Submitted by Silvania Ribas (silvania@mackenzie.br) on 2018-04-12T14:13:35Z No. of bitstreams: 1 FABIANO AUGUSTO AKIYAMA SHIMABUKU.pdf: 1697720 bytes, checksum: 3ec8bcbac35f2f51487d244d8a64124f (MD5) / Rejected by Paola Damato (repositorio@mackenzie.br), reason: Assuntos em caixa alta on 2018-04-28T16:27:20Z (GMT) / Submitted by Silvania Ribas (silvania@mackenzie.br) on 2018-05-02T17:47:24Z No. of bitstreams: 1 FABIANO AUGUSTO AKIYAMA SHIMABUKU.pdf: 1697720 bytes, checksum: 3ec8bcbac35f2f51487d244d8a64124f (MD5) / Rejected by Paola Damato (repositorio@mackenzie.br), reason: No título, "operação lava-jato": é um nome próprio então cx alta as primeiras letras Nos assuntos com exceção desse que é cx alta o resto dos assuntos cx baixa on 2018-05-04T14:27:44Z (GMT) / Submitted by Silvania Ribas (silvania@mackenzie.br) on 2018-05-30T15:09:26Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIANO AUGUSTO AKIYAMA SHIMABUKU.pdf: 1697720 bytes, checksum: 3ec8bcbac35f2f51487d244d8a64124f (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-06-08T20:53:33Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIANO AUGUSTO AKIYAMA SHIMABUKU.pdf: 1697720 bytes, checksum: 3ec8bcbac35f2f51487d244d8a64124f (MD5) / Made available in DSpace on 2018-06-08T20:53:33Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) FABIANO AUGUSTO AKIYAMA SHIMABUKU.pdf: 1697720 bytes, checksum: 3ec8bcbac35f2f51487d244d8a64124f (MD5) Previous issue date: 2017-08-10 / This study had as objective identifying how corruption cases, investigated by Operação Lava Jato, have impacted Petrobras’ sustainability, based on assessment of financial and sustainability reports and based on assessment of its stock prices. The analysis period was 2011 to 2016, according to the available reports (financial statements and sustainability reports (Global Reporting Initiative – GRIE)). The analysis procedures have used qualitative and quantitative methods. The qualitative research has analised deeply performance of the main methods to fight corruption according to the global research made by Association of Certified Fraud Examiners (ACFE): Complaint Channel, Internal Controls, Internal Audit and External Audit. The quantitative research has made an study of event over the change of Petrobras stock prices as from the homologation of Paulo Roberto da Costa awarding delation, former company’s director – operational beginning of Operação Lava Jato. The main results have evidenced that: i) fraud activity last over ten years when Operação Lava Jato began; ii) antifraud procedures, internally and externally, were ineffective; iii) change of Petrobras stocks were impacted by elections running on the same period of Operação Lava Jato; iv) antifraud effective measures only were implemented after Operação Lava Jato; v) Petrobras has reduced its financial position and its investments on social and environmental areas. / Este estudo teve como objetivo identificar como os casos de corrupção, investigados no âmbito da Operação Lava Jato, influenciaram a sustentabilidade da Petrobras, com base na avaliação dos relatórios financeiros e de sustentabilidade e na análise dos preços das ações da companhia. O período de análise estendeu-se de 2011 a 2016 de acordo com a disponibilidade dos relatórios utilizados [demonstrativos financeiros e relatórios de sustentabilidade (Global Reporting Initiative, o GRI)]. Os procedimentos de análise utilizaram método qualitativo e quantitativo. A pesquisa qualitativa analisou em profundidade o desempenho dos principais métodos de combate à corrupção citados em pesquisa global realizada pela Association of Certified Fraud Examiners (ACFE): Canal de Denúncias, Controles Internos, Auditoria Interna e Auditoria Externa. A parte quantitativa da pesquisa efetuou um estudo de evento sobre a variação dos preços das ações da Petrobras a partir da homologação da delação premiada de Paulo Roberto Costa, ex-diretor da empresa – marco operacional da operação Lava Jato. Os principais resultados evidenciaram que:(i) a atividade fraudulenta na empresa perdurava há mais de dez anos, quando a operação Lava Jato foi deflagrada;(ii) os procedimentos antifraudes tanto interna, quanto externamente, eram inoperantes; (iii) a variação das ações da Petrobras foram influenciadas pelos eventos eleitorais coincidentes com a deflagração da operação Lava Jato; (iv) medidas efetivas antifraude somente foram efetivadas após a operação Lava Jato; (v) efetivamente, a Petrobras reduziu seu patrimônio e investimentos tanto na área social quanto ambiental.

