54 resultados para Antithetic variates
Resumo:
Pós-graduação em Geociências e Meio Ambiente - IGCE
Resumo:
É feita uma análise da evolução dos conhecimentos sobre as coquinas-reservatório da Formação Lagoa Feia, com base em cinco publicações de geologia de desenvolvimento dos campos de Badejo, Linguado e Pampo. Trata-se de uma única acumulação, onde o controle é misto, ou seja, estrutural, estratigráfico e principalmente diagenético. Falhas antitéticas herdadas do rifteamento pós-basáltico exercem um importante papel no controle das coquinas, promovendo crescimento da seção nos blocos baixos, e servindo de conduto para a circulação de água meteórica, relacionada à discordância pós-coquina que promove dissolução e criação de porosidade secundária nas coquinas. A compreensão do modelo de acumulação do óleo é fundamental tendo em vista oportunidades para projetos de recuperação suplementar de óleo.
Caracterização estrutural do Lineamento de Piúma e sua influência na porção norte da Bacia de Campos
Resumo:
The detailed study of the Brazilian continental margin basins became possible with the advancement of geophysical tools, with emphasis on seismic reflection. Characterizing the structural and stratigraphic elements of Brazil’s marginal basins they realized that there was a relationship with structures present on the adjacent continental basement. So many works began to be made to understand this relationship and know the major factors that influenced the evolution of the continental margin. The study area of this work includes the northern portion of the Campos Basin and the continental outcropping adjacent areas, which corresponds to the northern of Rio de Janeiro state and the southern of Espirito Santo state. This area stands an important structural feature of NW-SE direction with a projection to the Campos Basin called Lineamento de Piúma. The outcropping basement rocks belongs to the Ribeira Belt which was bonded to other mobile bands forming the continent Western Gondwana during the Brasiliano Cycle, which later fragmented giving rise to the Atlantic Ocean. The opening of the ocean results on the formation of the marginal basins of Brazil. These basins have continental, transitional and marine facies. On Campos Basin the continental phase resulted on the formation of horsts and grabens bounded by synthetic and antithetic faults. Continuing rifting formed the saline lakes that deposited siliciclastic and carbonate sediments. The transitional phase resulted on thick packages consist of evaporites (halite and anhydrite) that was deposited in lagoon environment, tectonically quiet arid and semi-arid. The marine phase it deposited siliciclastic and carbonate in the Campos Basin resulting in shales, marls, limestones, ritmito, turbidites, sandstones and others. The objective of this study is to investigate the possible continuation... (Complete abstract click electronic access below)
Resumo:
The Linguado Field is located in the extreme southwest portion of Campos Basin. It’s associated with Structural Badejo High and can be divided in two groups of faults: one manly formed by antithetic faults, with NW-SE direction, continuous to Badejo Fault, and another identified by N-S faults. Besides these faults had affected the basement and the stratification of basin, these systems also had contributed to coquina permoporosity development, that show 80% of recoverable oil volume of the field. The carbonate marine sequence, Albian age, it was deposited under the salt. This forms structures as like as pillows and raft as a result of the halocinese. Structurally the Linguado Field coquina has monoclinal direction with east dip, it’s cut by faults with slip up to 50 meters. In addition to structural control, stratigraphy and diagenesis also were important to carbonate trap oil. The identification of recoverable oil levels in the low phase of the coquina from Lagoa Feia Group was done by well data. The seismic 2D and 3D, with the well data, was used to structural interpretation to regional scale either to reservoir scale.
