Este trabalho apresenta uma análise semântica dos verbos e adjetivos do Guarani Paraguaio baseada nos pressupostos da Semântica Formal. Mais especificamente, este trabalho se propõe a analisar a interação de verbos e adjetivos com um morfema de grau da língua, a partícula . São analisados neste trabalho adjetivos, verbos e construções causativas com verbos deadjetivais a partir de suas possíveis leituras com o morfema . Demonstra-se aqui que o morfema funciona como um modificador da relação de predicação entre o adjetivo ou o evento e um argumento nominal. Essa relação está dada em termos de uma estrutura de graus, de acordo com a semântica escalar proposta por Kennedy (1999b) e Kennedy & McNally (2005). Essas teorias partem do pressuposto de que adjetivos mapeiam entidades em graus de estruturas abstratas de uma propriedade, as escalas, e por isso adjetivo contém uma variável de grau d em sua entrada lexical. Essa variável é quantificada através de um morfema de grau. Proponho aqui que além do modificador que satura a variável de grau dada no seu léxico, o adjetivo também pode receber um modificador de grau quando houver uma escala de quantidade, dada composicionalmente de acordo com o modelo de Bochnak (2010). Nesse sentido, não atuaria sobre a variável de grau dada pelo léxico do adjetivo, mas sobre uma escala de quantidade construída na sintaxe. Em relação a verbos, modificaria a relação de mapeamento do evento sobre entidades, medido por uma estrutura de graus. Uma das vantagens desta proposta é que isso permitiria que adjetivos fossem modificados simultaneamente por e outros modificadores de grau que atuam sobre a escala de intensidade de adjetivos, o que de fato ocorre na língua. Para sustentar minha hipótese de análise, apresento alguns dados do Guarani Paraguaio em que o morfema co-ocorre com outros intensificadores de grau. Em relação aos verbos deadjetivais, mostrarei que estes não possuem uma leitura atélica como os verbos deadjetivais do Inglês e do Português Brasileiro. Isso serve de evidência para concluir que não modifica a escala de propriedade dada pelo adjetivo formador do verbo, mas que atua no mapeamento do evento na estrutura de graus dada por seu argumento nominal. Em suma, este trabalho mostra que opera sempre sobre escalas de quantidade e nunca sobre a variável de grau do léxico de verbos e adjetivos. / This dissertation presents a semantic analysis of verbs and adjectives Paraguayan Guarani based on the assumptions of Formal Semantics. More precisely, this study aims to analyze the interaction of verbs and adjectives with the particle , a degree morpheme of the language studied here. In this dissertation, I analyze adjectives, verbs and causative constructions with deadjectival verbs and the possible readings of the modification of towards these predicates. It is shown here that the morpheme acts as a modifier of the relationship between the adjective or the event and a nominal argument. This relation is described in terms of a degree structure, according to the semantic of scales proposed by Kennedy (1999b) and Kennedy & McNally (2005). This theory is based on the assumption that adjectives map entities onto degrees of abstract structures of properties - the scales and, for this, adjectives have a degree argument in their lexical entry. The degree variable is saturated by a degree morpheme. I propose here that besides the modifier that saturates the degree variable of the lexicon, the adjective can also be modified by another degree modifier that operates on a quantity scale, which is compositionally given, according to Bochnak (2010). In this sense, does not saturate the degree variable given by the lexicon of the adjective or the verb, but it applies to a quantity scale that is built in syntax. Regarding verbs, modifies the mapping of the event onto entities, which is measured by a degree structure. One of the advantages of this account is that it allows that and other degree intensifiers modify adjectives simultaneously. And it actually happens in Guaraní. In order to support my analysis, I present some data of Paraguayan Guaraní that illustrate how combines to other degree modifiers. I also show that deadjectival verbs cannot have an atelic reading similar to Brazilian Portuguese and English deadjectival verbs. This is used as an evidence to point out that does not modify the property scale of the verb introduced by the adjective, but it only acts on the mapping of the event onto the degree structure of its nominal argument. In conclusion, this work shows that always operates on quantity scales and never on the degree variable of the lexicon of verbs and adjectives.

