Gold tailings contained in Tailing Storage Facilities (TSFs) contain pyrite which on exposure to air and water becomes a source of acid mine drainage (AMD). AMD has high salinity, elevated levels of heavy metals and low pH, which presents serious threats to surface and groundwater systems. These characteristics in tailings present a hostile environment for plant establishment and growth (Witkowski and Weiersbye 1998a). Therefore, it was hypothesized that organic mulch sourced from sewage sludge and water hyacinth could improve tailings fertility on TSFs in the Highveld gold mines of South Africa. The aim of this study was to develop a greenhouse study to understand how four indigenous plants (Asparagus laricinus Burch. (Asparagaceae), Eragrostis curvula (Schrad.) Nees. (Poaceae), Hyparrhenia hirta (L.) Stapf (Poaceae) and Sutherlandia frutescens (L.) R.Br. (Fabaceae) naturally colonizing the Highveld gold TSFs would survive, grow and accumulate metals from tailings amended using different percentages of water hyacinth and/or sewage sludge, and the susceptibility of the amended tailings to metal leaching. Tailings amended with WH: SS-1.0% proved to be the overall best amendment from the 19 treatments based on the variable tested (e.g. plant growth, plant metal uptake and metal leaching). Amending gold tailings with water hyacinth and/or sewage sludge improved seedling survival, plant survival and growth as compared to non-amended tailings. Tailings amended with dry water hyacinth (WH) created the most favourable plant growing conditions especially at 0.5% of amendment, while those amended only with sewage sludge (SS) presented the most challenging plant growth conditions for all four study species. Amending tailings with water hyacinth and/or sewage sludge showed no significant difference in tailings fertility. However, C (%) and total N decrease significantly after plant growth in all treatments. Hyparrhenia plants grown in tailings amended with WH: SS-1.0% accumulated significantly higher concentrations of Al, Cr, Ni and Zn, while those growing in tailings amended with WH-0.5% accumulated significantly lower concentration of Al, Co, Cr, Fe and Zn as compared to other treatments. Tailings amended with WH-1.0% leached significantly higher concentrations of Mn, while those amended with WH: SS-0.5% and WL-2.0% leached significantly higher concentrations of S as compared to other treatments. All four species accumulated significantly higher concentrations of Al, Co, Cr, Cu, Fe and Ni in the roots than the shoots, except for A. laricinus which accumulated significantly higher concentrations of S, Co, Cr, Mn, Ni and Zn in the shoots than the roots. Sutherlandia frutescens retained all the elements tested in its root biomass. Future field studies in the use of water hyacinth and sewage sludge as organic tailings amendments will be required to get a better understanding of these two potential tailings amendment treatment.

MSc., Faculty of Science, University of the Witwatersrand, 2011 / The behaviour and physiology of every insect, during all developmental stages, is largely determined by temperature. Metabolic rate, flight activity, nutrition, growth rate, oviposition and longevity can all be correlated to temperature. Consequently, insect development occurs within a definite temperature range which can be experimentally determined. This serves as a basis from which models that estimate insect growth, development and reproduction can be formulated. Such studies on temperature-dependent development are therefore important for understanding predator-prey relationships and insect population dynamics relevant in epidemiology, pest management and biological control of weeds and insect pests. The biological control of water hyacinth, Eichhornia crassipes (Pontederiaceae), in South Africa currently relies on six established agents. However, the results of this programme do not compare well with the achievements made elsewhere. This has been attributed to a number of constraining factors, chief among which is a wide variety of climatic regions, low minimum temperatures and a high incidence of frosting which slows the build-up of natural enemy populations. This research verified and augmented the thermal tolerance data available for three of South Africa’s more efficacious agents used against water hyacinth, namely Neochetina eichhorniae, N. bruchi (Curculionidae) and Eccritotarsus catarinensis (Miridae). Using these data, plant productivity and insect activity was modelled against fine-scale temperature data incorporating three distinct microclimates from 14 field sites distributed throughout South Africa’s climatic regions. Water hyacinth and its natural enemies were found to be negatively affected by low average temperatures. However, the relative consequences for each species at a population level were quite different. Similar thresholds for development, close to 10°C, meant that periods available for growth in areas where temperature is limiting were roughly the same for both plant and insects. Nevertheless, although plant growth largely ceased each winter and aerial parts were often extensively damaged from frost, low temperatures rarely led to significant plant mortality. By contrast, reduced insect recruitment coupled with a high susceptibility to cold- and frost-induced mortality of all life-history stages, pushed insect populations into winter bottlenecks and even caused local extinctions. The ability to overwinter effectively appears to the primary cause for limited control in colder regions. Surviving post-winter insect populations were therefore small, inflicted minimal damage due to reduced feeding rates, and were generally asynchronous with the recovery of water hyacinth. This asynchronous development translated into a lag period of roughly 42 days between the onset of water hyacinth growth and the time at which the plant was subjected to meaningful herbivory. Free from early season herbivory, coupled with the fact that vegetative reproduction continued through winter, water hyacinth populations were able to quickly recover and outpaced the detrimental affects caused by insect feeding well into the growth season. The implications for supplementary management strategies are also discussed in light of these outcomes.