Resumo:
A tectono-stratigraphic study of bivalve coquina-reservoir of Linguado Field allowed to identify two trends of permoporosity development. The delineation of these depositional-diagenetic traps were made through structural and stratigrafic cross-sections and maps. It resulted in the identification of shelf-ramp systems (tilted to SSE), it tickens from 60 to 70 meters and ends against an antithetic fault. The main coquina is bounded by fine siliciclastic units, white clay (low Gamma Ray values) or shale (high Gamma Ray values) lithologies, influencing diagenesis of basal or top coquina limestones (cimented, non-porous). Also in the middle of coquina-reservoir the “clayer” material is also associated with cemented carbonates, with also compartimentalize the reservoir into two subzones. The coquina porosity of the subzones is taken from density-neutron logs, while induction log estimates permeabilities and fluid saturations. It’s noticed the porosity development into pairs, good one followed by a regular/poor one and vice versa. These pairs form verticals succession, pair cycles where porosity improves or decreases upwards. These two scales of pore heterogeneity impose strong layering to the reservoir, and influences fluid saturations, oil-water contacts and porosity cut-offs. In a cross-section with density and induction logs, it can be observed the porosity variation along the shelf-ramp coquina (between 3LI_0004_RJS e 3RJS_0157C_RJ), the porosity is better developed in a downdip direction in the case of the two shelf wells, and also be the three ramp wells. The southern west downdip, 3RJS_0157C_RJ well, has best porosity pairs-cycles; however, its lowest structural conditions favour water saturation. Therefore it is fundamental for reservoir fluid evaluation a cross-plot analysis of RHOB-NPHI and Induction logs
Resumo:
Background: In a classical study, Durkheim mapped suicide rates, wealth, and low family density and realized that they clustered in northern France. Assessing others variables, such as religious society, he constructed a framework for the analysis of the suicide, which still allows international comparisons using the same basic methodology. The present study aims to identify possible significantly clusters of suicide in the city of Sao Paulo, and then, verify their statistical associations with socio-economic and cultural characteristics. Methods: A spatial scan statistical test was performed to analyze the geographical pattern of suicide deaths of residents in the city of Sao Paulo by Administrative District, from 1996 to 2005. Relative risks and high and/or low clusters were calculated accounting for gender and age as co-variates, were analyzed using spatial scan statistics to identify geographical patterns. Logistic regression was used to estimate associations with socioeconomic variables, considering, the spatial cluster of high suicide rates as the response variable. Drawing from Durkheim's original work, current World Health Organization (WHO) reports and recent reviews, the following independent variables were considered: marital status, income, education, religion, and migration. Results: The mean suicide rate was 4.1/100,000 inhabitant-years. Against this baseline, two clusters were identified: the first, of increased risk (RR = 1.66), comprising 18 districts in the central region; the second, of decreased risk (RR = 0.78), including 14 districts in the southern region. The downtown area toward the southwestern region of the city displayed the highest risk for suicide, and though the overall risk may be considered low, the rate climbs up to an intermediate level in this region. One logistic regression analysis contrasted the risk cluster (18 districts) against the other remaining 78 districts, testing the effects of socioeconomic-cultural variables. The following categories of proportion of persons within the clusters were identified as risk factors: singles (OR = 2.36), migrants (OR = 1.50), Catholics (OR = 1.37) and higher income (OR = 1.06). In a second logistic model, likewise conceived, the following categories of proportion of persons were identified as protective factors: married (OR = 0.49) and Evangelical (OR = 0.60). Conclusions: This risk/ protection profile is in accordance with the interpretation that, as a social phenomenon, suicide is related to social isolation. Thus, the classical framework put forward by Durkheim seems to still hold, even though its categorical expression requires re-interpretation.
Resumo:
The thesis contemplates 4 papers and its main goal is to provide evidence on the prominent impact that behavioral analysis can play into the personnel economics domain.The research tool prevalently used in the thesis is the experimental analysis.The first paper provide laboratory evidence on how the standard screening model–based on the assumption that the pecuniary dimension represents the main workers’choice variable–fails when intrinsic motivation is introduced into the analysis.The second paper explores workers’ behavioral reactions when dealing with supervisors that may incur in errors in the assessment of their job performance.In particular,deserving agents that have exerted high effort may not be rewarded(Type-I errors)and undeserving agents that have exerted low effort may be rewarded(Type-II errors).Although a standard neoclassical model predicts both errors to be equally detrimental for effort provision,this prediction fails when tested through a laboratory experiment.Findings from this study suggest how failing to reward deserving agents is significantly more detrimental than rewarding undeserving agents.The third paper investigates the performance of two antithetic non-monetary incentive schemes on schooling achievement.The study is conducted through a field experiment.Students randomized to the main treatments have been incentivized to cooperate or to compete in order to earn additional exam points.Consistently with the theoretical model proposed in the paper,the level of effort in the competitive scheme proved to be higher than in the cooperative setting.Interestingly however,this result is characterized by a strong gender effect.The fourth paper exploits a natural experiment setting generated by the credit crunch occurred in the UK in the2007.The economic turmoil has negatively influenced the private sector,while public sector employees have not been directly hit by the crisis.This shock–through the rise of the unemployment rate and the increasing labor market uncertainty–has generated an exogenous variation in the opportunity cost of maternity leave in private sector labor force.This paper identifies the different responses.