Magíster en Ciencias, Mención Geología / Geólogo / La mayoría de los campos volcánicos monogenéticos están constituidos principalmente por productos piroclásticos de composición basáltica. Los volúmenes emitidos por cada centro eruptivo tienden a ser pequeños, menores a 1 km3, donde su actividad puede durar días a años, mientras que el campo volcánico completo se puede desarrollar y perdurar por millones de años, pudiendo superar en volumen a un volcán poligenético. En este sentido, el Campo Volcánico Laguna del Maule (CVLdM) representa un caso excepcional con más de 350 km3 de material basáltico a riolítico, eruptado mayormente de manera efusiva desde el Pleistoceno. En este trabajo se propone un modelo volcanológico-petrológico de la dinámica eruptiva de las lavas post-glaciales emplazadas en la parte Oeste del CVLdM, analizando la evolución del magma en profundidad, el ascenso de magma por los conductos eruptivos y el emplazamiento de lavas en superficie. Se estudió la morfometría, mineralogía y química de seis lavas y un domo del CVLdM para modelar las condiciones termodinámicas pre-eruptivas del magma y su evolución, incluyendo posibles procesos magmáticos causantes de su migración y ascenso a la superficie. Las lavas analizadas tienen una composición química andesítica a riolítica, morfología de bloques, volúmenes de 0.03 a 1.16 km3, largos máximos de 10 km, anchos máximos de 5 km y espesores máximos de 140 m. Los resultados indican la presencia de un sistema magmático formado en cuatro etapas, comenzando con la acumulación de magma andesítico basáltico a andesítico debido a múltiples intrusiones. Posteriormente, procesos de cristalización desarrollaron un reservorio tipo mush cristalino (13-17 km, 970-1025 °C) con extracción y ascenso de líquido intersticial. Una tercera etapa de estancamiento del magma en ascenso proveniente de la extracción más profunda (7-11 km, 900-970 °C), permitió la formación de un nuevo mush cristalino más evolucionado. Finalmente, una nueva extracción y ascenso del líquido intersticial riolítico formó un reservorio magmático riolítico pobre en cristales (~5 km, 760-800 °C) bajo el lago. El constante recalentamiento debido a múltiples intrusiones permitó al sistema magmático permanecer activo en el largo plazo, producto de variadas intrusiones de magma máfico en el caso del reservorio profundo y magma silícico en el caso del reservorio más somero.

The emplacement of continental flood basalt provinces is often ascribed to fissure eruption. However, in many provinces the locations of actual vent complexes remains illusive. In southern Africa, the Karoo continental flood basalt province was erupted during the Jurassic between 183 and 179 Ma. The southernmost outcrop of the Karoo continental flood basalt lavas is the Lesotho remnant; and is comprised of the Drakensberg Group which forms the uppermost portion of the Karoo Supergroup. The geochemical stratigraphy for the Drakensberg Group is well established. At the base, there are a number of small volume compositionally diverse units, which form the Barkly East Formation, overlying which, there are larger volume, compositionally less variable units of the Lesotho Formation, which form the bulk of the volcanic sequence. The Lesotho remnant is associated with an abundance of dykes in the adjacent vicinity. This suggests that the lavas were fed from local rather than distal eruption sites. This study presents whole rock major and trace element data for 94 dykes and three sills from the northern Lesotho - northeastern Free State region and demonstrates that on the basis of geochemistry, all 97 intrusions can be correlated with various units of the northern Barkly East and Lesotho Formations. In addition, the petrographical; characteristics, orientation and distribution of the dykes do not correlate with geochemistry. Geochemical discrimination diagrams have been used to identify five compositionally diverse dykes, which are similar to the northern Barkly East Formation units. Three dykes are characteristic of the Letele unit and two are compositionally similar to the Wonderkop unit. Although the geochemical characteristics of the Lesotho Formation units are rather well constrained, the composition of these units is typified by considerable overlap in composition. Therefore, since unambiguous classification of dykes with geochemical similarities to the various units of the Lesotho Formation is unachievable using an empirical approach, the multivariate forward-stepwise discriminant function analysis (DFA) technique was used to facilitate the classification of the remaining 89 dykes and three sills. Forward-stepwise DFA classified 23 dykes as having compositional similarities to the Mafika Lisiu unit, 29 as having compositions of the Maloti or Senqu types; and 32 as having the composition of the Mothae type. In addition, eight dykes are compositionally similar to the Oxbow dykes, which intrude the Senqu unit in northern Lesotho. These results suggest that that the Lesotho remnant was fed from local eruption sites and that long distance magma transport for the bulk of the Lesotho remnant basalt lavas is unlikely.

