The spliceosome is a complex, dynamic ribonucleoprotein (RNP) complex that undergoes numerous conformational changes during its assembly, activation, catalysis and disassembly. Defects in spliceosome assembly are thought to trigger active dissociation of faulty splicing complexes. A yeast genetic screen was performed to identify components of the putative discard pathway. This study found that weak mutant alleles of SPP382 suppress defects in several proteins required for spliceosome activation (Prp38p, Prp8p and Prp19p) as well as substrate mutations (weak branch point mutants). This evolutionary conserved protein had been found in both yeast and mammalian splicing complexes. However, its role in splicing had not been elucidated. This study focused on understanding the cellular role of Spp382p in splicing and particularly in the discard pathway. Spp382p was found to be essential for normal splicing and for efficient intron turnover. Since Spp382p binds Prp43p and is required for intron release in vitro, spp382 mediated suppression of splicing factor mutations might reflect lowered Prp43p activity. In agreement with this, we find that prp43 mutants also act as suppressors. This leads us to propose a model in which defects in spliceosome assembly, like those caused by prp38-1, prompt Spp382p-mediated disassembly of the defective complex via Prp43p Bolstering this theory, we find that Spp382p is specifically recruited to defective complexes lacking the 5 exon cleavage intermediate and spp382 mutants suppress other splicing defects. I show by stringent proteomic and two-hybrid analyses that Spp382p interacts with Cwc23p, a DnaJ-like protein present in the spliceosome and co-purified the Prp43p-DExD/H-box protein. In this study, I also show that Cwc23p is itself essential for splicing and normal intron turnover. Enhanced expression of another protein, Sqs1p, structurally related to Spp382p and also found associated with Prp43p is inhibitory to both growth and splicing. Synthetic lethal and dosage suppression studies bolster a functional linkage between Spp382p, Cwc23p, Sqs1p and Prp43p and together, the data support the existence of a Spp382p -dependent spliceosome integrity (SPIN) complex acting to remove defective spliceosomes.

No description available.

Faculty of Engineering School of Civil and Enviromental Engineering 9506023j PMISTRY@WEBMAIL.co.za / This report investigates the viability of satellite remote sensing in monitoring the rehabilitation of coal discard dumps. Four levels of thermal monitoring data were assessed in this project. These were: ground and below surface temperature probes; aerial thermal and atmospheric monitoring surveys; high altitude aircraft; and satellites. Remote sensing methods measure only variation of temperatures on the surface of the dump. Fires on discard dumps are sub-surface fires, and the depth and extent of the fire below the surface cannot be easily inferred. The resolution of satellite sensors is a limiting factor for detecting individual hotspots on dumps. Small mine dumps occupy just a few pixels and the position of fires cannot be accurately assessed. Although the larger dumps are discernable, the variation of temperatures across the dump cannot be easily determined. For the present, aircraft monitoring may be the most viable means of monitoring spontaneous combustion in coal discard dumps, until satellite resolutions improve further.

No description available.