O Brasil é o país mais rico do mundo em espécies de psitacídeos (cerca de 74), sendo 17 delas ameaçadas de extinção. Entre elas está a arara-azul (Anodorhynchus hyacinthinus) que é considerada vulnerável e pode se tornar ameaçada num futuro próximo, em conseqüência do intenso tráfico ilegal e perda do seu habitat. No presente estudo estimamos os níveis de variabilidade e caracterizamos a estrutura genética de populações naturais de A. hyacinthinus. Analisamos 10 locos de microssatélites de 98 indivíduos e seqüências concatenadas de genes mitocondriais (ND5, citocromo-b e ND2; 2123 pb total) de 80 indivíduos. O índice de diversidade genética foi considerado baixo em relação a outras espécies de psitacídeos. Além disso, os índices RST e a análise bayesiana dos dados de microssatélites indicaram moderada estruturação genética entre indivíduos de quatro regiões geográficas (Pantanal norte, Pantanal sul, norte e nordeste), mas os índices de FST indicaram diferenciação somente entre três regiões (norte e nordeste sem diferenciação). A estruturação entre essas três regiões foi congruente com a forte estruturação genética apontada pelos índices de FST e pela rede de haplótipos das seqüências mitocondriais. Baseado nos dados mitocondriais o tempo de divergência entre os grupos genéticos de A. hyacinthinus foi estimado em 16 a 42 mil anos atrás, o que corresponde ao final do Pleistoceno. Ainda, os resultados apontaram para uma população demograficamente estável ao longo do tempo, o que pode indicar que a baixa variabilidade pode ser uma característica da espécie. Entretanto, a rede de haplótipos apresenta forma em estrela com alguns haplótipos de baixa freqüência, o que pode indicar expansão recente, principalmente para região nordeste. Baseado nos dados de estruturação genética populacional, foi possivel indicar a possível origem de indivíduos apreendidos e sem procedência conhecida, o que é importante para realizar ações preventivas de repressão e fiscalização. Adicionalmente, foram analisados sete locos de microssatélites de filhotes amostrados no mesmo ninho (mesma estação reprodutiva, estações reprodutivas consecutivas e estações alternadas) em duas regiões do Pantanal. Os resultados sugerem que a espécie é predominantemente monogâmica estrita, mas há pelo menos 12,5% de paternidade extra-par e 6,5% de parasitismo de ninho. Além disso, foram confirmados dados obtidos em campo de que muitos casais utilizam o mesmo ninho em anos consecutivos e alternados. Finalmente, padronizamos a sexagem molecular de amostras de penas de muda. Concluindo, os resultados genéticos obtidos nesse trabalho trazem informações sobre os processos envolvidos na história evolutiva dessa espécie, além de contribuir com informações sobre o comportamento reprodutivo das araras-azuis proporcionando mais subsídios para elaboração de programas de conservação. / Brazil has the highest number of parrot species in the world (about 74), 17 of them endangered. Among them is the hyacinth macaw (Anodorhynchus hyacinthinus), which is considered vulnerable and could become endangered in the near future, due to the intense illegal traffic and loss of habitat. In this study we estimated levels of variability and characterized the genetic structure of natural populations of hyacinth macaws. We analyzed 10 microsatellite loci from 98 individuals and concatenated sequences of mitochondrial genes (ND5, cytochrome b and ND2, 2,123 bp total) from 80 individuals. The genetic diversity index was low compared to those from other species of parrots. In addition, RST indeces and Bayesian analysis of microsatellite data showed moderate genetic structure among individuals of four regions in Brazil (north Pantanal, south Pantanal, north and northeast), but FST indeces indicate differentiation only between three regions (north and northeast without differentiation). This is in accordance with the strong genetic structure indicated by FST indeces and haplotype network based on mitochondrial sequences. Based on the mitochondrial data, the time of divergence of the genetic groups of hyacinth macaws was estimated to have occurred 16 to 42 thousand years ago, which corresponds to the late Pleistocene. Still, the results suggest that the population has been demographically stable over time, which may indicate that the low variability levels may be a characteristic of the species. However, the haplotype network presents a star shape, which indicate recent expansion, specially in the northeast. Additionally, given the population genetic structure data, it was possible to identify the most probable region of origin of apprehended individuals, this information is important to plan preventive and repressive control. Additionally, we analyzed seven microsatellite loci of chicks sampled in the same nest (same breeding season, alternate breeding seasons and consecutive seasons) in two regions of the Pantanal. The results suggest that the species is predominantly monogamous, but there is at least 12.5% of extra-pair paternity and 6.5% of brood parasitism. Furthermore, the genetic data is congruent with field observations that suggest that many couples return to the same nest in consecutive and alternative breeding seasons. Finally, we standardized for a molecular sexing protocol for molten feathers. In conclusion, the genetic results obtained in this study provide information about the processes involved in the evolutionary history and the reproductive behavior of hyacinth macaws that may help plan conservation actions.

