Análise estatística de padrões sísmicos: decomposição em multiescala

O processamento de registros sísmicos é uma tarefa muito importante dentro da Geofísica e que representa um desafio permanente na exploração de petróleo. Embora esses sinais forneçam uma imagem adequada da estrutura geológica do subsolo, eles são contaminados por ruídos e, o ground roll é a componente principal. Este fato exige um esforço grande para o desenvolvimento de metodologias para filtragem, Dentro desse contexto, este trabalho tem como objetivo apresentar um método de remoção do ruído ground roll fazendo uso de ferramentas da Física Estatística. No método, a Análise em Ondeletas é combinada com a Transformada de Karhunen-Loève para a remoção em uma região bem localizada. O processo de filtragem começa com a Decomposição em Multiescala. Essa técnica permite uma representação em tempo-escala fazendo uso das ondeletas discretas implementadas a filtros de reconstrução perfeita. O padrão sísmico original fica representado em multipadrões: um por escala. Assim, pode-se atenuar o ground roll como uma operação cirúrgica em cada escala, somente na região onde sua presença é forte, permitindo preservar o máximo de informações relevantes. A atenuação é realizada pela definição de um fator de atenuação Af. Sua escolha é feita pelo comportamento dos modos de energia da Transformada de Karhunen-Loève. O ponto correspondendo a um mínimo de energia do primeiro modo é identificado como um fator de atenuação ótimo

Um estudo na teoria do movimento brownianno com viscosidade variável

In this work we investigate the stochastic behavior of a large class of systems with variable damping which are described by a time-dependent Lagrangian. Our stochastic approach is based on the Langevin treatment describing the motion of a classical Brownian particle of mass m. Two situations of physical interest are considered. In the first one, we discuss in detail an application of the standard Langevin treatment (white noise) for the variable damping system. In the second one, a more general viewpoint is adopted by assuming a given expression to the so-called collored noise. For both cases, the basic diffententiaql equations are analytically solved and al the quantities physically relevant are explicitly determined. The results depend on an arbitrary q parameter measuring how the behavior of the system departs from the standard brownian particle with constant viscosity. Several types of sthocastic behavior (superdiffusive and subdiffusive) are obteinded when the free pamameter varies continuosly. However, all the results of the conventional Langevin approach with constant damping are recovered in the limit q = 1

Análise das curvas de luz do CoroT usando diferentes processos comparativos: estimando períodos de rotação estelar

One of the main goals of CoRoT Natal Team is the determination of rotation period for thousand of stars, a fundamental parameter for the study of stellar evolutionary histories. In order to estimate the rotation period of stars and to understand the associated uncertainties resulting, for example, from discontinuities in the curves and (or) low signal-to-noise ratio, we have compared three different methods for light curves treatment. These methods were applied to many light curves with different characteristics. First, a Visual Analysis was undertaken for each light curve, giving a general perspective on the different phenomena reflected in the curves. The results obtained by this method regarding the rotation period of the star, the presence of spots, or the star nature (binary system or other) were then compared with those obtained by two accurate methods: the CLEANest method, based on the DCDFT (Date Compensated Discrete Fourier Transform), and the Wavelet method, based on the Wavelet Transform. Our results show that all three methods have similar levels of accuracy and can complement each other. Nevertheless, the Wavelet method gives more information about the star, from the wavelet map, showing the variations of frequencies over time in the signal. Finally, we discuss the limitations of these methods, the efficiency to give us informations about the star and the development of tools to integrate different methods into a single analysis

Representações espectrais de sistemas complexos: aplicações à síntese de superfícies brownianas fracionárias anisotrópicas, filtragem de sinais e identificação de correlações

In this thesis, we study the application of spectral representations to the solution of problems in seismic exploration, the synthesis of fractal surfaces and the identification of correlations between one-dimensional signals. We apply a new approach, called Wavelet Coherency, to the study of stratigraphic correlation in well log signals, as an attempt to identify layers from the same geological formation, showing that the representation in wavelet space, with introduction of scale domain, can facilitate the process of comparing patterns in geophysical signals. We have introduced a new model for the generation of anisotropic fractional brownian surfaces based on curvelet transform, a new multiscale tool which can be seen as a generalization of the wavelet transform to include the direction component in multidimensional spaces. We have tested our model with a modified version of the Directional Average Method (DAM) to evaluate the anisotropy of fractional brownian surfaces. We also used the directional behavior of the curvelets to attack an important problem in seismic exploration: the atenuation of the ground roll, present in seismograms as a result of surface Rayleigh waves. The techniques employed are effective, leading to sparse representation of the signals, and, consequently, to good resolutions

