This study embraces two aspects of closed system culture: (a) a comparative study of four different biological filtration treatments, and (b) a quantitative determination of the nitrogen flow in a particular biological filtration system. Twenty 0,5 g juvenile Penaeus indicus Milne Edwards were cultured for approximately two months in four different kinds of sea water recirculatory systems with bacterial filtration, algal filtration, algar plus bacterial filtration and water exchange (25% every 3 days). Growth was comparable to that found in the literature for P. indicus. Nitrification occurred in all systems irrespective of the type of biological filtration employed. Ammonia, nitrite and nitrate levels were reduced by the algae, but nitrate accumulated to approximately 30 mg NO¯³ -Nℓ¯¹ in those systems without algae. Depletion of trace elements (Cu, Fe, Zn, Hn and Co) by the algae did not occur due to trace metal replenishment from the addition of food. No marked changes occurred in the concentrations of the major cations (Ca⁺⁺, Mg⁺⁺, Na⁺ and K⁺), but a small increase in Ca⁺⁺ levels was detectable in those systems with oyster shell chips in the filtration medium. Only minor changes occurred in oxygen or pH values in the various systems tested. Inorganic carbon levels showed major increases in the algal filtration systems, while a slight drop occurred in the bacterial filtration systems. The increase in the algal filtration systems was thought to be due to the formation of carbonates and bicarbonates by the reaction of respiratory CO₂ with unionized ammonia and water. Suggestions are made as to how closed systems can be improved upon. By determining the rate of excretion of P.indicus as related to size and temperature, its faecal production, and the nitrogen content of P.indicus, its food and faeces, the nitrogen flow within a system could be calculated. P.indicus was found to have an assimilation efficiency of 88,93% and a food conversion ratio of 3,49:1. Of the total dietary nitrogen input into the system, P.indicus ingested 69,02% - 19,80% of which was used for growth, 41,58% excreted and 7,64% lost as faeces. The remaining 30,98% of the total nitrogen input can be regarded as excess food nitrogen. The total nitrogen loading on the biological filtration system was found to be 80,20% of the total input of dietary nitrogen. The ability of various types of filamentous algae to remove these nitrogen compounds was determined. Suggestions are made as to the application of this information on nitrogen flow to the culture of P.indicus

Glutathione (y-glutamylcysteinylglycine) is a vital and ubiquitous component of biological systems that has been demonstrated to have a protective role against the toxicity of a wide array of xenobiotics and their metabolic by-products. It has been shown to detoxify many metals by direct and indirect mechanisms; but this is not the case with Al. Inputs of this metal into the environment have increased substantially since the industrial revolution, due to its use in industrial processes and the advent of acid rain. As such, it is crucial that the full implications of such exposure upon the environment is investigated thoroughly. Levels of Cu have also increased, but, on account of its greater acute toxicity, it has been the focus of a much larger amount of research. These two metals (but principally Al) are the focus of both the ecotoxicological and biochemical research herein. Work involving aspects of Al and Cu behaviour and toxicity has been carried out at both an ecosystem and organism level. Ecosystem studies, in the form of chemodynamics experiments, have been conducted in an attempt to understand and contrast their transport in the aqueous environment and the speciation that occurs as a result. These concentrations have then been put into the context of what happened to two test species (the brine shrimp Artemiafranciscana and the bacterium Vibrio fischerii), and, in the case of Al, a field study entailing chemical and biological monitoring. In addition, studies were undertaken which showed that Al bioaccumulates in A. franciscana (which is farmed for aquaculture and is increasingly utilised in toxicity studies as a substitute for higher animals). Further toxicity tests, involving the depletion of glutathione in A. franciscana, showed that the tripeptide has a protective effect against the toxicity of the metal to these creatures. An analytical method (utilising high performance liquid chromatography with electrochemical detection) was then developed for measuring reduced and oxidized glutathione in A. franciscana. This was then applied to investigate the relationship between glutathione redox status and Al exposure in aqueous systems. Reduced glutathione was shown to be depleted and subsequently induced by Al exposure, and to have a protective role against Al toxicity. Furthermore, its redox status indicated that free radical production was not the underlying mechanism responsible for the deleterious effects of Al in A. franciscana, as with many other metals studied. NMR studies were conducted which showed an interaction between Al and glutathione. These studies suggest a possible detoxification and excretion mechanism for Al involving glutathione.

