Evolução top-hat hidrodinâmica em campos de velocidades peculiares primordiais

We investigate the cosmology of the vacuum energy decaying into cold dark matter according to thermodynamics description of Alcaniz & Lima. We apply this model to analyze the evolution of primordial density perturbations in the matter that gave rise to the first generation of structures bounded by gravity in the Universe, called Population III Objects. The analysis of the dynamics of those systems will involve the calculation of a differential equation system governing the evolution of perturbations to the case of two coupled fluids (dark matter and baryonic matter), modeled with a Top-Hat profile based in the perturbation of the hydrodynamics equations, an efficient analytical tool to study the properties of dark energy models such as the behavior of the linear growth factor and the linear growth index, physical quantities closely related to the fields of peculiar velocities at any time, for different models of dark energy. The properties and the dynamics of current Universe are analyzed through the exact analytical form of the linear growth factor of density fluctuations, taking into account the influence of several physical cooling mechanisms acting on the density fluctuations of the baryonic component of matter during the evolution of the clouds of matter, studied from the primordial hydrogen recombination. This study is naturally extended to more general models of dark energy with constant equation of state parameter in a flat Universe

Evolução da atividade cromosférica, abundância de lítio e rotação das estrelas análogas e gêmeas solares

The study of solar-type stars also includes the familiar solar analogs and twins. These objects have been one of the major research subjects in astrophysics nowadays. A direct comparison of solar activity with chromospheric activity indices for a set of stars very similar to the Sun (twins and analogs) provides an excellent opportunity to study the evolution of stellar activity on timescales of the order of the lifetime on the main sequence. This work deals with the relationship between the abundance of lithium, chromospheric activity, X-ray emission and rotation period in terms of stellar ages. We explore the influence of stellar evolution in the global properties of the stars and the aspects linked to its coronal, chromospheric and magnetic activity. Our main objective is to probe the law of decay of each of these parameters based on a sample of stars classified as well-connected as analogs stars and solar twins.

Aglomerado estelar M67: processos de diluição e a evolução do Momentum Angular

Galactic stellar clusters have a great variety of physical properties that make valuable probes of stellar and galactic chemical evolution. Current studies show a discrepancy between the standard evolutionary models and observations, mainly considering the level of mixing and convective dilution of light elements, as well as to the evolution of the angular momentum. In order to better settle some of these properties, we present a detailed spectroscopic analysis of 28 evolved stars, from the turn-off to the RGB, belonging to the stellar open cluster M67. The observations were performed using UVES+FLAMES at VLT/UT2. We determined stellar parameters and metallicity from LTE analysis of Fe I and Fe II lines between 420 1100 nm. The Li abundance was obtained using the line at 6707.78 ˚A, for the whole sample of stars. The Li abundances of evolved stars of M67 present a gradual decreasing when decreasing the effective temperature. The Li dilution factor for giant stars of M67 with Teff ∼ 4350K is at least 2300 times greater than that predicted by standard theory for single field giant stars. The Li abundance as a function of rotation exhibits a good correlation for evolved stars of M67, with a much smaller dispersion than the field evolved stars. The mass and the age seem to be some of the parameters that influence this connection. We discovered a Li-rich subgiant star in M67 (S1242). It is member of a spectroscopic binary system with a high eccentricity. Its Li abundance is 2.7, the highest Li content ever measured for an evolved star in M67. Two possibilities could explain this anomalous Li content: (i) preservation of the Li at the post turn off stage due to tidal effects, or (ii) an efficient dredge-up of Li, hidden below the convective zone by atomic diffusion occurring in the post turn off stage. We also study the evolution of the angular momentum for the evolved stars in M67. The results are in agreement with previous studies dedicated to evolved stars of this cluster, where stars in the same region of the CM-diagram have quite similar rotations, but with values that indicate an extra breaking along the main sequence. Finally, we analize the distributions of the average rotational velocity and of the average Li abundance as a function of age. With relation to the average Li abundances, stars in clusters and field stars present the same type of exponencial decay law t−β. Such decay is observed for ages lesser than 2 Gyr. From this age, is observed that the average Li abundance remain constant, differently of the one observed in the rotation age connection, where the average rotational velocity decreases slowly with age