The 7.7 Ma Kimberly Member of the Cassia Formation is part of a succession of A-type rhyolites associated with the Yellowstone hotspot track. It was sampled by the Kimberly core that was drilled on the Snake River Plain as part of Project HOTSPOT (Shervais, et al., 2013). The Kimberly Member is a 170 m thick high-silica rhyolite lava flow containing quartz, plagioclase, anorthoclase, sanidine, augite, pigeonite, magnetite, ilmenite, zircon, and apatite. δ 18O of zircon ranges from 0 to 4.9‰ (Colón et al., 2018), typical low values for the Snake River Plain. Quartz is intensely embayed. Exsolved and resorbed pigeonite cores are mantled by augite. REE-poor apatite cores are resorbed and oscillatory zones truncated by rims with SiO2 as high as 12.8 wt% and LREEtot up to 4.7%. There are three chemically distinct feldspars. Rounded and pitted anorthoclase (Or21 Ab64 An15) mantles plagioclase (An20 to An40) cores. Sanidine (Or47 Ab48 An05) forms thin, subhedral drapes on the outer edges of anorthoclase. Sanidine also fills some of the sieved holes in plagioclase and anorthoclase. There are two chemically distinct glasses, a light glass (~95%) and a dark glass (~5%). Relative to the light glass, the dark is enriched in Al2O3 , CaO, and Na2O and depleted in Fe2O3 and K2O. The dark glass is depleted in Rb and enriched in Sr and Ba, but they have similar concentrations of the high field strength elements (Y, Zr, Nb, Hf, and Ta). LREE are slightly more enriched in the dark glass than in the light glass. Temperatures of 926°C (magnetite-ilmenite thermometry with QUILF), 894°C (pigeonite-augite pairs with QUILF), and 889°C (zircon-saturation) are calculated for the magma. Although Fe-Ti oxides appear to have equilibrated with melt before eruption, most of the other phases preserve strong evidence of disequilibrium. These complex mineral textures also indicate assimilation and mixing processes. We propose a pigeonite-bearing, dry, metasomatized, A-type granite was fragmented and assimilated by the Kimberly member, mantling exsolved pigeonite with augite. Also incorporated into the Kimberly member were volcanic xenocrysts indicative of rhyolite assimilation or magma mixing. These components are embayed volcanic quartz, and composite plagioclase-anorthoclase grains (mantled by sanidine upon assimilation). Complex zircon grains could be sourced from metasomatized rhyolite or intrusion, and complex apatite grains could be due to mixing or assimilation. We propose the distinct glass types are caused by mingling of the Kimberly magma with the melted metasomatized assimilant. This scenario demonstrates the complexity of open system processes involved in some Snake River Plain magmas.

A Pleistocene lava tube cave in southeast Oregon has a seasonally fluctuating lake occupying the last 1200 to 2000 feet. Three endemic invertebrate species inhabit the lake: Kenkia rynchida Hyman; Asellus sp.; and stygobromus hubbsi. Shoemaker. Little is known however, about their environment. The purpose of this study was to describe various physical and chemical parameters of Malheur Cave Lake.

