Tiriant poveikį vandens ekosistemoms labai svarbu yra įvertinti ne tik nuotekų cheminius rodiklius, bet taip pat įvertinti kompleksinį toksinių medžiagų poveikį jautriems organizmams, kurie reprezentuotų tiriamai ekosistemai sukeliamą poveikį. Šiame darbe buvo atliktas Vilniaus miesto nuotekų kokybės tyrimas, nustatant nuotekų cheminę kokybę, bei toksiškumą vertinant sausumos ir vandens augalais, sėjamąja salota (Lactuca sativa L.), mažąja plūdena (Lemna minor L.) bei dafnijų (Daphnia magna) judrumo slopinimo testu. Darbo tikslas buvo palyginti skirtingų biotestų: sausumos augalų – sėjamosios salotos (Lactuca sativa L.) ir vandens augalų – mažosios plūdenos (Lemna minor L.) augimo slopinimo ir dafnijų (Daphnia magna) judrumo slopinimo testų jautrumą ir tinkamumą bendram nuotekų toksiškumui vertinti. Atlikus cheminę analizę gauta, kad nevalytose nuotekose pH= 7, NH4+ – 100 mg/l, NO2- – 0,03 mg/l, NO3- – 1 mg/l , PO4-3 – 18 mg/l, o nuotekose po išvalymo pH = 7,5, amonio koncentracija sumažėjo 10 kartų (NH4+ – 10 mg/l), nitritų koncentracija padidėjo 16,7 karto (NO2- - 0,5 mg/l), nitratų 20 kartų (NO3- –20 mg/l), o fosfatų koncentracija sumažėjo 30 kartų (PO4-3 – 0,6), tačiau nors ir amonio jonų koncentracija valytose nuotekose sumažėjo, ji viršijo nuotekoms taikomą DLK 1,5 karto. Atlikus sėjamosios salotos (Lactuca sativa L.) biotestavimą, nustatyta, kad šaknelės augimo slopinimas buvo jautriausias galutinis rodiklis. Mažosios plūdenos (Lemna minor L.) testas parodė, jog... [toliau žr. visą tekstą] / The examination of the impact on aquatic life is very important to evaluate not only the water chemical parameters, but also to assess a complex toxic effects on sensitive organisms that are representative of the investigated ecosystem effects. This work was carried out in Vilnius water quality test for chemical water quality and toxicity evaluation of terrestrial and aquatic plants, lettuce (Lactuca sativa L.), the duckweed (Lemna minor L.) and Daphnia (Daphnia magna) acute immobilisation tests. After physicochemical analysis revealed that untreated wastewater pH = 7, NH4+ – 100 mg/l, NO2- – 0.03 mg /l, NO3- – 1 mg /l, PO4-3 – 18 mg/l, and after treatment the effluent pH were 7.5, ammonium concentrations decreased by a factor of 10 (NH4+ – 10 mg /l), nitrite levels increased 16.7 times (NO2- – 0.5 mg / l), 20 times the nitrate (NO3- – 20 mg /l) and phosphate concentration decreased by 30 times (PO4-3 – 0.6), but while ammonium ion concentration in treated wastewater has decreased, it exceeded the limits applicable to discharges of 1.5. The lettuce (Lactuca sativa L.) bioassay showed that root growth inhibition was the most sensitive end point. Duckweed (Lemna minor L.) test showed that the most sensitive indicator was the mass of duckweed. Daphnia (Daphnia magna) mortality undiluted untreated wastewater after 48h was 100% and in treated wastewater – 40%. After a comparative study found that the main agent causing the effluent toxicity to Daphnia was ammonium. The... [to full text]

The access to clean water is one of the prerequisites for a modern, industrialized society. The amount of water withdrawn for human activities has risen exponentially during the last 100 years. This rise in water use is accompanied by the production of vast quantities of contaminated water. These wastewaters may be contaminated by substances ranging from heavy metals and organic compounds to nutrients like nitrogen and phosphorous. The aggregate effect of combinations of water contaminants can be difficult to predict as different contaminant substances may interact, leading to additive, synergistic or antagonistic toxic effects in a receiving aquatic ecosystem. With increasing water quality legislation, the pressure to characterize and potentially treat contaminated waters increases. Suitable effect-based assessment methods may greatly reduce the costs of both the wastewater characterization process and the water treatment evaluation. The overall aim of this thesis was to show how a combination of ecotoxicity bioassays may be employed in water treatment method development for initial characterization, assessment of treatment requirements and finally treatment evaluation. The wastewaters characterized originated from different activities such as waste management, metal surfacing and explosives destruction. To fully assess the hazard of the waters sampled, a holistic approach using a combination of chemical tests and bioassays was taken. A combination of acute and chronic assays was used to determine mode-of-action effects and apical endpoints in the aquatic environment. The basic battery consisted of the acute Vibrio fischeri test, the chronic algae test using Pseudokirchneriella subcapitata and either the planktonic crustacean Daphnia magna (for aqueous samples) or the meiobenthic crustacean Heterocypris incongruens (for whole-sediment/soil samples).  