The intention of this study is to give a qualitative and quantitative description of the usage of connectors, especially mais, parce que and donc, and of some epistemic modifiers in the spoken French of Swedish advanced learners. The study includes eight advanced learners, six highly advanced learners and eight native speakers from the French learner corpus InterFra, all interviewed by the same native speaker. In total, 22 interviews of learners (39,000 words) and eight interviews of native speakers (23,000 words) were examined. One of the goals was to find typical advanced learner features (interlanguage features) in connector and modifier usage, and also to describe individual variation in the group. We highlight the importance of comparative studies and of taking into account recent studies of spoken French to establish advanced interlanguage features, as normative French grammar fails to account for some spoken usage of connectors. The aim in studying interlanguage features that involve connectors and modifiers is twofold: first, we try to understand the function of certain connectors/modifiers at the semantic, discourse organizing, interactional and speech act levels. Second, we look at the syntactic dependence and integration of discourse sequences introduced by parce que and modifiers like je crois (que). The study of mais (chapters 2 and 3) showed that learners used turn-introducing mais more often than native speakers. Mais was also found to be an important reformulation marker in the learner group. In the study of parce que (chapter 4), we found that the macro-syntactic (paratactic) parce que was frequent in both speaker groupes, but that a function like introducing ”specifications” was more frequent in the learner group, while parce que introducing parenthetic remarks (incises) – commonly used by native speakers of French – was found in only a few cases in the learner corpus. We suggest that this latter usage is a property of the highly advanced user. The study of epistemic phrases like je crois/ je pense/ je trouve (que) (chapter 5) revealed a small quantitative difference in syntactic dependence between the two groupes of speakers: the learners more frequently used independent expressions. From a qualitative point of view, the difference was partly due to the high number of isolated phrases (like je crois oui) and post-positioned phrases in the learner material. Both groups of speakers used modifiers as discourse-structuring devices and as fillers, but their use as fillers was more frequent in the learner group. Finally (chapter 6), by carrying out a prosodic analysis (variation in fundamental frequency) coupled with an analysis of the information structure, we segmented the speech into functional discourse units (les paragraphes oraux). This analysis suggested some characteristics of highly advanced learner usage for the position of the connector donc. One such feature was the incorporation of donc in a constituent of the discourse unit, both from a syntactic and prosodic point of view.

Neste trabalho foi estudado o comportamento eletroquímico de materiais à base de carbono Printex 6L, sem e com a adição de compostos orgânicos da classe das quinonas (2-terc-butil-9,10-antraquinona (TBA) e 2-etil-9,10-antraquinona (EA)) para a produção de peróxido de hidrogênio (H2O2) a partir da reação de redução do oxigênio gasoso (O2). Na primeira etapa, foi utilizada a técnica de microcamada porosa depositada sobre um eletrodo de disco/anel rotatório, sendo que a partir dos resultados obtidos foram confeccionados eletrodos de difusão gasosa (EDG) para a eletrogeração de H2O2. Os melhores resultados utilizando a microcamada porosa foram para os materiais com a adição dos modificadores, sendo que o material com 1,0% (m/m) de TBA na demonstrou ser o mais eficiente na geração de peróxido de hidrogênio, apresentando eficiência 20% maior comparado ao Printex 6L sem modificador. Com o eletrodo de difusão gasosa confeccionado com o composto orgânico escolhido, na melhor porcentagem de adição mássica de modificador, obteve-se a concentração de 301 mg L-1, sendo que com o eletrodo confeccionado com Printex 6L sem modificador obteve-se a concentração de 175 mg L-1, sob as mesmas condições experimentais. A eficiência cinética também apresentou os mesmos resultados quanto à eficiência dos materiais escolhidos, sendo de 5,94 mg L-1 min-1 para o material com 1,0% de TBA, no potencial de -1,0 V (vs. ECS), e de 3,05 mg L-1 min-1 para o eletrodo de difusão gasosa sem modificador, no potencial de -0,8 V (vs. ECS). / In this work, the electrochemistry behavior of the materials prepared with Printex 6L, with and without addition of organic compounds of the class of