Sistema inteligente para detecção de manchas de óleo na superfície marinha através de imagens de SAR

Oil spill on the sea, accidental or not, generates enormous negative consequences for the affected area. The damages are ambient and economic, mainly with the proximity of these spots of preservation areas and/or coastal zones. The development of automatic techniques for identification of oil spots on the sea surface, captured through Radar images, assist in a complete monitoring of the oceans and seas. However spots of different origins can be visualized in this type of imaging, which is a very difficult task. The system proposed in this work, based on techniques of digital image processing and artificial neural network, has the objective to identify the analyzed spot and to discern between oil and other generating phenomena of spot. Tests in functional blocks that compose the proposed system allow the implementation of different algorithms, as well as its detailed and prompt analysis. The algorithms of digital image processing (speckle filtering and gradient), as well as classifier algorithms (Multilayer Perceptron, Radial Basis Function, Support Vector Machine and Committe Machine) are presented and commented.The final performance of the system, with different kind of classifiers, is presented by ROC curve. The true positive rates are considered agreed with the literature about oil slick detection through SAR images presents

Aplicação do Sensoriamento Remoto e do Sistema de Informações Geográficas na Detecção de Manchas de Óleo na Região do Pólo de Exploração de Guamaré, R.N.

Objective to establish a methodology for the oil spill monitoring on the sea surface, located at the Submerged Exploration Area of the Polo Region of Guamaré, in the State of Rio Grande do Norte, using orbital images of Synthetic Aperture Radar (SAR integrated with meteoceanographycs products. This methodology was applied in the following stages: (1) the creation of a base map of the Exploration Area; (2) the processing of NOAA/AVHRR and ERS-2 images for generation of meteoceanographycs products; (3) the processing of RADARSAT-1 images for monitoring of oil spills; (4) the integration of RADARSAT-1 images with NOAA/AVHRR and ERS-2 image products; and (5) the structuring of a data base. The Integration of RADARSAT-1 image of the Potiguar Basin of day 21.05.99 with the base map of the Exploration Area of the Polo Region of Guamaré for the identification of the probable sources of the oil spots, was used successfully in the detention of the probable spot of oil detected next to the exit to the submarine emissary in the Exploration Area of the Polo Region of Guamaré. To support the integration of RADARSAT-1 images with NOAA/AVHRR and ERS-2 image products, a methodology was developed for the classification of oil spills identified by RADARSAT-1 images. For this, the following algorithms of classification not supervised were tested: K-means, Fuzzy k-means and Isodata. These algorithms are part of the PCI Geomatics software, which was used for the filtering of RADARSAT-1 images. For validation of the results, the oil spills submitted to the unsupervised classification were compared to the results of the Semivariogram Textural Classifier (STC). The mentioned classifier was developed especially for oil spill classification purposes and requires PCI software for the whole processing of RADARSAT-1 images. After all, the results of the classifications were analyzed through Visual Analysis; Calculation of Proportionality of Largeness and Analysis Statistics. Amongst the three algorithms of classifications tested, it was noted that there were no significant alterations in relation to the spills classified with the STC, in all of the analyses taken into consideration. Therefore, considering all the procedures, it has been shown that the described methodology can be successfully applied using the unsupervised classifiers tested, resulting in a decrease of time in the identification and classification processing of oil spills, if compared with the utilization of the STC classifier

Análise wavelet e modelo de manchas em curvas de luz estelares dos telescópios espaciais Kepler e CoRoT

