The main aims of the investigation conducted here are to draw out important debates in theory and in the South African social context over the concepts of responsibility and accountability for human rights abuse, and to look at how these were present within, and impacted on, discussions within and around the Truth and Reconciliation Commission. The TRC did not specifically discuss or define theoretical concepts of responsibility or accountability. However, I argue that it is possible to draw out some important features of its implicit approach ??? particularly in terms of its emphasis on collective responsibility and social context (in addition to individual responsibility), and its emphasis on moral arguments for individuals and collectives to accept responsibility and hold themselves accountable by contributing to future change. This ambitious and complex approach raised some important theoretical issues, which have been discussed and debated in the theoretical literature. These include: the relationship between individual responsibility, collective responsibility and the influence of ???the system???; the nature of collective responsibility; the nature of morality; the distinction between moral and political responsibility; and how individuals and collectives can or should be held accountable. In South Africa, these theoretical debates inter-mingled with a range of other factors, including individual and collective interests, motives and political perspectives. From an analysis of the existing literature on the TRC and original interviews conducted with key informants, I draw out three main opposing views which I argue arose in the South African social context about responsibility and accountability, and what the TRC could and should have done to address these. In a detailed analysis of the TRC???s hearings and Final Report, I draw out how theoretical debates, and these three opposing views, were present within and impacted on the TRC???s work. I argue that it was impossible for the TRC to satisfy everyone and resolve these debates, and that its approach led to unrealistic expectations of its work and its role more generally. This has impacted negatively on how the TRC was and is perceived.

It is known in many gold operations that less than 2% of the cyanide consumed accounts for the gold and silver dissolution. The majority of the cyanide is consumed by minerals contained in the gold ore to produce many different cyanide soluble complexes or used in converting cyanide to other related species such as thiocyanate and cyanate. The high costs associated with cyanide and thiocyanate detoxification and excessive cyanide utilisation encountered when treating ores with high cyanide consumption constitutes a significant proportion of the overall processing costs. This study examines the possibility of recovering free cyanide from thiocyanate using a process based on the Acidification-Volatilisation-Regeneration (AVR) circuit in conjunction with a pre-concentration stage using commercially available ionexchange resin. From thermodynamic modelling based on the STABCAL program it was found that it was thermodynamically possible to recover cyanide from thiocyanate if the oxidation of cyanide to cyanate can be stopped. Addition of copper to the system found that the majority of the thiocyanate exists as copper(I) thiocyanate (CuSCN) solid. Using ion-exchange resins can be an effective way to concentrate thiocyanate from tailing solutions or slurries. Four different models were successfully used to model the equilibria between thiocyanate and chloride on commercial ion-exchange resins. By normalising the equilibria data when applying the Mass action law the equilibria becomes independent of ionic strength within the range of concentration considered. An advantage of this is that only one unique equilibrium constant is used to describe the ion-exchange process. The electrochemical and kinetic studies showed that the reaction between thiocyanate and hydrogen peroxide is catalysed by hydrogen ions. Secondly under acidic conditions the rate of cyanide recovery by the AVR circuit was faster than at higher pH conditions. The overall reaction of thiocyanate with respect to the concentration of thiocyanate and hydrogen peroxide is an overall third order reaction. The derived third order rate expression is first order with respect to thiocyanate concentration and second order with respect to hydrogen peroxide concentration. Previous studies showed that the production of cyanide inhibits the reactions between thiocyanate and hydrogen peroxide, but by removing cyanide from the reaction by air stripping, this was not observed. Addition of copper to the system did not show a catalytic effect on the reaction but it was found that copper (II) ions suppresses competing reactions that occurred without affecting the reaction between thiocyanate and hydrogen peroxide.