quinones, being the compounds: 2-tert-butyl-9,10-anthraquinone (TBA) and 2-ethyl-9,10-anthraquinone (EA). These materials were used to promote the electrogeneration of hydrogen peroxide through the oxygen reduction reaction. In the first phase, it was used the technique of porous microlayer deposited on the rotating ring/disk electrode, and after has been confectioned gas diffusion electrodes (GDE). The best results using the porous microlayer were for the materials with addition of modifiers, and the material with 1.0% (m/m) of 2-terc-butyl-9,10-anthraquinone was demonstrated to be the most efficient in generating hydrogen peroxide, presenting an efficiency 20% higher when compared to Printex 6L without the modifier. The gas diffusion electrode made with the chosen organic compound, in the best massic percentage of modifier, obtained the concentration of 301 mg L-1, and the electrode made with Printex 6L without the modifier obtained the maximum concentration of 175 mg L-1, under the same experimental conditions. The kinect efficiency also demonstrated the same results regarding the efficiency of the chosen materials, which means 5.94 mg L-1 min-1 for the material with 1.0% of 2-terc-butyl-9,10-anthraquinone, in the potential of -1.0 V(vs. SCE), and 3.05 mg L-1 min-1 for the gas diffusion electrode without the modifier, in the potential of -0.8 V (vs. SCE).

In this work, we report the synthesis of submicrometer calcium carbonate particles using the simplest approach of mixing solutions of calcium chloride and ammonium carbonate inorganic precursors in presence of crystallization modifiers. The typical crystallization of CaCO3 into large calcite crystals with rhombohedral morphology changed to very small (down to 0.8 μm) uniform spherical vaterite particles upon addition of small amounts (0.01 to 2.00 mg/mL) of the anionic homopolymer poly(sodium 4-styrenesulfonate) (PSS).The reaction temperature must be preferably kept low around 25 °C. Heating induces the formation of an unstable hydrated phase, which is quickly converted back to the most stable structure, however with some broadening in the particle size distribution. In contrast, large spheres made of a collection of calcite polycrystallite aggregates formed in presence of poly(acrylic acid) (PAA) under otherwise the same experimental conditions. Crystal growth in a preorganized environment created by selective distribution of Ca(II) ions onto the shell of polyestyrene-b-poly(acrylic acid) (PS-b-PAA) core-shell spherical micelles revealed a rather poor control of size and morphology. Therefore, PSS anionic homopolymer can be applied to the synthesis of submicrometer CaCO3 particles from solutions of inorganic salts, which is a much cheaper and sustainable method than controlled CO2 gas production and diffusion. Representative polymer@CaCO3 particle systems were used to prepare PCL-based composites, of which the rheological behavior was accessed by oscillatory rheology. / No presente trabalho, que se refere à síntese de partículas submicrométricas de carbonato de cálcio usando uma abordagem mais simples da mistura de soluções de cloreto de cálcio e carbonato de amônio, precursores inorgânicos na presença de modificadores de cristalização. A cristalização típica de CaCO3 em grandes cristais de calcita com morfologia romboédrica os quais sofreram alteração para partículas pequenas (abaixo de 0,8 um) e uniformes de vaterita se deu após a adição de pequenas quantidades (0,01 a 2,00 mg/ml) do homopolímero aniônico poli (estirenosulfonado de sódio) (PSS). A temperatura da reação deve ser preferencialmente mantida em torno de 25 °C. O aquecimento induz a formação de uma fase hidratada instável, que é rapidamente convertida para a estrutura mais estável, porém, com um aumento de tamanho da partícula. Em contrapartida, com a utilização de poli (ácido acrílico) (PAA), produziu-se grandes esferas formadas por um conjunto de agregados policristalinos de calcita sob as mesmas condições experimentais. O crescimento de cristais em um ambiente pré-organizado criado pela distribuição seletiva dos íons de Ca II na corona de poliestireno-b-poli (ácido acrílico) (PS-b- PAA), formando micelas esféricas do tipo núcleo- corona revelou um fraco controle do tamanho e da morfologia. Portanto, o homopolímero aniônico PSS pode ser aplicado à síntese de partículas submicrométricas de CaCO3 a partir de soluções de sais inorgânicos, tal método apresenta-se mais barato e sustentável tendo liberação de CO2 de forma controlada. Sistemas representativos de partículas de polímero@CaCO3 foram utilizados para preparar os compósitos à base de Poli (Caprolactona) (PCL), onde o comportamento reológico foi analisado por reologia oscilatória.