Evolução de estruturas primordiais

Understanding the way in which large-scale structures, like galaxies, form remains one of the most challenging problems in cosmology today. The standard theory for the origin of these structures is that they grew by gravitational instability from small, perhaps quantum generated, °uctuations in the density of dark matter, baryons and photons over an uniform primordial Universe. After the recombination, the baryons began to fall into the pre-existing gravitational potential wells of the dark matter. In this dissertation a study is initially made of the primordial recombination era, the epoch of the formation of the neutral hydrogen atoms. Besides, we analyzed the evolution of the density contrast (of baryonic and dark matter), in clouds of dark matter with masses among 104M¯ ¡ 1010M¯. In particular, we take into account the several physical mechanisms that act in the baryonic component, during and after the recombination era. The analysis of the formation of these primordial objects was made in the context of three models of dark energy as background: Quintessence, ¤CDM(Cosmological Constant plus Cold Dark Matter) and Phantom. We show that the dark matter is the fundamental agent for the formation of the structures observed today. The dark energy has great importance at that epoch of its formation

Evolução do reparo por excisão de nucleotídeo

The phylogeny is one of the main activities of the modern taxonomists and a way to reconstruct the history of the life through comparative analysis of these sequences stored in their genomes aimed find any justification for the origin or evolution of them. Among the sequences with a high level of conservation are the genes of repair because it is important for the conservation and maintenance of genetic stability. Hence, variations in repair genes, as the genes of the nucleotide excision repair (NER), may indicate a possible gene transfer between species. This study aimed to examine the evolutionary history of the components of the NER. For this, sequences of UVRA, UVRB, UVRC and XPB were obtained from GenBank by Blast-p, considering 10-15 as cutoff to create a database. Phylogenetic studies were done using algorithms in PAUP programs, BAYES and PHYLIP package. Phylogenetic trees were build with protein sequences and with sequences of 16S ribosomal RNA for comparative analysis by the methods of parsimony, likelihood and Bayesian. The XPB tree shows that archaeal´s XPB helicases are similar to eukaryotic helicases. According to this data, we infer that the eukaryote nucleotide excision repair system had appeared in Archaea. At UVRA, UVRB and UVRC trees was found a monophyletic group formed by three species of epsilonproteobacterias class, three species of mollicutes class and archaeabacterias of Methanobacteria and Methanococci classes. This information is supported by a tree obtained with the proteins, UVRA, UVRB and UVRC concatenated. Thus, although there are arguments in the literature defending the horizontal transfer of the system uvrABC of bacteria to archaeabacterias, the analysis made in this study suggests that occurred a vertical transfer, from archaeabacteria, of both the NER genes: uvrABC and XPs. According the parsimony, this is the best way because of the occurrence of monophyletic groups, the time of divergence of classes and number of archaeabacterias species with uvrABC system

Detecção de predadores por dicromatas e tricromatas humanos e a sua implicação na evolução da visão de cores em primatas