Endocrine disrupting compounds are ubiquitous in aquatic environments. Exposure to these compounds may cause deiodination of thyroid hormones in fish and also affect certain behaviors. Behavioral change may be a useful indicator of deiodination on an organismal level, and may indicate effects to populations, especially if these behaviors affect reproduction. We exposed Pimephales promelas (Fathead Minnow) to effluent from a recently upgraded wastewater treatment facility. The effluent contained a matrix of low-level (< 1.0 µg/L) concentrations of endocrine disrupting compounds pre- and post-upgrade. We examined the behavior of adult Fathead Minnow exposed to treated wastewater for 90 days and the behavior of their offspring at 12-20 days old. There was no significant difference in 11 of the 12 behaviors we documented for adult fish in control and treatment tanks (p > 0.05). However, treatment fish were significantly more aggressive towards a decoy fish compared to control fish (p < 0.05). There was no significant difference found in the predator avoidance behaviors examined in the F1 generation. Although our results did not find any significant differences between control and treatment fish in regard to most behaviors we would typical associate with thyroid deiodination, such behaviors may have manifested following a longer exposure period or by having a larger sample size. Other future considerations should include looking at different behaviors (e.g. social behaviors) and further characterization of the finished effluent.

1, Eighteen species of aquatic Hyphomycetes are recorded from South Africa for the first time. All except two of these can be assigned to described species. The other two are new species of Articulospora and Anguillospora and are described in this thesis. Three unidentified spore types, an "Articulospora" type and "Anguillospora" type and a Y-shaped spore are also described. 2. Spore development in ten species is described. 3. A key to the fungi described in this thesis is given. 4. General notes on the ecology of these fungi and a table recording the fungi found in the Eastern Cape Province of South Africa, their distribution within the localities and the nature of the material on which they are growing are given. 5. The gross characteristics of plate cultures of six species, five growing on malt agar, Czapek agar, plain agar and maize agar and one on malt agar only are described. 6. Growth of four species in liquid culture using the Czapek-Dox medium is reported. 7. The results of an investigation into the effect of variations in temperature and medium on the growth of plate cultures of five species are analysed, discussed and conclusions are drawn. 8. Growth of certain isolates of four species on twigs is described.

Nicaragua faces tremendous problems in relation to environmental and social conditions as well as continuing conflicts over access to natural and economic resources. The loss of forests and other essential eco-systems, the extinction of unique species, the degradation of soils and farmland, poverty, ill heath, exploitation and great inequalities of wealth and power remain on-going processes and essential characteristics of Nicaragua. These conditions represent an environmental crisis that threatens the country's ecological and social well-being. The thesis considers the historical causes of the environmental crisis looking at the impact of the introduction of particular political and economic structures, the development of the dictatorship of Somocisnio in Nicaragua and the impact of US hegemony in the region. It further considers why the strategies adopted by successive administrations and international organisations have failed to adequately address Nicaragua's environmental problems. The need for radical political and economic change as a means to address the underlying structural causes of environmental degradation is investigated in relation to Nicaragua. However, the examination of the effects of the Sandinista Revolution in Nicaragua is also used to reveal important insights into the impact of structural change on the environment and the necessity to include other, reformist components in any solution. Post-Revolutionary strategies and the current emphasis on NGO and community based sustainable agricultural programmes are examined in detail to evaluate the importance of this approach for environmental protection. In addition to an examination of the effectiveness of the strategies of the post-revolutionary state, a case study analysis of Programa Campesino-a-Campesfno, the most prominent and successful example of the new, community-based initiatives, is used to illustrate the generic problems and opportunities present in the new 'paradigm' of localism and sustainable agriculture. While these new initiatives may provide key components to a solution, the study considers whether by themselves, they have the capacity to address the underlying causes of degradation. The study concludes that the environmental crisis is primarily a result of the particular development model that has arisen in the region since the colonial conquest, and which has facilitated the development of a system based on the highly unequal distribution of resources and power. Consequently, the causes of the crisis are essentially structural in nature, requiring that radical changes be made to the political and economic structures of society. However, the lesson of Nicaragua's Sandinista Revolution, during which environmental degradation continued despite a series of structural and socio-political changes, indicates that structural changes do not of themselves, guarantee environmental sustainability. Equally, the limitations of programmes such as Campesino-a-Campesino reveal that a reliance on agroecological and community-based methodologies is also flawed. Therefore, progress towards social and environmental justice in Nicaragua requires a combination of radical changes to political and economic structures, alongside the use of ecologicalbased agricultural and land management practices. This means that inequalities in land and natural resource ownership are addressed in order to provide sustainable economic and ecological systems within which Nicaraguans can attempt the longterm management and protection of their environment. The introduction of these new practices must include the participation and skills of local populations in any process of change. Redistribution of wealth and resources must be accompanied by a redistribution of power so that the control and development of these changes and initiatives, develop from, and reside in, the hands of ordinary Nicaraguans.