<div>Comparisons provide an important tool for exploring the syntax and semantics of gradable properties. American Sign Language (ASL) appears to have several such constructions, but they have yet to receive much linguistic analysis. This study establishes basic empirical facts concerning clausal boundaries, constituency structure, compatibility with various indicators for the presence of degrees, and composition of the standard of comparison for the MORE- and BEAT-construction in ASL. Such facts are needed for any formal syntactic or semantic treatment of the constructions. Motivated by typological observations, this study proposes that a reasonable set of initial hypotheses is that the ASL MORE-construction is a comparison of degrees and that the BEAT-construction is a comparison of individuals (as both terms are defined in Kennedy 2007). Results from the tests conducted in this study are largely consistent with those analyses, but also show where there is room for further refinement. Results additionally demonstrate that both more and beat qualify as explicit rather than implicit comparatives, confirming previous work in Wilbur et al. (2018) concerning the latter. An incidental finding of this study involves the distributional patterns for</div><div>two modifiers frequently used with gradable properties, intensive aspect and Y-OO, indicating both have a semantics distinct from that of the English very even though</div><div>frequently translated between English and ASL with that modifier. Finally, this study contributes to the discussion of comparison constructions cross-linguistically by illustrating</div><div>the need to conduct cross-linguistic work that looks beyond what is considered the default comparison of the languages under investigation.</div>

A successful supercritical fluid extraction method includes removal of the analyte from the matrix into the bulk fluid as well as trapping or concentration of the analyte prior to analysis. In the first phase of this research, the trapping capacities of three solid-phase traps (glass beads, 50/50 (w/w) glass beads/octadecylsilica), 50/50 (w/w) Porapak Q®/glass beads) were determined as a function of trap composition for a mixture of components varying in polarity and volatility. The Porapak Q®/glass beads mixture was found to be the most successful solidphase investigated exhibiting the highest trapping capacity. The use of the Porapak Q®/glass beads as a solid-phase trap was investigated in later extraction studies in this dissertation. The extraction of highly polar, multifunctional analytes may not be completely successful with modified carbon dioxide, therefore, a secondary modifier (i.e. additive) may be added directly to the extraction fluid in hopes of improving the recoveries. In the second phase of this research, the effect of secondary modifiers in the subcritical fluid extraction of lovastatin from in-house prepared tablet powder mixtures and MEVACOR® tablets was investigated. The effect of in-line methanol-modifier percentage, additive type (acidic, basic, neutral) to the in-line methanol, and additive concentration on the extraction efficiency were examined. The extraction recoveries of lovastatin from MEVACOR® tablets were shown to be highly dependent on methanol concentration and additive type. Isopropylamine was shown to be the most successful additive investigated. An optimized and reproducible extraction method was developed. The extraction of ionic compounds with carbon dioxide may be difficult due to the high polarity of the compounds. In the