Information provided by previous workers shows a considerable diversification of lava types in the early Tertiary deposits of the Kettle River region of British Columbia. The aim of the present study is to establish, on the basis of mineralogical and chemical evidence, whether or not these lavas form a single magma series. A suitable spectrochemical technique was adapted for the determination of Sr, Ba, CaO, MgO, and FeO in rock samples and mineral extracts. A method based on the work of Shaw and Filby, using lanthanum as an internal standard for determination of Sr, Ba, and Ca, is extended to include the determination of MgO and FeO. Extension of the available chemical data was possible using a fused glass bead technique for refractive index determination of the lavas. In view of good correlation between refractive index and the most refractory constituents of the lavas CaO, MgO, and FeO, the refractive index serves as a good magmatic differentiation index. Examination of the refractive indices of three suites of samples, taken from widely separated points within the Kettle River region, shows that the lavas range from semi-basic to acid composition with intermediate types, andesites and trachyandesites, predominating. There is a marked paucity of basaltic rocks. The stratigraphic distribution of the lavas reveals no consistant trends toward either acid or basic compositions; neither is there any relation between stratigraphic position and lava types within the region concerned. In spite of close age and spatial association of the lavas, petrological evidence points to a three-fold division of these rocks (termed 'A', 'B' , and 'C' series). 'A' series is similar to the silica-enrichment 'calc-alkali' trend showing regular mineral and chemical progression from andesites to latite and rhyolite. 'B' series is characterized by a somewhat less well defined group of two-feldspar lavas, trachyandesites, and trachytes. An unusual undersaturated lava, termed 'analcite rhomb-porphyry' or 'shackanite' is thought to be genetically related to 'B' series but probably belongs to a poorly developed semi-basic alkali trend, 'C' series. A mechanism involving crystal fractionation of hornblende, or alternately, augite and plagioclase, is envisaged as the probable mode of origin for many of the rocks of 'A' series. On the other hand, Daly's view that the shackanite lavas were formed as a result of limestone assimilation is supported by field evidence as well as mineral and chemical data. The rocks of 'B' series, the trachyandesites and trachytes, are intermediate in composition to 'A' and 'C' series and have probably formed by process of crystal fractionation in consequence of normal cooling conditions and limestone assimilation. / Thesis / Master of Science (MSc)

Volcanic eruptions pose hazards to life and insfrastructure, and contribute to the resurfacing of earth and other planetary bodies. Lavas and magmas are multi-phase suspensions of silicate melts (liquids), solid crystals, and vapor bubbles, and solidify into glass and rock upon cooling. The interactions between phases place important controls on the dynamics and timescales of magma and lava transport and emplacement. The purpose of this thesis is to explore the role of multiphase interactions in controlling eruption dynamics and inform conceptual and numerical models for hazard prediction. In Chapters 1 and 2, centimeter to meter scale analog experiments are used to explore the multi-phase rheological properties and flow behaviors of bubble- and particle-bearing suspensions. Optical imaging of dam-break experiments presented in Chapter 1 expand existing experimental parameter ranges for lava analogs to higher bubble concentrations than existing datasets (up to 82% by volume bubbles and 37% by volume particles). I develop a constitutive relationship for threephase relative viscosity, and demonstrate that at the low strain-rate conditions relevant to many natural lava flows, accounting for the rheological effect of bubbles can result in the prediction of slower runout speeds. Chapter 2 expands upon the work of Chapter 1 using different analog materials observed using nuclear magnetic resonance imaging (MRI) phase-contrast velocimetry (PCV) to measure velocity in the flow interior of three-phase dam-break experiments. I find that for high-aspect ratio particles (sesame seeds), phase segregation into shear bands readily occurs, even at low particle fraction (20%) and results in strain localization. I suggest that the presence of shear bands can lead to faster flow runout than predicted using assumptions of bulk rheology. Chapter 3 analyzes thermal infrared (IR) time-lapse photography and videography of Hawaiian to Strombolian explosive activity during the 2021 eruption of Cumbre Vieja volcano, La Palma, Canary Islands, Spain. Images are analyzed to find time series of apparent plume radius, velocity, and apparent volume flux of high-temperature gas and lava. I compare with other measures of eruptive activity, including remote observations of plume height, SO₂ flux, effusive flux, tremor, and events at the volcano edifice including edifice collapses and the opening of new vents. I find correlations between tremor and explosive flux, but no correlation with SO2 flux or effusive flux, which I interpret as evidence of bubble segregation, highlighting the role of phase segregation and temporal variability in material properties in natural systems. Finally, in Chapter 4, I develop a novel finite element model to explore the interaction between a viscous