Forecasting eruptions using volcano seismology is a subject that affects the lives and property of millions of people around the world. However, there is still much to learn about the inner workings of volcanoes and how this relates to the chance of eruption. This dissertation attempts to increase the breadth of knowledge aimed at helping to understand when a volcano is likely to erupt and how large that eruption might be. Chapters 2 and 3 focus on a technique that uses changes in the local stress field beneath a volcano to determine the source of these changes and help forecast eruptions, while Chapter 4 focuses on a technique that shows great potential to be used to image magma chambers beneath volcanoes by using receiver functions. In Chapters 2 and 3 the source mechanisms of shallow volcano-tectonic earthquakes recorded at Mount St. Helens are investigated by calculating hypocenter locations and fault plane solutions (FPS) for shallow earthquakes recorded during two eruptive periods (1981-1986 and 2004-2008) and two non-eruptive periods (1987-2004 and 2008-2011). FPS show a mixture of normal, reverse, and strike-slip faulting during all periods, with a sharp increase in strike-slip faulting observed in 1987-1997 and an increase in normal faulting between 1998 and 2004 and again on September 25-29, 2004. FPS P-axis orientations (a proxy for ó1) show a ~90° rotation with respect to regional ó1 (N23°E) during 1981-1986 and 2004-2008, bimodal orientations (~N-S and ~E-W) during 1987-2004, and bimodal orientations at ~N-E and ~S-W from 2008-2011. These orientations are believed to be due to pressurization accompanying the shallow intrusion and subsequent eruption of magma as domes during 1981-1986 and 2004-2008, and the buildup of pore pressure beneath a shallow seismogenic volume during 1987-2004 and 2008-2011. Chapter 4 presents a study using receiver functions, which show the relative response of the Earth beneath a seismometer. Receiver functions are produced by deconvolving the vertical component of a seismogram from the horizontal components. The structure of the ground beneath the seismometer can then be inferred from the arrivals of P-to-S converted phases. Receiver functions were computed for the Katmai Volcanic Group, Alaska, at two seismic stations (KABU and KAKN) between January 2005 and July 2011. Receiver functions from station KABU clearly showed the arrival of the direct P-wave and the arrival from the Moho; however, receiver functions from station KAKN did not show the arrival from the Moho. In addition, changes in the amplitude and polarity of arrivals on receiver functions suggested that the structure beneath both KABU and KAKN was complex. Station KABU is likely underlain by dipping layers and/or anisotropy, while station KAKN may lie over a basin structure, an attenuating body, or some other highly complex structure. However, it is impossible to say for certain what the structure is under either station as the azimuthal coverage is poor and thus the structure is unable to be modeled. This dissertation also includes a section (Chapter 6) on the assessment of spreadsheet-based modules used in two Introductory Physical Geology courses at the University of South Florida (USF). When faculty at USF began using spreadsheet-based modules to help teach students math and geology concepts the students complained that they spent more time learning how to use Excel than they did learning the concepts presented in the modules. To determine whether the sharp learning curve for Excel was hindering learning we divided the students in two Introductory Physical Geology courses into two groups: one group was given a set of modules which instructed them to use Excel for all calculations; the other group was simply told to complete the calculations but was not instructed what method to use. The results of the study show that whether or not the students used Excel had very little to do with the level of learning they achieved. Despite complaints that Excel was hindering their learning, students in the study attained high gains for both the math and geology concepts presented in the modules whether they used Excel or not.