Analogous to sunspots and solar photospheric faculae, which visibility is modulated by stellar rotation, stellar active regions consist of cool spots and bright faculae caused by the magnetic field of the star. Such starspots are now well established as major tracers used to estimate the stellar rotation period, but their dynamic behavior may also be used to analyze other relevant phenomena such as the presence of magnetic activity and its cycles. To calculate the stellar rotation period, identify the presence of active regions and investigate if the star exhibits or not differential rotation, we apply two methods: a wavelet analysis and a spot model. The wavelet procedure is also applied here to study pulsation in order to identify specific signatures of this particular stellar variability for different types of pulsating variable stars. The wavelet transform has been used as a powerful tool for treating several problems in astrophysics. In this work, we show that the time-frequency analysis of stellar light curves using the wavelet transform is a practical tool for identifying rotation, magnetic activity, and pulsation signatures. We present the wavelet spectral composition and multiscale variations of the time series for four classes of stars: targets dominated by magnetic activity, stars with transiting planets, those with binary transits, and pulsating stars. We applied the Morlet wavelet (6th order), which offers high time and frequency resolution. By applying the wavelet transform to the signal, we obtain the wavelet local and global power spectra. The first is interpreted as energy distribution of the signal in time-frequency space, and the second is obtained by time integration of the local map. Since the wavelet transform is a useful mathematical tool for nonstationary signals, this technique applied to Kepler and CoRoT light curves allows us to clearly identify particular signatures for different phenomena. In particular, patterns were identified for the temporal evolution of the rotation period and other periodicity due to active regions affecting these light curves. In addition, a beat-pattern vii signature in the local wavelet map of pulsating stars over the entire time span was also detected. The second method is based on starspots detection during transits of an extrasolar planet orbiting its host star. As a planet eclipses its parent star, we can detect physical phenomena on the surface of the star. If a dark spot on the disk of the star is partially or totally eclipsed, the integrated stellar luminosity will increase slightly. By analyzing the transit light curve it is possible to infer the physical properties of starspots, such as size, intensity, position and temperature. By detecting the same spot on consecutive transits, it is possible to obtain additional information such as the stellar rotation period in the planetary transit latitude, differential rotation, and magnetic activity cycles. Transit observations of CoRoT-18 and Kepler-17 were used to implement this model.

Retinopatia de Purtscher-like e pancreatite aguda

Retinopatia de Purtscher-like é uma baixa súbita da visão associada à imagem de múltiplas áreas branco-amareladas (manchas algodonosas) e hemorragias no pólo posterior de ambos os olhos. O exato mecanismo da injúria ainda não é claro, mas provavelmente seria de natureza embólica. Tem sido descrita em uma variedade de condições, incluindo pancreatite aguda, síndrome de embolia gordurosa, insuficiência renal,nascimento (parto e pós-parto), desordens do tecido conectivo, entre outras. Serão relatados três casos de pancreatite aguda confirmada pelos exames laboratoriais e história clínica, associadas a alterações no exame do fundo de olho, compatíveis com esta retinopatia

Coordenação entre as respostas da catalase e da ascorbato peroxidade em folhas de feijão caupi submetidas a diferentes fontes de peróxido de hidrogênio