flow with a solidified crust, and the effect of these interactions on lava flow and lava dome emplacement. I develop a model that couples a temperature-dependent viscous interior with an elastic shell flowing into air, water, or dense atmospheres. The model expands upon existing numerical simulations used in volcanology to have direct applications to lava flows and domes on the sea floor, which accounts for a large portion of the volcanism on Earth, and volcanism on other planetary bodies. Additionally, the formation of levees or solidified flow fronts that fracture and lead to a restart of flow. These lava flow breakouts pose a significant hazard, but there are currently no volcanological community codes capable of using a physics-based approach to predict the timing or location of breakouts. The model in Chapter 4 is the first to allow for assessment of the likelihood of failure at the scale of a flow lobe. Chapter 4 describes the model formulation and verification, and validation against centimeter-scale molten basalt experiments. The dissertation as a whole integrates work using a variety of methods including analog experiments, observations of natural eruptions, and numerical simulations to contribute to our understanding of the effects of multi-phase interactions on volcanic eruptions.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2019-03-11T12:11:51Z No. of bitstreams: 1 Bernardo Leandro Carvalho Costa_.pdf: 1049393 bytes, checksum: b0299852175bedb17c52e68f4898787d (MD5) / Made available in DSpace on 2019-03-11T12:11:51Z (GMT). No. of bitstreams: 1 Bernardo Leandro Carvalho Costa_.pdf: 1049393 bytes, checksum: b0299852175bedb17c52e68f4898787d (MD5) Previous issue date: 2018-11-20 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / La présente recherche se propose d’opposer différentes perspectives d’observation du constitutionnalisme. Il s'appuie sur une démonstration des conceptions traditionnelles de la Constitution, élaborées au coeur d'un modèle étatique libéral et non intervenant, afin de mettre en évidence les faiblesses de cette construction théorique liée à la description des éléments constitutifs d'un État relativisés dans le contexte de la globalisation. À partir des preuves de cette limitation dans une perspective de société mondiale, dans laquelle la circulation des lois entre différents pays est évidente, on tentera de démontrer la pertinence des études de sociologie des Constitutions pour la vérification de nouveaux problèmes de droit constitutionnel au niveau mondial, que ce soit dans le cadre de la coordination entre les tribunaux et la législation à différents niveaux ou dans la réglementation autonome du secteur privé. En tant que bon exemple de thème mondial, le blanchiment d’argent sera mis en évidence, en mettant l’accent sur la gouvernance mondiale du Groupe international d’action financière, en collaboration avec plusieurs pays. Après avoir démontré différentes ramifications des propositions de la sociologie des constitutions, une analyse quantitative des décisions de mérite sera demandée concernant le degré de recours en matière de blanchiment d’argent dans le cadre de l'opération Lava Jato, afin de vérifier s'il existe, dans ce cas, un intérêt mondial, mention de lois de droit international intériorisées par le système juridique brésilien. S'il existe une référence significative dans les arrêts analysés, nous tenterons de démontrer en quoi ces données peuvent prouver l'évolution des Constitutions transnationales dans des problèmes de nature globale, ce qui met en évidence la nécessité d'une articulation par les tribunaux entre les normes nationales et internationales de la résolution. Problèmes communs entre différents pays. / O presente trabalho pretende contrastar diferentes perspectivas de observação do constitucionalismo. Parte-se de uma demonstração das tradicionais concepções de Constituição, elaboradas no cerne de um modelo de Estado liberal e não interventor, para evidenciar as insuficiências dessa construção teórica vinculada à descrição de elementos constitutivos de um Estado, que são relativizadas no contexto da globalização. A partir da evidência dessa limitação em uma perspectiva de sociedade mundial, em que a circulação de normas entre diferentes países e evidente, buscar-se-á demonstrar a relevância dos estudos em Sociologia das Constituições para a constatação de novos problemas do Direito Constitucional que estão alçados a nível global, seja no âmbito de articulação entre tribunais e legislação de diferentes níveis ou na regulação autônoma do setor privado. Como um grande exemplo de tema de natureza global será demonstrado o da lavagem de dinheiro, destacando-se a atuação de uma governança global do Grupo de Ação Financeira Internacional, em união com diversos países, no seu combate. Uma vez demonstradas diferentes ramificações das propostas da Sociologia das Constituições, buscar-se-á fazer uma análise quantitativa de decisões de mérito em grau recursal envolvendo lavagem de dinheiro na Operação Lava Jato, com o intuito de verificar se há, nesse caso de interesse mundial, menção a normas de direito internacional que foram internalizadas pelo ordenamento jurídico brasileiro. Em havendo referência significativa nos acórdãos analisados, buscar-se-á demonstrar como esses dados podem comprovar a evolução de Constituições Transnacionais em problemas de natureza global, que evidenciam a necessidade de articulação, pelos tribunais, entre normas de direito nacional e internacional, na resolução de problemas comuns entre diferentes países.

