La digestion anaérobie est un moyen de traitement des déchets solides produisant de l'énergie sous forme de biogaz (méthane et dioxyde de carbone). L'optimisation de la production de méthane passe par une sélection des déchets à fort potentiel méthane. Actuellement, la mesure du potentiel méthane est réalisée par le test BMP (Biochemical Methane Potential), qui repose sur une fermentation pouvant durer plus de 30 jours, ce qui est trop long pour une installation industrielle. Une méthode rapide de détermination du potentiel méthane est donc nécessaire. Le BMP est lié uniquement à la quantité et à la qualité de la matière organique. Cette méthode doit donc réaliser une analyse globale et rapide de la matière organique. L'objectif de la thèse a été d'identifier et d'étudier une méthode rapide d'analyse de la matière organique de déchets solides permettent de prédire le potentiel méthane. Suite au travail bibliographique, la spectroscopie proche infrarouge s'est révélée la méthode la plus appropriée: analyse globale et rapide, non destructive, préparation d'échantillon réduite, possibilité d'utiliser des fibres optiques pour déporter la mesure. Nous avons ensuite étudié des étalonnages pour prédire le potentiel méthane d'un ensemble homogène de 74 déchets. Un coefficient de corrélation de 0,76 et un écart standard de prédiction (RMSEP) de 28 ml CH4.g-1 MV ont été obtenus. Ensuite, les coefficients du modèle ont été analysés par rapport aux molécules présentes et rapprochés des variables sélectionnées par algorithme génétique afin de valider ce modèle d'un point de vue chimique. Enfin, la robustesse de ce modèle vis à vis de l'origine des échantillons et de l'humidité a été testée. Les résultats montrent clairement le fort potentiel de la spectroscopie proche infrarouge pour la prédiction du potentiel méthane. Pour une utilisation industrielle, il ressort qu'une attention particulière doit être portée sur l'ensemble d'étalonnage, qui doit être le plus exhaustif possible. / Anaerobic digestion is a solution to process solid waste, while producing energy by biogas production (methane and carbon dioxide). Methane production could be optimized by selecting only wastes with high methane potential. Currently, the BMP (Biochemical Methane Potential) test is conducted to predict the methane potential. This test is based on a fermentation process. It is time consuming, sometimes, lasting over 30 days, which is too long from an industrial point of view. A rapid method for determining the methane potential is therefore urgently needed. The BMP value depends only on the quantity and the quality of the organic matter, so a method capable of determining the quality and quantity of organic matter is searched for. The objective of this thesis was to identify and study such a method. First, a bibliographic study led us to chose the near infrared (NIR) spectroscopy method: fast and global analysis of the organic matter, non-destructive method, few or no sample preparation, and remote monitoring by use of fiber optics. Second, a calibration for predicting the BMP of and homogenous sample set has been built based on a 74-waste sample set. A correlation coefficient of R² = 0,76 and a standard error of prediction (RMSEP = 28 ml CH4.g-1 VS). Then, the regression coefficients (called b coefficients) were analysed with regard to the molecules in the waste and were compared to the variables selected from the spectrum, in order to validate the model from a chemical point of view. Finally, the robustness of the model, regarding the waste origins and the moisture was tested with heterogeneous samples set. Results show the potential of the near infrared spectroscopy to predict the methane potential quickly, but attention must be paid on the calibration data set when an industrial implementation is dealt with..