In addition to the basic test battery, the mode-of-action Salmonella typhimurium test was used to assess genotoxic effects. Results from the water hazard characterization show that ecotoxicological tests contribute to the evaluation of treatment methods for complex wastewaters by assessing the aggregate biological effect of water treatment. The tests may be used as a screening method to indicate where further treatment may be required, even when chemical measurements show a satisfactory reduction of known contaminants. The toxic effect exerted by the assessed waters did not always correlate with measured levels of contaminants or the chemical measures of bioavailability, e.g. leached fraction. The water treatment evaluation showed that the industrial by-product pine bark is an effective adsorbent for capturing metal contaminants from landfill leachates and stormwater. The pine bark column filter had higher zinc removal efficiency than the polonite filter and the combination filter column with pine bark/polonite. In conclusion, a pine bark filter is a suitable alternative to activated carbon for small-scale, decentralized treatment of wastewaters. Furthermore, the ecotoxicity tests were able to detect effects of unknown contaminants and provided unique characterization data, which complemented the information provided by the chemical analyses. / CLEAN / BIOREX

South Africa is one of the most important mining countries in the world, hosting the world's largest reserves of platinum group metals (PGMs). Even though mining is clearly an important activity in South Africa, contributing approximately US$ 7.4 billion annually to the countries' gross domestic product (GDP), the costs to the environment are not insignificant. One of the most severe environmental aspects associated with mining is the storage of mineral waste on tailings storage facilities due to their impacts on air quality, ground water quality, aesthetics and land use. It is also unknown whether the environmental effects of tailings storage facilities increase or decrease over time. The aim of this study was to determine the ecotoxicity of platinum tailings storage facilities of different ages by means of soil physical and chemical analysis, earthworm ecotoxicological studies, dehydrogenase activity and soil mesofauna studies. Samples were obtained from three platinum tailings storage facilities of different ages of which two were already rehabilitated while the third was still operational at the time this study was performed. The latter was used as a negative control for the purpose of the study. Soil samples were physically and chemically analysed. Earthworm ecotoxicological studies were conducted to determine changes in biomass, reproduction, mortality, neutral red retention times and tissue metal concentrations. Dehydrogenase activity was determined before the introduction of earthworms and manure, after introductions of manure and after introductions of earthworms and manure. Soil mesofauna were extracted and identified in order to determine species richness, diversity, abundance and functional grouping. Soil chemical analysis indicated that concentrations of certain heavy metals, especially chrome (Cr), present in platinum tailings materials could have a potential effect on microorganisms, microbial processes and earthworms. Earthworm ecotoxicological results indicated that earthworms that bioaccumulated higher levels of heavy metals showed poor hatchability of cocoons. Dehydrogenase activity indicated that earthworms play a significant role in increasing the number and biomass of soil microbes because significant increases in dehydrogenase activity were noticed after the addition of earthworms to platinum tailings materials. Results from the earthworm ecotoxicological studies, dehydrogenase activity, and soil mesofauna composition indicated that environmental impacts of tailings storage facilities did not increase with age, but is more likely to be an indication of the rehabilitation measures administered to the different tailings storage facilities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