L'intégration de méthodes de prédiction des éruptions volcaniques dans une stratégie de surveillance globale peut être un outil d'aide à la décision précieux pour la gestion des crises, si les limites des méthodes utilisées sont connues. La plupart des tentatives de prédictions déterministes des éruptions volcaniques et des glissements de terrain sont effectuées avec la méthode FFM (material Failure Forecast Method). Cette méthode consiste à ajuster une loi de puissance empirique aux précurseurs de sismicité ou de déformation des éruptions. Jusqu'à présent, la plupart des travaux de recherche se sont attachés à faire des prédictions a posteriori, basées sur la séquence complète de précurseurs, mais le potentiel de la méthode FFM pour la prédiction en temps réel, en n'utilisant qu'une partie de la séquence, n'a encore jamais été évaluée. De plus, il est difficile de conclure quant-à la capacité de la méthode pour prédire les éruptions volcaniques car le nombre d'exemples publiés est très limité et aucune évaluation statistique de son potentiel n'a été faite jusqu'à présent. Par conséquent, il est important de procéder à une application systématique de la FFM sur un nombre important d'éruptions, dans des contextes volcaniques variés. Cette thèse présente une approche rigoureuse de la FFM, appliquée aux précurseurs sismiques des éruptions volcaniques, développée pour une application en temps réel. J'utilise une approche Bayésienne basée sur la théorie de la FFM et sur un outil de classification automatique des signaux ayant des mécanismes à la source différents. Les paramètres d'entrée de la méthode sont les densités de probabilité des données, déduites de la performance de l'outil de classification. Le paramètre de sortie donne la distribution de probabilité du temps de prédiction à chaque temps d'observation précédant l'éruption. Je détermine deux critères pour évaluer la fiabilité d'une prédiction en temps réel : l'étalement de la densité de probabilité de la prédiction et sa stabilité dans le temps. La méthode développée ici surpasse les applications classiques de la FFM, que ce soit pour des applications en a posteriori ou en temps réel, en particulier parce que l'information concernant l'incertitude sur les donnée est précisément prise en compte. La classification automatique des signaux sismo-volcaniques permet une application systématique de cette méthode de prédiction sur des dizaines d'années de données pour des contextes volcaniques andésitiques, au volcan Colima (Mexique) et au volcan Mérapi (Indonésie), et pour un contexte basaltique au Piton de la Fournaise (La Réunion, France). Je quantifie le nombre d'éruptions qui ne sont pas précédées de précurseurs, ainsi que les crises sismiques qui ne sont pas associées à des épisodes volcaniques. Au total, 64 séquences de précurseurs sont étudiées et utilisées pour tester la méthode de prédiction des éruptions développée dans cette thèse. Ce travail permet de déterminer dans quelles conditions la FFM peut être appliquée avec succès et de quantifier le taux de réussite de la méthode en temps réel et en a posteriori. Seulement 62% des séquences précurseurs étudiées dans cette thèse sont utilisable dans le cadre de la FFM et la moitié du nombre total d'éruptions sont prédites a posteriori. En temps réel, seulement 36% du nombre total d'éruptions auraient pu être prédites. Cependant, ces prédictions sont précises dans 83% des cas pour lesquels les critères de fiabilités sont satisfaites. Par conséquent, il apparaît que l'on peut avoir confiance en la méthode de prédiction en temps réel développée dans cette thèse mais que la FFM semble être applicable en temps réel uniquement si elle est intégrée dans une statégie de prédiction plus globale. Cependant, elle pourrait être potentiellement utile combinée avec d'autres méthodes de prédictions et supervisée par un observeur. Ces résultats reflètent le manque de connaissances actuelles concernant les mécanismes pré-éruptifs. / Eruption forecasting methods are valuable tools for supporting decision making during volcanic crises if they are integrated in a global monitoring strategy and if their potentiality and limitations are known. Many attempts for deterministic forecasting of volcanic eruptions and landslides have been performed using the material Failure Forecast Method (FFM). This method consists in adjusting an empirical power law on precursory patterns of seismicity or deformation. Until now, most of the studies have presented hindsight forecasts, based on complete time series of precursors, and do not evaluate the method's potential for carrying out real-time forecasting with partial precursory sequences. Moreover, the limited number of published examples and the absence of systematic application of the FFM makes it difficult to conclude as to the ability of the method to forecast volcanic eruptions. Thus it appears important to gain experience by carrying out systematic forecasting attempts in various eruptive contexts. In this thesis, I present a rigorous approach of the FFM designed for real-time applications on volcano-seismic precursors. I use a Bayesian approach based on the FFM theory and an automatic classification of the seismic events that do not have the same source mechanisms. The probability distributions of the data deduced from the performance of the classification are used as input. As output, the method provides the probability of the forecast time at each observation time before the eruption. The spread of the posterior probability density function of the prediction time and its stability with respect to the observation time are used as criteria to evaluate the reliability of the forecast. I show that the method developed here outperforms the classical application of the FFM both for hindsight and real-time attempts because it accurately takes the uncertainty of the data information into account. The automatic classification of volcano-seismic signals allows for a systematic application of this forecasting method to decades of seismic data from andesitic volcanoes including Volcan de Colima (Mexico) and Merapi volcano (Indonesia), and from the basaltic volcano of Piton de la Fournaise (Reunion Island, France). The number of eruptions that are not preceded by precursors is quantified, as well as the number of seismic crises that are not followed by eruptions. Then, I use 64 precursory sequences and apply the forecasting method developed in this thesis. I thus determine in which conditions the FFM can be successfully applied and I quantify the success rate of the method in real-time and in hindsight. Only 62% of the precursory sequences analysed in this thesis were suitable for the application of FFM and half of the total number of eruptions are successfully forecast in hindsight. In real-time, the method allows for the successful predictions of only 36% of the total of all eruptions considered. Nevertheless, real-time predictions are successful for 83% of the cases that fulfil the reliability criteria. Therefore, we can have a good confidence on the method when the reliability criteria are met, but the deterministic real-time forecasting tool developed in this thesis is not sufficient in itself. However, it could potentially be informative combined with other forecasting methods and supervised by an observer. These results reflect the lack of knowledge concerning the pre-eruptive mechanisms.