Les naines brunes sont des astres incapables de déclencher et soutenir des réactions nucléaires dans leur cœur. En l’absence de cette source d’énergie, leur luminosité diminue avec le temps jusqu’à leur extinction complète. Leur flux aux longueurs d’onde de 0,8 à 2,35 μm est particulièrement altéré par l’humidité contenue dans l’atmosphère terrestre, ce qui complique l’étude de ces astres. Le but de la présente recherche est de vérifier si la division par un spectre d’étoile A0 est un moyen de corriger l’altération causée par l’atmosphère terrestre sur cette partie de leur spectre. Tout d’abord, des notions, pertinentes à la compréhension de ce travail, sont abordées. L’introduction présente quelques notions sur les naines brunes et sur l’atmosphère terrestre. Le deuxième chapitre concerne le traitement des données. Il traite de la calibration, de la mise en évidence du problème de non-répétabilité de la position de la fente du spectromètre SIMON ainsi que de ses causes. Il porte aussi sur l’uniformisation de la réponse des pixels et de la soustraction du ciel pour extraire les spectres. La méthode employée pour étudier l’effet de l’atmosphère terrestre sur les spectres de naines brunes y est présentée. Le troisième chapitre analyse les résultats obtenus par l’utilisation de l’étoile de référence de type A0 comme calibration pour corriger le spectre de naine brune, en assumant un même effet de l’atmosphère terrestre sur les deux types d’astres. Nous ne pouvons conclure, avec certitude, que l’absorption tellurique affecte de la même façon les deux spectres ni de quelle façon exactement ils sont affectés. Une recherche supplémentaire nécessitant de nouvelles prises de données à des masses d’air et à des taux d’humidité variés est requise. / Brown dwarfs are celestial bodies unable to sustain nuclear reactions. For this reason their luminosity declines until complete extinction. Their flux, particularly in the band between 0,8 and 2,35 μm, is absorbed by the water vapor in the terrestrial atmosphere. The goal of this research is to find a way to correct this part of their spectra affected by this effect. First, general notions needed to understand the project are exposed. The second chapter concerns the data reduction. The calibration, the problem of the position repeatability of the slit of the spectrometer SIMON and his cause are exposed. It discusses techniques to even up the pixels’ response and the substraction of the sky from the spectra. The method used to study the atmosphere effect on brown dwarf spectra is presented. The third chapter analyses the results that use the A0 reference star to correct the brown dwarf spectrum. We cannot conclude that the A0 spectrum is affected in the same way as the brown dwarf spectrum by the terrestrial atmosphere. The data from a single night do not allow a good analysis of this effect as a function of air mass and humidity level. Others missions are needed.

L'UMR ITAP d'IRSTEA à Montpellier et la société Pellenc SA souhaitent développer un système de mesure par spectrométrie visible - proche infrarouge permettant d'évaluer la qualité des olives et d'en suivre la maturité. La mesure doit être effectuée sur une seule olive et de manière non destructive. Les critères de maturité retenus pour une première phase d'étude sont les teneurs en eau et en huile. L'objectif de ces travaux est d'optimiser la mesure des critères de maturité par spectrométrie portable, en s'adaptant aux contraintes induites par l'objet d'étude et en levant des verrous imposés par la technologie retenue. En lien avec les objectifs industriels, trois questions scientifiques ont été soulevées :QS1 : Comment obtenir les valeurs de référence des critères de maturité à partir d'une seule olive ?QS2 : Comment mesurer le spectre d'une olive ? Quelle configuration optique est la plus adaptée à l'objet mesuré ? Quel volume de l'olive est interrogé lors de la mesure spectrale ? Le noyau intervient-il dans cette mesure ?QS3 : Comment étalonner la mesure spectrale ? Les modèles de prédiction sont-ils robustes au regard d'une variété non incluse dans leur étalonnage ? Comment inclure la masse du noyau dans les valeurs prédites ?Afin de répondre à ces questions, des études expérimentales et comparatives ont été menées. Pour la détermination de la teneur en huile (QS1) deux méthodes ont été évaluée, la résonance magnétique nucléaire (RMN) et l'extraction à l'hexane, lorsqu'elles sont appliquées à la pulpe d'une olive unique. L'étude sur les différentes configurations optiques (QS2) a permis de mettre en évidence l'impact de chacune sur la mesure spectrale et ainsi déterminer si l'ensemble de ces configurations proposées (transmission, réflexion diffuse avec propagation guidée de la lumière au moyen d'une sphère, réflexion diffuse avec propagation libre de la lumière et rétrodiffusion) sont envisageables pour la mesure sur une seule olive. De plus, ces travaux se sont intéressés au volume de peau et de pulpe réellement interrogé lors de la mesure spectrale par une étude de la perte de lumière transmise à travers la peau et la pulpe. Le questionnement de l'étalonnage des mesures spectrales (QS3) a consisté en une analyse fine des modèles construits mais aussi en une étude de la robustesse et des différentes méthodes envisageables pour l'améliorer (sélection de longueurs d'onde, mise à jour des modèles, correction “biais-pente”, méthode DOP). Le dernier