This study investigates coal discard cover soil fertility and its potential for degradation, particularly in terms of its salinisation and acidification potential. Seven rehabilitated coal discard dumps in the Witbank, Ermelo and Newcastle regions were used as study areas. All areas were rehabilitated with a cover soil layer, revegetated and annually fertilised with nitrate fertilisers, super phosphate, kraal manure and lime. Performance guideline for pH of 5.5-(6.5 i0.5)-7.5 and electrical conductivity guideline of preferably less than 200 mS.rn-' but not higher than 400 mS.m-' were set based on literature information. Soil chemical data from a three-year fertilisation programme were used to assess the fertility of the cover soil surface (0-150mm). Data collected over a three year period as well as additional electrical conductivity and pH measurements from the cover soil surface, subsoil, cover soil/coal contact zone and underlying coal itself were used to assess the occurrence of salinisation and acidification of the cover soil. The soil fertility varied significantly among dumps as well as over the three years. Results indicated an increase in ammonium acetate extractable macro elements (calcium, magnesium and potassium). With the exception of manganese, no micro-element toxicities were recorded. Iron concentrations were slightly elevated in some of the sandy cover soil layers. No increase in soluble nitrogen (nitrate and ammonium) was found and most soluble nitrogen was in the form of nitrates. In general the Bray extractable phosphate increased during the study period. It can be predicted that with the following fertiliser programme increases of exchangeable macro-elements as well as available phosphorus can be expected. The study could not indicate an increase in adsorbed or available nitrogen. Organic carbon was initially not analysed therefore no comments can be made whether organic matter increased. Four of the seven dumps surveyed had comparably similar organic carbon levels to the background samples. Overall the fertiliser programme increased the electrical conductivity and decreased the acidity of the cover soil surface. Acidity and salinity was in general not a problem at the surface of the cover soil and pH was even slightly higher in cover soil samples. The acidity and especially salinity increased at the subsoil and so did the sulphate concentrations. Calcium and magnesium sulphate were predominantly responsible for higher electrical conductivity measurements. The percentage exchangeable sodium was also predominantly less than 2% indicating that sodicity is not currently a problem in cover soil. Soil fertility was satisfactory for vegetation growth and macroelement concentrations were in the correct ratio although calcium was slightly high. An elevated sulphate concentration, in comparison to the natural grassland soils, as well as a high salinity and high acidity in the subsoil layers indicate that salinisation and acidification could deteriorate without proper management. A slightly acidic cover soil can also be attributed partially to its natural acidic pH due to the wellweathered and leach property of burrow pit. Higher than recommended salinity levels were found in subsoil samples but the occurrence of acidification of the subsoil was more dump specific. In relation to acidity and salinity guidelines only the cover soil of one dump was concerning and the larger dumps subsoil acidity and salinity were elevated. The following management strategies are proposed: a) The acidification potential, and therefore the pyrite content of the coal discard must be considered during decisions making on the rehabilitation method (clay barriers), topsoil depth, maintenance and mine closure potential. b) The occasional monitoring of the subsoil's and coal contact acidity is recommended, although not much can be done to stop acidification after cover-soil placement. c) To ensure a more sustained from of nitrogen supplementation over the long term the use of selected legumes should be investigated. Research in Europe and Australia suggested that nitrogen fixation could contribute substantially to the nitrogen for plant uptake. d) The physical properties of the topsoil (bulk density 8 soil compaction) are also being neglected and needs to be assessed occasionally and interpreted together with chemical analyses. Observations in other studies indicate that this could be the most fundamental problem for vegetation growth and not necessarily soil fertility, since soil physical properties could have a major impact on root development. Key words: Coal discard, mine rehabilitation, soil fertility, topsoil degradation, salinisation, and acidification / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2004.