Orientador: Maria Letícia Cintra / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T06:34:44Z (GMT). No. of bitstreams: 1 Lage_Denise_D.pdf: 12121159 bytes, checksum: f93ebe72b9dc8acf40f7ff2245de6a21 (MD5) Previous issue date: 2014 / Resumo: O líquen plano (LP) pode afetar a pele e/ou as mucosas. Histologicamente apresenta infiltrado linfo-histiocitário na junção epitélio-tecido conjuntivo e apoptose de células epiteliais basais. No LP oral (LPO), ocorre erosão frequente pela maior intensidade da necrose. O LP cutâneo (LPC) e o LPO apresentam características histopatológicas similares, mas o curso clínico é diverso. O LPC costuma ter seu curso limitado, enquanto o LPO é frequentemente recidivante. A erupção liquenoide a droga (ELD) desenvolve-se após semanas da ingestão do medicamento e a resolução do quadro é lenta após a interrupção, dificultando o diagnóstico diferencial com o LP idiopático. Os achados clínicos e histológicos podem ser indistinguíveis daqueles do LP, mas a patogênese da ELD não é conhecida. Diferenças locais no sistema imune da mucosa oral e pele poderiam explicar a diversidade no comportamento clínico do LP. Quanto à ELD, há poucas publicações sobre as alterações imunes que atuam no seu desenvolvimento. A citotoxidade celular é mediada, dentre outros mecanismos, por grânulos contendo granzima B e perforina, produzidos por linfócitos T citotóxicos e células natural killers. Com o objetivo de estudar a citotoxicidade celular na patogênese destas doenças, foram analisadas 29 amostras de LPO, 16 de LPC e 6 de ELD. Os cortes foram corados pela H&E e técnica de imuno-histoquímica, para a demonstração de linfócitos CD4 e CD8, macrófagos HAM 56+ e MAC 387+, granzima B, perforina e ICAM-1. As amostras de LPO apresentaram maior densidade de células granzima B+ e perforina+, em comparação às do LPC. Nos dois grupos de doenças, quanto maior era o número de células perforina+, maior era o de células granzima B+. Maior número de células CD4-positivas foi encontrado nas lesões ativas, quando comparado com o das regressivas, no LPO, mas não no LPC. À comparação entre o LPC e a ELD, quanto maior o número de células CD8-positivas, maior era o número de células que expressavam a perforina no grupo LPC. Quanto maiores eram os valores da granzima B, maiores os da perforina, no grupo LPC. Quanto maiores eram os valores da granzima B, maiores os de células apoptóticas agregadas, no grupo da ELD. Nas amostras do LPC, quanto maiores os valores das células T, maiores os dos macrófagos HAM56-positivos e vice-versa. Nas amostras da ELD, foi encontrada correlação negativa entre o número de células T e o de histiocitos jovens (MAC 387+). Havia correlação positiva entre o número de células T e o de células CD8, no grupo da ELD. O mesmo não ocorreu, no grupo do LPC. Concluindo, a expressão aumentada dos grânulos citotóxicos no LPO pode estar associada à maior gravidade da doença na mucosa. Os resultados favorecem um papel mais importante da granzima B e linfócitos TCD8+, no mecanismo patogenético da ELD, comparativamente com o da perforina, de maior importância no LPC. É possível que a ação da granzima B esteja ligada ao número abundante de clusters encontrado na ELD. Embora o LPC e a ELD apresentem semelhanças clínicas e histológicas, a etiopatogênese parece ser distinta / Abstract: Lichen planus (LP) can affect the skin and/or mucous membranes. Histologically it presents lymphohistiocytic infiltrate in the epithelium-connective tissue junction and apoptosis of basal epithelial cells. In oral LP (OLP), erosion occurs frequently by higher intensity of necrosis. Cutaneous LP (CLP) and OLP present similar histopathological features, but the clinical course is diverse. Spontaneous remission is common in CLP, but OLP follows a prolonged course, with periods of remission and relapse. Lichenoid drug eruption (LDE) develops after weeks of drug intake and the resolution of lesions is slow after drug discontinuation, hampering the differential diagnosis with (idiopathic) LP. Clinical and histological findings of LDE may be indistinguishable from those of LP, but LDE pathogenesis is poorly understood Local differences in the immune system of the skin and oral mucosa could explain the diversity in the clinical behavior of CLP and OLP. Regarding LDE, there are few publications on the immune changes that act in its development. Cellular cytotoxicity is mediated, among other mechanisms, by granules containing perforin and granzyme B, produced by cytotoxic T lymphocytes and NK cells. In order to study cellular cytotoxicity in the pathogenesis of these diseases, we analyzed 29 samples of OLP, 16 of CLP and 6 of LDE. The sections were stained for H&E and immunohistochemically targeted with CD4, CD8, HAM 56, MAC387, granzyme B, perforin and