By elucidating the origins of the banlieue rouge, a belt of communist-dominated suburbs surrounding Paris that arose during the interwar years and reached its apogee under the Fourth Republic, this thesis addresses the problem of why twentieth-century France was home to a pro-Soviet communist party with mass support. Specifically, a local study of the PCF in Arcueil and Cachan, two neighbouring communes south of Paris with divergent political evolutions since World War I, is used to discern how and why the Parti communiste fran??ais (PCF) came to exert hegemony in the working-class suburbs of Paris. After surveying the historiography of communism in France and beyond, this thesis concludes that the communist banlieue rouge was born of working-class alienation from bourgeois society that was nourished by a communist counter-society that was contingent upon the PCF???s capacity to adapt and respond to local circumstances. Using archival sources and statistical analysis, it demonstrates that in Arcueil and Cachan rapid suburbanisation and an attendant proletarianisation created the pre-conditions for the rise of the PCF. This study finds that during the interwar period the PCF rapidly emerged as an electoral force in both suburbs as it set about laying the foundations of a communist counter-society, especially in Arcueil where it won control of local government in 1935. In Arcueil, the PCF spearheaded the local Resistance movement during World War II and then under the Fourth Republic went on to consolidate a nascent communist communal identity, while in Cachan its influence fell victim to Cold War politics. The pre-conditions for the rise of communism were apparent earlier and to a greater degree in Arcueil, an industrialised, working-class suburb with long-standing radical traditions, than in the traditionally conservative Cachan. In Arcueil, the PCF was more successful than its counterpart in Cachan at exploiting an alienation that was not only part of the deep-seated historical traditions of the French working class but was also part of everyday life f or workers forced to live in miserable conditions. In suburbs such as Arcueil, suburban working-class pride at being a social outcast was conflated with communism to create a durable communist communal identity.

Ectomycorrhizal fungi are able to ameliorate heavy metal stress to host trees in polluted soils. Their sensitivity or tolerance to heavy metals is usually examined based on growth and proliferation on heavy metal amended media. However, there are no data on cellular effects of heavy metals and detoxification in live cells of these fungi. Organelle morphology has recently been recognized as an indication of cellular health and its changes can be used to assess cytotoxicity. The aim of this study was, therefore, to investigate short term effects of common heavy metal pollutants, Zn2+ and Ni2+ on the morphology of vacuoles, mitochondria and microtubules in hyphal tip cells of two Paxillus involutus strains. Vacuoles, mitochondria and microtubules were labeled with Oregon Green?? 488 carboxylic acid diacetate, 3,3'-dihexyloxacarbocyanine iodide ((DiOC6(3)) and anti-??- tubulin antibodies, respectively. They were treated with 0-1 mmol L-1 NiSO4 or 0-100 mmol L-1 ZnSO4 or K2SO4 (SO4 2- control) and examined by fluorescence microscopy. Vacuoles and mitochondria in untreated hyphal tip cells of strain P2 which originated from a heavy metal-rich soil were motile and tubular forming networks. Exposure to the metals caused tubular vacuole thickening and vesiculation as well as fragmentation of tubular mitochondria in living hyphal tip cells. The highest K2SO4 concentration also had severe effects on mitochondria. These effects were metal, concentration and exposure time dependent. NiSO4 caused these effects at a hundred fold lower concentration than ZnSO4 and induced severe microtubule disruption. Vacuole tubularity recovered after removal of the metal solutions depending on the metal, concentration and exposure time. Mitochondrial tubularity recovered to pretreatment morphology in a shorter time and even during exposure to the highest metal concentration. Vacuoles of strain P46 which originated from a non-polluted soil were pleomorphic, but mainly spherical with occasional tubular interconnections. The vacuoles were too sensitive to UV light exposure required for fluorescence microscopy to investigate their response to heavy metals. The mitochondrial network and microtubules resembled those of strain P2. The highest ZnSO4 and NiSO4 concentrations caused similar trends in response of mitochondria and microtubules of the two strains. However, mitochondria of strain P46 were less sensitive at lower metal concentrations. The highest K2SO4 concentration had more severe effects on mitochondria of strain P46 than in strain P2 from which tubularity was not recovered. This investigation is the first to reveal that heavy metals affect organelle morphology in two strains of an ectomycorrhizal fungus. Nickel effects on the organelles are likely to result from microtubule disruption. Metal induced mitochondrial fragmentation is possibly an apoptotic response and the recovery of tubular organelle networks suggests cellular detoxification.