third phase of this research, the addition of ion-pairing additives to the matrix in hopes of forming an ion-pair complex of reduced analyte polarity was investigated. Therefore, a screening study consisting of a fractional-factorial design was performed in order to identify the factors which contribute most to the recovery of an anionic species, triphenylphosphinetrisulfonate (TPPTS), from a spiked-sand surface employing supercritical fluid extraction with carbon dioxide. The experimental parameters investigated were: type of ion-pairing additive (i.e. tetralkylammonium hydrogen sulfates) and its concentration, carbon dioxide density, extraction temperature, static extraction time, CO₂ mass used, liquid CO₂ flow rate, and the volume of methanol spiked into the matrix prior to extraction. Of the eight factors investigated, four factors were identified as significantly affecting the recovery of the anionic species. They were: 1) ion-pairing reagent added to the spiked sand surface and its concentration; 2) static extraction time; and 3) volume of methanol present in the extraction vessel. The experimental parameters and settings identified as influential by the statistical approach were later shown in concert to yield 100% recovery of TPPTS from the spiked-sand. In the fourth phase, the extraction of a cationic species, pseudoephedrine hydrochloride, from spiked-sand and Suphedrine tablets, with pure and methanol-modified CO₂ was examined. Once the extraction was shown to feasible, several strategies were compared in terms of their effectiveness in enhancing the analyte's extractability. The first strategy involved the addition of ion-pairing additives. Several sodium salts of alkylsulfonic acids varying in lipophilicity and concentration were investigated. The addition of 1-heptanesulfonic acid, sodium salt, in methanol, in a 5:1 mole ratio of reagent to analyte was shown to be the most useful in recovering the drug from the spiked-sand. The second strategy considered the influence of acids and bases and other modifier compositions such as a methanol/water mixture with or without 1-heptanesulfonic acid, sodium salt, on the pseudoephedrine recovery. The recoveries obtained from the drug spiked-sand were shown to comparable in the presence of a methanol/water solution, a tetrabutylammonium hydroxide in methanol solution, and a methanol solution with 1-heptanesulfonic acid, sodium salt. Next the extraction of pseudoephedrine hydrochloride from Suphedrine tablets was performed with pure and modified CO₂. Similar to the sand-spike studies, the effect of the addition of the ion-pairing reagent and other in-cell modifiers were examined. Once again, the recoveries obtained when the matrix was in the presence of a methanol/water mixture and a methanol solution containing 1-heptanesulfonic acid, sodium salt were similar. Finally, the identity of the extracted analyte was determined via IR analyses, and it was shown that pseudoephedrine hydrochloride was indeed extractable from the tablets with in-line modified CO₂ in the absence of any in-cell modifier. In the last phase of this research, a supercritical fluid chromatographic separation with evaporative light scattering detection was developed for the separation of five phospholipids varying in polarity and ionic characteristics. Several parameters were investigated and shown to be influential in the separation. They were: 1) stationary phase composition, 2) addition of an acidic additive and its concentration, 3) mobile phase ramp rate, and 4) column outlet pressure. / Ph. D.