ICAM-1. OLP specimens exhibited higher density of cytotoxic granules (perforin and granzyme B) when compared with CLP. In both groups of diseases, the greater the number of perforin+ cells, the greater was the number of granzyme B+ cells. Increased number of CD4+ cells was found in active lesions as compared with the regressive ones in OLP but not in the CLP. The comparison between CLP and LDE revealed that the greater the number of CD8+ cells, the greater the number of cells expressing perforin in CLP group. The higher were the values of granzyme B, the higher the perforin values in the CLP group; the higher were the values of granzyme B, the higher the number of clusters of apoptotic cells in the LDE group. Within CLP group, the higher were the values of T cells, the greater the number of HAM56+ macrophages and vice versa. In LDE samples, negative correlation was found between the number of T cells and young histiocytes (MAC 387+). There was a positive correlation between the number of T cells and CD8 cells in LDE group, but not in CLP group. Concluding, increased expression of cytotoxic granules in OLP may be associated with greater mucosa severity. The results favor a greater role of granzyme B and CD8+ lymphocytes in the pathogenic mechanism of LDE, when compared with perforin, of greater importance in CLP. It is possible that the action of granzyme B is connected to the abundant number of clusters found in LDE. Although CLP and LDE present clinical and histological similarities, the etiopathogenesis appears to be distinct / Doutorado / Anatomia Patologica / Doutora em Ciências Médicas

No description available.

INTRODUÇÃO: O conhecimento sobre os tipos celulares envolvidos na patogenia da urticária constitui um elemento essencial para a compreensão da fisiopatologia desta doença. Poucos autores têm dado atenção às interações entre mastócitos e dendrócitos da derme na urticária. Os objetivos deste estudo são orientados no sentido de descreverem-se os tipos de degranulação mastocitária na urticária aguda associada a medicamentos, e o de analisarem-se as interações entre dendrócitos da derme e mastócitos. MÉTODOS: Sete doentes com urticária aguda associada com medicamentos foram incluídos neste estudo. Foram obtidas biopsias cutâneas das lesões urticadas e da pele aparentemente normal destes doentes. Os quatorze fragmentos coletados foram divididos em duas partes (28 fragmentos): uma das partes foi enviada para processamento pela coloração de hematoxilina-eosina, para a coloração de Azul de Toluidina e reações de imunoistoquímica com anticorpos anti-CD34, antifator XIIIA (anti- FXIIIa) e antitriptase e o outro fragmento foi processado para uso na microscopia imunoeletrônica, utilizando-se anticorpos para triptase e FXIIIa, além de dupla imunomarcação com ouro com o uso de anticorpos antitriptase e anti-FXIIIa. RESULTADOS: células imunomarcadas com anticorpos anti-CD34 foram observadas de forma esparsa na derme superficial e de forma mais proeminente na derme reticular. Havia múltiplos dendrócitos dérmicos FXIIIa+ na derme superficial e média, dispersos nas regiões subepidérmicas e em torno doa vasos da derme, tanto na pele urticada com na pele aparentemente normal. O número destas células foi similar nos dois grupos de amostras. Não houve diferença estatística entre o número de células triptase-positivas na pele aparentemente normal e na pele urticada, em todos os doentes. Nós observamos mastócitos íntegros na maioria das amostras da pele aparentemente normal. Tanto as amostras de pele aparentemente normal quanto as amostras de pele urticada apresentavam mastócitos em processo de degranulação do tipo anafilático, com inúmeros grânulos extruídos. Após a dupla imunomarcação com ouro, na imuno-microscopia eletrônica de transmissão foram observadas partículas de ouro de 10 nm (FXIIIa) e 15 nm (Triptase) marcando concomitante os grânulos dos mastócitos indicando que tanto a triptase como o FXIIIa encontraram-se presentes nos grânulos destas células. De forma interessante, nós encontramos uma forte evidência de que grânulos contendo tanto FXIIIa, como triptase, extruídos dos mastócitos são fagocitados pelos dendrócitos da derme. CONCLUSÕES: na urticária aguda associada a medicamentos o padrão de degranulação observado foi do tipo anafilático. Este estudo constitui a primeira demonstração da expressão do FXIIIa nos grânulos intracitoplasmáticos e nos grânulos extruídos dos mastócitos, dispersos na matriz extracelular, nos doentes com urticária aguda associada a medicamentos. Outro fato inédito foi a demonstração da fagocitose dos grânulos extruídos dos mastócitos pelos dendrócitos da derme FXIIIa+ / BACKGROUND: The knowledge about the cell types involved in urticaria is an essential element for understanding the pathophysiology