Among placental mammals, primates are the only ones to present trichromatic color vision. However, the distribution of trichromacy among primates is not homogeneous: Old World primates shows an uniform trichromacy (with all individuals being trichromats) and New World primates exhibit a color vision polymorphism (with dichromatic males and dichromatic or trichromatic females). Visual ecology studies have investigated which selective pressures may have been responsible for the evolution of trichromacy in primates, diverging from the dichromat standard found in other mammals. Cues associated with foraging and the socio-reproductive status were analyzed, indicating a trichromatic advantage for the rapid detection of visually conspicuous objects against a green background. However, dichromats are characterized by an efficient capture of cryptic and camouflaged stimuli. These advantages regarding phenotype may be responsible for the maintenance of the visual polymorphism in New World primates and for the high incidence of color blindness in humans (standing around 8% in Caucasian men). An important factor that has not yet been experimentally taken into account is the predation risk and its effect on the evolution of trichromacy in primates. To answer this question, we prepared and edited pictures of animals with different coats: oncillas (Leopardus spp.), puma (Puma concolor) and ferret (Galictis cuja). The specimens were taxidermized and the photographs were taken in three different vegetation scenarios (dense forest, cerrado and grassland). The images of the predators were manipulated so that they fit into two categories of stimulus size (small or large). After color calibration and photo editing, these were presented to 40 humans (20 dichromats and 20 trichromats) by a computer program, which presented a set of four photos at a time (one picture containing the taxidermized animal amid the background vegetation and three depicting only the background vegetation) and recorded the response latency and success rate of the subjects. The results show a trichromatic advantage in detecting potential predators. The predator detection was influenced by the background, the predator species, the dimension of the stimulus and the observer s visual phenotype. As humans have a high rate of dyschromatopsias, when compared to wild Catarrhini or human tribal populations, it is possible that the increased rate of dichromats is a result of reduced pressure for rapid predator detection. Since our species came to live in more cohesive groups and resistant to attack by predators, with the advent of agriculture and the formation of villages, it is possible that the lower risk of predation has reduced the selection in favor of trichromats

CrossMDA2: Uma abordagem para minimizar o problema da fragilidade de pointcuts na evolução de sistemas orientados a aspectos

This work proposes a model based approach for pointcut management in the presence of evolution in aspect oriented systems. The proposed approach, called conceptual visions based pointcuts, is motivated by the observation of the shortcomings in traditional approaches pointcuts definition, which generally refer directly to software structure and/or behavior, thereby creating a strong coupling between pointcut definition and the base code. This coupling causes the problem known as pointcut fragility problem and hinders the evolution of aspect-oriented systems. This problem occurs when all the pointcuts of each aspect should be reviewed due to any software changes/evolution, to ensure that they remain valid even after the changes made in the software. Our approach is focused on the pointcuts definition based on a conceptual model, which has definitions of the system's structure in a more abstract level. The conceptual model consists of classifications (called conceptual views) on entities of the business model elements based on common characteristics, and relationships between these views. Thus the pointcuts definitions are created based on the conceptual model rather than directly referencing the base model. Moreover, the conceptual model contains a set of relationships that allows it to be automatically verified if the classifications in the conceptual model remain valid even after a software change. To this end, all the development using the conceptual views based pointcuts approach is supported by a conceptual framework called CrossMDA2 and a development process based on MDA, both also proposed in this work. As proof of concept, we present two versions of a case study, setting up a scenario of evolution that shows how the use of conceptual visions based pointcuts helps detecting and minimizing the pointcuts fragility. For the proposal evaluation the Goal/Question/Metric (GQM) technique is used together with metrics for efficiency analysis in the pointcuts definition

Um modelo conceitual baseado em MDD e padrões para evolução de sistemas OA

Aspect-Oriented Software Development (AOSD) is a technique that complements the Object- Oriented Software Development (OOSD) modularizing several concepts that OOSD approaches do not modularize appropriately. However, the current state-of-the art on AOSD suffers with software evolution, mainly because aspect definition can stop to work correctly when base elements evolve. A promising approach to deal with that problem is the definition of model-based pointcuts, where pointcuts are defined based on a conceptual model. That strategy makes pointcut less prone to software evolution than model-base elements. Based on that strategy, this work defines a conceptual model at high abstraction level where we can specify software patterns and architectures that through Model Driven Development techniques they can be instantiated and composed in architecture description language that allows aspect modeling at architecture level. Our MDD approach allows propagate concepts in architecture level to another abstraction levels (design level, for example) through MDA transformation rules. Also, this work shows a plug-in implemented to Eclipse platform called AOADLwithCM. That plug-in was created to support our development process. The AOADLwithCM plug-in was used to describe a case study based on MobileMedia System. MobileMedia case study shows step-by-step how the Conceptual Model approach could minimize Pointcut Fragile Problems, due to software evolution. MobileMedia case study was used as input to analyses evolutions on software according to software metrics proposed by KHATCHADOURIAN, GREENWOOD and RASHID. Also, we analyze how evolution in base model could affect maintenance on aspectual model with and without Conceptual Model approaches

