The purposes of this study were to characterize the complexation of toxic metals with algal toxins and to determine the effects of arsenic and copper on the growth of Karenia brevis under specific experimental conditions. Microcystins, pahayokolides, brevetoxins and okadaic acid were used as representatives of algal toxins while arsenic, copper, cadmium, cobalt, iron, manganese and mercury were selected as typical toxic metals (including metalloids here) in the aquatic environment. The stabilities of the toxin-metal complexes were determined using equilibrium dialysis and/or centrifugal ultrafiltration technique. A direct exposure of arsenic and copper to the K. brevis was carried out to determine the effects of these metals to the growth of the algal cell. The results indicated that Cu2+, Hg2+, Co2+, Cd2+ and Fe2+ were capable of complexing with the algal toxins. Moreover, the exposure experiments demonstrated that the high concentration of arsenic and copper could affect the growth of the K. brevis.

Submitted by Michele Mologni (mologni@unoeste.br) on 2017-06-09T18:06:27Z No. of bitstreams: 1 Rafael Gervasoni Ferreira Leite.pdf: 551041 bytes, checksum: 2d93c9ae3fe4163e7faba1743109a057 (MD5) / Made available in DSpace on 2017-06-09T18:06:27Z (GMT). No. of bitstreams: 1 Rafael Gervasoni Ferreira Leite.pdf: 551041 bytes, checksum: 2d93c9ae3fe4163e7faba1743109a057 (MD5) Previous issue date: 2015-09-17 / The control of leafcutter ants is constant in agroecosystems, in which, among the different methods adopted, the chemical one (toxic baits) is the most used. Substances that are extracted from plants, as insecticides, have many advantages when compared to the use of synthetic products. This project’s objective was to evaluate the insecticidal and/or fungicidal potential of the plants Asclepias curassavica, Rosmarinus officinalis and Equisetum ssp. in the control of the leaf-cutting ants Atta sexdens rubropilosa. We made use of 40 colonies of Atta sexdensbred in a laboratory. The plants were collected, dried in a high temperature test chamber for 48 hours, grinded in a Wiley mill and macerated in ethanol 96º up to exhaustion. After being filtered, the product obtained was evaporated under reduced pressure for the production of ethanolic extracts. We conducted reagent acceptance tests, topical application of ethanolic extracts at 4% on the back of the ants and topical application of baits made with plant extracts at 4%. All of the plant extracts adopted affected the de development of the fungi garden negatively. Asclepias-curassavica-based baits provoked the mortality of 22.5% of the colonies in a 7-day period. / O controle de formigas cortadeiras é constante nos agroecossistemas sendo empregados diferentes métodos, onde o químico (iscas tóxicas) é o mais utilizado. Substâncias extraídas de plantas, na qualidade de inseticidas, têm inúmeras vantagens quando comparado ao emprego dos sintéticos. A pesquisa teve como objetivo avaliar o potencial inseticida e/ou fungicida das plantas Asclepias curassavica (falsa-erva-de-rato), Rosmarinus officinalis (alecrim) e Equisetum ssp. (cavalinha) no controle de formigas cortadeiras Atta sexdens rubropilosa. Foram utilizadas 40 colônias de Atta sexdens rubropilosa mantidas em laboratório. As plantas foram colhidas, secas em estufa de ar circulante durante 48 horas, trituradas em moinho tipo Willye e maceradas em etanol 96º até exaustão. Após a filtragem, o produto obtido foi evaporado sob pressão reduzida para obtenção dos extratos etanólicos. Foram realizados teste de aceitação do reagente, aplicação tópica dos extratos etanólicos dos vegetais a 4% no dorso das formigas e aplicação de iscas confeccionadas com extratos vegetais a 4%. Todos os extratos vegetais utilizados influenciaram negativamente o desenvolvimento do jardim de fungo. Iscas produzidas a base de Asclepias curassavica provocaram mortalidade de 22,5% das colônias num período de 7 dias.