Submitted by Andrei Francalacci de Castro Faria (andrei.francalacci@bndes.gov.br) on 2016-06-07T19:21:30Z No. of bitstreams: 1 Dissertação Andrei Francalacci.pdf: 2215041 bytes, checksum: 671600e92ce454211d0c6493c0ba75bc (MD5) / Approved for entry into archive by GILSON ROCHA MIRANDA (gilson.miranda@fgv.br) on 2016-06-10T12:18:57Z (GMT) No. of bitstreams: 1 Dissertação Andrei Francalacci.pdf: 2215041 bytes, checksum: 671600e92ce454211d0c6493c0ba75bc (MD5) / Approved for entry into archive by GILSON ROCHA MIRANDA (gilson.miranda@fgv.br) on 2016-06-20T16:21:18Z (GMT) No. of bitstreams: 1 Dissertação Andrei Francalacci.pdf: 2215041 bytes, checksum: 671600e92ce454211d0c6493c0ba75bc (MD5) / Made available in DSpace on 2016-06-27T18:56:29Z (GMT). No. of bitstreams: 1 Dissertação Andrei Francalacci.pdf: 2215041 bytes, checksum: 671600e92ce454211d0c6493c0ba75bc (MD5) Previous issue date: 2016-05-31 / We studied the effects on Petrobras shares arising from the presentation of the earnings announcements of 2014´s third and fourth quarter, the first announcements made after the beginning of the corruption investigation called Operação Lava Jato. We evaluate the impact on prices of the company's stocks with an Event Study. As a control, we analyzed the effects of the disclosure of 1,152 quarterly earnings announcements on other 48 stocks that are part of the IBOVESPA´s theoretical portfolio in the period between 2010 and 2015. We seek to identify the presence of abnormal returns and verify that all information is automatically transferred to prices, suggesting the semi-strong efficiency of the Brazilian stock market in accordance with the Market Efficiency Hypothesis (EMH) developed by Fama (1970). At the end we compare the results of the two specific earning announcements studied with the observed results of other earnings announcements of Petrobras. No evidence was found of market efficiency during the 2010-2015 period neither for the group of 48 stocks, NÃO_PETRO, nor for the PETRO group, formed by the two Petrobras shares. We then analyzed the results in two periods. The first, called Bonanza (2010-2013), showed the same results as the 2010-2015 period, with no significant abnormal returns in the event window [0,1]. The results of the Crisis period (2014 -2015) showed that the information of the earning announcements ha a statistical significant impacted on the prices of the studied stocks. To analyzing the results of the individual earning announcements of Petrobras, we identified the need for additional information, extrapolating the scope of an event study. / Este trabalho propõe-se a estudar os efeitos sobre as ações da Petrobras decorrentes da apresentação dos balanços do terceiro e quarto trimestre de 2014, primeiros balanços apresentados após as denúncias da Operação Lava Jato. Avaliamos os impactos nos preços das ações da empresa através de um Estudo de Evento. Como controle, analisamos os efeitos da divulgação de 1.152 balanços trimestrais sobre outras 48 ações de que fazem parte da Carteira Teórica do IBOVESPA no período entre 2010 e 2015. Buscamos identificar a presença de retornos anormais e verificar se toda informação se transfere automaticamente aos preços, sugerindo a eficiência semiforte do mercado de ações brasileiro de acordo com a Hipótese de Eficiência do Mercado (HEM) desenvolvida por Fama (1970). Ao final comparamos os resultados específicos dos balanços em estudo com os resultados observados em outros balanços da própria Petrobras. Não foram encontradas evidências de eficiência de mercado durante o período 2010-2015 nem para o grupo de 48 ações, chamadas de NÃO_PETRO, nem para o grupo PETRO, formado pelas duas ações da Petrobras. Ao dividir os mesmos grupos em dois momentos, os resultados para o período batizado de Bonança (2010-2013), permanecem iguais ao do período completo, ao passo que o período chamado de Crise (2014 -2015) apresenta retornos anormais estatisticamente significativos nas janelas de eventos. Ao avaliar os retornos de balanços individuais da Petrobras, identificamos a necessidade de informações adicionais, extrapolando o escopo de um estudo de evento.