Resumo:
Erhöhte Spiegel von oxidativem Stress bedingen Atherosklerose, eine Krankheit die über 50% aller Todesfälle in der westlichen Welt ausmacht. Es ist entscheidend Mechanismen zur Abwehr dieser Krankheit zu ergründen.rnDa genetische Polymorphismen des körpereigenen Enzyms Paraoxonase 2 (PON2) mit kardiovaskulären Erkrankungen assoziiert sind, wurden ihre Regulation und potentiell antioxidativen Funktionen in vaskulären Zellen analysiert. Mittels verschiedener molekularbiologischer Methoden konnte ich erstmals zeigen, dass PON2 in vaskulären Zellen vornehmlich subzellulär im ER lokalisiert ist. Anhand verschiedener Experimente wurde PON2 als potenter Faktor zur Reduktion von ROS identifiziert. Erhöhte ROS-Spiegel führen zur Aktivierung eines als unfolded protein response (UPR) bekannten ER-Stress-Signalwegs. Dieser ist neben Atherosklerose in eine Vielzahl von Erkrankungen involviert und hat kritischen Einfluss auf das Überleben oder Absterben von Zellen. Durchgeführte Promoter-Reporter Studien bewiesen die Induktion der Protein-Expression von PON2 nach Aktivierung des UPR-Signalwegs, was als kompensatorischer Mechanismus der Zelle zur Vermeidung UPR-induzierter Apoptose verstanden werden könnte. PON2 wehrt oxidativen Stress und die UPR-induzierte Apoptose ab und ist ein protektiver Faktor vor Atherosklerose.rnIn einem Krebsmodell könnte PON2 aber als antiapoptotischer Faktor entscheidend am Überleben von Tumorzellen beteiligt sein. Gerade diese beiden gegensätzlichen Aspekte der antiapoptotischen Funktion des Proteins zeigen die Notwendigkeit für weitere Untersuchungen zu PON2 auf.rn
Resumo:
The aim of this Thesis is to obtain a better understanding of the mechanical behavior of the active Alto Tiberina normal fault (ATF). Integrating geological, geodetic and seismological data, we perform 2D and 3D quasi-static and dynamic mechanical models to simulate the interseismic phase and rupture dynamic of the ATF. Effects of ATF locking depth, synthetic and antithetic fault activity, lithology and realistic fault geometries are taken in account. The 2D and 3D quasi-static model results suggest that the deformation pattern inferred by GPS data is consistent with a very compliant ATF zone (from 5 to 15 km) and Gubbio fault activity. The presence of the ATF compliant zone is a first order condition to redistribute the stress in the Umbria-Marche region; the stress bipartition between hanging wall (high values) and footwall (low values) inferred by the ATF zone activity could explain the microseismicity rates that are higher in the hanging wall respect to the footwall. The interseismic stress build-up is mainly located along the Gubbio fault zone and near ATF patches with higher dip (30°
Resumo:
The significance of the multi-isotopic record preserved in K-feldspars is assessed on samples from the Aar metagranite, Central Alps, Switzerland having very tight independent geological constraints. Stepwise leaching reveals that two diachronically grown K-feldspar generations coexist: Kfs-1 (≥ 35 Ma old, Ca-poor, Rb-Cl-rich, with low 87Sr/86Sr and high 206Pb/204Pb) and Kfs-2 (≤ 10 Ma old, antithetic isotopic signatures deriving from external fluids). Microtextures imaged by cathodoluminescence, backscattered electrons, and electron probe microanalysis are patchy and chemically heterogeneous, with pronounced enrichments in Ba in the retrogressed regions. This confirms the simultaneous presence of fluid-dominated retrogression and recrystallization and isotopic inheritance. The staircase-shaped 40Ar/39Ar age spectrum correlates with the Ca/K and Cl/K signatures. This reflects a mixture of heterochemical K-feldspar generations, and not an intracrystalline Ar gradient caused by diffusion. The shape of the age spectrum and the in vacuo release kinetics proceed from entirely different physical and geological phenomena. What K-feldspars can be effectively used for is to constrain the timing of the fluids that interacted with them by multi-isotopic analyses, rather than to model a “cooling history” from 39Ar release alone. The identification of multiple mineral generations by imaging combined with multi-isotopic analysis enables the accurate dating of the events of a multistage evolution after the initial crystallization of the rock in which the minerals occur.