Rheumatoid Arthritis (RA) is the most common type of chronic inflammatory arthritis (Thompson, 1998). When appropriately prescribed, therapeutic exercise is useful in the care of patients with RA (Semble et aI., 1990). A pre-test - post-test randomized groups design was adopted for the study to compare the effects of a land- and water-based exercise programme in RA patients. A total of ten subjects, diagnosed with RA functional class I or II according to Steinbrocker, were assigned to either a group performing water-based exercises (W, n=4), a group performing land-based exercises (L, n=4), or a control group, who were requested to continue with their present sedentary lifestyle (C, n=2). For inclusion in the study, subjects were required to be on stable medication. Categories of dependent variables measured, were disease activity, haematology, functional and psychological status as well as physical status. There was a reduction in total swollen and tender joint counts in both experimental groups, but not the control group. The reduction was greater in group W than group L. Total tender joint count (DC) decreased by 53% (p<0.1O) and the total swollen joint count (SJC) decreased by 31% (p>0.05) in group W. In group L, the total TIC decreased by 4,7% (p>0.05) and the total SIC decreased by 8,5% (p>0.05). The haematological values remained globally unchanged in all three groups concerning the hemolglobin (Hb) values. There were changes in the erythrocyte sedimentation rate (ESR) in the groups, however changes were not significant (p>0.05). The ESR decreased by 29% in group Wand by 33% in group C. There was a slight increase in group L's ESR (11,9%) but values remained within the normal range. There was an improvement in the patients self-assessed disability and psychological status in the experimental groups while there was a deterioration in the control group's. Health Assessment Questionnaire (HAQ) scores improved by 15% in group W (p>0.05), 18% in group L (p>0.05) and deteriorated by 13% in group C (p>0.05). There was no change in the total Profile of Mood States (POMS) score of the control group, however, significant (p<0.05) improvements were observed in the experimental groups. There was a 163% improvement in group L's and a 990/0 improvement in group W's affective states. As far as physical condition is concerned, in genera~ there was an improvement in group Wand group L's physical condition, while there was no improvements noted in group C. Group W showed the following changes in physical condition: Body mass decreased by 9,2% (p>0.05). Mean blood pressure values remained unchanged. 50-ft walk time improved by 18% (p<0.05). Right and left grip strength increased by 18% and 35% respectively, (p<0.05). Absolute VO2max increased by 28% and relative VO2max increased by 30% (p<0.05). Right knee flexor strength increased by 43% (p<0.05) and left knee flexor strength by 24% (p>0.05). Increases in right and left knee extensor strength were 32% (p>0.05) and 34% (p>0.05) respectively. Improvement in joint mobility was also noted. There was a significant (p<0.05) improvement in both right and left wrist extension range of motion(ROM). Right wrist extension ROM improved by 49% and left wrist extension ROM improved by 31%. Improvements were also noted in wrist flexion ROM however changes were not significant (p>0.05). There was an 12% and 19% increase in right and left wrist flexion ROM respectively. In addition, there was a 12% (p<0.05) increase in right knee flexion ROM and a 14% increase in left knee flexion ROM (p<0.05). Mean body mass and blood pressure remained unchanged. 50-ft walk test time improved by 15% (p<0.05). Right and left grip strength increased by 4,8% and 16.1% respectively (p>0.05). Relative VO2max increased by 16.6% and absolute VO2max by 31% (p<0.05). Right knee flexor strength increased by 22.1% and left knee flexor strength by 23.8% (p>O.05). Increase in right and left knee extensor strength was 9% and 2,4% respectively (p>O.05). Right wrist extension ROM increased by 20.7% and left wrist extension ROM increased by 15,7% (p>0.05). There was a significant (p<0.05) increase in left wrist flexion (7,6%), but right wrist flexion ROM decreased by 2.6% (p>0.05). Improvements in right and left knee flexion ROM were also significant (p<0.05), 9,2% and 7,4%, respectively. Group C showed the following changes in physical condition: Mean body mass increased by 2% (p>O.05), while blood pressure and 50-ft walk time remained globally unchanged. Left grip strength decreased by 16% (p>O.05) and right grip strength remained the same. Although not significant (p>O.05), there was a 11% decrease in relative VO2max and a 6,7% decrease in absolute VO2max. Muscle strength also showed deterioration in group C. Right and left knee flexor strength decreased by 1,8% and 12%, respectively (p>0.05). Left knee extensor strength remained unchanged while right knee extensor strength decreased by 9,7% (p>0.05). Right wrist extension ROM decreased by 4.7% and left wrist extension ROM increased by 6.7%, although the increase was not significant (p>O.05). While right wrist flexion ROM decreased by 1,3% and left wrist flexion ROM decreased by 21% (p>0.05). There were no significant (p>O.05) changes in group C's right and left knee flexion ROM. Right knee flexion ROM decreased by 1,2% and left knee flexion ROM increased by 1,2%. Based on the above results of the study, both exercise interventions are beneficial in the treatment of RA. Appropriate land-based exercises do not appear to enhance disease activity, however, the water-based exercise programme was superior in controlling the disease activity. Further research is required, using larger samples and evaluating the long-term effects of various exercise interventions. / Dissertation (MA (Human Movement Sciences))--University of Pretoria, 2006. / Biokinetics, Sport and Leisure Sciences / unrestricted