The plants are often exposed to variations in environmental conditions that may trigger metabolic disturbances leading to a consequent loss in productivity of crops. These stressful conditions usually induce an accumulation of reactive oxygen species (ROS) in the cell, a condition known how oxidative stress. Among these species, hydrogen peroxide (H2O2) is an important molecule involved in numerous signaling mechanisms. The present study aimed to understand the relationship between the different enzymatic mechanisms of elimination of H2O2 by catalase (CAT) and ascorbate peroxidase (APX) in leaf tissues of seedlings of the species Vigna unguiculata L. Walp, under conditions of oxidative stress induced by application of CAT inhibitor, 3-amino-1,2,4-triazole (3-AT), and H2O2 itself on the roots. Three experiments were conducted. The first experiment was performed applying the compound 3-AT (5 mM) during the time (hours). In the second experiment, seedlings were exposed to different concentrations of H2O2 (2.5, 5.0, 7.5, 10 mM) for 48 h. The third strategy included the pre-treatment with H2O2 (2.5 mM) for 24 h, followed by subsequent treatment with the inhibitor 3-AT and recovery control condition. Treatment with 3-AT causes a strong inhibition of CAT activity in leaf tissues accompanied by an increase of activity of APX. However a decrease in oxidative damage to lipids is not observed as indicated by TBARS. It was observed that activity of APX is directly linked to the content of peroxide. Inductions in the activities of CAT and APX were observed mainly in the seedlings treated with 2.5 mM H2O2. This can be associated with a decrease in oxidative damage to lipids. In contrast, one same tendency was not observed in treatments with higher concentrations of this ROS. These results suggest that the concentration of 2.5 mM H2O2 can induce responses antioxidants later in seedling cowpea. This concentration when applied as pre-treatment for 24 h promoted an induction systems removers CAT and APX, both in activity and in terms of gene expression. However this increment was not observed in the recovered plants and the plants subsequently subjected to 3-AT. Additionally, the pretreatment was not sufficient to attenuate the inhibition of CAT activity and oxidative damage to lipids caused by the subsequent application of this inhibitor. The results showed that the application of 3-AT and H2O2 in the root systems of seedlings of cowpea promote changes in the parameters analyzed in leaf tissues that indicate a direct response to the presence of these factors or systemic signaling mecanisms. H2O2 appears to activate the responses of two antioxidant systems in this study thar does not promote greater protection in case of additional treatment with 3-AT. This demonstrates the importance of the CAT system. In this work, complete results indicate that there is a difference between the signaling and the effects caused by exposure to H2O2 and by treatment with 3-AT

Estrutura genética populacional de Heliconius erato e Heliconius melpomene (Lepidoptera: Nymphalidae) em fragmentos de Mata Atlântica do Rio Grande do Norte

Extensive studies using molecular markers on butterflies have shown how a highly fragmented landscape may result in the reduction of gene flow among patches of habitat and, consequently, increase genetic differentiation among populations. However, little is known about Heliconius geographical structure and the effects of fragmentation on the connectivity of populations. Furthermore, findings on the effects of the population structure on the dynamics of mimicry evolution in Heliconius butterflies need to be tested in H. erato and H. melpomene specimens found in other locations other than Central and northern South Americas. For the present study, we had two motivations: (1) compare the population structure of H. erato and H. melpomene given the highly fragmented Brazil s Atlantic Forest habitat; and (2) studying population structure of co-mimics could give us insights into the dynamics of mimicry evolution. For this, we analysed the spatial structure and connectivity of eight populations of Heliconius butterflies, in a total of 137 H. erato specimens and 145 H. melpomene specimens, using nine microsatellites loci, 1144 AFLPs markers and 282 mitochondrial DNA sequences. In general, both species exhibited evidence of population subdivision but no isolation by distance indicating some extent of genetic differentiation among populations. Contrary to Kronforst & Gilbert s (2008) Costa Rican Heliconius, H. melpomene exhibited more genetic differentiation than H. erato based on nuclear markers. However, for mitochondrial DNA, H. erato populations showed more genetic differentiation than H. melpomene. Our results corroborate to other studies on Heliconius butterflies concerning the pronounced population subdivision and local genetic drift found in this genus. Nevertheless, the pattern of this differentiation varies significantly from the pattern found in studies conducted in Central America, where H. erato is generally more differentiated and structured than H. melpomene, based on nuclear markers. This different pattern may reflect different evolutionary histories of Heliconius species in Northeastern Brazil s Atlantic Forest

Biologia populacional comparada de duas espécies de heliconius (Lepidoptera: Nymphalidae) em um ambiente sazonal de floresta atlântica do nordeste brasileiro