point traité par ces travaux de thèse est la prise en compte de la masse du noyau dans les valeurs prédites et l'évaluation des différentes méthodes pour réaliser cette correction.L'ensemble des résultats obtenus au cours de cette thèse ont servi à fournir des éléments pour guider la conception d'un outil portable de mesures par spectrométrie sur olives individuelles. / ITAP Research Unit of IRSTEA and Pellenc SA company want to developa visible - near infrared spectroscopy measurement system in order to assess the quality of olives and monitor their ripeness. The measurement has to be non-destructive and performed on a single olive. The ripeness criteria selected are water and oil content. The main objective of this work is to optimize the measurement of these criteria, recorded by a portable spectrometer, by taking into account the constraints linked to the studied object and by overcoming the obstacles imposed by the technology used. In relation to the industrial objectives, three scientific questions were raised :SQ1 : How to get the reference values of the ripeness criteria from a single olive ?SQ2 : How to measure the spectrum of one olive ? Which optical configuration isbest suited for an olive ? Which volume of the olive is actually analyzed during thespectral measurement ? Does the spectrum contain information about the kernel ?SQ3 : How to calibrate the spectral measurement ? Are the prediction models robustregarding a variety not used for the calibration step ? How to include the kernel mass in the predicted values ?In order to answer those questions, experimental and comparative studies have been led. As the determination of water content is easily transposable to a single olive, only the measurement of oil content is studied (SQ1). Two existing methods nuclear magnetic resonance and hexane extraction have been characterized end evaluated when they are applied to the pulp of a single olive.The comparative study conducted on different optical configurations(SQ2) has high-lighted the impact of each configuration (transmission, diffuse reflectance with guidedpropagation of light through a sphere, diffuse reflectance with free propagation of light and interactance) on the spectral measurement. This study has also determined if all of these configurations are suitable for the whole olive measurements. Furthermore, the real volume analyzed during the spectral measurement has been investigated by studying the loss of transmitted light through the skin and the pulp.In order to answer SQ3, the present work provides optimized models for prediction ofwater content on the one hand and oil content on the other hand. The robustness study leads us to consider different methods (Model Update, Biais and Slope, DOP, wavelength selection) depending on the correction set used and therefore the finality of the future device. Concerning the introduction of kernel mass in predicted values, it has be done using various methods which are more or less destructive. The choice of one of these methods has been be determined by the technical possibilities of the device and the minimum expected accuracy of water and oil content predictions.Therefore, the results of this thesis provide some elements to guide the development of a portable spectrometer for measurements on individual olive fruits.

Master of Public Health / Department of Diagnostic Medicine/Pathobiology / Deon Van der Merwe / Cyanobacteria are Gram-negative photosynthetic bacteria capable of producing toxins responsible for morbidity and mortality in humans and domestic animals. Many are capable of forming concentrated blooms that impact the environment by limiting the growth of sub-surface plants and phytoplankton. Harmful algal blooms (HABs) are also capable of producing multiple types of toxins, creating a potential hazard to recreational water users and animals drinking water from or near a bloom. Characterization of HABs is necessary to prevent these human and animal exposures and includes classifying of the type of cyanobacteria present and whether or not they are capable of toxin production, and the exact type of cyanotoxin that is actually present in bloom. Current methods used to classify cyanobacteria and cyanotoxins include microscopy, bioassays, ELISA, PCR, HPLC, and LC/MS. All of these methods, however, have limitations that include time, labor intensity, or cost. Fourier-Transform Infrared Spectroscopy (FTIR) is another potential tool for cyanobacterial classification that is not limited by these factors. To examine the practicality of this method, library screening with default software algorithms was performed on diagnostic samples received at the Kansas State University Veterinary Diagnostic Lab, followed by PCA of samples meeting minimum quality requirements to produce cluster analyses and dendrograms. Both spectrometers and software packages used were successful at distinguishing cyanobacteria from green algae in clean samples with 89.13% agreement. PCA resulted in clear classification of cyanobacteria or green algae demonstrated by a large order of magnitude difference produced by average Euclidian distance dendrograms. While this method is only capable of differentiating cyanobacteria from green algae or other aquatic environmental constituents, its simple, rapid use and low cost make it a beneficial screening tool when coupled with toxin-detection methods to characterize HABs.