This study investigates coal discard cover soil fertility and its potential for degradation, particularly in terms of its salinisation and acidification potential. Seven rehabilitated coal discard dumps in the Witbank, Ermelo and Newcastle regions were used as study areas. All areas were rehabilitated with a cover soil layer, revegetated and annually fertilised with nitrate fertilisers, super phosphate, kraal manure and lime. Performance guideline for pH of 5.5-(6.5 i0.5)-7.5 and electrical conductivity guideline of preferably less than 200 mS.rn-' but not higher than 400 mS.m-' were set based on literature information. Soil chemical data from a three-year fertilisation programme were used to assess the fertility of the cover soil surface (0-150mm). Data collected over a three year period as well as additional electrical conductivity and pH measurements from the cover soil surface, subsoil, cover soil/coal contact zone and underlying coal itself were used to assess the occurrence of salinisation and acidification of the cover soil. The soil fertility varied significantly among dumps as well as over the three years. Results indicated an increase in ammonium acetate extractable macro elements (calcium, magnesium and potassium). With the exception of manganese, no micro-element toxicities were recorded. Iron concentrations were slightly elevated in some of the sandy cover soil layers. No increase in soluble nitrogen (nitrate and ammonium) was found and most soluble nitrogen was in the form of nitrates. In general the Bray extractable phosphate increased during the study period. It can be predicted that with the following fertiliser programme increases of exchangeable macro-elements as well as available phosphorus can be expected. The study could not indicate an increase in adsorbed or available nitrogen. Organic carbon was initially not analysed therefore no comments can be made whether organic matter increased. Four of the seven dumps surveyed had comparably similar organic carbon levels to the background samples. Overall the fertiliser programme increased the electrical conductivity and decreased the acidity of the cover soil surface. Acidity and salinity was in general not a problem at the surface of the cover soil and pH was even slightly higher in cover soil samples. The acidity and especially salinity increased at the subsoil and so did the sulphate concentrations. Calcium and magnesium sulphate were predominantly responsible for higher electrical conductivity measurements. The percentage exchangeable sodium was also predominantly less than 2% indicating that sodicity is not currently a problem in cover soil. Soil fertility was satisfactory for vegetation growth and macroelement concentrations were in the correct ratio although calcium was slightly high. An elevated sulphate concentration, in comparison to the natural grassland soils, as well as a high salinity and high acidity in the subsoil layers indicate that salinisation and acidification could deteriorate without proper management. A slightly acidic cover soil can also be attributed partially to its natural acidic pH due to the wellweathered and leach property of burrow pit. Higher than recommended salinity levels were found in subsoil samples but the occurrence of acidification of the subsoil was more dump specific. In relation to acidity and salinity guidelines only the cover soil of one dump was concerning and the larger dumps subsoil acidity and salinity were elevated. The following management strategies are proposed: a) The acidification potential, and therefore the pyrite content of the coal discard must be considered during decisions making on the rehabilitation method (clay barriers), topsoil depth, maintenance and mine closure potential. b) The occasional monitoring of the subsoil's and coal contact acidity is recommended, although not much can be done to stop acidification after cover-soil placement. c) To ensure a more sustained from of nitrogen supplementation over the long term the use of selected legumes should be investigated. Research in Europe and Australia suggested that nitrogen fixation could contribute substantially to the nitrogen for plant uptake. d) The physical properties of the topsoil (bulk density 8 soil compaction) are also being neglected and needs to be assessed occasionally and interpreted together with chemical analyses. Observations in other studies indicate that this could be the most fundamental problem for vegetation growth and not necessarily soil fertility, since soil physical properties could have a major impact on root development. Key words: Coal discard, mine rehabilitation, soil fertility, topsoil degradation, salinisation, and acidification / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2004.

As a highly targeted species, red snapper have been overfished since the 1970’s. Inadequate monitoring and reporting of discard rates impedes regulatory measures which are in place to allow red snapper populations to reach a healthy, sustainable level. This study documented the relationship between morphometric measurements and otolith analysis of red snapper caught from a recreational headboat fishing exclusively in the GOM’s EEZ of the upper Texas coast. The collected data of this research show that of the 594 red snapper caught within the sample group, 76% of the fish were discarded; analysis of the lengths of these discarded fish show that 15.5% were of regulation size (16 inches) or larger, clear evidence that high-grading is occurring. The effort for the total amount of red snapper caught by each individual angler within the sample group was measured to determine on average, approximately two red snapper were caught per person, per hour. The size distribution ranged from 16 to 32 inches with a mean total length of 21.32 inches for retained fish while discarded fish ranged from 5.5 to 22.5 inches with a mean of 14.23. Weight distribution ranged from 1.5 to 18.5 pounds with a mean of 5.81 pounds for retained fish and 0.20 to 6 pounds with a mean of 1.57 pounds for discarded fish. Age distribution ranged from 3 to 14 years of age; red snapper can live over 50 years, however relatively none (2.42%) older than 10 years were present in the sample, demonstrating a highly truncated population. Because fecundancy increases with age in females, longevity extends reproduction potential for red snapper. Management of reef fishes, and red snapper in particular, are difficult due to variances in growth rates and habitat use, complex population structure, and increasing reproduction levels with maturity. Recommendations for management include implementing an educational outreach program, reducing effort and discard rates, lowing rates of exploitation, and creating a marine reserve. Future research should address the entire Texas coast population of for-hire vessels (charter and headboats) to obtain data on discard rates and age distribution of red snapper.