Since Actinomycetes have been isolated from finished public drinking water, it is believed that the organisms are unaffected by the chlorination and flocculation of water treatment plants and pass as spores through the filters into the general distribution system. For this reason it was deemed imperative to study the toxic effects of these organisms.

<p> Non-parametric ANOVA tests, ordination, and Bayesian generalized linear models (GLMs) revealed strong physical, chemical, and biological differences among the study sites. Lower trophic foodweb indexes (<i>i.e.</i>, chlorophyll-a (chl-a) concentration, zooplankton biomass, and planktivorous fish abundance) were investigated in association with environmental variables in three terminal sloughs within the upper San Francisco Estuary. Non-metric multidimensional scaling (NMDS) showed tight clustering of data from each site. Kruskal-Wallis tests confirmed the NMDS by identifying statistically-significant differences among sites and between paired sites within each of the three regions (<i>i.e.</i>, Cache Slough, Lindsey Slough, Suisun Marsh). Bayesian GLMs identified temperature and dissolved inorganic nitrogen as primary correlates with chl-a concentration, and temperature and chl-a concentration as primary correlates with zooplankton biomass. Planktivorous fish data were insufficient to fit a GLM. Up-slough sites in Cache Slough and Suisun Marsh consistently showed greater abundances of chl-a and zooplankton relative to down-slough sites in each region. However, that pattern was reversed in Lindsey Slough. Possible reasons for this discrepancy include adjacent land-use and management practices, relative importance of alternate foodweb pathways, and the presence of a major water diversion. This study emphasizes the importance of site-specific foodweb dynamics and local anthropogenic effects, particularly in relation to design of tidal wetland restoration projects.</p><p>