O alto da Bacia Hidrográfica do Rio Ribeira de Iguape foi submetido a intensa atividade mineira, cujo objeto mineral principal era a obtenção de chumbo (Pb). Durante longo período as condições de explotação foram rudimentares, não havendo controle sobre o impacto ambiental gerado durante as fases de extração e beneficiamento do minério, cujos rejeitos (escória e concentrado) foram lançados por anos diretamente no rio Ribeira de Iguape. Com o propósito de se criar uma indicação clara do comprometimento ambiental ou não da bacia hidrográfica do rio Ribeira de Iguape quanto ao teor dos metais Cd, Pb, Cr, Zn e Cu, este trabalho exibe resultados de valores que podem servir de referência em teor para estes metais. Para tanto, foram coletadas amostras de duas espécies de moluscos bivalves, Anodontites tenebricosus e Corbicula fluminea e de sedimento aluvionar, em uma porção localizada a montante das fontes de contaminação pelas atividades de mineração e fundição. Os moluscos foram coletados por exame tátil do substrato, seus tecidos foram separados das conchas, liofilizados e analisados em espectrômetro de massa (ICP/MS) e em espectrômetro de absorção atômica (AES). Os valores médios foram em sua maioria inferiores aos valores obtidos por outros autores em pontos localizados ao longo do rio Ribeira de Iguape sob a influência das atividades de mineração e fundição. Em relação às amostras de sedimento aluvionar estas foram separadas em duas porções, uma contendo sedimentos com minerais não magnéticos e a outra sedimentos com minerais magnéticos. Estas amostras foram tratadas granulometricamente e analisadas por fluorescência de raio X (FRX), a fim de se obter a concentração dos metais contidos em cada fração granulométrica. Nas amostras de sedimento não magnético, o composto químico em maior concentração foi SiO2. Quanto aos metais potencialmente tóxicos aqui investigados, todos foram encontrados nestas amostras. Já em relação ao sedimento magnético, as amostras exibiram constituição química composta principalmente por Fe2O3. Os metais Pb, Cr, Zn e Cu, foram encontrados em maior concentração nas amostras referentes as frações granulométricas mais finas, sendo a concentração do Cr nitidamente mais elevada. A elevada concentração deste metal nas amostras de sedimento magnético, quando comparada com as obtidas nas amostras não magnéticas, pode indicar uma provável origem do Cr a partir do mineral cromita (FeCr2O4). Estes dados juntamente com informações contida na literatura específica, indicam que provavelmente a origem do Cr, Pb, Zn e Cu na bacia do rio Ribeira de Iguape possui origem geogênica. De maneira geral, as concentrações dos metais potencialmente tóxicos aqui verificadas, tanto nas amostras referentes às duas espécies de moluscos quanto nas amostras de sedimentos, são inferiores, em sua maioria, às obtidas em pontos ao longo do rio Ribeira de Iguape estudados por outros autores onde há influência das atividades de mineração, o que permite considerar esses dados como referência. / The Ribeira do Iguape River Basin (RIRB) was historically influenced by intense mining activities mainly related to lead (Pb) extraction. For many decades, such exploitation was conducted under rudimentary conditions without control of environmental impacts produced during the stages of ore extraction and beneficiation. Thus, mining wastes and metallurgical slags were directly discharged into the Ribeira de Iguape River, causing environmental contamination by metals. The present investigation has the purpose of developing reference values to some metals (Cd, Pb, Cr, Zn and Cu) to RIRB, in order to provide information that allow the environmental monitoring and the determination of environmental contamination to Ribeira do Iguape River Basin. To achieve that, samples of two bivalves species were collected: Corbicula fluminea and Anodontites tenebricosus. Besides, alluvial sediments from a site located upstream to the contamination sources for metals (mining and smelting activities) were also collected. For both species, soft tissues were firstly separated from their respective shells, freeze-dried and then analyzed in a mass spectrometer (ICP/MS) and atomic absorption spectrometer (AAS). Alluvial sediment samples were splitted into two aliquots, one containing magnetic minerals and another with sediment containing non-magnetic minerals. These samples were separated for particle size and analyzed by X-ray fluorescence (XRF) in order to obtain the metals concentrations for each class of particle size. For presence of metals in bivalves, concentrations were mostly lower than those reported by other authors along RIRB areas influenced by mining and smelting residues. In the non-magnetic sediment fraction, the prominent substance was SiO2. Regarding to potentially toxic metals investigated in this study, all of them were found in such samples. On the other hand, in the magnetic sediment fraction, the prominent chemical was Fe2O3. Pb, Cr, Zn and Cu were found in highest concentrations in the finer grain fractions. The Cr concentration was noticeably high. The higher concentration of this metal in magnetic sediment fractions, when compared to the non-magnetic ones, may indicate a probable source of Cr, Pb, Zn e Cu from the mineral chromite (FeCr2O4). These data, together with that from specific literature, indicate that the origin of Cr at RIRB is probably natural .In general, the potentially toxic metals concentrations found in this study for both species of mussel and sediment are mostly lower than the concentrations obtained by others authors for other portions of Ribeira de Iguape River under influence of mining activities, thus, such results suggest that these concentrations may be considered as local reference values for RIRB.