Les arythmies sont des perturbations du rythme cardiaque qui peuvent entrainer la mort subite et requièrent une meilleure compréhension pour planifier leur traitement. Dans cette thèse, nous intégrons des données structurelles et fonctionnelles à un maillage 3D tétraédrique biventriculaire. Le modèle biophysique simplifié de Mitchell-Schaeffer (MS) est utilisé pour étudier l’hétérogénéité des propriétés électrophysiologiques (EP) du tissu et leur rôle sur l’arythmogénèse. L’ablation par radiofréquence (ARF) en éliminant les activités ventriculaires anormales locales (LAVA) est un traitement potentiellement curatif pour la tachycardie ventriculaire, mais les études EP requises pour localiser les LAVA sont longues et invasives. Les LAVA se trouvent autour de cicatrices hétérogènes qui peuvent être imagées de façon non-invasive par IRM à rehaussement tardif. Nous utilisons des caractéristiques d’image dans un contexte d’apprentissage automatique avec des forêts aléatoires pour identifier des aires de tissu qui induisent des LAVA. Nous détaillons les sources d’erreur inhérentes aux données et leur intégration dans le processus d’apprentissage. Finalement, nous couplons le modèle MS avec des géométries du coeur spécifiques aux patients et nous modélisons le cathéter avec une approche par un dipôle pour générer des électrogrammes normaux et des LAVA aux endroits où ils ont été localisés en clinique. Cela améliore la prédiction de localisation du tissu induisant des LAVA obtenue par apprentissage sur l’image. Des cartes de confiance sont générées et peuvent être utilisées avant une ARF pour guider l’intervention. Les contributions de cette thèse ont conduit à des résultats et des preuves de concepts prometteurs. / Cardiac arrhythmias are heart rhythm disruptions which can lead to sudden cardiac death. They require a deeper understanding for appropriate treatment planning. In this thesis, we integrate personalized structural and functional data into a 3D tetrahedral mesh of the biventricular myocardium. Next, the Mitchell-Schaeffer (MS) simplified biophysical model is used to study the spatial heterogeneity of electrophysiological (EP) tissue properties and their role in arrhythmogenesis. Radiofrequency ablation (RFA) with the elimination of local abnormal ventricular activities (LAVA) has recently arisen as a potentially curative treatment for ventricular tachycardia but the EP studies required to locate LAVA are lengthy and invasive. LAVA are commonly found within the heterogeneous scar, which can be imaged non-invasively with 3D delayed enhanced magnetic resonance imaging (DE-MRI). We evaluate the use of advanced image features in a random forest machine learning framework to identify areas of LAVA-inducing tissue. Furthermore, we detail the dataset’s inherent error sources and their formal integration in the training process. Finally, we construct MRI-based structural patient-specific heart models and couple them with the MS model. We model a recording catheter using a dipole approach and generate distinct normal and LAVA-like electrograms at locations where they have been found in clinics. This enriches our predictions of the locations of LAVA-inducing tissue obtained through image-based learning. Confidence maps can be generated and analyzed prior to RFA to guide the intervention. These contributions have led to promising results and proofs of concepts.