L’étude des propriétés fractales des séries biologiques fait l’objet d’un intérêt croissant. Néanmoins la littérature met en évidence une ambiguïté quand à l’explication causale de la présence de ces séries temporelles ne permettant pas de distinguer entre l’adaptation effective réalisée par un sujet ou ses capacités d’adaptabilité globales. La présente thèse a pour objectif de décorréler ces deux notions, notamment en liant le niveau comportemental au niveau cérébral. Notre première étude a permise de mettre en évidence que les propriétés mono-fractales pourraient refléter l’adaptabilité des sujets tandis que les propriétés multifractales seraient liées à l’adaptation effective réalisée au cours de la tâche. La seconde étude à mise en évidence une corrélation entre les propriétés multifractales et le nombre de réseaux cérébraux mis en oeuvre au cours de la tâche, reflétant l’adaptation effective aux contraintes expérimentales imposées. Les résultats de ces travaux de thèse nous ont permis de mieux comprendre la signification fonctionnelle des analyses fractales en terme d’adaptation effective et d’adaptabilité. / The study of fractal properties in biological time series is of increasing interest. Nevertheless, the literature highlights an ambiguity on the causal explanation of the presence of these time series which does not make it possible to distinguish between the effective adaptation made by a subject or his overall adaptability capacities. The aim of this dissertation is to decorrelate these two notions, notably by linking the behavioral level to the cerebral level. Our first study allowed to highlight that the mono-fractal properties could reflect the adaptability of the subjects whereas the multifractal properties would be related to the effective adaptation carried out during the task. The second study showed a correlation between the multifractal properties and the number of brain networks implemented during the task, reflecting the effective adaptation to the experimental constraints imposed. The results of this work have allowed us to better understand the functional meaning of fractal analyzes in terms of effective adaptation and adaptability.

A ocorrência de monofluoroacetato de sódio (MFA-Na) em plantas foi registrada, pela primeira vez, em Dichapetalum cymosum. Posteriormente, esta substância tóxica foi encontrada em outras espécies de plantas, como Palicourea marcgravii, causadora de morte súbita. Amorimia rigida, que é bastante conhecida e frequente no Nordeste do Brasil, está entre as plantas tóxicas, que também causam morte súbita em bovinos, com quadro clínico semelhante ao decorrente da ingestão de plantas que contém fluoroacetato de sódio e ao apresentado por animais intoxicados experimentalmente com este tóxico. À A. rigida são imputadas significativas perdas econômicas, motivo pelo qual o objetivo do presente estudo foi identificar a substância tóxica nela presente e também estabelecer bioindicadores de efeito, quando da intoxicação por esta planta. No estudo por cromatografia em camada delgada de celulose - tendo como fase móvel solução de etanol/hidróxido de amônio/piridina/água (95:3:1:1, v/v/v/v) e como agente derivatizante o azul do Nilo - do extrato aquoso obtido da planta seca e moída, foi detectada a presença de MFA-Na. O fracionamento do extrato hidroalcoólico de A. rigida em coluna XAD-2 forneceu 4 frações: H2O 100% (F1), H2O:MeOH 80/20 (F2), H2O:MeOH 40/60 (F3) e MeOH 100% (F4) das quais, como indicado pelo monitoramento por CCDC, apenas a fração F1 continha o MFA-Na. Essa fração foi submetida à cromatografia em camada delgada preparativa, para isolamento do princípio ativo o qual, em estudo por espectrometria de infravermelho e em comparação com padrão de MFA-Na, comprovou a presença de mistura de mono, di e trifluoroacetato nas folhas desta planta. No estudo bioquímico, animais intoxicados com o padrão de MFA-Na e com o extrato de A. rigida apresentaram alterações nos níveis séricos de cálcio e citrato, sendo estas moléculas consideradas bioindicadoras de efeito a exposição ao MFA-Na. / The first occurrence of sodium