Estudo comparativo da evolução e sobrevida de pacientes com claudicação intermitente, com ou sem limitação para exercícios, acompanhados em ambulatório específico

CONTEXTO: Os fatores de risco para doença aterosclerótica, que influenciam na evolução natural dessa doença, estão bem estabelecidos, assim como o benefício do programa de exercícios para pacientes claudicantes. Entretanto, faltam informações sobre a relação entres limitações clínicas e fatores de risco, com desempenho do programa de caminhadas e suas implicações na evolução e mortalidade destes pacientes. OBJETIVO: Comparar, ao longo do tempo, a distância de claudicação e sobrevida de pacientes claudicantes em ambulatório específico, com ou sem limitação para exercícios. MÉTODOS: Foi feito um estudo tipo coorte retrospectivo de 185 pacientes e 469 retornos correspondentes, no período de 1999 a 2005, avaliando-se dados demográficos, distância média de claudicação (CI) e óbito. Os dados foram analisados nos programas Epi Info, versão 3.2, e SAS, versão 8.2. RESULTADOS: A idade média foi de 60,9±11,1 anos, sendo 61,1% do sexo masculino e 38,9% do sexo feminino. Oitenta e sete por cento eram brancos, e 13%, não-brancos. Os fatores de risco associados foram: hipertensão (69,7%), tabagismo (44,3%), dislipidemia (32,4%) e diabetes (28,6%). Nos claudicantes para menos de 500 m, a CI inicial em esteira foi de 154,0±107,6 m, e a CI final, de 199,8±120,5 m. Cerca de 45% dos pacientes tinham alguma limitação clínica para realizar o programa de exercícios preconizado, como: angina (26,0%), acidente vascular cerebral (4,3%), artropatia (3,8%), amputação menor ou maior com prótese (2,1%) ou doença pulmonar obstrutiva crônica (1,6%). Cerca de 11,4% dos pacientes tinham infarto do miocárdio prévio, e 5,4% deles usavam cardiotônico. O tempo de seguimento médio foi de 16,0±14,4 meses. A distância média de CI referida pelos pacientes aumentou 100% (de 418,47 m para 817,74 m) ao longo de 2 anos, nos grupos não-limitante (p < 0,001) e não-tabagista (p < 0,001). A sobrevida dos claudicantes foi significativamente menor no grupo com limitação. A análise de regressão logística mostrou que a limitação para realização de exercícios, isoladamente, influenciou significativamente na mortalidade (p < 0,001). CONCLUSÃO: A realização correta e regular dos exercícios e o abandono do fumo melhoram a distância de claudicação, além de reduzir a mortalidade nesses casos, seja por meio de efeitos positivos próprios do exercício, seja por meio de controle dos fatores de risco e de seus efeitos adversos.

Caracterização genética e evolução dos vírus dengue no Estado do Rio Grande do Norte