Rotação diferencial em estrelas do tipo solar

Stellar differential rotation is an important key to understand hydromagnetic stellar dynamos, instabilities, and transport processes in stellar interiors as well as for a better treatment of tides in close binary and star-planet systems. The space-borne high-precision photometry with MOST, CoRoT, and Kepler has provided large and homogeneous datasets. This allows, for the first time, the study of differential rotation statistically robust samples covering almost all stages of stellar evolution. In this sense, we introduce a method to measure a lower limit to the amplitude of surface differential rotation from high-precision evenly sampled photometric time series such as those obtained by space-borne telescopes. It is designed for application to main-sequence late-type stars whose optical flux modulation is dominated by starspots. An autocorrelation of the time series is used to select stars that allow an accurate determination of spot rotation periods. A simple two-spot model is applied together with a Bayesian Information Criterion to preliminarily select intervals of the time series showing evidence of differential rotation with starspots of almost constant area. Finally, the significance of the differential rotation detection and a measurement of its amplitude and uncertainty are obtained by an a posteriori Bayesian analysis based on a Monte Carlo Markov Chain (hereafter MCMC) approach. We apply our method to the Sun and eight other stars for which previous spot modelling has been performed to compare our results with previous ones. The selected stars are of spectral type F, G and K. Among the main results of this work, We find that autocorrelation is a simple method for selecting stars with a coherent rotational signal that is a prerequisite to a successful measurement of differential rotation through spot modelling. For a proper MCMC analysis, it is necessary to take into account the strong correlations among different parameters that exists in spot modelling. For the planethosting star Kepler-30, we derive a lower limit to the relative amplitude of the differential rotation. We confirm that the Sun as a star in the optical passband is not suitable for a measurement of the differential rotation owing to the rapid evolution of its photospheric active regions. In general, our method performs well in comparison with more sophisticated procedures used until now in the study of stellar differential rotation

Aspectos anatômicos do olho e neuroquímicos da retina do mocó (Kerodon rupestris)

The visual system is an important link between the animal and the environment, com profound influences on the habits and lifestyle in various habitats. Adaptive mechanismsto the temporal niche are present in the visual system of many vertebrates, involving changins in ocular dimensios and design, retinal cell distribution and organization of neurochemical circuits related to the retinal resolution or sensitivity. The sensory system of the eye is represented by the retina, whose organization is responsible by receipty, initial analysis, and transmission of the information to the brain. The knowledge of the position of the eyes in the head and the distribution of retinal cells allow to identify adaptive aspects of each species to its visual field, which is characteristic to the ecological niche it occupies. In this research, we study eye anatomical characteristics and retina neurochemical features of the rock cavy (Kerodon rupestris), a tipical Brazilian rodent from the suborder Hystricomorpha, family Caviidae. The rock cavy has lateral eyes well constitute bony orbit and well differentiated extrinsic muscle. The study of the descriptive and morphometric anatomy of the showed mean values of axial diameter 10.7±0,5mm and equatorial diameter 11.6±0.7mm. The pupil is slit shaped and the lens has mean axial diameter 5.4±0.03 mm, corresponding to ~45% of the axial diameter of the eye. The posterior nodal distance and the retinal magnification factor were estimated at 6.74 mm e 118 μm/grau, respectively. Flat mounts were processed for Nissl stain, and the topographic distribution of ganglion cells showed a moderate visual band, just below the optic disc, with higher density in the ventral retina. Retinal vertical sections and flat mounts were processed for immunohistochemistry to visualize tyrosine hydroxilase (TH) and thus two types of TH+ cells were detected. Type 1 cells had strong TH-immunoreactivity, the body cell varied from 120.047 to 269.373 μm2 stratifying in the sublamina 1 of the IPL. Type 2 cells were weakly TH-imunoreactive, had cell body located mostly in the IPL, varying from 54.848 to 177.142 μm2, constituting ~10% of the TH+ cells. Both cell types exhibited similar topographic distribution with higher density found in a horizontal band along of the naso-temporal axis in the dorsal retina. The total population of dopaminergic cells was 2,156±469,4 cells, occupying an average area of 198,164 μm2. The presence of cones and rods was detected by immunohistochemistry in vertical sections and flat mounts. S cones density is around 10 times smaller than L cones, with different degree of spatial organization. Other retinal neuronal populations of the rock cavy were also detected in vertical sections with specific markers. Comparative analysis of the anatomical characteristics of the rock cavy eye 12 suggest that it was designed to acquire higher sensitivity to light, at expense of image sharpness, compatible with a vision at mesopic conditions. Additionally, the distribution of the 2 subtypes of dopaminergic cells in a naso-temporal band in the dorsal retina seems suitable to a gain in sensitivity, coherent with an animal with predominantly crepuscular activity pattern