Overall hypothesis in a series of lactation studies reported in this dissertation was that supplementing different rumen modifiers would have consistent responses on ruminal fermentation and lactational performance under optimal ruminal fermentative conditions. First experiment investigated the influence magnesium exchanged zeolite on ruminal fermentation and lactational performance. Intake of dry matter (DM), milk yield, milk fat concentration, and feed efficiency were not affected. Milk protein concentration tended (P = 0.15) to be higher for the zeolite total mixed ration (TMR). Ruminal pH tended to increase (P = 0.11) by feeding the sodium bicarbonate or the zeolite. A second lactation experiment determined the influence of quebracho condensed tannin extract (CTE) on ruminal fermentation and lactational performance. Supplementing CTE decreased intakes of DM and nutrients regardless of forage level thereby increasing feed efficiency. Milk yield and components were not affected. Milk urea N (MUN) and total VFA concentration decreased by supplementing CTE. Cows fed CTE had decreased ruminal ammonia-N and MUN concentrations, indicating that less ruminal N was lost as ammonia. A third lactation trial assessed whole safflower seeds (SS) on ruminal fermentation, lactational performance, and milk fatty acids. Feeding the Nutrasaff SS TMR (NSST) decreased intake of neutral detergent fiber. Digestibilities of nutrients, milk yield and components, ruminal pH, ruminal VFA, and ammonia-N were similar. Ruminal C16:0 fatty acid (FA) concentration increased with the cottonseed TMR (CST), while C18:1 cis-9 and C18:2 n-6 tended (P = 0.10 and P = 0.09, respectively) to increase with SS supplementation. Supplementing SS decreased milk C16:0 concentration, whereas it increased C18:1 cis-9 and C18:1 trans-9. Milk C18:1 trans-11 FA and cis-9, trans-11 conjugated linoleic acid increased and tended (P = 0.07) to increase with feeding the NSST. Feeding zeolite would cost-effectively replace sodium bicarbonate as a ruminal buffer, whereas CTE may change the route of N excretion, having less excretion into urine, but more into feces. Whole SS can be an effective fat supplement to lactating dairy cows without negative impacts on lactational performance and milk FA. These studies demonstrate that the three rumen modifiers can positively manipulate ruminal fermentation.

Yes / The tribological performance of the piston assembly of an automotive engine is highly influenced by the complex flow mechanisms that supply lubricant to the upper piston rings. As well as affecting friction and wear, the oil consumption and emissions of the engine are strongly influenced by these mechanisms. There is a significant body of work that seeks to model these flows effectively. However, these models are not able to fully describe the flow of lubricant through the piston assembly. Some experimental studies indicate that droplets of lubricant carried in the gas flows through the piston assembly may account for some of this. This work describes an investigation into the nature of lubricant misting in a fired gasoline engine. Previous work in a laboratory simulator showed that the tendency of a lubricant to form mist is dependent on the viscosity of the lubricant and the type and concentration of viscosity modifier. The higher surface area-to-volume ratio of the lubricant if more droplets are formed or if the droplets are smaller is hypothesised to increase the degradation rate of the lubricant. The key work in the investigation was to measure the size distribution of the droplets in the crankcase of a fired gasoline engine. Droplets were extracted from the crankcase and passed through a laser diffraction particle sizer. Three characteristic droplet size ranges were observed: Spray sized (250–1000 μm); Major mist (30–250 μm); and Minor mist (0.1–30 μm). Higher base oil viscosity tended to reduce the proportion of mist-sized droplets. The viscoelasticity contributed by a polymeric viscosity modifier reduced the proportion of mist droplets, especially at high load.