The rehabilitation of degraded soils, such as those associated with post-mining sites, requires knowledge of the soil ecosystem and its physical, chemical, and biological composition in order for rehabilitation efforts to fulfil the long-term goal of reconstructing a stable ecosystem for rehabilitated mine soil. This study addresses the need for appropriate assessment criteria to determine the progress of rehabilitation and subsequently the success of management practices. Significant contributions made by this investigation included the establishment of minimum and maximum values for microbial community measurements from two case studies of rehabilitated coal discard sites. Furthermore, it was shown that there was no relationship between changes in microbial community function and structure and the rehabilitation age of the sites. Following this, the considerable impact of management practices on microbial communities was illustrated. The first part of the study investigated the temporal changes in microbial community function and structure in a chronosequence of rehabilitated coal discard sites aged 1 to 11 years. The most important observation made during the investigation of the microbial communities in the different aged soil covers of the rehabilitated coal discard sites, was that there was no relationship between rehabilitation age and microbial activity or abundance of certain microbial groups. What was responsible for a clear differentiation between sites and a shift in microbial community attributes was the management practices applied. A comparison of two chronosequences of rehabilitated coal discard sites was achieved by an application of the 'space-for-time' hypothesis. Sites of different ages and at separate locations ('space') were identified to obtain a chronosequence of ages ('time'). The two chronosequences included sites aged 1 to 11 years (chronosequence A) and 6 to 17 years (chronosequence B), respectively. Sites in the same chronosequence were managed identically, while there was a distinct difference in management practices applied to each chronosequence. The long-term effect of the different management regimes on the soil microbial community function and structure was investigated. Again, there was no relationship between rehabilitation age and microbial community measurements. Fluctuations of selected microbial properties occurred in both chronosequences and similar temporal trends existed over the rehabilitation periods. However, the less intensively managed chronosequence (8) seemed more stable (less fluctuation occurred) over the rehabilitation period than the more intensively managed chronosequence (A). It was therefore concluded that the microbial communities in the less managed sites maintained their functional and structural integrity within bounds in the absence of management inputs or disturbance. While there was similarity in the trends over time for individual microbial community measurements, the seemingly more stable conditions in chronosequence 6 are important in terms of the goal of rehabilitation. / Thesis (Ph.D. (Environmental Science)--North-West University, Potchefstroom Campus, 2007