Expressão de zif-268 durante a aquisição, evocação e extinção de uma memória aversiva

In the behavioral paradigm of discriminative avoidance task, both short and long-term memories have been extensively investigated with behavioral and pharmacological approaches. The aim of the present study was to evaluate, using the abovementioned model, the hippocampal expression of zif-268 - a calcium-dependent immediate early gene involved with synaptic plasticity process - throughout several steps of memory formation, such as acquisition, evocation and extiction. The behavioral apparatus consisted of a modified elevaated plus-maze, with their enclosed arms disposed in "L". A pre-exposure to the maze was made with the animal using all arms enclosed, for 30 minutes, followed by training and test, during 10 minutes each. The between sections interval was 24h. During training, aversive stimuli (bright light and loud noise) were actived whenever the animals entered one of the enclosed armas (aversive arm). Memory acquisiton, retention and extinction were evaluated by the percentage of the total time spent exploring the aversive arm. The parameters evaluated (time spent in the arms and total distance traveled) were estimated with an animal tracking software (Anymaze, Stoelting, USA). Learning during training was estimated by the decrease of the time spent exploring the aversive arm. One hour after the beginning of each section, animals were anaesthetized with sodium-thiopental (i.p.) and perfused with 0.9% heparinized saline solution followed by 4% paraformaldehyde. Brains were cryoprotected with 20% sucrose, separeted in three blocks and frozen. The middle block, containing the hippocampus, was sectioned at 20 micro meters in the coronal plane and the resutant sections were submitted to zif-268 immunohistochemistry. Our results show an increased expression of zif-268 in the dentate gyrus (DG) during the evocation and extinction stages. There is a distinct participation of the DG during the memory evocation, but not during its acquisition. Inaddition, all hippocampal regions (CA1, CA3 and DG) presented an increased zif-268 expression during the process of extinction.

A questão do estilo na psicanálise lacaniana

Lacanian psychoanalysis has won a considerable space in brazilian university: a search for Lacan in the field of subject of the CAPES Thesis Bank shows 1.032 results! However the difference in the style of knowledge production and language usage is considerable between academic psychology and lacanian theory. The difficulty in reading and understanding Lacan is something pointed out by supporters and critics alike. In addition to that, his disciples choose many times to imitate his baroque, complex style, full of neologisms, causing perplexity in many unprepared audiences. What is the origin of such an enigmatic and polemic style of expression? How it became so widespread under the sign of repetition? And which are the consequences of this style to the communication, transmission and teaching of lacanian psychoanalysis? Through these questions it is our goal to contribute to the dialogue between lacanian psychoanalysis and the academy, to provide a better understanding of the causes of this style, analyzing the consequences it has to the transmission of psychoanalysis. We chose to perform a theoretical study, using authors that have treated Lacan s style and the history of psychoanalysis from a critical point of view, like Beividas (2000), Roustang (1987, 1988) and Gellner (1988), and also those that have defended and justified its legitimacy, like Glynos e Stavrakakis (2001), Fink (1997) and Souza (1985), using as well some works by Freud and Lacan. The study of these texts has led us to three main themes: 1) the difficulty of the lacanian text; 2) Lacan, heir of Freud; 3) consequences of the lacanian style. In the first one, we enumerate many different explanations and interpretations given by commentators about the difficulty and particularity of the lacanian discourse; in the second, we show how Lacan came to occupy the place of great idealization that was before destined to Freud, what made his style something to be taken as a model, to be imitated by disciples; in the third, we explore the way in which the concepts are treated in lacanian psychoanalysis, arguing that their multiple meanings point out that the final goal is not to build a clear and coherent theory, but to try to aim directly at the subject, to catch him