A determinação direta de arsênio total em águas por espectrometria de absorção atômica com filamentos de tungstênio (150 W) modificados quimicamente com irídio ou ródio, representa uma alternativa para a atomização eletrotérmica de arsênio, que foi avaliada na presente dissertação. A utilização do revestimento com Ir como modificador químico proporcionou um aumento da massa característica de arsênio de 3,5 vezes. As medidas foram feitas com altura de observação selecionada para proporcionar a melhor razão sinal/ruído sem diminuir a sensibilidade do sinal analítico. Avaliaram-se dois programas de aquecimento: com temperatura de secagem constante (com diminuição gradativa da tensão aplicada) e com temperatura de secagem variável (com tensão aplicada de maneira constante). Não houve diferença na sensibilidade entre os dois programas estudados, indicando que a modificação química leva à formação de um precursor atômico com estabilidade térmica elevada. De fato, utilizando-se a modificação química permanente com 1000 müg Ir, e adotando-se programa de aquecimento com temperatura de secagem variável, a temperatura máxima de pirólise foi de aproximadamente 1700 °C ( temperatura de atomização de 2700 °C). Avaliou-se o comportamento eletrotérmico do As na presença dos concomitantes Na, K, Ca e Mg em 0,1% v/v HNO3. Interferências mais severas foram observadas na presença de cálcio acima de 10 \'mü\'g l-1, e acima de 100 \'mü\'g l-1 para os demais concomitantes. As interferências podem estar relacionadas com o elevado gradiente de temperatura entre a superfície do filamento e a fase gasosa do volume de observação, ou mesmo devido à formação de compostos refratários, particularmente para Ca e Mg, na fase condensada, ou seja, na superfície do atomizador. O emprego do método das médias móveis no tratamento dos sinais transientes gerados na atomização do arsênio também foi avaliada. Com o filamento posicionado na altura de observação 2 mm, foram utilizados os fatores 0, 3, 5, 7 e 9, observando-se melhora considerável nos limites de detecção instrumental e do método,utilizando-se média móvel com fator 7. Nestas condições, e depositando-se 20 \'mü\'l de amostra sobre o filamento, o limite de detecção foi de 3,2 \'mü\'g l-1 As e a massa característica de 37,0 pg As. A exatidão foi avaliada analisando-se diferentes amostras de águas provenientes da região do Quadrilátero Ferrífero do Estado de Minas Gerais, por espectrometria de fluorescência atômica com geração de hidretos e por espectrometria de absorção atômica com o filamento de tungstênio modificado com Ir. A comparação dos resultados mostrou que o método proposto pode ser utilizado para o controle de qualidade de águas desta região. Aproximadamente 150 queimas podem ser feitas com um único filamento de tungstênio / The direct determination of arsenic in waters by atomic absorption spectrometry with 150 W tungsten coils, treated with Ir or Rh, was evaluated as a possible alternative for the eletrothermal atomization of As. The use of iridium as a permanent chemical modifier did improve the characteristic mass of arsenic by 3.5 fold. Measurements were made by choosing an appropriate observation height in order to get the best signal to noise ratio. Two heating programs were tested, either by keeping the applied voltage constant or by using an inverted voltage ramp during the drying step. There were no significant differences in the sensitivities between both heating programs, indicating that the permanent modification lead to the formation of an atomic precursor of high thermal stability. Indeed, with the permanent chemical modification with 1000 \'mü\'g Ir, the maximum pyrolysis temperature was approximately 1700 °C (atomization temperature 2700 °C), allowing a heating program with temperature variation during the drying step. Method selectivity was carried out by evaluating the eletrothermal behavior of As in the presence of up to 1000 \'mü\'g l-1 Na, K, Ca and/or Mg in 0,1% v/v HNO3. The most serious interferences were observed with Ca in concentrations higher than 10 \'mü\'g l-1 and when the concentrations were higher than 100 \'mü\'g l-1 for Na, K or Mg, which can be attributed either to the gradient of temperature between the surface of the atomizer and the observation volume or to the formation of refractory compounds in the condensed phase, particularly with Ca and Mg. The absorbance transient signals treatment by the method of moving averages up to factor 9 was also evaluated, with a remarkable improvement in the instrumental and method detection limits. With the center of the observation volume 2 mm above the tungsten coil surface, and a moving average of factor 7, the limit of detection was 3,2 \'müg\' l-1 As and the characteristic mass 37,0 pg As. Accuracy was evaluate by analysing water samples collected in a contaminated area from the Quadrilátero Ferrífero, Minas Gerais State, by hydride generation atomic fluorescence spectrometry and by tungsten coil eletrothermal atomic absorption spectrometry. Results showed that the proposed method fits for the purpose of CONAMA 357 regulation for drinking water quality in the aforementioned contaminated area. Approximately 150 firings can be done with a single tungsten coil atomizer by using 20 \'mü\'l sample volume