of this disease. Few authors have been attempting on interactions among mast cells and dermal dendrocytes in urticaria. The aims of this study are to describe the types of mast cell degranulation in drug-induced acute, besides to analyze the interactions between mast cell and dermal dendrocyte in urticaria. METHODS: Seven patients with drug-induced acute urticaria were enrolled in the study. We token skin biopsies of urticarial lesion and apparently normal skin. The fourteen fragments collected were divided into two parts (28 sections): one to haematoxylin-eosin stain, Toluidine blue stain and immunohistochemisty reactions with anti-CD34, anti-FXIIIa and anti-tryptase antibodies and other part to immunogold electron microscopy using single antibodies to tryptase and FXIIIa, besides double immunogold labelling with anti-tryptase and anti-FXIIIa. RESULTS: immunolabelled CD34+ cells were observed scattered in the superficial dermis and more prominent in the reticular dermis. There were multiple FXIIIa+ dermal dendrocytes in upper and mid dermis, dispersed in subepidermal areas and around blood vessels, both in apparently normal skin and urticarial lesion of drug-induced acute urticaria. The number of these cells was similar in both groups. There was no difference in tryptase positive cells number between apparently normal skin and urticarial lesions, in all patients. We observed intact mast cells in the majority of the sections of the apparently normal skin. Some sections demonstrated a few mast cells in degranulation process, in anaphylactic degranulation type. In urticarial lesions, several mast cells showed degranulation process, in anaphylactic degranulation type. After double immunogold staining, 10 nm (FXIIIa) and 15 nm (Tryptase) gold particles were seen together over the granules in mast cells indicating that tryptase and FXIIIa are each localized into granules of these cells. Interestingly, we found a strong evidence of than the exocytosed mast cell granules contents both FXIIIa and Tryptase immunolabelled are phagocytised by dermal dendrocytes. CONCLUSIONS: In drug-induced acute urticaria the degranulation pattern of mast cells found was composed by anaphylatic. This is the first report, in acute urtuicaria, concern of the expression of FXIIIa in the cytoplasmic mast cell and in extruded granules into extracellular matrix. Phagocytosis of the extruded mast cell granules by FXIIIa+ dermal dendrocytes in urticaria was observed

Comprehension of eruptive histories is critical in understanding the evolution of magmatic systems at arc volcanoes and may supply evidence to the petrogenesis of intermediate and evolved magmas. Within the 300 ka eruptive history of Mount St. Helens, Washington, the Kalama Eruptive Period, 1479- ~1750 CE was bracketed by interludes of quiescence (Hoblitt et al., 1980) and thus likely represents an entire eruptive cycle within a span of 300 years. Study of the magmatic evolution during this short time period provides key information regarding inputs and the plumbing system of Mount St. Helens. This research aims to enhance comprehension of processes leading to the petrogenesis of intermediate magmas by providing whole rock and phase geochemical data of an eruptive cycle, thereby providing constraints on the magmatic evolution of the Kalama Eruptive Period. The eruptive sequence is divided into early, middle and late subperiods. The early Kalama began with two dacitic plinian eruptions and continued with smaller eruptions of dacite domes (64.4-66.5 wt% SiO₂) that included quenched mafic inclusions (53.7-57.7 wt% SiO₂). The middle Kalama signified the onset of basaltic andesite and andesite eruptions ranging between 55.5-58.5 wt % SiO₂. Subsequently, summit domes that began as felsic andesite (61-62.5 wt% SiO₂) and transitioned to dacite (62.5-64.6 wt% SiO₂) dominated the late Kalama. Previous work on Kalama-aged rocks suggests magma mixing is an integral process in their production. Compositions and textures of crystal phases, in addition to the presence of xenocrysts in middle and late Kalama rocks, confirm mechanical mixing of magmas likely produced many of the sampled compositions. New petrographic observations were integrated with new whole rock and phase EMP and LA-ICP-MS data and the known stratigraphy in order to constrain the magmatic and crustal components active during the Kalama Eruptive Period. New findings include: 1. Two populations of quenched mafic inclusions, one olivine-rich and one olivine-poor, are identified from the early Kalama based on mineralogy, textures, and major and trace element chemistry. Major element modeling shows crustal anatexis of plutonic inclusions found in early Kalama dacites could produce the felsic magma source of the olivine-poor population. The olivine-rich population incorporated cumulate material. 