South Africa is one of the most important mining countries in the world, hosting the world's largest reserves of platinum group metals (PGMs). Even though mining is clearly an important activity in South Africa, contributing approximately US$ 7.4 billion annually to the countries' gross domestic product (GDP), the costs to the environment are not insignificant. One of the most severe environmental aspects associated with mining is the storage of mineral waste on tailings storage facilities due to their impacts on air quality, ground water quality, aesthetics and land use. It is also unknown whether the environmental effects of tailings storage facilities increase or decrease over time. The aim of this study was to determine the ecotoxicity of platinum tailings storage facilities of different ages by means of soil physical and chemical analysis, earthworm ecotoxicological studies, dehydrogenase activity and soil mesofauna studies. Samples were obtained from three platinum tailings storage facilities of different ages of which two were already rehabilitated while the third was still operational at the time this study was performed. The latter was used as a negative control for the purpose of the study. Soil samples were physically and chemically analysed. Earthworm ecotoxicological studies were conducted to determine changes in biomass, reproduction, mortality, neutral red retention times and tissue metal concentrations. Dehydrogenase activity was determined before the introduction of earthworms and manure, after introductions of manure and after introductions of earthworms and manure. Soil mesofauna were extracted and identified in order to determine species richness, diversity, abundance and functional grouping. Soil chemical analysis indicated that concentrations of certain heavy metals, especially chrome (Cr), present in platinum tailings materials could have a potential effect on microorganisms, microbial processes and earthworms. Earthworm ecotoxicological results indicated that earthworms that bioaccumulated higher levels of heavy metals showed poor hatchability of cocoons. Dehydrogenase activity indicated that earthworms play a significant role in increasing the number and biomass of soil microbes because significant increases in dehydrogenase activity were noticed after the addition of earthworms to platinum tailings materials. Results from the earthworm ecotoxicological studies, dehydrogenase activity, and soil mesofauna composition indicated that environmental impacts of tailings storage facilities did not increase with age, but is more likely to be an indication of the rehabilitation measures administered to the different tailings storage facilities. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

Made available in DSpace on 2014-06-11T19:32:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-23Bitstream added on 2014-06-13T18:44:30Z : No. of bitstreams: 1 goncalves_jf_dr_jabo.pdf: 1447890 bytes, checksum: 213f62c5c0d5c7deaaea4b29c3aa4e09 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A produção de alimentos é prejudicada devido a incidência de diversas pragas e doenças. A fim de poder controlá-las, utilizam-se uma grande quantidade e variedade de produtos químicos. Em muitos casos, esses produtos incidem sobre uma vasta gama de organismos, fato este que causa um grande impacto no meio ambiente. A fim de minimizar os efeitos negativos do uso de produtos químicos com grande espectro de ação, há grande empenho no desenvolvimento de produtos cujos alvos sejam específicos. Neste sentido, o uso do controle biológico tem se apresentado como uma alternativa bastante interessante. Dentre os vários sistemas utilizados no controle biológico de pragas, a bactéria Bacillus thuringiensis é a opção de maior destaque. No entanto, inúmeros casos de resistência têm surgido ao longo destes últimos anos, devido aos produtos codificados pelos genes com ação entomopatogênica estarem sendo utilizados de maneira descontrolada. Desse modo, a busca par novas proteínas Cry é tarefa importante dentro da estratégia de controle biológico de pragas agrícolas. Com o intuito de se identificar novas genes cry par meio de análises de PCR Múltiplas, seguida de análise por RFLP, identificaram-se 3 isolados de B. thuringiensis cujos fragmentos de genes analisados diferiram entre si e das linhagens padrão