Advances in our understanding of osteoarthritis (OA) have made development of sensitive measurement tools a priority. The literature review in this thesis found that one of the measurement tools, arthroscopy, had not been fully evaluated. This body of work evaluated the performance of arthroscopic assessments of articular cartilage (AC) in early OA with specific reference to the OMERACT filter. Preliminary studies in plastic knee arthroscopy simulation models found that estimates of AC lesion area had poor accuracy and reliability. Measurements of lesion diameter were greatly improved by the use of specially designed measurement probes but these did not prove feasible in vivo. Ovine studies evaluated discriminant and criterion validity. Biomechanical assessments served as the gold standard for AC stiffness while macroscopic, thickness and histologic assessments were used for gross structural damage. An hybrid gold standard assessment was devised to validate arthroscopic estimates of Severity and Extent of chondropathy. Arthroscopic global assessments discriminated between normal and very early OA but discrimination between different states of OA was less impressive. Assessments of the Severity of chondropathy had acceptable accuracy and moderate reliability. While arthroscopy could not examine the entire articular surface and estimates of Extent of chondropathy were subject to very large error they broadly resembled those of the hybrid gold standard assessment and they enhanced composite score performance. Composite score validity was further improved by inclusion of estimates of chondro-osteophyte. An empirical approach to composite algorithm weighting to optimise discriminant validity was developed. This approach compared favourably with previously described methods. Composite scores proved best at discriminating between normal and very early OA but were also capable of detecting small changes in OA. Arthroscopic asessments of AC damage meet the OMERACT filter criteria of Truth and Discrimination. Assessments using current arthroscopic technology should include estimates of the Extent of all grades of chondropathy. The optimal scoring algorithm should be determined empirically. Arthroscopic assessments using existing technology may be used to validate noninvasive assessments of the Severity chondropathy but not of Extent. Future efforts to improve arthroscopic assessments of AC should focus on reducing random error associated with estimates of extent.

Ectomycorrhizal fungi are able to ameliorate heavy metal stress to host trees in polluted soils. Their sensitivity or tolerance to heavy metals is usually examined based on growth and proliferation on heavy metal amended media. However, there are no data on cellular effects of heavy metals and detoxification in live cells of these fungi. Organelle morphology has recently been recognized as an indication of cellular health and its changes can be used to assess cytotoxicity. The aim of this study was, therefore, to investigate short term effects of common heavy metal pollutants, Zn2+ and Ni2+ on the morphology of vacuoles, mitochondria and microtubules in hyphal tip cells of two Paxillus involutus strains. Vacuoles, mitochondria and microtubules were labeled with Oregon Green?? 488 carboxylic acid diacetate, 3,3'-dihexyloxacarbocyanine iodide ((DiOC6(3)) and anti-??- tubulin antibodies, respectively. They were treated with 0-1 mmol L-1 NiSO4 or 0-100 mmol L-1 ZnSO4 or K2SO4 (SO4 2- control) and examined by fluorescence microscopy. Vacuoles and mitochondria in untreated hyphal tip cells of strain P2 which originated from a heavy metal-rich soil were motile and tubular forming networks. Exposure to the metals caused tubular vacuole thickening and vesiculation as well as fragmentation of tubular mitochondria in living hyphal tip cells. The highest K2SO4 concentration also had severe effects on mitochondria. These effects were metal, concentration and exposure time dependent. NiSO4 caused these effects at a hundred fold lower concentration than ZnSO4 and induced severe microtubule disruption. Vacuole tubularity recovered after removal of the metal solutions depending on the metal, concentration and exposure time. Mitochondrial tubularity recovered to pretreatment morphology in a shorter time and even during exposure to the highest metal concentration. Vacuoles of strain P46 which originated from a non-polluted soil were pleomorphic, but mainly spherical with occasional tubular interconnections. The vacuoles were too sensitive to UV light exposure required for fluorescence microscopy to investigate their response to heavy metals. The mitochondrial network and microtubules resembled those of strain P2. The highest ZnSO4 and NiSO4 concentrations caused similar trends in response of mitochondria and microtubules of the two strains. However, mitochondria of strain P46 were less sensitive at lower metal concentrations. The highest K2SO4 concentration had more severe effects on mitochondria of strain P46 than in strain P2 from which tubularity was not recovered. This investigation is the first to reveal that heavy metals affect organelle morphology in two strains of an ectomycorrhizal fungus. Nickel effects on the organelles are likely to result from microtubule disruption. Metal induced mitochondrial fragmentation is possibly an apoptotic response and the recovery of tubular organelle networks suggests cellular detoxification.