Neurodegenerative Erkrankungen (NDs) wie Alzheimer (AD), Parkinson (PD), und amyotrophe lateral Sklerose (ALS) sind Hirnerkrankungen, die durch unlösliche Proteinaggregate in Neuronen oder im Extrazellularraum charakterisiert sind. In dieser Arbeit habe ich für verschiede bekannte und vorhergesagte neurodegenerative Krankheitsproteine (NDPs) Proteininteraktionsnetzwerke erstellt, um mögliche gemeinsame Krankheitsmechanismen genauer zu studieren. Mit Hilfe eines automatisierten Hefe-Zwei-Hybrid-Systems (Y2H) konnte ich 18.663 Protein-Protein-Interaktionen (PPIs) für 449 wildtyp und 22 mutierte Proteine identifizieren. Eine genaue funktionelle Analyse der Interaktionspartner von korrespondierenden wildtyp und mutierten Proteinen ergab deutliche Unterschiede zum einen im Fall von allen untersuchten Proteinen und insbesondere im Fall vom ALS Krankheitsprotein TDP-43. Die identifizierten PPIs wurden außerdem verwendet um krankheitsspezifische Netzwerke zu erstellen und um Proteine zu identifizieren, die mit mehreren NDPs verbunden sind. Ich habe auf diese Weise vier Proteine (APP, IQSEC1, ZNF179 und ZMAT2) gefunden, die mit bekannten NDPs with Huntingtin, TDP-43, Parkin und Ataxin-1 interagieren und so fünf verschiedene NDs miteinander verbinden. Die Reduktion der mRNA Expression von IQSEC1, ZNF179 oder ZMAT2 mit Hilfe von siRNA führte zu einer Verstärkung von pathogenen Mechanismen wie der Aggregation von mutiertem Huntingtin und TDP-43 sowie der Hyperphosphorylierung des Proteins Tau. Außerdem habe ich 22 Proteine entdeckt, die die Aggregation von TDP-43 deutlich verändern und außerdem Mitglieder in sieben vorhergesagten Proteinkomplexen sind. Die Proteinkomplexe habe ich durch Kombination von Interaktionsdaten und Daten eines siRNA Screenings vorhergesagt. Zusätzlich habe ich herausgefunden, dass die Proteine eines vorhergesagten Komplexes, nämlich HDAC1, pRB, HP1, BRG1 und c-MYC, die Aggregation von TDP-43 durch Veränderung von dessen Genexpression beeinflussen. / Neurodegenerative diseases (NDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD) or amyotrophic lateral sclerosis (ALS) are progressive brain disorders characterized by the accumulation of insoluble protein aggregates in neuronal cells or the extracellular space of patient brains. To elucidate potential common pathological mechanisms in different NDs, I created comprehensive interaction networks for various known and predicted neurodegenerative disease proteins (NDPs). I identified 18,663 protein-protein interactions (PPIs) for 449 bioinformatically selected wild-type target proteins and 22 mutant variants of 11 known NDPs by using an automated yeast two-hybrid (Y2H) system. The functional analysis of the interaction partners of corresponding wild-type and mutant NDPs revealed strong differences in the case of all 11 NDPs and especially for the ALS protein TDP-43. The identified PPIs were used to generate networks for individual NDs such as AD or PD and to identify proteins that are connected to multiple NDPs. For example, I found that five neurodegenerative diseases are connected by four proteins (APP, ZMAT2, ZNF179 and IQSEC1) that link known NDPs such as huntingtin, TDP-43, parkin, ataxin-1 and SOD1. Analysis of publicly available gene expression data suggested that the mRNA expression of the four proteins is abnormally altered in brains of ND patients. Moreover, the knock-down of IQSEC1, ZNF179 or ZMAT2 aggravates pathogenic disease mechanisms such as aggregation of mutant huntingtin or TDP-43 as well as hyperphosphorylation of tau. Additionally, I identified 22 modifiers of TDP-43 aggregation, which are members in 7 protein complexes. These complexes were predicted based on combined data from PPI as well as siRNA screenings. Finally, I found that the proteins HDAC1, pRB, HP1, BRG1 and c-MYC, which form one of the predicted complexes, influence TDP-43 aggregation by altering its mRNA expression.