Nas últimas décadas o crescimento industrial decorrente do desenvolvimento tecnológico e outras atividades consideradas indispensáveis à vida humana, estão gerando graves problemas ambientais, que está despertando uma preocupação a nível mundial. Dentre os vários contaminantes os metais tóxicos têm recebido atenção especial, pela sua persistência ao ingressar nos ecossistemas acumulando-se por toda a cadeia alimentar, uma vez que são extremamente tóxicos, mesmo em quantidades muito baixas. No Brasil, a legislação ambiental vigente já estabelece normas bastante rigorosas no que diz respeito ao descarte de águas contaminadas por metais tóxicos. Para que o tratamento deste tipo de efluentes seja feito adequadamente, e para que possam ser impostos limites máximos cada vez mais compatíveis com a sustentabilidade da vida moderna, torna-se relevante a preocupação com novas tecnologias mais eficientes e econômicas que permitam a remoção de metais tóxicos do ambiente contaminado. Hoje o tratamento do ambiente contaminado é realizado empregandose tecnologias convencionais baseadas em princípios físico-químicos, as quais estão sendo consideradas ineficientes e economicamente inviáveis. Alternativamente, uma nova tecnologia, a biorremediação, vem ganhando cada vez mais importância, devido às vantagens que oferece: simplicidade, eficiência e baixo custo. Para isto é necessário ser avaliada a utilização de microorganismos resistentes e eficazes na remoção do metal, pois, nesta fase são necessários que sejam selecionados organismos com características favoráveis ao processo. Dentro deste contexto, a proposta desse projeto foi isolar e caracterizar micro-organismos de uma área de mineração, avaliando os mecanismos e estratégias para o seu uso na remediação de áreas contaminadas a fim de otimizar a sua capacidade de adsorver íons de metais tóxicos, com vistas à utilização destas bactérias para a biossorção de efluentes de mineração. Foram isoladas e identificadas 105 cepas resistentes a cobre, destas 12 cepas foram capazes de crescer à 7.5 mM de cobre. Experimentos de adsorção com metais tóxicos (Cu, Cd e Ni) mostraram que tais cepas são promissoras na ampliação de tecnologias para uma mineração menos impactante, como a exploração de fontes de metais em baixa concentração, transformando o resíduo em fonte de extração economicamente viável e ambientalmente favorável. / Recently, technological development has been resulted in an industrial growth and has been creating serious environmental problems as concern worldwide. Toxic metals have received special attention among many others contaminants, because their persistence in ecosystems and their capability of accumulation throughout the food chain (even in low amounts). Environmental legislation in Brazil has very strict standards regarding discharge of toxic metals contaminated water. For a successful treatment of such effluents, it is relevant to concern about new technologies more efficient and economics to allow the removal of metals heavy from contaminated environment. Today the treatment of contaminated area is carried out conventional technologies based on physicochemical principles, which are inefficient and uneconomical. Alternatively, a new technology, called bioremediation, is being more important due to the advantages it offers: simplicity, efficiency and low cost. Bioremediation may be a viable alternative for areas contaminated by toxic metals. It\'s needed to evaluate the use of resistant and effective microorganisms in removing the metal, because it\'s required to be selected organisms with favorable characteristics for the process. In this context, the aim of this project is isolating and characterizing microorganisms from a mining area, evaluating the mechanisms and strategies for using in the remediation of contaminated areas, in order to optimize its adsorb heavy metal ions ability and use these bacteria for bioremediation of mining effluents. This work isolated and identified 105 strains resistant to copper, 12 of them were able to grow up to 7.5 mM copper, adsorption experiments with toxic metals (Cu, Cd and Ni) showed that these strains are promising in expanding technologies for sustainable mining, such as the exploitation of low concentration metal sources, turning waste into economically viable mining and environmentally friendly.