Dengue is considered as the most important arthropod-borne viral disease throughout the world due to the high number of people at risk to be infected, mainly in tropical and subtropical regions of the planet. The etiologic agent is Dengue Virus (DENV), it is a single positive-stranded RNA virus of the family Flavivirus, genus Flaviviridae. Four serotypes are known, DENV-1, DENV-2, DENV-3 and DENV-4. One of the most important characteristic of these viruses is the genetic variability, which demands phylogenetic and evolutionary studies to understand key aspects like: epidemiology, virulence, migration patterns and antigenic characteristics. The objective of this study is the genetic characterization of dengue viruses circulating in the state of Rio Grande does Norte from January 2010 to December 2012. The complete E gene (1485 pb) of DENV1, 2 e 4 from Brazilian (Rio Grande do Norte) patients was sequenced. Phylogenetic analysis was performed using MEGA 5.2 software, Tamura-Nei model and Neighbor-Joining trees were inferred for the datasets. In Brazil, there is just one DENV-1 genotype (genotype V), one DENV-2 genotype (Asian/American) and two DENV-4 genotypes (genotypes I and II). Brazilian strains of DENV-1 are subdivided in two different lineages (BR-I and BR-II), the Brazilian strains of DENV-2 are subdivided in four lineages (BRI-IV) and genotype II of DENV-4 is subdivided in three Brazilian lineages (BRI-III). The viruses isolated in RN belong to lineage BR-II (DENV-1), BR-IV (DENV-2) and BR-III (DENV-4).The Caribbean and near Latin American countries are the main source of these viruses to Brazil. Amino acids substitutions were detected in three domains of E protein, this makes clear the necessity of studies that associate epidemiological and molecular data to better understand the effects of these mutations. This is the first study about genetic characterization and evolution of Dengue viruses in Rio Grande do Norte, Brazil

Evolução da terminoliga princípio contábil baseada na Escola Norte-Americana

This research has as objective of study the evolution of the accountancy princliple terminology which is present in the accounting conceptual framework. The scene of this research will have as target the North American School of Accounting. The choice of the searched terminology is its relevance in the study of the Accounting Theory. To understand the evolution of the accountancy thought, will be boarded: the influence of the Feudal System and the Mercantilism in the European economic conception; the importance of the Industrial Revolution in the beginning of the accounting standards and the influence of England in the formation of the North American School of Accounting. With relation to U.S.A., the development of the economic-financial scene of the American society will be evaluated, focusing the contribution in the search of the construction of an applied theoretical framework to the Accounting. The economic-financial development of U.S.A. provided the sprouting of new users with specific necessities. The necessity of the user for useful information for the decision taking, unchained the process of research directed toward the establishment of an applied Accountancy terminology. In this process, the paper exerted for the responsible accountancy organisms for the accounting standards will be boarded, as well as the professionals associations which had invested in researches, aiming at to elaborate a body of accountancy principles and to adjust the accountancy procedures to the necessities of the users. To reach the research objective, a bibliographical revision in specialized literature will be effected, adopting the historical method, in the period that understands the development of the North American School of Accounting. As result of the research, it can conclude that the evolution process of the terminology which is studied presents a structural logical problem, because the impossibility of the construction of a theoretical framework, having as bases the principle terminology. The impossibility occurred in function of the reach attributed to the term, which made a difficult in its application in the elaboration of the accountancy procedures

Evolução da paisagem do baixo curso do rio de Piranhas-Assu (1988-2024): uso de autômatos celulares em modelo dinâmico espacial para simulação de cenários futuros

The lower course of Piranhas-Assu river, located in the north coast of Rio Grande do Norte, Brazil, arouses a keen interest as a study field, once it concentrates, besides petroleum and gas exploration, activities related to shrimp culture, salt and horticulture, factors that also deserve special attention. Thus, the awareness of the study field environmental stage demands studies from researchers and discernment from society, as a way of understanding the inter-relation between environment and men. Therefore, this work attempts at understanding and studying the dynamics of land use in the lower course of Piranhas-Assu river, through a multitemporal analysis of present and past, accomplishing future projections through simulation models. The work is divided in stages that include the research, analysis, interpretation of results, and the generation of simulation models, to analyze the landscape tendencies, making possible to identify indicators which cause such changes in the lower course of the river. From Geographical Database, the necessary exploratory analyses were accomplished to the following items: land use evolution, natural and environmental vulnerability, multiple geodiversity indexes, and preparation of the data to be used in the simulation model. Later, the construction of the landscape simulation model was conducted. Sequentially, simulations of future sceneries were accomplished through the execution of the model in a specific software environment. Last, the analyses of landscape tendencies in the study field were carried out. The lower course of Piranhas-Assu River didn't show any intense dynamics in landscape changing, once in the period taken into account (from 1988 to 2004) class stability proved to be superior to its transformations. Activities related to agriculture and livestock are the ones that influence, mostly, the landscape dynamics. The production of sea shrimp and petroleum also infers in the landscape, although in smaller proportion. INCRA s public policies excessively determined the dynamics of the landscape in the lower course of Piranhas-Assu River, RN. In respect to its natural vulnerability, the lower course of Piranhas-Assu River, RN, features more vulnerable than stable areas. The landscape simulation, in the first taken period (2004-2009), indicated considerable increases and decreases of antropic activities, if compared to its sequent periods (2009-2014, 2014-2019 and 2019-2024). The simulation, in a wider analysis, showed that the determining factors for the space mobility of antropic activities, in the focused area, are related to the pre-existence of communities with agricultural capability and to the existence of access routes and drainage. Considering the area that features fixed and mobile dunes, located in Porto do Mangue district, we recommend its conversion into a conservation area