Resumo:
Environmental data sets of pollutant concentrations in air, water, and soil frequently include unquantified sample values reported only as being below the analytical method detection limit. These values, referred to as censored values, should be considered in the estimation of distribution parameters as each represents some value of pollutant concentration between zero and the detection limit. Most of the currently accepted methods for estimating the population parameters of environmental data sets containing censored values rely upon the assumption of an underlying normal (or transformed normal) distribution. This assumption can result in unacceptable levels of error in parameter estimation due to the unbounded left tail of the normal distribution. With the beta distribution, which is bounded by the same range of a distribution of concentrations, $\rm\lbrack0\le x\le1\rbrack,$ parameter estimation errors resulting from improper distribution bounds are avoided. This work developed a method that uses the beta distribution to estimate population parameters from censored environmental data sets and evaluated its performance in comparison to currently accepted methods that rely upon an underlying normal (or transformed normal) distribution. Data sets were generated assuming typical values encountered in environmental pollutant evaluation for mean, standard deviation, and number of variates. For each set of model values, data sets were generated assuming that the data was distributed either normally, lognormally, or according to a beta distribution. For varying levels of censoring, two established methods of parameter estimation, regression on normal ordered statistics, and regression on lognormal ordered statistics, were used to estimate the known mean and standard deviation of each data set. The method developed for this study, employing a beta distribution assumption, was also used to estimate parameters and the relative accuracy of all three methods were compared. For data sets of all three distribution types, and for censoring levels up to 50%, the performance of the new method equaled, if not exceeded, the performance of the two established methods. Because of its robustness in parameter estimation regardless of distribution type or censoring level, the method employing the beta distribution should be considered for full development in estimating parameters for censored environmental data sets. ^
Resumo:
PURPOSE The SWISSspine registry (SSR) was launched in 2005 to assess the safety and effectiveness of balloon kyphoplasty (BKP). In the meantime, repeated reports on high rates of adjacent vertebral fractures (ASF) after BKP of vertebral insufficiency fractures were published. The causes for ASF and their risk factors are still under debate. The purpose of this study was to report the incidence and potential risk factors of ASF within the SSR dataset. METHODS The SSR data points are collected perioperatively and during follow-ups, with surgeon- and patient-based information. All patients documented with a monosegmental osteoporotic vertebral insufficiency fracture between March 2005 and May 2012 were included in the study. The incidence of ASF, significant associations with co-variates (patient age, gender, fracture location, cement volume, preoperative segmental kyphosis, extent of kyphosis correction, and individual co-morbidities) and influence on quality of life (EQ-5D) and back pain (VAS) were analyzed. RESULTS A total of 375 patients with a mean follow-up of 3.6 months was included. ASF were found in 9.9 % (n = 37) and occurred on average 2.8 months postoperatively. Preoperative segmental kyphosis >30° (p = 0.026), and rheumatoid arthritis (p = 0.038) and cardiovascular disease (p = 0.047) were significantly associated with ASF. Furthermore, patients with ASF had significantly higher back pain at the final follow-up (p = 0.001). No further significant associations between the studied co-variates and ASF were seen in the adjusted analysis. CONCLUSIONS The findings suggest that patients with a preoperative segmental kyphosis >30° or patients with co-morbidities like rheumatoid arthritis and a cardiovascular disease are at high risk of ASF within 6 months after the index surgery. In case of an ASF event, back pain levels are significantly increased. LEVEL OF EVIDENCE IV.
Resumo:
La relación entre comunidad y sociedad puede rastrearse de los orígenes de la sociología hasta la actualidad. Fue un punto central en el pensamiento de la segunda generación de padres fundadores -Durkheim, Tönnies, Weber-, lo fue luego en la sociología de Talcott Parsons, y es aún un fuerte centro de debate entre las diversas corrientes contemporáneas, tanto dentro de la sociología como en las ciencias políticas y la filosofía. En este sentido, la relación comunidad-sociedad continúa hasta el día de hoy suscitando polémicas e inspirando numerosos y sugerentes trabajos. No obstante, si bien en sus diferentes tratamientos presenta incontables diferencias, un elemento común es analizar la relación como dos polos excluyentes y antitéticos. Este trabajo se propone describir cómo dos pensadores provenientes de corrientes diferentes como Talcott Parsons y Helmut Plessner buscaron pensar ambos conceptos -comunidad y sociedad- no cómo elementos excluyentes, sino como dimensiones necesarias y presentes en todo nivel de la vida humana. Así, la intención es demostrar cómo dichos autores lograron integrar ambas dimensiones, a la vez que advertir sobre las consecuencias y dificultades de los intentos de superación o eliminación de esta relación.
Resumo:
The study of the large-sample distribution of the canonical correlations and variates in cointegrated models is extended from the first-order autoregression model to autoregression of any (finite) order. The cointegrated process considered here is nonstationary in some dimensions and stationary in some other directions, but the first difference (the “error-correction form”) is stationary. The asymptotic distribution of the canonical correlations between the first differences and the predictor variables as well as the corresponding canonical variables is obtained under the assumption that the process is Gaussian. The method of analysis is similar to that used for the first-order process.
Resumo:
In the Monte Carlo simulation of both lattice field theories and of models of statistical mechanics, identities verified by exact mean values, such as Schwinger-Dyson equations, Guerra relations, Callen identities, etc., provide well-known and sensitive tests of thermalization bias as well as checks of pseudo-random-number generators. We point out that they can be further exploited as control variates to reduce statistical errors. The strategy is general, very simple, and almost costless in CPU time. The method is demonstrated in the twodimensional Ising model at criticality, where the CPU gain factor lies between 2 and 4.