O presente trabalho teve por objetivo avaliar o efeito do alumínio sobre a fermentação alcoólica utilizando diferentes linhagens industriais de leveduras (CAT-1, BG-1, PE-2, Fleischmann e colônias de leveduras selvagens isoladas do processo de produção de álcool combustível denominadas C1, C5, C6, C8, C10 e C11) em diferentes concentrações de alumínio e também analisar o acúmulo do metal nessas leveduras durante o processo fermentativo com reciclos de células, semelhante ao processo industrial, para tal, foram avaliados parâmetros como: produção de etanol, rendimento fermentativo, formação de biomassa, produção de glicerol, utilização da trealose, eficiência fermentativa e acúmulo de Al pelas leveduras. Os experimentos foram divididos em três partes: 1a avaliar a ação tóxica do alumínio frente às leveduras industriais BG-1, CAT-1, Fleischmann e PE-2 na fermentação de mosto de caldo de cana (19% ART) com 130 ppm Al; 2a avaliar a ação tóxica do alumínio frente à levedura industrial CAT-1 e as colônias de leveduras C1, C5, e C6 isoladas de uma destilaria produtora de álcool combustível fermentando mosto de caldo de cana (19% ART) com 54 ppm Al com 5 reciclos de células e a 3a foi avaliar a ação tóxica do alumínio frente à levedura industrial CAT-1 e as colônias de leveduras C8, C10, e C11 isoladas de uma destilaria produtora de álcool combustível fermentando mosto de caldo de cana (19% ART) com 54 ppm Al com 5 reciclos de células. Os resultados mostram que no primeiro experimento, a ação tóxica do alumínio em mosto de caldo acarreta efeitos estressantes diferenciados dependendo da linhagem de levedura avaliada. As linhagens CAT-1 e BG-1 são as mais tolerantes ao alumínio, quando comparadas com a PE-2 e Fleischmann, sendo esta última a mais vulnerável em relação a todos os parâmetros estudados. No segundo experimento os resultados obtidos nos permitem concluir que nível tóxico de alumínio em mosto de caldo exerce uma ação diferenciada em relação às leveduras industriais. Inferindo que a CAT-1 foi a mais tolerante ao metal mesmo acumulando mais alumínio, o rendimento foi o maior e os teores de trealose também foram menores. No entanto, de uma forma geral se pode inferir que as leveduras C6 e CAT-1 são mais tolerantes ao alumínio do que a levedura C1 e C5. No terceiro ensaio, concluiu-se que a CAT-1 foi a mais tolerante ao metal Al comparada com as linhagens selvagens C8, C10 e C11, tendo como principal efeito na diminuição da viabilidade e aumento do tempo fermentativo. No geral a linhagem de levedura CAT- 1 apresentou melhor desempenho fermentativo frente a ação tóxica do alumínio. / This study aimed to assess the effect of aluminium on the alcoholic fermentation using different strains of industrial yeasts (CAT-1, BG-1, PE-2, Fleischmann and wild yeast colonies isolated from production of alcohol fuel called C1, C5 , C6, C8, C10 and C11) in different concentrations of aluminium and also examine the accumulation of metal in yeast during fermentation with reused of cells, similar to industrial process, for such parameters have been assessed as: production of ethanol, fermentation rate, formation of biomass, glycerol production, use of trehalose, fermentative efficiency and accumulation of Al by yeasts. The experiments were divided into three parts: 1st available the toxic action of the aluminum front of industrial yeasts BG-1, CAT-1, Fleischmann and PE-2 in the fermentation of grape juice from cane (19% TS) with 130 ppm Al. 2nd available the toxic action of the aluminium front of the yeast industrial CAT-1 and the colonies of yeast C1, C5 and C6 isolated from a distillery producing alcohol fuel molasses fermenting of sugar cane juice (19% TS) with 54 ppm Al with 5 recyclation of cells and the 3rd was to evaluate the toxic action of the aluminium front of the industrial CAT-1 yeast and yeast colonies of C8, C10 and C11 isolated from a distillery producing alcohol fuel molasses fermenting of sugar cane juice (19% TS) with 54 ppm Al with 5 recyclation of cell. The results showed that in the first experiment, the toxic action of aluminium in the broth must involve stressful effects depending on different strain of yeast evaluated. The strain CAT-1 and BG-1 are the most tolerant to aluminium, compared with PE-2 and Fleischmann, the latter being the most vulnerable regarding all parameters studied. In the second the results allow us to conclude that toxic levels of aluminum in the broth must exercise a differentiated action in relation to industrial yeast. Deducing that the CAT-1 was the most tolerant even the metal accumulated more aluminum, the yield was the highest levels and levels of trehalose were also lower. However, in general it can be inferred that the yeast C6 and CAT-1 are more tolerant to aluminum than the yeast C1 and C5. In the third test, it was concluded that the CAT-1 was the most tolerant to the metal Al compared with the wild strains C8, C10 and C11, with the main effect in reducing the viability and growth of fermentation time. Overall the strain of yeast CAT-1 showed better performance fermentation front of toxic action of aluminium.