Evolução geodinâmica e condicionamento estrutural dos terrenos Piancó-Alto Brígida e Alto Pajeú, domínio da zona transversal, NE do Brasil

This thesis aims to advance in the geological knowledge of the region comprising the Piancó-Alto Brígida (TPAB) and Alto pajeú (TAP) terranes, in the Transversal Zone Domain (Borborema Province, NE Brazil), with the main objective of understanding the geodynamic evolution and the structural framework of these units. To reach this objective, and besides field work and interpretation of traditional aerial photographs, other tools were employed like of remote sensing products (Landsat 7 ETM+, aeroradiometrics, aeromagnetics and topographical images), lithogeochemical (whole rock) analyses and geochronological dating (U-Pb in zircon), besides integration with literature data. In the area, several precambrian geological units outcrop, represented in the TAP by the paleoproterozoic Serra Talhada and Afogados da Ingazeira complexes, Riacho Gravatá Complex (metavolcano-sedimentary sequence of Stenian-Tonian age) and Cariris Velhos orthogneisses (of Tonian age). The TPAB comprises the Santana do Garrote (lower unit) and Serra do Olho d'Água (upper unit) formations of the Cachoeirinha Group (Neoproterozoic III), besides the Piancó orthogneisses and Bom Jesus paragneisses; the latter correspond to an older (basement ?) block and a possible high grade equivalent of the Cachoeirinha Group (or Seridó Group ?), respectively. Several Brasiliano-age plutons occur in both terranes.The aeromagnetic data show the continuity, at depth, of the main shear zones mapped in the region. The Patos, Pernambuco, Boqueirão dos Cochos, Serra do Caboclo, Afogados da Ingazeira/Jabitacá and Congo-Cruzeiro do Nordeste shear zones reach depths greater than to 6-16 km. The aeromagnetic signature of other shear zones, like the Juru one, suggests that these structures correspond to shallower crustal features. The satellite images (Landsat 7 ETM+) and aerogamaspectrometric images discriminate different geological units, contributing to the mapping of the structural framework of the region. The Serra do Caboclo Shear Zone was characterized as the boundary/suture between the TPAB and TAP. This structure is an outstanding, pervasive feature that separates contrasting geological units, such as the Neoproterozoic III Cachoeirinha Group in the TPAB and the Riacho Gravatá Complex and the Cariris Velhos metaplutonics, of Stenian-Tonian age, in the TAP. Occupying different blocks, these units are not found in authoctonous relations, like unconformities and intrusive contacts. Concerning the Cariris Velhos (ca. 1,0 Ga old) event is recorded by radiometric ages of the Riacho Gravatá Complex metavolcanics and intrusive augen and orthogneisses, all of them displaying geochemical affinities of arc or collisional settings. A structural signature of this event was not recorded in the region, possibly due to its low grade/low strain style, obliterated by the overprinting of younger, higher grade/high strain Brasiliano-age fabrics.The first tectonic event (D1) observed in the Cariris Velhos lithotypes presents contractional kinematics with transport to the NW. Neoproterozoic III geochronologic dates, obtained in late-D1 granitoids, imply a Brasiliano age (ca. 610-600 Ma) for this deformation event. The second tectonic event (D2) characterized in the region corresponds to the Brasiliano transcurrent kinematics of the outstanding shear zones and associated granitoid plutons. The geochronological (U-Pb in zircon) data obtained during this thesis also confirms the occurrence of the Cariris Velhos magmatic suite in the TAP, as well as the Neoproterozoic III age to the Cachoeirinha Group in the TPAB. The TAP (Riacho Gravatá Complex, augen and orthogneisses) is interpreted as a continental arc possibly accreted to a microcontinent during the Cariris Velhos (Stenian-Tonian) event. Later on, this terrane collided with the TPAB at the beginning of the Brasiliano orogeny (D1 contractional deformation), and both domins were reworked by the transcurrent shear deformation of the D2 event