Novas tecnologias vêm sendo constantemente desenvolvidos pelo mundo, alterando os hábitos de consumo da população. Neste novo cenário, surgem os Equipamentos Eletroeletrônicos (EEE), cada vez mais demandados e ao mesmo tempo descartados, que se não destinados corretamente ao fim de seu uso, podem acarretar em problemas a saúde humana e ao meio ambiente. Dessa forma, entender como está o atual comportamento do consumidor em relação aos Resíduos de Equipamentos Eletroeletrônicos (REEE) é primordial para diagnosticar as dificuldades de descarte dos equipamentos após o fim da vida útil e ao mesmo tempo propor ações corretivas. Assim, o presente trabalho buscou avaliar o comportamento do consumidor institucional, especialmente de empresas privadas, no município de Gravataí/RS frente a problemática atual dos Resíduos de Equipamentos Eletroeletrônicos. A pesquisa foi desenvolvida por meio de um formulário eletrônico, com questões previamente elaboradas, sendo enviado para o endereço eletrônico das empresas que tinham cadastro ativo junto ao órgão gestor municipal. O local de estudo selecionado foi motivado por ser um importante polo industrial do Rio Grande de Sul, com um número considerável de empresas, atuando em diferentes ramos de atividades. Foram obtidos um total de 48 respostas, sendo a grande maioria de empresas pequeno porte (40) e do ramo de atuação em prestação de serviços (67%). Em relação a gestão dos resíduos eletroeletrônicos, a maioria das empresas respondentes (77%) afirmaram conhecer os riscos associados a este tipo de resíduo e 32 empresas entre as 48 respondentes assinalaram que geram REEE em suas dependências, sendo as lâmpadas fluorescente/Led o tipo de resíduo mais gerado. Além disso, foi questionado quais as principais atitudes de descarte dos EEE no final de sua vida útil, obtendo como principal resposta armazenamento (25 %). Este questionamento foi discriminado para alguns tipos de resíduos, como celulares e tablets, e as respostas mostraram que a maioria deixa somente armazenado (31%), seguido por descarte em pontos de coleta (19%) e revenda (13%). Em relação as principais dificuldades de destinação final, a falta de pontos de coleta (44 %) e a existência de pouca informação a respeito deste tipo de resíduo (34%), foram apontadas como os principais problemas. Também, a maioria das empresas afirmou conhecer o que é o sistema de logística reversa (22 de 32). Por fim, fez-se algumas considerações sobre diferentes propostas para minimizar a questão do descarte dos REEE institucionais, apresentando o sistema depósitoreembolso como instrumento econômico e ambiental, em que os consumidores têm um incentivo para devolver produtos usados e receber reembolso financeiro. Além deste sistema, as próprias empresas que atuam no ramo de reciclagem de resíduos eletrônicos obtendo ganhos econômicos podem colaborar com a destinação final dos REEE gerados nas empresas do município. / New technologies are being constantly developed around the world, changing the consumption habits of the population. In this new scenario, the Electro-Electronic Equipments (EEE) arise, increasingly demanded and at the same rate, discarded, and if not correctly disposed after its use, they can lead to environmental and human health problems. Therefore, understanding the current behavior of consumers regarding to Waste Electrical and Electronic Equipment (WEEE) is essential to diagnose the difficulties of disposing the equipments after their lifespan and, at the same time, to propose corrective actions. Thus, the present work aimed to evaluate the behavior of the institutional consumer, especially private companies, in the city of Gravataí / RS in relation to the current problem of Waste Electrical and Electronic Equipment. The research was developed through an electronic form, with previously elaborated questions, sent to the electronic address of the companies that had active registration in the municipal managing agency. The selected study site was motivated because it is an important industrial center of Rio Grande do Sul, with a significant number of companies, operating in different branches of activities. A total of 48 responses was obtained, being the large majority from small companies (40%) and service providers (67%). Regarding to electronic waste management, most respondents (77%) reported knowing the risks associated with this type of waste, and 32 companies among the 48 respondents indicated that they generate WEEE in their dependencies, being fluorescent / Led lamps the most generated type of waste. In addition, the main disposal alternatives of EEE after their lifespan were questioned, obtaining storage as the main answer (25%). This survey was broken for some types of residues, such as cell phones and tablets, and the answers showed that most only store it (31%), followed by collection at collection points (19%) and resale (13%). Regarding the main difficulties of final destination, the lack of collection points (44%) and the lack of information about this type of waste (34%) were identified as the main problems. Also, most companies reported knowing what the reverse logistics system is (22 of 32). Lastly, some considerations about different proposals to minimize the issue of institutional WEEE disposal were made, presenting the deposit-refund system as an economic and environmental instrument, in which consumers have an incentive to return used products and receive financial reimbursement. In addition to this system, companies that operate in the electronic waste recycling sector earning economic gains can collaborate with the final destination of the WEEE generated in the companies of the city.

Thesis (Ph.D. (Environmental Science)--North-West University, Potchefstroom Campus, 2007.