Tropical environments often face strong seasonal variations in climate, such as alternate periods of dry and rain, that may often be important influence in the annual X the organisms lives. Here we assess how population dynamics of two butterfly species (Heliconius erato and Heliconius mepomene) respond to environmental and seasonal variations. A mark-release-recapture study carried out in an Atlantic forest reserve, 15 Km from Natal, Rio Grande do Norte, Brazil, for 3 years, during the dry and rainy season, with three visits weekly done. Information such as species, wing lenght, site of capture, pollen load and phenotype (number of spots) (in H. erato only) were noted for each capture. Seasonal variation exists in capture rates of the two species, with great capture rates during the rainy season. Despite finding differences in the mean density of individuals of the two species among the different collection areas, this difference was only significant between floodplain and central areas, and no influence of seasonality was observed in the mean density between the areas. Seasonality in wing size was only observed for H. erato, with larger wings during the rainy season. Females carried larger pollen loads than males both species, but species were similar. Only males differed seasonally, with larger pollen loads during the rainy season. The distribution of the number of wing spots did not vary between the dry and rainy seasons, and the number of spots in males and females was similar. Therefore, we conclude that there was a strong influence of seasonal variation in the population dynamic of the two Heliconius species, as well as in several aspects of their biology

Movimento de borboletas frugívoras e conectividade funcional em uma paisagem de Mata Atlântica

An organisms movement within and between habitats is an essential trait of life history, one that shapes population dynamics, communities and ecosystems in space and time. Since the ability to perceive and react to specific conditions varies greatly between organisms, different movement patterns are generated. These, in turn, will reflect the way species persist in the original habitat and surrounding patches. This study evaluated patterns of movement of frugivorous butterflies in order to estimate the connectivity of a landscape mosaic in an area of Atlantic Forest. For this purpose, we used the capture-mark-recapture method on butterflies trapped with fermented fruit bait in three distinct habitats. The first represents a typical Atlantic forest fragment, while the other two represent man-made matrix habitats. One contains a coconut plantation and the other a plantation of the exotic Acacia mangium species. Five traps were randomly placed in each landscape unit in areas of 40 x 40m. Using recapture data and relating it to distance between captures and habitat structure, I found that movement frequencies, both within and between landscape units were different for the analyzed species, suggesting that they do not interpret and react to the landscape in the same way. Thus this study was able to measure landscape functional connectivity. For most species, the exchange between forest and coconut plantations occurred with low frequency compared to exchanges between the forest and acacia plantations, which share more structural similarities. This seems to indicate that a matrix that is more similar to patches of native vegetation can shelter species, permit their movement and, consequently, contribute to the landscape connectivity

Dunas costeiras de Jenipabu: Status de conservação e diretrizes para restauração da vegetação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Identificação das condições gerais de conservação dos reservatórios integrantes do sistema de abastecimento de água de Natal

Infrastructure works are included in strategic areas for the social development. For that matter that all of the investments are very important for the social development. When the population has enough water and an acceptable quality, and it includes a wastewater gathering and its treatment, the whole society became less susceptible to the water diseases. Even the Water Supply and the Sewage depend for its perfect operation of reservoirs, or of the accumulation of water to provide the popular necessity, either due to retention or for the treatment wastewarer. These structures present very specific environmental conditions, because the microclimate created around them, like high environmental humidity and for the existence of many harmful substances for the concrete, such as chloride ions presents in water. The reservoir that compose the System of Water Supply of Natal were built between 1970s and 1980s, a period whom the technical and scientific community did not have in-depth studies about the reinforced concrete mechanism of deterioration. Therefore, these reservoirs have been suffered accelerated deterioration progress, and they have been shown many pathological manifestations strikingly visible. In front of all these problems this academic work aims to identify the generally conditions of conservation of all the reservoirs components of the Water Supply System of Natal. This academic work objectives to develop a recuperation plan for use in these reservoirs, in this academic work it was achieved all the survey of pathological manifestation existing in each reservoir. It was made with local visits, photographic recorders of all manifestations viii and realization of in loco tests. The other step consisted in a application of GDE/UnB metodolgy reformulated by Fonseca (2007). In the step of local visits in each reservoir it was evaluated carbonation depth, by spreading a phenolphthalein solution with 1% of concentration; evaluation of contamination of chlorides, by spreading silver nitrate solution with 1% of concentration, and evaluation of width cracks. After the conclusion of all the testings, it was established that all reservoir, studied in this academic work, have showed an advanced deteriorating condition. It´s presents prevalent pathological manifestations as unacceptable cracks, spots, efflorescence and reinforcement corrosion, and in some cases, chlorides contamination. After the conclusion of the testings and its concatenation it was able to implementing, using GDE/UnB methodology, the order of the restoration its service life and initial safety conditions