2. Four distinct lava populations erupted during the early part of the middle Kalama (X lavas), including two found exclusively in lahar deposits: M-type lahars are the most mafic, B-type lahars are more mixed, the Two Finger Flow was previously grouped with other middle Kalama-age lavas, and the X lava (in situ) has unique geochemical and textural character. X tephras likely correlate with the lavas. 3. There were at least three mafic source contributions at Mount St. Helens during the eruptive period: the parent to the X deposits, the cumulate material in the olivine-rich QMIs, and the calc-alkaline parent to the MKLV and SDO. The magma reservoir at Mount St. Helens has been modeled as a single, elongate chamber (Pallister et al., 1992). Multiple coeval basaltic or basaltic andesite parents fluxing into the magmatic system beneath the volcano could indicate a more complex magma chamber structure. / Graduation date: 2011

Ce travail de thèse est consacré à la problématique de l'extraction de signaux dans le domaine des sciences de l'atmosphère. Le point commun des problèmes considérés est la notion de détection et d'estimation de signaux cachés. L'approche par la modélisation probabiliste s'est avérée y être bien adaptée. Nous nous sommes attachés à répondre à différentes questions telles que : quel type d'information s'attend-on à trouver dans un jeu de données ? Le signal supposé caché se trouve-t-il réellement dans les données d'étude ? Comment détecter l'instant d'occurrence d'un phénomène, comment le caractériser (timing, amplitude ...) ? Si un tel signal est détecté, quelle (in)certitude est associée à cette détection ? Nous répondons à ces différentes questions au travers du développement de différents modèles probabilistes de détection d'évènements cachés. Nous nous sommes intéressés à différents modèles non stationnaires, dont deux sont notamment présentés dans un cadre multivarié. Au travers de trois modèles probabilistes décrivant des signaux cachés divers (rupture de variance, signaux éruptifs et changement de moyenne), nous avons aussi développé des méthodes associées de détection. Le premier modèle est appliqué à la détection de nuages stratosphériques polaires dans des profils lidar, le deuxième à des éruptions volcaniques dans des séries chronologiques de sulfate et enfin le troisième est appliqué à la détection de la date de l'onset de la mousson Africaine dans des données géophysiques liées à la dynamique atmosphérique et aux précipitations. Les différentes méthodes mises en place font appel à une variété de techniques de modélisation probabiliste allant de la maximisation de rapport de vraisemblance associée à des tests d'hypothèses à la résolution de filtres de Kalman dans un cadre non stationnaire et non linéaire pour la décomposition de séries multivariées couplée à la détection des signaux cachés. Les difficultés techniques liées à l'extraction de signaux cachés sont analysées et les performances des différents algorithmes sont évaluées. Les résultats obtenus confirment l'intérêt des méthodes probabilistes appliquées à ces problématiques de signaux cachés en sciences de l'atmosphère.

Nous étudions d'abord l'influence du mode annulaire Sud (SAM) sur la circulation méridienne de retournement Atlantique (AMOC) dans une simulation de contrôle avec IPSLCM4. Une phase positive du SAM, correspondant à une intensification des vents d'Ouest soufflant au Sud de 45° S, entraîne après 8 ans une accélération de l'AMOC, via une téléconnection atmosphérique peu réaliste. Une accélération de l'AMOC suit de 70 ans une phase positive du SAM, due à la propagation d'anomalies de sel du Sud vers le Nord de l'Atlantique. Ensuite, nous étudions dans quelle mesure l'Oscillation Multidécennale Atlantique (AMO) reflète les fluctuations de l'AMOC. Nous utilisons un filtre basé sur un modèle linéaire inverse (LIM) pour décomposer la température de surface de l'océan (SST) Atlantique Nord en une partie liée à la dérive globale, une à El Nino (ENSO), une à la variabilité de basse fréquence du Pacifique, et un résidu. Dans la simulation historique de IPSLCM5, enlever la dérive globale de l'AMO avec LIM induit de meilleures corrélations avec l'AMOC que lorsque ce signal est soustrait par une dérive linéaire. Enlever l'influence de ENSO de l'AMO améliore très légérement ses corrélations avec l'AMOC, tandis qu'enlever la variabilité de basse fréquence du Pacifique les dégrade. La robustesse de ces résultats est vérifiée dans des simulations de contrôle avec 5 modèles. Cette déconstruction de l'AMO est aussi effectuée dans les observations. Enfin, l'impact du forçage volcanique sur les liens AMO-AMOC est étudié dans une simulation du dernier millénaire avec IPSLCM4.