monofluoroacetate in plants was reported in Dichapetalum cymosum. Further, this toxic substance was found in other plant species, as Palicourea marcgravii, which causes \"sudden death\". Amorimia rigida, which is well known and frequent in northeastern Brazil, it is among the poisonous plants that have identical lethal effects in cattle to that caused by the ingestion of plants containing sodium fluoroacetate. These intoxication signs are the same that ones presented by experimentally poisoned animals with this toxic. Significant economic losses can be imputed to A. rigida, therefore our aim was to identify its toxic compound and also to establish its biomarkers of effect. The study by cellulose thin layer chromatography using as mobile phase solution of ethanol /ammonium hydroxide/pyridine/water (95:3:1:1, v/v/v/v) and Nile blue as the derivatizing agent - of the aqueous extract of milled dried plant showed the presence of MFA-Na. The fractionation of the hydroalcoholic extract of A. rigida by XAD-2 column chromatography gave four fractions: 100% H2O (F1), H2O: MeOH 80/20 (F2) H2O: MeOH 40/60 (F3) and 100% MeOH (F4); only F1 fraction contained MFA-Na, according to CCDC monitoring. This fraction was subjected to preparative thin layer chromatography, in order to isolate the toxic principle which, in a study by infrared spectroscopy and by comparison with standard MFA-Na, confirmed being a mixture of mono-, di and trifluoroacetate. In the biochemical study, animals intoxicated by MFA-Na and by A. rigida extract showed serum calcium/citrate imbalances; such alterations may be considered biomarkers of MFA-Na exposure effect.

A presente Dissertação relata a síntese e o estudo conformacional das α-fenilseleno-α-dietóxifosforilacetofenonas para-substituídas p-X-Φ-C(O)CH[SeΦ][P(O)(OEt2] (X=OMe 1, Me 2, H 3, F 4, Cl 5, Br 6 e NO2 7) através da banda de estiramento da carbonila no infravermelho, em solventes de polaridade crescente apoiado por cálculos ab initio HF/6-3IG**. A comparação entre a freqüência e a intensidade relativa dos componentes do dubleto, para os derivados 6 e 7, e do singleto para os derivados 1-5, no solvente apolar tetracloreto de carbono, e dos componentes do dubleto, nos solventes de polaridade crescente (clorofórmio, diclorometano e acetonitrila), para os derivados 1-7, com os dados do cálculo ab initio de 3 (composto de referência), indicou que ambas as conformações estáveis (g1 e g2) apresentam a ligação C-Se na geometria anti-clinal (gauche) em relação à carbonila (C=O), enquanto que a ligação C-P assume uma geometria sin-periplanar (cis) em relação à carbonila. A análise dos contatos interatômicos de átomos relevante em comparação com a soma de seus raios de van der Waals, indicou que ambas as conformações g1 e g2 são fortemente estabilizadas pelo sinergismo das interações orbitalares e eletrostáticas π*(CO) / nSe e Oδ-[CO].....Pδ+[PO]. Analogamente, as interações mais fracas Oδ-[OR]..... Cδ+[CO], 0-Hδ+[SeΦ]....Oδ-[PO] e 0-Hδ+[ΦC(O)]....Oδ-[CO] estabilizam as conformações g1 e g2, aproximadamente na mesma extensão. No entanto, somente a conformação g1 é estabilizada pela interação eletrostática (ligação de hidrogênio) Hδ+[α-CH].....Oδ-[OR], enquanto que sómente a conformação g2 é desestabilizada pelo Efeito de Campo Repulsivo entre os dipolos Cδ+=.Oδ- e Pδ+-ORδ- Assim sendo, pode-se concluir que no dubleto de VCO no IV, o componente de maior freqüência e de menor intensidade corresponde à conformação menos estável g2 (do cálculo) enquanto que o componente de menor freqüência e mais intenso corresponde à conformação mais estável g1 (do cálculo). Estes dados estão de pleno acordo com os deslocamentos de freqüência mais negativos da carbonila (ΔVCO) do confôrmero mais estável g1 em relação ao menos estável g2. / This thesis reports the synthesis and the conformational study of some para-substituted α-phenylseleno-α-diethoxyphosphoryl-acetophenones p-X-Φ-C(O)CH[SeΦ][P(O)(OEt)2] (X=OMe 1, Me 2, H 3, F 4, Cl 5, Br 6 e NO2 7) through the analysis of the carbonyl stretching IR band, in solvents of increasing polarity, supported by ab initio