conhecidas até o momento. Ao analisar essas sequências gênicas depositadas no GenBank, verificou-se que dois desses fragmentos de DNA pertencentes aos isolados 113 e 133 possuíam alta similaridade com os genes efetivos contra nematoides, uma terceira sequência caracterizada a partir do isolado 123 não foi similar a nenhuma outra sequência depositada no GenBank atualmente. Os isolados cuja sequência de aminoácidos de suas proteínas Cry predita in silica mostraram-se similares a genes cry... / Food production is strongly harmed by a large amount of plant pests and diseases. Aiming to control these problems, a large quantity and variety of chemical compounds have been used. In many cases, these products cause a severe environmental impact over a wide range of non-target organisms. In order to minimize the negative effects of using chemical products with great action spectrum, there is a great effort to develop products of which targets are specific. Therein, the biological control has been presenting itself as a very interesting alternative. Among the various systems used in biological control, the bacteria Bacillus thuringiensis is the option pinpointed as the best notability. However, some resistance towards its use as a biological controlling agent have been reported recently due to the uncontrolled use of products decoded by genes of entomopathogenic action. Thus, the search of new Cry proteins is an important task inside the strategy of biological control of field pests. In order to overcome these situations efforts on the isolation and characterization of new B. thuringiensis isolates using molecular techniques such as PCR and RFLP were adopted and three B. thurigiensis isolates were compared among them and were considered different among the known and described standard type strains up to the present time. When part of the obtained gene sequences were compared to those deposited on the GeneBank, it was possible to observe that for two of them, isolate 113 and 133, a high degree of similarity with sequences described as active against nematodes; the third isolate, 123, had no similarity to any deposited sequence up to date. The isolates, which aminoacid sequence of their Cry proteins in silico were similar to cry genes earlier deposited on GenBank, had their respective gene fully characterized. To this, several... (Complete abstract click electronic access below)

A água é de grande importância para a sobrevivência da vida, o rio Corumbataí abastece as cidades de Analândia, Corumbataí, Rio Claro, Piracicaba entre outras. A toxicologia ambiental vem sendo disseminada como ferramenta no monitoramento ambiental, pois através de bioensaios é possível avaliar a qualidade dágua. O objetivo deste estudo foi avaliar a qualidade do corpo hídrico em questão através de testes de toxicidade crônica, aplicação de protocolo rápido, determinação de metais em sedimento em suspensão e a toxicidade aguda de dois herbicidas (ametrina e glifosato) com Ceriodaphnia silvestrii. As coletas foram realizadas mensalmente no período de agosto/2009 à julho de 2010. Para as 12 coletas verificou-se que pelo menos um ou mais pontos apresentavam concentração de Fe acima do valor máximo permitido pelo CONAMA. A oscilação da pontuação do protocolo de avaliação rápida esteve diretamente relacionada com os aspectos visuais e olfativos. No ensaio crônico com Ceriodaphnia silvestrii houve variação na reprodução dos organismos e através de análises estatísticas foi possível observar que o pH, oxigênio dissolvido, condutividade, Zn, Ti e Ni influenciaram na toxicidade da amostra. Os herbicidas ametrina e glifosato apresentaram a CE50 (48h) respectivamente de 0,50 e 4,5 mg L-1. Conclui-se que a toxicidade crônica foi influenciada pelos parâmetros físico-químicos e metais durante os 12 meses de coleta.O protocolo de avaliação rápida complementa os resultados obtidos dos testes de toxicidade crônica. Através dos ensaios de toxicidade agudo verificou-se que a ametrina é nove vezes mais tóxica do que o glifosato / Water is very importance for survive of life, the Corumbataí river provides water for Analândia, Corumbataí, Rio Claro and Piracicaba and others cities. The environmental toxicology has been disseminated how a tool in environmental monitoring, because through the bioassays is possible evaluate the quality of water body. The objective of this study was assess the quality of the water body in focus through chronic tests, rapid