INTRODUÇÃO: O conhecimento sobre os tipos celulares envolvidos na patogenia da urticária constitui um elemento essencial para a compreensão da fisiopatologia desta doença. Poucos autores têm dado atenção às interações entre mastócitos e dendrócitos da derme na urticária. Os objetivos deste estudo são orientados no sentido de descreverem-se os tipos de degranulação mastocitária na urticária aguda associada a medicamentos, e o de analisarem-se as interações entre dendrócitos da derme e mastócitos. MÉTODOS: Sete doentes com urticária aguda associada com medicamentos foram incluídos neste estudo. Foram obtidas biopsias cutâneas das lesões urticadas e da pele aparentemente normal destes doentes. Os quatorze fragmentos coletados foram divididos em duas partes (28 fragmentos): uma das partes foi enviada para processamento pela coloração de hematoxilina-eosina, para a coloração de Azul de Toluidina e reações de imunoistoquímica com anticorpos anti-CD34, antifator XIIIA (anti- FXIIIa) e antitriptase e o outro fragmento foi processado para uso na microscopia imunoeletrônica, utilizando-se anticorpos para triptase e FXIIIa, além de dupla imunomarcação com ouro com o uso de anticorpos antitriptase e anti-FXIIIa. RESULTADOS: células imunomarcadas com anticorpos anti-CD34 foram observadas de forma esparsa na derme superficial e de forma mais proeminente na derme reticular. Havia múltiplos dendrócitos dérmicos FXIIIa+ na derme superficial e média, dispersos nas regiões subepidérmicas e em torno doa vasos da derme, tanto na pele urticada com na pele aparentemente normal. O número destas células foi similar nos dois grupos de amostras. Não houve diferença estatística entre o número de células triptase-positivas na pele aparentemente normal e na pele urticada, em todos os doentes. Nós observamos mastócitos íntegros na maioria das amostras da pele aparentemente normal. Tanto as amostras de pele aparentemente normal quanto as amostras de pele urticada apresentavam mastócitos em processo de degranulação do tipo anafilático, com inúmeros grânulos extruídos. Após a dupla imunomarcação com ouro, na imuno-microscopia eletrônica de transmissão foram observadas partículas de ouro de 10 nm (FXIIIa) e 15 nm (Triptase) marcando concomitante os grânulos dos mastócitos indicando que tanto a triptase como o FXIIIa encontraram-se presentes nos grânulos destas células. De forma interessante, nós encontramos uma forte evidência de que grânulos contendo tanto FXIIIa, como triptase, extruídos dos mastócitos são fagocitados pelos dendrócitos da derme. CONCLUSÕES: na urticária aguda associada a medicamentos o padrão de degranulação observado foi do tipo anafilático. Este estudo constitui a primeira demonstração da expressão do FXIIIa nos grânulos intracitoplasmáticos e nos grânulos extruídos dos mastócitos, dispersos na matriz extracelular, nos doentes com urticária aguda associada a medicamentos. Outro fato inédito foi a demonstração da fagocitose dos grânulos extruídos dos mastócitos pelos dendrócitos da derme FXIIIa+ / BACKGROUND: The knowledge about the cell types involved in urticaria is an essential element for understanding the pathophysiology of this disease. Few authors have been attempting on interactions among mast cells and dermal dendrocytes in urticaria. The aims of this study are to describe the types of mast cell degranulation in drug-induced acute, besides to analyze the interactions between mast cell and dermal dendrocyte in urticaria. METHODS: Seven patients with drug-induced acute urticaria were enrolled in the study. We token skin biopsies of urticarial lesion and apparently normal skin. The fourteen fragments collected were divided into two parts (28 sections): one to haematoxylin-eosin stain, Toluidine blue stain and immunohistochemisty reactions with anti-CD34, anti-FXIIIa and anti-tryptase antibodies and other part to immunogold electron microscopy using single antibodies to tryptase and FXIIIa, besides double immunogold labelling with anti-tryptase and anti-FXIIIa. RESULTS: immunolabelled CD34+ cells were observed scattered in the superficial dermis and more prominent in the reticular dermis. There were multiple FXIIIa+ dermal dendrocytes in upper and mid dermis, dispersed in subepidermal areas and around blood vessels, both in apparently normal skin and urticarial lesion of drug-induced acute urticaria. The number of these cells was similar in both groups. There was no difference in tryptase positive cells number between apparently normal skin and urticarial lesions, in all patients. We observed intact mast cells in the majority of the sections of the apparently normal skin. Some