by So Lai Man, Rachel. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 83-103). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Table of Contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.ix / Chapter 1. --- Literature Review --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Overview of metal ions pollution --- p.2 / Chapter 1.3 --- Treatment of metal ions in wastewater --- p.4 / Chapter 1.3.1 --- Conventional methods --- p.4 / Chapter 1.3.2 --- Microbial methods --- p.5 / Chapter 1.4 --- Phytoremediation --- p.6 / Chapter 1.4.1 --- Rhizofiltration --- p.10 / Chapter 1.4.2 --- Mechanisms of metal ion removal by plant root --- p.12 / Chapter 1.5 --- Using water hyacinth for wastewater treatment --- p.15 / Chapter 1.5.1 --- Biology of water hyacinth --- p.15 / Chapter 1.5.2 --- Water hyacinth based systems for wastewater treatment --- p.21 / Chapter 1.6 --- Biology of rhizosphere --- p.23 / Chapter 2. --- Objectives --- p.26 / Chapter 3 --- Materials and Methods --- p.28 / Chapter 3.1 --- Metal ion stock solution --- p.28 / Chapter 3.2 --- Plant material and growth conditions --- p.28 / Chapter 3.2.1 --- Preparation of Hoagland solution --- p.28 / Chapter 3.3 --- Metal ion resistance of water hyacinth --- p.31 / Chapter 3.4 --- Effect of metal ion concentration on the bacteria population --- p.31 / Chapter 3.4.1 --- Minimal medium (MM) --- p.31 / Chapter 3.5 --- Isolation of rhizospheric metal ion-resistant bacteria --- p.34 / Chapter 3.6 --- Metal ion removal capacity of isolated bacteria --- p.34 / Chapter 3.7 --- Colonization efficiency of a metal ion-adsorbing bacterium onto the root --- p.35 / Chapter 3.7.1 --- Suppression of the bacterial population in the rhizosphere by an antibiotic --- p.35 / Chapter 3.7.2 --- Colonization efficiency --- p.36 / Chapter 3.8 --- Effect of colonizing the metal ion-adsorbing bacteria on the metal ion removal capacity of roots --- p.37 / Chapter 4. --- Results --- p.38 / Chapter 4.1 --- Selection of optimum metal ion concentration for water hyacinth and rhizo spheric bacteria --- p.38 / Chapter 4.1.1 --- Metal ion resistance of water hyacinth --- p.38 / Chapter 4.1.2 --- Effect of metal ion concentration on population of rhizospheric bacteria --- p.43 / Chapter 4.1.3 --- Selection for optimum metal ion concentration for water hyacinth and rhizospheric bacteria --- p.43 / Chapter 4.2 --- Screening for bacterial strain with high metal ion resistance and removal capacity --- p.46 / Chapter 4.2.1 --- Enrichment of the metal ion-resistant bacteria in the rhizosphere --- p.46 / Chapter 4.2.2 --- Isolation of the natural bacterial population in rhizosphere --- p.50 / Chapter 4.2.3 --- Determination