Advances in our understanding of osteoarthritis (OA) have made development of sensitive measurement tools a priority. The literature review in this thesis found that one of the measurement tools, arthroscopy, had not been fully evaluated. This body of work evaluated the performance of arthroscopic assessments of articular cartilage (AC) in early OA with specific reference to the OMERACT filter. Preliminary studies in plastic knee arthroscopy simulation models found that estimates of AC lesion area had poor accuracy and reliability. Measurements of lesion diameter were greatly improved by the use of specially designed measurement probes but these did not prove feasible in vivo. Ovine studies evaluated discriminant and criterion validity. Biomechanical assessments served as the gold standard for AC stiffness while macroscopic, thickness and histologic assessments were used for gross structural damage. An hybrid gold standard assessment was devised to validate arthroscopic estimates of Severity and Extent of chondropathy. Arthroscopic global assessments discriminated between normal and very early OA but discrimination between different states of OA was less impressive. Assessments of the Severity of chondropathy had acceptable accuracy and moderate reliability. While arthroscopy could not examine the entire articular surface and estimates of Extent of chondropathy were subject to very large error they broadly resembled those of the hybrid gold standard assessment and they enhanced composite score performance. Composite score validity was further improved by inclusion of estimates of chondro-osteophyte. An empirical approach to composite algorithm weighting to optimise discriminant validity was developed. This approach compared favourably with previously described methods. Composite scores proved best at discriminating between normal and very early OA but were also capable of detecting small changes in OA. Arthroscopic asessments of AC damage meet the OMERACT filter criteria of Truth and Discrimination. Assessments using current arthroscopic technology should include estimates of the Extent of all grades of chondropathy. The optimal scoring algorithm should be determined empirically. Arthroscopic assessments using existing technology may be used to validate noninvasive assessments of the Severity chondropathy but not of Extent. Future efforts to improve arthroscopic assessments of AC should focus on reducing random error associated with estimates of extent.