sections demonstrated a few mast cells in degranulation process, in anaphylactic degranulation type. In urticarial lesions, several mast cells showed degranulation process, in anaphylactic degranulation type. After double immunogold staining, 10 nm (FXIIIa) and 15 nm (Tryptase) gold particles were seen together over the granules in mast cells indicating that tryptase and FXIIIa are each localized into granules of these cells. Interestingly, we found a strong evidence of than the exocytosed mast cell granules contents both FXIIIa and Tryptase immunolabelled are phagocytised by dermal dendrocytes. CONCLUSIONS: In drug-induced acute urticaria the degranulation pattern of mast cells found was composed by anaphylatic. This is the first report, in acute urtuicaria, concern of the expression of FXIIIa in the cytoplasmic mast cell and in extruded granules into extracellular matrix. Phagocytosis of the extruded mast cell granules by FXIIIa+ dermal dendrocytes in urticaria was observed

Surface manifestations of hydrothermal fluids such as fumaroles and hot springs provide valuable information about the level of activity of a volcano during quiescent period. Geochemical study of gas and spring waters is useful to elaborate geochemical model for magmatic-hydrothermal system. Furthermore, temporal geochemical monitoring of these fluids with time provides a better understanding in processes occurring inside the volcano and can be useful to detect any changes in the activity of the magmatic-hydrothermal system. This thesis investigates two hydrothermal systems at Kelud and Papandayan volcanoes that are located at Java Island in Indonesia. Kelud is considered as one of the most dangerous volcanoes of Java because of its frequent eruptions. After the last eruption that occurred in 1990, a new lake rapidly filled the crater of Kelud volcano. Water samples collected since 1993 are near neutral Na-K chloride fluids and are typical of aged hydrothermal system where the acidity has been completely neutralized by fluid-rock interaction and where the emission of acid magmatic gases has stopped. Two sudden increases in lake temperature in 1996 and 2001 were accompanied by rapid changes in lake water compositions and suggest the existence of two hydrothermal systems feeding the lake: a shallow hydrothermal system dominated by Ca-Mg sulfate waters and a deepest aquifer with neutral alkali chloride waters. From 2001 to 2005, measurements of CO2 emitted by the surface of the lake were performed by using the accumulation chamber method modified in order to work at the surface of a crater lake. Two statistical methods were used to process data: the graphical statistical and stochastic simulation methods. The results of graphical statistical approach showed that two different degassing processes are acting at the lake surface: one corresponding to CO2 fluxes resulting from rising bubbles and the other corresponding to equilibrium diffusion of dissolved CO2 at the water-air surface. Total CO2 emission rate estimated by stochastic simulation ranges from 105 t/day for 2001 to 32 t/day for 2005. Thermal energy released by the lake was also estimated by using an energy balance model with a new constraint using the CO2 flux. The thermal flux decreased from 200 MW (2001) to 100 MW (2002) and then remained stable. Correlation between the chemical data of waters, the fluxes of CO2 and energy show that a constant decrease in the level of activity of the volcano since 1993 occurred although the lake temperature has been stable since 2003. Since the last magmatic eruption that occurred in 1772, phreatic eruptions occur on Papandayan volcano with the last one in 2002. The volcanic material ejected during this eruption is essentially made of altered rocks from within the hydrothermal system. The interaction of acid waters with the host rocks corresponds to an advanced argilic alteration. The chemical compositions of waters from Papandayan volcano and Kelud lake waters are contrasting. Indeed, the spring waters sampled since 1994 are acid sulfate-chloride waters and acid sulfate waters. The chemical and isotopic analyses of gases and waters suggest a significant magmatic contribution in SO2, HCl and HF to the hydrothermal system. The chemical composition of waters sampled after the 2002 eruption have provided information about origin of this eruption. Decrease in chloride concentration and in delta 34S of dissolved sulfates showed that the magmatic contribution in these fluids are less important and that the waters are likely to be formed by the condensation of steam (H2O, H2S) rising from a boiling aquifer.