HF/631G** computations of 3 (parent compound). The comparison between the frequency and the relative intensity of the doublet components for derivatives 6 and 7, and of the singlet for derivatives 1-5, in non polar solvent, carbon tetrachloride, and of the doublet components, in solvents of increasing polarity (chloroform, dichloromethane and acetonitrile), for derivatives 1-7, with the ab initio data for 3, has indicated that both stable conformations (g1 and g2 ) display the C-Se bond in an anti-clynal (gauche) geometry with respect to the carbonyl (C=O) bond, while the C-P bond assumes a syn-periplanar (cis) geometry relative to the carbonyl group. The analysis of the interatomic contacts between some relevant atoms in comparison with the sum of their van der Waals radii has shown that both g1 and g2 conformations are strongly stabilized almost to the same extension by the synergism of the π*(CO) / nSe and Oδ-[CO] .....Pδ+[PO] orbital and electrostatic interactions. Similarly, the weaker Oδ-[OR] ..... Cδ+[CO], o-Hδ+[SeΦ] ....Oδ-[PO] and o-Hδ+[ΦC(O)] ....Oδ-[CO] interactions stabilise the referred conformations almost to the same extent. However, conformer g1 only is stabilised by the electrostatic interaction (hydrogen bond) ) Hδ+[α-CH] ....Oδ-[OR], while the conformer g2 is the only one which is significantly destabilised through the Repulsive Field Effect which takes place between the Cδ+=Oδ- and Pδ+-ORδ- dipoles. Therefore it may be concluded that the less intense higher vco frequency doublet component should correspond to the less stable g2 conformation, while the more intense lower VCO frequency doublet component should be related to the more stable g1 conformation. Further support for these trends are given by the larger negative carbonyl frequency shifts (ΔVCO) for the g1 conformer relative to the g2 one, for the whole series.

A matéria orgânica e a biomassa microbiana do solo consistem em sensíveis indicadores de qualidade do solo e de seus estoques de carbono e nitrogênio que, juntamente com a textura, têm auxiliado na escolha de formas de manejo agronômico mais sustentáveis. Os métodos disponíveis para a determinação da matéria orgânica (Walkley-Black modificado da EMBRAPA SOLOS, 1997) e da biomassa microbiana (Vance et al., 1987a) têm sido largamente utilizados, porém possuem alguns inconvenientes como a geração de resíduos altamente tóxicos e a grande demanda de tempo para analisar um pequeno número de amostras. A espectroscopia, por sua vez, tem se mostrado uma alternativa mais rápida e limpa para a identificação e quantificação de compostos orgânicos. Por esse motivo, este trabalho teve como objetivo testar métodos espectroscópicos, tanto no infravermelho próximo (NIRS) quanto no médio com refletância difusa (DRIFTS), com o uso de calibração multivariada, para a quantificação destes indicadores. Os teores de argila, silte, areia, carbono orgânico total e carbono microbiano, assim como o quociente microbiano (CMIC/COT), foram espectrometricamente preditos de modo satisfatório. Em geral, obtiveram-se melhores resultados utilizando DRIFTS. / Organic matter and microbial biomass are sensible ways to indicate soil quality as well as carbon and nitrogen stocks. These properties, added to clay, silt and sand contents, have been helped to choose sustainable agronomic soil managements. Current methods for organic matter (Walkley-Black modified by EMBRAPA SOLOS, 1997) and microbial biomass (Vance et al., 1987a) determinations have been widely used despite the generation of toxic waste and large time requirement for analyzing a small number of samples. Spectroscopy, in turn, has been shown a clean and rapid alternative method for this purpose. Thus, the aim of the study was to evaluate the near-infrared reflectance spectroscopy (NIRS) and the mid-infrared diffuse reflectance spectroscopy (DRIFTS) on soil organic matter, microbial biomass and texture determination. Clay, silt, sand, total organic carbon and microbial carbon contents as even as microbial quotient are accurately quantified by infrared spectroscopy. In general, DRIFTS provided better results.