Metodologia para rastreamento com modificação dos zeros e rejeição de distúrbio aplicada a sistemas incertos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acessibilidade aos espaços urbanos :uma dimensão psicológica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Síntese, caracterização de ferritas espinélio com propriedades magnéticas e absorvedoras de microondas

Were synthesized spinel-type ferrites with general formula Ni0,8Mg0.2-xMxFe2O4, where M represents the doping Mn, Co or Mn + Co simultaneously, x ranges for the values 0.02, 0.05 and 0.1. The value of x was divided by 2 in cases where M equals Mn and Co conjugates. We used the citrate precursor method and heat treatment to obtain the phases at 1100°C. The materials were characterized by XRD, TGA/ DTGA, SEM, MAV and reflectivity measurements by the method of waveguide. Powders to 350°C/3.5 h were crystalline and nanosized. According to the results this temperature all powders have a percentage of ferrite phase over 90%. The composition had the addition of Mn and Co simultaneously showed a higher percentage of secondary phase NiO, 5.8%. The TGA/DTGA curves indicate that this sample reached phase (s) crystalline (s) at lowest temperatures. The X-ray diffractograms of the samples calcined at 350°C and 1100°C were treated with the Rietveld refinament technique. The powders calcined at 1100 °C/3h in air show to be 100% except spinel phase composition with 0.02 doping. The micrographs show clusters of particles with sizes smaller than 1 μm in calcination temperature of 1100°C which agreed with the result of Rietveld refinement. In the compositions doped with Mn were higher values of magnetization (45.90 and 53.20 Am2/kg), which did not cause high microwave absorption. The theoretical calculation of magnetization (MT) was consistent with the results, considering that there was agreement between the increase of magnetization experimental and theoretical. It was observed that there was the interrelation of the final effect of absorption with the thickness of MARE, the composition of ferrimagnetic materials and in particular the specific values of frequency. The analysis shows that the reflectivity increases in the concentration of cobalt increased the frequency range and also for absorption 10.17 GHz and 84%, respectively. The best result of chemical homogeneity and the value of 2.96 x 10-2 tesla coercive field were crucial for high performance ferrite absorber with 0.1 cobalt. The Cobalt has high magnetocrystalline anisotropy, it is associated with an increased coercive field, Hc. Therefore, this property improves the results of reflectivity of spinel ferrites

Atividade biológica de células-tronco da polpa de dentes decíduos humanos submetidas à criopreservação

Dental pulp stem cells have been widely investigated because of their ability to differentiate into both dental and non-dental cells, with potential use in therapies involving tissue engineering. The technique of cell cryopreservation represents a viable alternative for the conservation of these cells, since it stops reversibly, in a controlled manner, all of cell biological functions in an ultra low temperature. The present study aimed to evaluate, using in vitro experiments, the influence of a cryopreservation protocol on the biologic acti vity of stem cells from human exfoliated deciduous teeth (SHED). Cells obtained from the pulp of three deciduous teeth on end-stage exfoliation or with indicated extraction were expanded in α-MEM culture medium supplemented with antibiotics and 15% fetal bovine serum. At second subculture (P2), a group of cells were submitted to cryopreservation for 30 days in 10% DMSO diluted in fetal bovine serum, at -80º C, while the remind cells continued under normal conditions of cell culture. Cell proliferation was evaluated in both groups (not cryopreserved or cryopreserved) by Trypan blue stain essay at intervals of 24, 48 and 72h after plating. Cell cycle analysis of SHEDs submitted or not to the cryopreservation protocol was performed in the same intervals. Events related to cell death were studied by Annexyn V and PI expression under flow cytometry at the intervals of 24 and 72h. The presence of nuclear morphological changes was evaluated by DAPI staining at 72h interval. It was observed that both groups exhibited an upward cell proliferation curve, without considerable changes in cell viability throughout the experiment. The distribution of cell in the cell cycle phasis was consistent with cell proliferation in both groups. There were no nuclear morphological damages in the end range of the experiment. therefore, it is concluded that the proposed cryopreservation protocol is efficient for storing the studied cell type, allowing its use in future experimental studies