Evolução tectono-estrutural do Campo de Xaréu (Sub-bacia de Mundaú, Bacia do Ceará - NE do Brasil: abordagem multiescala e pluriferramental

The Xaréu Oil Field, located in the center-southern portion of the Mundaú Sub-Basin (eastern portion of the Ceará Basin), is characterized by a main Iramework of NW-trending and NE-dipping faults. The faults in the Xaréu Oil Field, among which the Xaréu Fautt stands out, are arranged according to an extensional-listriclan, rooted on a detachment surface corresponding to the Mundaú Fault, the border fautt of Mundaú Sub-Basin. During the tectonic-structural evolution of the Xaréu Oil Field and the Mundaú Sub-Basin, the Mundaú Fault played a crucial role on the control of the geometry of both compartments. The main carbonatic unit in the Xaréu Oil Field, named the Trairí Member(Paracuru Formation of Late Aptian to Early Albian age), contains the largest oil volume in the field, concentrated in structurally-controlled accumulations. The Trairí Member is composed by a variety of carbonatic rocks (massive, bedded or laminated calcilutites, ostracodites, calcarenites and carbonatic rudites, all of them presenting variable degrees of dolomitization). The carbonatic rocks are interbedded into thick packages of black shales and marls, besides local beds of siliciclastic conglomerates, sandstones, siltnes and argillites. From the spatial association and the genetic relationships between the carbonatic and siliciclastic units, it is possible to group them in three lithofacies associations (Marginal Plain, Ramp and Lacustrine Interior) that, together, were developed in a lacustrine system associated to a marginal sabkha. Structural studies based on drill coresthat sample the Trairí Member in the Xaréu Oil Field allowed to characterize two generations of meso- to microscale structures: the D1 group presents a typical hydroplastic character, being characterized by intra/interstratal to oblique-bedding shear zones. The hydroplastic character related to these structures allowed to infer their development at an early-lithilication stage of the Trairí Member, leading to infer an Early Cretaceous age to them. The second group of structures identified in the drill cores, nominated D2 and ascribed to a Neogene age, presents a strictly brttle character, being typilied by normal faults and slickenfibers of re-crystallized clayminerals, ali olthem displaying variable orientations. Although the present faults in the Xaréu Oil Field (and, consequently, in the Mundaú Sub-Basin) were classically relerred as struetures of essentially normal displacement, the kinematics analysis of the meso-to microscaie D1 struetures in the drill cores led to deline oblique displacements (normal with a clockwise strike-slip component) to these faults, indicating a main tectonic transport to ENE. These oblique movements would be responsible for the installation of a transtensive context in the Mundaú Sub-Basin, as part of the transcurrent to translormant opening of the Atlantic Equatorial Margin. The balancing of four struetural cross-sections ofthe Xaréu Oil Field indicates that the Mundaú Fault was responsible for more than 50% of the total stretching (ß factor) registered during the Early Aptian. At the initial stages of the "rifting", during Early Aptianuntil the Holocene, the Mundaú Sub-Basin (and consequently the Xaréu Oil Fleld) accumulated a total stretching between 1.21 and 1.23; in other words, the crust in this segment of the Atlantic Equatorial Margin was subjeeted to an elongation of about 20%. From estimates of oblique displacements related to the faults, it ws possible to construct diagrams that allow the determination of stretching factors related to these displacements. Using these diagrams and assuming the sense 01 dominant teetonictransport towards ENE, it was possible to calculate the real stretching lactors related to the oblique movement 0 of the faults in the Mundaú Sub-Basin. which reached actual values between 1.28 and 1.42. ln addnion to the