No sistema imune de artrópodes, em contraste com o dos vertebrados, não ocorre uma resposta a antígenos por meio da produção de imunoglobulinas específicas contra agentes infecciosos. Portanto, a imunidade adaptativa está ausente, sendo que o sistema imune nesses animais baseia-se somente numa resposta inata. Os mecanismos presentes na resposta imune inata dos artrópodes incluem: (i) o sistema de coagulação; (ii) a cascata da profenoloxidase; (iii) a liberação de moléculas que possuem ação direta contra microorganismos dentre elas, os peptídeos antimicrobianos (PAMs). Estas moléculas podem ser constitutivas, como observado em aracnídeos, ou terem sua expressão induzida após desafio imune, como observado em alguns insetos. PAMs são moléculas anfipáticas, geralmente catiônicas e compostas por 9 a 100 resíduos. O estudo desses peptídeos, além de possibilitar a descoberta de novas moléculas que tenham modo de ação alternativo aos antibióticos convencionais, permite uma compreensão mais ampla do sistema imunológico de diferentes grupos de animais, bem como a origem dos seus mecanismos na história evolutiva. Neste trabalho foi utilizado o opilião Acutisoma longipes como modelo experimental para a caracterização de PAMs presentes na sua hemolinfa, tendo em vista que não há registros de estudos dessa natureza que utilizaram representantes da ordem Opiliones. Primeiramente, foi demonstrada a ocorrência de diversas frações, obtidas da purificação da hemolinfa, com atividade anti-M. luteus, consistidas por peptídeos que aparentemente são constitutivos. Uma das frações mostrou-se pura e apresentou um peptídeo de 2,1 kDa cuja estrutura primária, composta por 18 resíduos, foi completamente elucidada (SGYLPGKEYVYKYKGKVF) por sequenciamento de novo e sequenciamento do N-terminal. Este peptídeo linear foi nomeado longipina. O peptídeo sintético apresentou atividade antimicrobiana contra as bactérias Escherichia coli e Micrococcus luteus, e as leveduras Candida albicans e C. tropicalis, além de não apresentar atividade hemolítica na máxima concentração testada (100 mM). Foi demonstrado que a longipina liga-se preferencialmente a vesículas unilamelares grandes (LUVs), constituídas de fosfolipídios aniônicos (POPG), que mimetizam as cargas da superfície das células de microorganismos. A ligação do peptídeo a LUVs compostas, na razão molar de 1:1, por POPG e POPC (zwiteriônico) provoca o extravasamento de marcadores (carboxifluoresceína) aprisionados nos seus interiores. Esse peptídeo encontra-se majoritariamente desestruturado em solução ou na presença de sistema mimético composto somente por POPC. Porém, na sua ligação com POPG:POPC 1:1, adota estruturas b e estrutura relacionada à presente em agregados intermoleculares de fibras amiloides. / The arthropods immune system, in contrast to the vertebrates one, lacks a response to antigens through the production of specific immunoglobulins to fight against infectious agents. Therefore, the adaptive immunity is absent, and their immune system is only supported by an innate response. The mechanisms present in the arthropods innate immune response include: (i) the clotting system; (ii) the prophenoloxidase cascade; (ii) the release of molecules that can directly act against microorganisms among them, the antimicrobial peptides (AMPs). These molecules can be constitutive, as observed in arachnids, or have their expression induced upon imune challenge, as observed in some insects. AMPs are amphipathic molecules, usually cationic and formed by 9 to 100 residues. The study of these peptides, besides allowing the discovery of new molecules that exert their mode of action alternatively from the conventional antibiotics, permits a wider understanding of the immunological system from different groups of animals, as well as the origin of their mechanisms in the evolutionary history. The harvestman Acutisoma longipes was used in this work as na experimental model for the characterization of AMPs from its haemolymph, taking into account that there are no records of using representatives of the Opiliones order in such kind of study. Firstly, it was demonstrated the occurrence of several fractions, obtained from the haemolymph purification, that presented anti-M. luteus activity, consisted by peptides that are apparently constitutive. One of these fractions was pure and presented a 2.1 kDa peptide which had its primary structure, composed by 18 residues, completely elucidated by de novo and N-terminal sequencing (SGYLPGKEYVYKYKGKVF). This linear peptide was named longipin. The synthetic peptide presented antimicrobial activity against Escherichia coli and Micrococcus luteus bacteria and Candida albicans and C. tropicalis yeasts, in addition to the absence of hemolytic activity at the highest concentration used (100mM). It was shown that longipin preferentially binds to large unilamellar vesicles (LUVs), constituted by anionic phospholipds (POPG), that mimics the membrane surface of microbe cells. The peptide biding to LUVs composed, in 1:1 molar ratio, by POPG and POPC (zwitterionic) causes dye leakage (carboxyfluorescein) from their inside. This peptide in solution or in the presence of POPC solely containing mimic system is mostly unstructured. However, upon its binding to POPG:POPC 1:1, it adopts b and intermolecular aggregates amyloid-like fibrils structures.