of the metal ion removal capacity of rhizospheric metal ion-resistant bacterial strains --- p.52 / Chapter 4.2.4 --- "Comparison of Cu2+, Ni2+ and Zn2+ removal capacities of Cu2+-resistant bacterial strains" --- p.53 / Chapter 4.3 --- Effect of inoculating Cu2+-resistant bacterial strain to the rhizosphere on the metal ion removal capacity of the root --- p.59 / Chapter 4.3.1 --- Bactericidal efficiency of oxytetracycline --- p.59 / Chapter 4.3.2 --- Effect of inoculating Cu2+-adsorbing bacterial cells into the rhizosphere --- p.62 / Chapter 4.3.3 --- Effect of bacterial cell density of inoculum on colonizing efficiency --- p.63 / Chapter 4.3.4 --- Colonizing efficiency and metal ion removal capacity of root by direct inoculation of metal ion-adsorbing bacterial cells into metal ion solution or pre-inoculation in Hoagland solution --- p.64 / Chapter 4.3.5 --- Effect of inoculating Strain FC-2-2 into the rhizosphere on the removal capacity of roots --- p.64 / Chapter 5. --- Discussion --- p.69 / Chapter 5.1 --- Selection of optimum metal ion concentration for water hyacinth and rhizospheric bacteria --- p.69 / Chapter 5.1.1 --- Metal resistance of water hyacinth --- p.69 / Chapter 5.1.2 --- Effect of metal ion concentration on population of rhizospheric bacteria population --- p.70 / Chapter 5.1.3 --- Selection for optimum concentration --- p.70 / Chapter 5.2 --- Screening for high metal ion-resistant and -removal bacterial strains --- p.71 / Chapter 5.2.1 --- Enrichment of the metal ion-resistant bacteria in the rhizosphere --- p.71 / Chapter 5.2.2 --- Select metal ion-resistant bacterial strain from the natural population in the rhizosphere --- p.72 / Chapter 5.2.3 --- Determination of the metal ion removal capacity of respective metal ion-resistant bacterial strain --- p.72 / Chapter 5.3 --- Effect of inoculating Cu2+-resistant bacterial strain in the rhizosphere on the metal ion removal capacity of the root --- p.74 / Chapter 5.3.1 --- Bactericidal efficiency of oxytetracycline --- p.74 / Chapter 5.3.2 --- Effect of inoculating Cu2十-adsorbing bacterial cells into the rhizosphere --- p.75 / Chapter 5.3.3 --- Effect inoculum cell density on the colonizing efficiency --- p.76 / Chapter 5.3.4 --- Comparison of colonizing efficiency and metal ion removal capacity of root by direct inoculation metal ion-adsorbing bacterial cells into metal solution or pre-inoculationin Hoagland solution --- p.77 / Chapter 5.3.5 --- Effect of inoculating strain FC-2-2 into the rhizosphere on the removal capacity of roots --- p.78 / Chapter 5.4 --- Limitation and future development --- p.79 / Chapter 6. --- Conclusion --- p.81 / Chapter 7. --- References --- p.83