Desenvolvimento de solução para SLAM utilizando visão de teto

This work intends to show a new and few explored SLAM approach inside the simultaneous localization and mapping problem (SLAM). The purpose is to put a mobile robot to work in an indoor environment. The robot should map the environment and localize itself in the map. The robot used in the tests has an upward camera and encoders on the wheels. The landmarks in this built map are light splotches on the images of the camera caused by luminaries on the ceil. This work develops a solution based on Extended Kalman Filter to the SLAM problem using a developed observation model. Several developed tests and softwares to accomplish the SLAM experiments are shown in details

Avaliação do crescimento de ocupação da bacia do rio Pitimbu com subsídios para estudos de possíveis impactos sobre os recursos hidricos

The Pitimbu River Watershed (PRW), belonging to Potiguar capital metropolitan area, State of Rio Grande do Norte, contributes, among other purposes, to human using and animal watering. This watershed is extremely important because, besides filling up with freshwater approximately 30% of the south part of Natal (South, East and West Zones), contributes to the river shore ecosystem equilibrium. Face to the current conjuncture, this study aims to evaluate the urban development dynamics in the PRW, applying Cellular Automata as a modeling instrument, and to simulate future urban scenarios, between 2014 and 2033, using the simulation program SLEUTH. In the calibration phase, urban spots for 1 984, 1992, 2004 and 2013 years were used, with resolution from 100 meters. After the simulation, it was found a predominance of organic growth, expanding the BHRP from existing urban centers. The spontaneous growth occurred through the fullest extent of the watershed, however the probability of effective growth should not exceed 21%. It was observed that, there was a 68% increase for the period between 2014 and 2033, corresponding to an expansion area of 1,778 ha. For 2033, the source of Pitimbu River area and the Jiqui Lake surroundings will increase more than 78%. Finally, it was seen an exogenous urban growth tendency in the watershed (outside-in). As a result of this growth, hydraulics resources will become scarcer

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

Em busca de um novo indicador Espectroscópico do período de rotação das Estrelas do tipo solar

The study of sunspots consistently contributed to a better understanding of magnetic phenomena of the Sun, as its activity. It was found with the dynamics of sunspots that the Sun has a rotation period of twenty-seven days around your axis. With the help of Project Sun-As-A-Star that solar spectra obtained for more than thirty years we observed oscillations of both the depth of the spectral line and its equivalent width, and analysis of the return information about the characteristics of solar magnetism. It also aims to find patterns of solar magnetic activity cycle and the average period of rotation of the Sun will indicate the spectral lines that are sensitive to magnetic activity and which are not. Sensitive lines how Ti II 5381.0 Å stands as the best indicator of the solar rotation period and also shows different periods of rotation cycles of minimum and maximum magnetic activity. It is the first time we observe clearly distinct rotation periods in the different cycles. The analysis also shows that Ca II 8542.1 Å and HI 6562.0 Å indicate the cycle of magnetic activity of eleven years. Some spectral lines no indicated connection with solar activity, this result can help us search for programs planets using spectroscopic models. Data analysis was performed using the Lomb-Scargle method that makes the time series analysis for unequally spaced data. Observe different rotation periods in the cycles of magnetic activity accounts for a discussion has been debated for many decades. We verified that spectroscopy can also specify the period of stellar rotation, thus being able to generalize the method to other stars

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