tectonic-structural studies in the Xaréu Oil Field, the interpretation of remote sensing products, coupled wnh characterization of terrain analogues in seleeted areas along the northern Ceará State (continental margins of the Ceará and Potiguar basins), provided addnional data and constraints about the teetonic-structural evolution of the oil lield. The work at the analogue sites was particularly effective in the recognition and mapping, in semidetail scale, several generations of struetures originated under a brittle regime. Ali the obtained information (from the Xaréu Oil Field, the remote sensor data and the terrain analogues) were jointly interpreted, culminating with the proposnion of an evolutionary model lor this segment of the Atlantic Equatorial Margin; this model that can be applied to the whole Margin, as well. This segmentof the Atlantic Equatorial Margin was delormedin an early E-W (when considered lhe present-day position of the South American Plate) transcurrent to transform regime with dextral kinematics, started Irom, at least, the Early Aptian, which left its record in several outcrops along the continental margin of the Ceará State and specilically in the Xaréu off Field. The continuous operation of the regime, through the Albian and later periods, led to the definitive separation between the South American and African plates, with the formation of oceanic lithosphere between the two continental blocks, due to the emplacement off spreading centers. This process involved the subsequent transition of the transcurrent to a translorm dextral regime, creating lhe Equatorial Atlantic Oceano With the separation between the South American and African plates already completed and the increasing separation between lhe continental masses, other tecton ic mechanisms began to act during the Cenozoic (even though the Cretaceous tectonic regime lasted until the Neogene), like an E-W compressive stress líeld (related to the spreading olthe oceanic floor along lhe M id-Atlantic Ridge and to the compression of the Andean Chain) effective Irom the Late Cretaceous, and a state of general extension olthe horizontal surface (due to the thermal uplift ofthe central portion of Borborema Province), effective during the Neogene. The overlap of these mechanisms during the Cenozoic led to the imprint of a complex tectonic framework, which apparently influenced the migration and entrapment 01 hydrocarbon in the Ceará Basin

Análise da evolução costeira do litoral setentrional do estado do rio grande do norte, região sob influência da indústria petrolífera

The northern coast of Rio Grande do Norte State is characterized by strong changes in coastal morphology, caused by various geological and climatic factors. In this region are installed the main socio-economic activities of the State, highlighting the oil industry, which exerts much of its activities in the coastal area studied. Erosion is a constant problem in this region because it affects the entire local populace to the destruction of houses and trade, rendering tourism, affecting the livelihood activities and industrial activities. The greatest risk is related to environmental damage that can be caused by the oil spill in this region. To understand what determines the changes in coastal morphology this Doctoral Thesis is proposed to identify the factors at local, regional and even global corroborate coastal dynamics to this coast in question. For this study, used several different products and tools for interpreting the conditions of the erosive effect that dominates the whole northern coast of the State, in an attempt to quantify and describe the causes and effects that affect the entire coastal zone monitored. The development of activities is built into the projects Rede 05 PETROMAR (CTPETRO-FINEP/PETROBRAS/CNPq), PETRORISCO, HIDROSEMA, PETROMAR e Rede 05/04 POTMAR (FNDCT/CTPETROFINEP/ CNPq), in the activities of multidisciplinary and inter-features in issues involving environmental monitoring and oil activity