assessment protocols, determination of metals in suspended matter and acute toxicity of two herbicides (ametryn and gliphosate) with Ceriodaphnia silvestrii. The water samples were collected monthly between august 2009 to july 2010. For the 12 samples verified at least one or more samples has more iron concentration than maximum value permitted of CONAMA. The oscillation of the rapid assessment protocols scores was directed associated with visual and olfactory aspects. In chronic assays with Ceriodaphnia silvestrii has the variation in the reproduction of the organisms and through the statics analyzes was possible observed that the pH, dissolved oxygen conductivity, Zn, Ti and Ni influenced in the toxicity of sample. The herbicides ametryn and glyphosate showed the EC50 (48h)respectively 0.50 and 4.5 mg L-1. It is conclude that the chronic toxicity was influenced by physics- chemistries parameters and metals during the 12 months. The rapid assessment protocol complete the results from chronic tests of toxicity. Through of acute toxicity assays verified that the ametryn is nine times more toxic than glyphosate.

The toxicity of ammonia has become an issue in recent years, especially in the Chesapeake Bay watershed. Currently, the EPA has set a chronic criterion of 0.035 mg/L (unionized ammonia). The chronic criterion is a four-day average concentration that cannot be exceeded more than once every three years. However, a lack of data exists on the toxicity of ammonia to saltwater organisms. Prior to this research, the chronic criterion was based on two saltwater and four freshwater organisms. This research was conducted to add additional data so more appropriate criteria may be set. Two saltwater fish, the Summer Flounder (Paralichthys dentatus), and the Atlantic Silverside (Menidia menidia) and one invertebrate, the Quahog Clam (Mercenaria mercenaria) were tested for acute toxicity to ammonia. The acute tests performed on the Summer Flounder (2 months old) were 48 and 96-hour tests performed in both synthetic seawater and natural seawater. Seven-day chronic tests were also performed on the Summer Flounder using synthetic seawater. Both 48 and 96-hour acute tests were performed on the Atlantic Silverside (10-14 days old.) using natural seawater. Both 48 and 96-hour acute tests were performed on the Quahog Clam (5mm shell height) using synthetic seawater. The 48-hour LC50s for the Summer Flounder in synthetic and natural seawater were 1.22 mg/L and 1.09 mg/L, respectively. The 96-hour LC50s for the Summer Flounder in synthetic and natural seawater were 1.07 mg/L and 0.889 mg/L, respectively. The 7-day chronic NOEC was 1.37 mg/L. The 48 and 96-hour LC50s for Atlantic Silverside in natural seawater were 1.52 mg/L and 1.18 mg/L, respectively. The 48 and 96-hour LC50s for Quahog Clam in synthetic seawater were 216 mg/L and 36.6 mg/L, respectively. The acute-chronic ratio for the Summer Flounder was 2.27. The refined chronic criterion was 0.081 mg/L based on this research and the research of others. Summer Flounder were more sensitive to ammonia in natural seawater than synthetic seawater. However, Atlantic Silverside showed no difference in sensitivity. / Master of Science

<p>  </p> <p>Miniature mass spectrometers are in a phase of rapid development due to their potential in offering simple yet powerful solutions for a wide variety of unmet biomedical needs. In particular, the combination of ambient ionization methods with miniature mass spectrometers offers an attractive solution for improving patient outcomes and reducing the healthcare burden on patients as well as clinicians opposed to current methods for disease prognosis and diagnosis. </p> <p>There has been a rapid expansion in the commercial offerings of miniature mass spectrometers from commercial vendors, both large and small, including Purspec, Bayspec, MassTech, Waters, and Advion. Despite the large number of instruments that have been made available and the success of many of these systems with analysis of a broad range of biological matrices, much work remains to perform bioanalysis of complex molecules with concentrations that often lie in the ng/mL-µg/mL range. Miniaturization of mass spectrometers is accompanied by design simplifications in comparison to benchtop instruments, so that sacrifices are often made in terms of performance. The figure of merit that is compromised, of course, depends on the design of the instrument itself. Thus, in