Neuromelanin (NM) is a dark polymer pigment present in specific populations of catecholaminergic neurons in the brain. Interest in this pigment has rekindled in recent years because of a hypothesised link between NM and the especial vulnerability of NM-containing neurons to cell death in Parkinson???s disease (PD). Many aspects of the biology of NM are yet to be characterised. It is not known if NM like the similar melanin of the skin is synthesised via an enzymatic pathway or solely through autoxidation as has traditionally been thought. Examination of the ultrastructure of NM granules showed that in contrast to peripheral melanosomes, an electron-lucent lipid component was present that represented 30% of pigment volume. The identity of the lipid component of NM has remained unclear since it was first suggested that NM contained lipid in the 1960???s. NM lipid was biochemically isolated from the substantia nigra of 32 human brains. Using reversed-phase high performance liquid chromatography, atmospheric pressure chemical ionisation mass spectrometry and 1H- and 13C NMR techniques, it was shown for the first time that the NM lipid is the polyisoprenoid dolichol. The age-related development and regulation of NM has not previously been described. Optical density and area measurements of unstained NM in ventral substantia nigra neurons spanning the ages of 24 weeks to 95 years old demonstrated three developmental phases. NM was not present at birth and initiation of pigmentation began at approximately 3 years of age, followed by a period of increasing pigment granule number and colouration until age 20. In PD brain, the ultrastructure of NM demonstrated that the amount of lipid did not change. However, filipin staining showed a reduction of cholesterol in PD NM containing neurons. In addition, immunogold staining of ??-synuclein demonstrated that this protein redistributed to the NM lipid in PD brain. The finding of phases in the development of NM, and the identification of lipid species in NM suggest that NM biology is regulated. This thesis has also demonstrated changes in the lipid and associated proteins in PD, suggesting NM???s chemical composition alters which may have functional consequences that contribute to PD.

Neuromelanin (NM) is a dark polymer pigment present in specific populations of catecholaminergic neurons in the brain. Interest in this pigment has rekindled in recent years because of a hypothesised link between NM and the especial vulnerability of NM-containing neurons to cell death in Parkinson???s disease (PD). Many aspects of the biology of NM are yet to be characterised. It is not known if NM like the similar melanin of the skin is synthesised via an enzymatic pathway or solely through autoxidation as has traditionally been thought. Examination of the ultrastructure of NM granules showed that in contrast to peripheral melanosomes, an electron-lucent lipid component was present that represented 30% of pigment volume. The identity of the lipid component of NM has remained unclear since it was first suggested that NM contained lipid in the 1960???s. NM lipid was biochemically isolated from the substantia nigra of 32 human brains. Using reversed-phase high performance liquid chromatography, atmospheric pressure chemical ionisation mass spectrometry and 1H- and 13C NMR techniques, it was shown for the first time that the NM lipid is the polyisoprenoid dolichol. The age-related development and regulation of NM has not previously been described. Optical density and area measurements of unstained NM in ventral substantia nigra neurons spanning the ages of 24 weeks to 95 years old demonstrated three developmental phases. NM was not present at birth and initiation of pigmentation began at approximately 3 years of age, followed by a period of increasing pigment granule number and colouration until age 20. In PD brain, the ultrastructure of NM demonstrated that the amount of lipid did not change. However, filipin staining showed a reduction of cholesterol in PD NM containing neurons. In addition, immunogold staining of ??-synuclein demonstrated that this protein redistributed to the NM lipid in PD brain. The finding of phases in the development of NM, and the identification of lipid species in NM suggest that NM biology is regulated. This thesis has also demonstrated changes in the lipid and associated proteins in PD, suggesting NM???s chemical composition alters which may have functional consequences that contribute to PD.

This thesis investigates the impact of insider trading regulation and its enforcement on bid-ask spreads, information asymmetry proxies, volatility, trade frequency and trade sizes. It employs an exclusive intra-day market-microstructure data-set for 29 countries and 32 exchanges and utilizes structural simultaneous equations models with distributed geometric lags estimated with GMM, controlling for market architecture, trading demand, minimum tick size and Fama-French factors. This thesis finds that enforcement of insider trading regulation in a country, rather than the strictness of written insider trading law, reduces information asymmetry and bid-ask spreads, increases volatility, and has an overall positive impact on traded value. The positive impact is mostly concentrated in the smallest stocks in the sample. The regulation of disclosure requirements has similar, but not identical, beneficial externalities in the market. The results support the prediction by Bhattacharya and Daouk (2002) that the fall in the cost of equity that results from insider trading prosecution in a country is due to a reduction in adverse selection. This thesis also find some support of the free inside information scenario of Medrano and Vives (2004), where volatility increases when insiders are forced to disclose the inside information before legally trading on it, if insider trading is not permitted and the regulation is enforced.