounds having IC50 values comparable with known LTCC blockers such as nimodipine. Representative compounds were evaluated for their ability to afford protection against apoptosis induced by 200 ?M H2O2. With the exception of compound 14c (the most potent LTCC blocker in the series, IC50 = 0.398 ?M), most compounds were able to afford protection at two or more concentrations evaluated. Compound 14c displayed inherent toxicity at the highest concentrations evaluated (100 ?M). We concluded that compounds representing both types of structures (pentacycloudecylamines and triquinylamines) have the ability to attenuate excessive Ca2+ influx through the LTCC. In general the aza–pentacycloundecylamines (8a–c) were the most potent LTCC blocker which also had the ability to offer protection in the cell viability assays. However, NGP1–01 (7a) had the most favorable pharmacological profile overall with good activity as an LTCC blocker (IC50 = 86 ?M) and the ability to significantly attenuate cell death in the cell viability assays, exhibiting no toxicity. In addition to their ability to modulate Ca2+ influx from the extracellular environment, these compounds also displayed the ability to modulate Ca2+ flux through intracellular Ca2+ channels. The mechanisms by which they act on intracellular Ca2+ channels still remains unclear, but from this preliminary study it would appear that these compounds are able to partially inhibiting Ca2+–ATPase activity whilst possibly simultaneously inhibiting the IP3R. In the absence of extracellular Ca2+ these compounds showed the ability in inhibit voltage–induced Ca2+ release (VICaR), possibly by modulating the gating charge of the voltage sensor being the dihydropyridine receptors. In future studies it might be worthwhile to do an expanded QSAR study and evaluate the aza–pentacycloundecylamines. To clarify the mechanisms by which the polycyclic compounds interact with intracellular Ca2+ channels we should examine the direct interaction with the individual Ca2+ channels independently. The polycyclic compounds evaluated in this study demonstrate potential as multifunctional drugs due to their ability to broadly regulate calcium homeostasis through multiple pathways of Ca2+ entry. This may prove to be more effective in diseases where perturbed Ca2+ homeostasis have devastating effects eventually leading to excitotoxicity and cell death. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.

Text in Afrikaans / By ontbinding van 'n huwelik buite gemeenskap van goed beskik die hof oor 'n diskresionere bevoegdheid om 'n herverdeling van bates van die onderskeie boedels te gelas. Die voorvereiste, naamlik 'n bydrae tot die instandhouding of vergroting van die boedel van die ander en die uitleg van die bewoording van die wet bring egter mee dat die hof se diskresie om 'n billike herverdeling te beveel ingekort is. Bydrae behoort op gelyke vlak tesarne met al die relevante faktore 'n rol te speel. Huwelikswangedrag behoort 'n beperkte rol te speel by herverdelingsbevele. In sekere gevalle sal dit egter onbillik wees om skuld as faktor te ignoreer. Die skuld van die party teen wie die verdeling gevra word behoort nie 'n rol te speel nie. Sekere wetswysiginge is nodig ten einde die doel van die wet, naamlik bereiking van geregtigheid tussen die partye, te bewerkstellig. / On dissolution of a maniage out of commwrity of property the court has discretionary power to order a distribution of the assets of the different estates. The precondition, namely a contribution to the maintenance or increase of the estate of the other, and the interpretation of the words of the act, however, results in a curtailment of the court's discretion to order a just and equitable distribution. Contribution should play a role on the same level as all the other relevant factors. Misconduct should play a restricted role in a redistribution order. However, in certain cases it would be inequitable to ignore misconduct as a factor. The misconduct of the party against whom the redistribution is sought should not play a role. Certain amendments of the act are necessary to achieve the aim of the act, namely the attaining of equity between the parties. / Private Law / LL. M.

The research posed two questions, namely (a) how much stress, if any, is experienced by house mothers in a childrens' home, and (b) which factors cause such stress. The methodology employed is descriptive research. It covered the total population of ten house mothers in a childres' home. Measuring instruments employed were; the Heimler scale for Social Functioning, the Glazer Stress Control Life Style Questionnaire, the Stress Questionnaire, and a self-formulated questionnaire. The results are as follows: 70% reported average to high stress, but are inclined to deny stress. 30% reported normal stress levels, Possible causes of stress are the work context of the childrens' home, age, period of service, and personality. / Die studie soek antwoorde op twee vrae, naamlik (a) hoeveel sires, indien enige, beleef huismoeders in 'n kinderhuis, en (b) wat veroorsaak sulke sires? Die metode wat gebruik was, is beskrywende navorsing. Die totale populasie van tien huismoeders in die spesifieke kinderhuis is betrek. Die klein omvang maak hierdie studie nie veralgemeenbaar nie. Die volgende meetinstrumente is benut ; die Heimlerskaal vir Maatskaplike Funksionering, die "Glazer Stress Control Life Style Questionnaire'', die "Stress Questionnaire", en 'n selfgeformuleerde vraelys. Die resultate is soos volg: 70% van die huismoeders in die studie vermeld gemiddelde tot hoe mates van stres, maar is geneig om stres te ontken. Dertig persent van die respondente vermeld normale hoeveelhede stres. Moontlike oorsake van sires is aangetoon as: die werkskonteks binne die kinderhuis, ouderdom, tydperk van diens, en persoonlikheid / Social Work / M.A. (Social Work: Mental Health)

The research posed two questions, namely (a) how much stress, if any, is experienced by house mothers in a childrens' home, and (b) which factors cause such stress. The methodology employed is descriptive research. It covered the total population of ten house mothers in a childres' home. Measuring instruments employed were; the Heimler scale for Social Functioning, the Glazer Stress Control Life Style Questionnaire, the Stress Questionnaire, and a self-formulated questionnaire. The results are as follows: 70% reported average to high stress, but are inclined to deny stress. 30% reported normal stress levels, Possible causes of stress are the work context of the childrens' home, age, period of service, and personality. / Die studie soek antwoorde op twee vrae, naamlik (a) hoeveel sires, indien enige, beleef huismoeders in 'n kinderhuis, en (b) wat veroorsaak sulke sires? Die metode wat gebruik was, is beskrywende navorsing. Die totale populasie van tien huismoeders in die spesifieke kinderhuis is betrek. Die klein omvang maak hierdie studie nie veralgemeenbaar nie. Die volgende meetinstrumente is benut ; die Heimlerskaal vir Maatskaplike Funksionering, die "Glazer Stress Control Life Style Questionnaire'', die "Stress Questionnaire", en 'n selfgeformuleerde vraelys. Die resultate is soos volg: 70% van die huismoeders in die studie vermeld gemiddelde tot hoe mates van stres, maar is geneig om stres te ontken. Dertig persent van die respondente vermeld normale hoeveelhede stres. Moontlike oorsake van sires is aangetoon as: die werkskonteks binne die kinderhuis, ouderdom, tydperk van diens, en persoonlikheid / Social Work / M.A. (Social Work: Mental Health)