addition to a good understanding of the operation of the mass spectrometer, it is crucial that the ionization method for the analyte be chosen judiciously, and that the method is suitably optimized to be able to perform the measurements to obtain high quality data for trace analysis. </p> <p>The custom built Mini-12 miniature MS systems at Purdue University is one such miniature mass spectrometer that can be used for making on-site measurements. In this work, I have described my efforts to perform trace analysis of a range of molecules (tenofovir diphosphate, cabotegravir, rilpivirine, and phosphatidylethanol) relevant to HIV treatment and prevention with the Mini-12 system. Based on the most favorable set of conditions for developing a particular assay, method performance parameters are listed for each of the applications described. In all the above applications, the desired detection limits are met by adopting a broad range of strategies with the focus of keeping the method amenable to use at the point-of-care, i.e., ensuring that sample preparation is completed in <4 minutes. The proof-of-concept results obtained with the custom built Mini-12 mass spectrometer at Purdue University lays the groundwork to (i) encourage the introduction of miniature mass spectrometer-based assays for the molecules listed in a clinical setting and (ii) extend the use of miniature mass spectrometer-based assays for other therapeutic regimens that require longitudinal monitoring.</p>

RNA-cleaving DNAzymes (RCDs) are a class of functional nucleic acids that can bind various targets ranging in size from small molecules to large proteins, which results in activation of cleavage activity. The activation of RCDs results in the cleavage of a ribonucleotide site in an otherwise all-DNA substrate, leading to two cleavage fragments. In this work, a previously identified DNAzyme that binds to a protein biomarker endogenous to Helicobacter pylori (J99) crude extracellular matrix was evaluated for coupling to an isothermal amplification method termed rolling circle amplification (RCA) as a way to improve the originally reported detection limit. Three RCD constructs were designed with the goal of generating a cleavage fragment that could act as a primer to initiate RCA. The first method used the original HP DNAzyme, which liberated a short cleavage fragment that could be used as a primer. However, the primer fragment was rapidly digested by the bacterial matrix, preventing RCA. A second method evaluated use of a circularized substrate and separate RCD to generate a primer, however this system was not capable of generating a cleavage fragment. A final method redesigned the original RCD to move the substrate region from the 3’ to the 5’ end of the RCD, causing the longer RCD-containing fragment to be the primer for RCA. In this case, target-triggered cleavage was observed and the resulting primer was sufficiently resistant to digestion to allow its use as a primer for RCA. Preliminary characterization of the rearranged RCD showed that it retained selectivity similar to the original RCD, but that the cleavage rate was slower. In addition, the RCA based reaction, while successful, did not produce improved detection sensitivity relative to unamplified assays. Methods to further improve RCA performance are discussed for future work. / Thesis / Master of Science (MSc)

<p>The notion of autonomous laboratories is of much interest to the chemical science community.  Promises of increased efficiency and throughput of discovery, beyond that of automated platforms, has already begun to be fulfilled by autonomous continuous flow reactors and desktop robots.  For fully autonomous laboratories to be further realized, various components in these systems require automation.  Herein this work, are presented multiple data-driven statistical methods for automating and optimizing various chemical systems and processes.  Presented are: the development and deployment of a general stochastic optimization algorithm, a machine learning-based solvent selection pipeline for organic transformations, a generalized data-dependent scoring methodology for antibody assay development, the prototyping of an automated platform for ion-molecule reactions inside a linear ion trap, and a review on recent developments for machine learning and mass spectrometry.  In summary, these works present various components for furthering the automation of chemistry.</p>