This thesis examines the implementation of air pollution control at the local level within the UK. Focusing upon the local air pollution control regime (LAPC) that is regulated by local authorities under the provisions of Part One of the Environmental Protection Act 1990, the research assesses whether this system has been effective in controlling localised emissions from industrial processes. To place the research in context, it essentially evaluates the implementation of LAPC with reference to its main objectives: to reduce industrial emissions and improve local air quality, to provide greater clarity and certainty for business and to allow the public greater access to local environmental information. The methodology adopted to undertake the research was based upon grounded theory and naturalistic inquiry. As such, the research programme was structured in phases where initially, essential baseline data was collected on the LAPC system. This quantitative data provided the foundations from which more detailed qualitative work was undertaken in the field in subsequent phases of the research. This allowed the research to build towards theory utilising an emergent, yet structured research design. As the research progressed, a range of complementary methods were used to collect data about the LAPC system. Initially, the research critically evaluated the major Reports that had been written on LAPC in order to establish benchmarks from which implementation of the LAPC system could be assessed. To keep the research within defined limits, a case study approach was adopted, using Lancashire as the case study area. Under the first phase of the research a questionnaire was used to survey the process operators within the region in order to collect baseline information about their processes and to obtain their views and perceptions of the LAPC system. Under the second phase qualitative research was carried out in the field. This involved detailed, semi-structured, faceto-face interviews with the process operators and the DETR and examination of documentary evidence within the Public Registers held by Lancashire's local authorities. The phased approach allowed the research to explore progressively deeper into the key areas associated with the implementation of the LAPC system. In particular, the research examined local authority enforcement and administration of the LAPC system to assess their regulatory performance and to determine the strategies they adopt to achieve compliance. The research also focused upon the process operators to assess their capacity to comply with the duties and responsibilities placed upon them under LAPC. The work offers a new perspective as it focuses upon both regulators and operators alike and examines their performance from the outset of LAPC to its closing stages. The research findings allow conclusions to be drawn on the relationship that exists between these "stakeholders" and the regulatory conditions that exist within the system. The research findings suggest that local authorities and process operators have had difficulty in discharging their duties under the LAPC system. For various reasons, the capacity of the regulators and the operators to achieve compliance has been compromised. The difficulties that the stakeholders have faced in striving to come to terms with the LAPC system have influenced their compliance strategies and affected the relationship that exists between them. This research identifies and examines these difficulties and assesses their performance under such conditions.

Earthworms are considered very important soil organisms, greatly influencing soil function through their feeding, burrowing and casting activities, e.g. comminution and incorporation of litter into soil, building and maintenance of soil structural porosity and aggregation, promoting changes in microbial communities and activities and influencing plant growth. Although research on earthworms is increasing rapidly, there is still inadequate knowledge of the basic biology and ecology of even common species, such as Lumbricus terrestris. This study aimed to examine aspects of adult, immature and hatchling L. terrestris dispersal, distribution and intraspecific interactions through a number of laboratory and field experiments. Results demonstrated that population density can significantly affect dispersal in L. terrestris. Intraspecific competition for food resources and space in combination with the need to secure mating opportunities interact to produce regular patterns in the horizontal distribution of individuals, observed at the scale of I m 2. Burrow reuse by offspring and other conspecifics was observed, in addition to permanence in distribution of L. terrestris over short periods (1 year). Intraspecific competition between adults (parents or not) and hatchlings/juveniles intensified as the latter grew in size. However, observations of cocoon deposition by adults in distinct locations within side burrows, could represent a form of "parental investment". Results from this study could assist in identifying some of the factors that influence L. terrestris population dynamics, however further research is required to fully understand how their combined effect may influence the behaviour of this species in natural environments.