In Taiwan, swine wastewater has become one of the major causes of the deterioration of surface water quality. To minimize the operational and maintenance cost of the conventional wastewater treatment utilities, less expensive natural treatment systems (e.g., aquatic plant treatment system) have been proposed to enhance the efficacy of existing three-stage treatment system (solid separation followed by anaerobic and aerobic treatment). Using the natural treatment system is an appropriate technology for treating livestock wastewater in tropical or subtropical regions or developing countries because it is inexpensive, easily maintained, and has environmentally friendly and sustainable characteristics. The main objectives of this study were to (1) examine the efficacy and capacity of using aquatic plant treatment system to polish the treated wastewater to meet the discharge standards in Taiwan (COD = 600 mg/L, BOD = 80 mg/L, and SS = 150 mg/L), (2) evaluate the potential of reusing the treated wastewater, (3) evaluate the feasibility of replacing the aerobic treatment process contained in the three-stage system with the aquatic plant system, and (4) improve the efficiency of sludge (obtained from the three-stage treatment system) composting process. In this study, a hog farm was selected as the case study site. An aquatic plant unit [13.5 (L) ¡Ñ 4 (W) ¡Ñ 3 (D)] planted with Eichhornia crassipes (water hyacinth) was placed after the aerobic system for wastewater polishment. Influent and effluent sa mples from each unit were collected and analyzed for water quality parameters including chemical oxygen demand (COD), biochemical oxygen demand (BOD), and suspended solids (SS). Water samples were collected monthly during the 15-month investigation period. Results show that the averaged COD, BOD, and SS concentrations were approximately 708, 83, and 123 mg/L, respectively after the three-stage treatment scheme. The observed COD, BOD, and SS concentrations dropped to 518, 56, and 48 mg/L, respectively which could meet the discharge standards. Thus, the aquatic plant treatment system played an important role in meeting the discharge standards for swine wastewater. More than 99% of all pollutants were removed by the three-stage system followed by the aquatic plant system. The effluent from the treatment system has been used for hog farm cleaning. Thus, the aquatic plant system has the potential to be applied as the final polishment process to enhance the treatment efficacy of swine wastewater. Results also show that it is feasible to replace the aerobic treatment process with the aquatic plant system from the cost and regulation compliance point of view. Results from the composting study show that rice straws could enhance the activity of microorganisms and also cause the increase the quantity of potassium in the compost pile. Moreover, mixing the water hyacinth in the compost pile could increase the quantity of nitrogen and phosphorous. Results also reveal that using ceramic bioballs as the filling materials could minimize the composting time due to the increase of permeability in the piles.

published_or_final_version / Botany / Master / Master of Philosophy

This research presents a comprehensive narrative of the development of slavery in early Indiana history. It chronicles the evolution from a French system of slavery to one influenced by Virginian legal code. In exploring the nature of the practiced slavery and the obstacles to slavery’s implementation, the evidence demonstrates that while Indiana did practice slavery, the state was never at risk of developing a plantation-style slave society. The 1820 Indiana Supreme Court case Polly v. Lasselle, which officially ended any legal form of slavery in the state, exemplifies the evolution of slavery and the constantly changing power relationship between owner and slave. By means of previously unused primary sources, this thesis creates a new account of the court case and places it within the context of Indiana’s slavery history. / Department of History

Thesis (M.Com. (Economics & Economic History)) - Rhodes University, 2008.

Thesis (M.Sc. (Zoology & Entomology)) - Rhodes University, 2009.

Thesis (Ph.D. (Zoology & Entomology)) - Rhodes University, 2009.