Este trabalho apresenta uma nova metodologia, simples e de baixo custo, para quantificação direta de urânio em compostos do ciclo do combustível nuclear, baseada na espectroscopia no infravermelho com transformada de Fourier (FTIR), utilizando a técnica de pastilhamento em KBr. Diferentes matrizes foram utilizadas para o desenvolvimento e validação analítica: nitrato de uranilo complexado com TBP (UO2(NO3)2.2TBP) em fase orgânica e nitrato de uranilo (UO2(NO3)2) em fase aquosa. O método para matriz de urânio em fase orgânica (UO2(NO3)2.2TBP em hexano/incorporado em KBr) apresentou linearidade (r = 0,9980) dentro da faixa analítica de 0,20% 2,85% de urânio na pastilha de KBr, LD de 0,02% e LQ de 0,03%, exatidão com recuperações acima de 101,0%, robustez e precisão (DPR < 1,6%). O método para matriz de urânio em fase aquosa (UO2(NO3)2/incorporado em KBr) apresentou linearidade (r = 0,9900) dentro da faixa analítica de 0,14% 0,29% de urânio na pastilha de KBr, LD de 0,01% e LQ de 0,02%, exatidão com recuperações acima de 99,4%, robustez e precisão (DPR < 1,6 %). Amostras de processo do ciclo do combustível nuclear foram submetidas a avaliação intralaboratorial e os resultados foram comparados estatisticamente por outras técnicas: Espectrometria de Fluorescência de Raios-X (FRX) e gravimetria. Os testes estatísticos (t-Student e Fischer) indicaram que a técnica por FTIR e as de referência são equivalentes, demonstrando que a nova metodologia pode ser empregada com sucesso nas análises de rotina para o controle de qualidade dos compostos nucleares. / This work presents a low cost, simple and new methodology for direct quantification of uranium in compounds of the nuclear fuel cycle, based on Fourier Transform Infrared (FTIR) spectroscopy using KBr pressed discs technique. Uranium in different matrices were used to development and validation: UO2(NO3)2.2TBP complex (TBP uranyl nitrate complex) in organic phase and uranyl nitrate (UO2(NO3)2) in aqueous phase. The parameters used in the validation process were: linearity, selectivity, accuracy, limits of detection (LD) and quantitation (LQ), precision (repeatability and intermediate precision) and robustness. The method for uranium in organic phase (UO2(NO3)2.2TBP complex in hexane/embedded in KBr) was linear (r = 0.9980) over the range of 0.20% 2.85% U/ KBr disc, LD 0.02% and LQ 0.03%, accurate (recoveries were over 101.0%), robust and precise (RSD < 1.6%). The method for uranium aqueous phase (UO2(NO3)2/embedded in KBr) was linear (r = 0.9900) over the range of 0.14% 1.29% U/KBr disc, LD 0.01% and LQ 0.02%, accurate (recoveries were over 99.4%), robust and precise (RSD < 1.6%). Some process samples were analyzed in FTIR and compared with gravimetric and X-ray fluorescence (XRF) analyses showing similar results in all three methods. The statistical tests (t-Student and Fischer) showed that the techniques are equivalent. The validated method can be successfully employed for routine quality control analysis for nuclear compounds.