Acoustic and psychoacoustic analysis of the noise produced by the police force firearms

Police officers are exposed to impact noise coming from firearms, which may cause irreversible injuries to the hearing system.Aim: To evaluate the noise exposure in shooting stands during gunfire exercises, to analyze the acoustic impact of the noise produced by the firearms and to associate it with tonal audiometry results.Study design: Cross-sectional.Materials and methods: To measure noise intensity we used a digital sound level meter, and the acoustic analysis was carried out by means of the oscillations and cochlear response curves provided by the Praat software. 30 police officers were selected (27 males and 3 females).Results: The peak level measured was 113.1 dB(C) from a .40 pistol and 116.8 dB(C) for a .38 revolver. The values obtained for oscillation and Praat was 17.9 +/- 0.3 Barks, corresponding to the rate of 4,120 and 4,580 Hz. Audiometry indicated greater hearing loss at 4,000Hz in 86.7% of the cases.Conclusion: With the acoustic analysis it was possible to show cause and effect between the main areas of energy excitation of the cochlea (Praat cochlear response curve) and the frequencies of low hearing acuity.

Testes de escuta dicótica em escolares com distúrbio de aprendizagem

O transtorno do processamento auditivo é uma entidade clínica que pode estar associado a diversos distúrbios da comunicação humana, entre estes o distúrbio de aprendizagem. OBJETIVO: Caracterizar e comparar o desempenho de escolares com e sem distúrbio de aprendizagem nos testes de Fala com Ruído e Escuta Dicótica de Dígitos e Verbal. MATERIAL E MÉTODO: Participaram 40 escolares, de ambos os gêneros, com faixa etária de 8 a 12 anos, divididos em dois grupos: GI: composto por 20 escolares com diagnóstico de distúrbio de Aprendizagem e GII: composto por 20 escolares com bom desempenho escolar, pareados segundo gênero, faixa etária e escolaridade com GI. Foram realizadas avaliações audiológicas básicas e Testes de Dicótico de Dígitos, Dissílabos Alternados (SSW) e Fala com Ruído. FORMA DE ESTUDO: Estudo transversal com corte histórica. RESULTADOS: Os escolares de GI apresentaram desempenho inferior ao dos escolares de GII, nos testes Dicótico de Dígitos e Dissílabos Alternados e desempenho sem diferença estatisticamente significante no Teste de fala com Ruído. CONCLUSÃO: Os achados sugerem que o grupo de escolares com distúrbio de aprendizagem apresenta desempenho inferior em relação ao grupo sem dificuldades, refletindo dificuldades no processamento das informações auditivas.

MARISA-MDD: uma abordagem para transformações entre modelos orientados a aspectos: dos requisitos ao projeto detalhado

Aspect Oriented approaches associated to different activities of the software development process are, in general, independent and their models and artifacts are not aligned and inserted in a coherent process. In the model driven development, the various models and the correspondence between them are rigorously specified. With the integration of aspect oriented software development (DSOA) and model driven development (MDD) it is possible to automatically propagate models from one activity to another, avoiding the loss of information and important decisions established in each activity. This work presents MARISA-MDD, a strategy based on models that integrate aspect-oriented requirements, architecture and detailed design, using the languages AOV-graph, AspectualACME and aSideML, respectively. MARISA-MDD defines, for each activity, representative models (and corresponding metamodels) and a number of transformations between the models of each language. These transformations have been specified and implemented in ATL (Atlas Definition Language), in the Eclipse environment. MARISA-MDD allows the automatic propagation between AOV-graph, AspectualACME, and aSideML models. To validate the proposed approach two case studies, the Health Watcher and the Mobile Media have been used in the MARISA-MDD environment for the automatic generation of AspectualACME and aSideML models, from the AOV-graph model