Connaître le mécanisme d’action (MechoA) des substances est une première étape clé pour l’évaluation de risque (éco)toxicologique. Les MechoAs désignent les interactions moléculaires entre les xénobiotiques et le matériel biologique, entraînant des effets toxiques.Des informations de MechoA ont été collectées pour des centaines de molécules chez différentes espèces, principalement le rat et le poisson. Une première méthode pour prédire les MechoAs à partir de la structure a été développée à l’aide de calculs quantiques. Elle a résulté en 70% de classifications correctes.Par la suite, une deuxième méthode de prédiction utilisant des alertes structurales a été développée, et utilise 6 MechoAs généraux incluant 23 MechoAs détaillés. Cette méthode a obtenu 92% de classifications correctes, tout en étant simple et rapide à mettre en œuvre. Nous l’avons comparée avec d’autres méthodes disponibles et notre arbre de décision a obtenu les meilleures statistiques. Cette méthode est en cours d’implémentation dans un logiciel, et sera disponible gratuitement.Des expériences en laboratoire ont aussi été effectuées et ont permis de consolider les données pour des substances mal caractérisées, en mesurant le logP, la solubilité aqueuse et la toxicité aigüe pour les daphnies. / A knowledge of the mechanism of action (MechoA) of substances is a crucial first step in (eco)toxicological risk assessment approaches. MechoAs refer to molecular interactions between xenobiotics and biological material, leading to an adverse outcome. MechoA information has been gathered for hundreds of molecules in several species, mainly rats and fish. A first method to predict MechoAs from the structure has been developed using quantum calculations. This resulted in 70% correct classifications. A second method to predict MechoAs using structural alerts was developed, using a classification with 6 general MechoAs including 23 detailed MechoAs. This method achieved 92% correct classifications, while being simple and fast to use. We compared this method with other available methods and our decision tree showed the best statistics. This method is currently being implemented into a software, and it will be made freely available as we consider it as a useful support in risk assessment. Some laboratory studies have also been performed and have consolidated data for substances which were not well characterised, measuring logKOW, water solubility and acute toxicity to daphnids.

京都大学 / 0048 / 新制・論文博士 / 博士(工学) / 乙第13336号 / 論工博第4185号 / 新制||工||1740(附属図書館) / (主査)教授 米田 稔, 教授 清水 芳久, 教授 高岡 昌輝 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22505号 / 農博第2409号 / 新制||農||1077(附属図書館) / 学位論文||R2||N5285(農学部図書室) / 京都大学大学院農学研究科食品生物科学専攻 / (主査)教授 保川 清, 教授 宮川 恒, 教授 入江 一浩 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Background: Gaming has emerged from a niche industry to a major global player making billions of dollars in revenue year after year. Many companies and industries alike are taking note of the increasing prominence and investing into the market. However, historically there have been many issues with diversity and inclusion due to the gaming and technology sphere largely being recognized as a male space. A phenomenon has been occurring of women carving out their own gaming spaces into cyberbalkanized communities to avoid gendered discrimination and harassment. Purpose: Research has been conducted on the topic of gender in esports and gaming by many academics but there is still room for further studies as many areas have not been explored. Limited studies have been conducted on female gaming organizations. Therefore, this study seeks to determine if women have a perception of value in relation to these organizations. Method: The method selected was a qualitative method to further explore this issue. Eleven semi-structured interviews were conducted to explore the perceptions of Swedish gamers on the topic of female gaming organizations. Thematic analysis was guided. Conclusion: The results show that while some of the previous criticisms are deemed applicable to this phenomenon, there continues to be a need for female organizations as they provide great resources to female gamers. Many are holding out hope that they will become unnecessary in the future but agree that they still hold value.

In the case of fires frequently wide range of inhomogeneous material is burnt. A lot of combustion products arise during this event, which may adversely affect the environment. Most often detected compounds are carbon dioxide, carbon monoxide, sulfur dioxide, sulphane, hydrogen cyanide, nitrous gases and also organic compounds, which show adverse effects for organism. It is possible to identify and quantify most of them by chemical analysis, but their impact on the ecosystem is not predictable on the basis of these results. An effective tool to predict the impact of combustion products on the ecosystem are ecotoxicity tests. In this thesis, the water leachates of samples from fire places were prepared and subjected to ecotoxicological tests. Two alternative test of ecotoxicity on aquatic organisms were used: the first on the organism Thamnocephalus platyurus (ThamnotoxkitFTM) and the second on the organism Daphnia magna (DaphtoxkitFTM). Another testing aquatic organism was Artemia salina. Ecotoxicity was also tested using a standard phytotoxicity tests; white mustard (Sinapis alba) and white onion (Allium cepa) root growth inhibition tests and lesser duckweed (Lemna minor) growth inhibition test. On the basis of obtained ecotoxicological values LC (EC, IC)50 the impact of matrices from fire places on the ecosystem was evaulated.