Abundância e distribuição sazonal de espécies autóctones de camarões peneídeos no canal de abastecimento do sistema primar de aquicultura orgânica (Laguna de Guaraíras, Tibau do Sul, Rio Grande do Norte, Brasil)

Guaraíras lagoon, located in Tibau do Sul in the eastern littoral of Rio Grande do Norte (Brazil), presents a permanent connection to the sea, which guarantees the occurrence of a rich biodiversity, which includes the autochthonous shrimp species Litopenaeus schmitti, Farfantepenaeus subtilis and Farfantepenaeus brasiliensis. In spite of being subject to a strong human intervention in the last decade, mainly related to the installation of shrimp (Litopenaeus vannamei) farms, the lagoon is still scarcely studied. The present study aims at characterizing the populations of the three autochthonous penaeid shrimp species inhabiting Guaraíras, taking into consideration their abundance and seasonal distribution in the inflow channel of Primar System of Organic Aquaculture (Tibau do Sul, Rio Grande do Norte, Brazil). Twelve monthly samples were carried out from May 2005 to April 2006 with the aid of a circular cast net in the inflow channel, which is daily supplied with water from Guaraíras. Sampling months were grouped in trimesters according to the total pluviosity, thus comprising four trimesters. Water salinity was monitored twice a week and temperature values registered on a daily basis at noon, during the study period. The daily pluviosity data from the municipality of Tibau do Sul were supplied by Empresa de Pesquisa Agropecuária do Rio Grande do Norte (EMPARN). Collected shrimp were identified, weighted, measured and sexed. L. schmitti specimens (0.2 g to 17.8 g) were distributed in 1.3 g weight classes intervals. From the eighth sampling month (December 2005) onwards, males were classified into three categories, in accordance with the development of their petasm: (a) rudimentary petasm, (b) partially formed petasm, and (c) completely formed petasm. Among the ecological variables, rainfall showed the greatest dispersion (s.d.=187.74Rainfall and abundance of L. schmitti were negatively correlated (r = -0.85) whereas its abundance and water salinity were positively correlated (r = 0.63). Among 1,144 collected individuals, 1,127 were L. schmitti, 13 were F. subtilis and 4 were F. brasiliensis, which corresponded to 98.51%, 1.14% and 0.35% of the total of collected individuals. L. schmitti occurred in 100 % of all samples. Differently, the presence of F. subtilis and F. brasiliensis was restricted to 33% and 17% of the collected samples, respectively. The present study confirmed the occurrence of L. schmitti, F. brasiliensis and F. subtilis in Guaraíras. However, this lagoon seems to be primarily inhabited by juvenile Litopenaeus schmitti. The population of L. schmitti analysed showed a seasonal pattern of distribution. In general, in the months of high salinity and absence of rain, the number of individuals was higher than in the wet months. Further studies on the reproductive biology and ecology of L. schmitti, F. brasiliensis and F. subtilis may elucidate questions referring to the abundance, period, and phase of occurrence of these shrimp genera in Guaraíras. Finally, the risks associated to the establishment of L. vannamei in the lagoon provide a novel outlet for studies in this biotope

Demanda química de oxigênio, clorofila a e comunidade fitoplanctônica como indicadores da qualidade da água no Canal do Pataxó/RN

The current study examined spatial-temporal modifications and water quality through chemical and biotic indicators during both dry (January, February and November 2006) and wet seasons (March to June 2006). This study was carried out in Armando Ribeiro Gonçalves Reservoir, RN, Canal do Pataxó and after the water station treatment (WST). The physical-chemical parameters were measured in situ and inorganic nutrients, chlorophyll a and Free Oxygen Demand (FOD) were analyzed in laboratory conditions. Quali quantitative analyses of phytoplankton were carried out utilizing Sedgwick-Rafter camera. Results indicate that DQO concentrations were low. FOD concentrations in the reservoir were comparatively higher in the dry season (5.21 mgL-1; 5.64 mgL-1 e 6.05 mgL-1) in relation to the wet season (4.52 mgL-1; 4.12 mgL-1 e 4.92 mgL-1), in surface, intermediate and bottom waters, respectively. FOD values were inferior to 1.0mgL-1in both Canal do Pataxó and after WST, which is considered adequate for public use reservoirs. Although FOD concentrations were low, Armando Ribeiro Gonçalves Reservoir, Canal do Pataxó and WST were classified as euthophizied, mesotrophic ad oligotrophic, respectively, considering the Index of Trophic State Criteria. Chlorophyll a concentrations in the study reservoir were higher in the surface (199.2 µgL-1) during the wet season, whereas in Canal do Pataxó concentrations decreased from 1.56 µgL-1 to 0.028 µgL-1, and after WST values were low (0.059 µgL-1). Dominance of cianobacterias, such as Planktotrhix agardhii (dry season) and Microcystis sp (wet season) was registered in all three areas. In the reservoir and Canal do Pataxó, density of cianobacterias, such as P. agardhii and Microcistys sp., was superior to the values allowed by the Health ministry (HM). However, after WST, density values of cianobacteria were inferior to values established by the HM

Análise da trajetória de poços horizontais em reservatório de óleo pesado

The application of thermal methods, to increase the recovery of heavy oil in mature fields through drainage with multilateral and horizontal wells, has been thoroughly studied, theorically, experimentally, testing new tools and methods. The continuous injection of steam, through a steam injector well and a horizontal producer well in order to improve horizontal sweep of the fluid reservoir, it is an efficient method. Starting from an heterogeneous model, geologically characterized, modeling geostatistics, set history and identification of the best path of permeability, with seismic 3D, has been dubbed a studying model. It was studied horizontal wells in various directions in relation to the steam and the channel of higher permeability, in eight different depths. Into in the same area were studied, the sensitivity of the trajectories of horizontal wells, according to the depth of navigation. With the purpose of obtaining the highest output of oil to a particular flow, quality, temperature and time for the injection of steam. The wells studied showed a significant improvement in the cumulative oil recovery in one of the paths by promoting an alternative to application in mature fields or under development fields with heavy oil

Caracterização batimétrica e fisicooceanográfica do canal de acesso ao porto de Cabedelo/PB: uma análise ambiental ao derrame de óleo

The State of Paraíba is one of the most dynamic states of Brazil, strategically located in the northeast, is notable for the excellent potential for integration of different transportation modes forming the states of Rio Grande do Norte, Pernambuco and Alagoas. The dynamic that occurs with port activity causes changes in the space where it is installed. And the elements of this space are always more than suffering direct or indirect influences as the flow in the port is expanded. Therefore, this region became subject to the accidental spillage of oil, because it presents a heavy traffic of ships of various sizes that can run aground or collide with oil causing accidental events. The study of geomorphological and sedimentological compositions of seafloor becomes important as more is known about the relationships between these parameters and associated fauna, and can identify their preferred habitats. The database background, acoustically collected along the proposed study area, is a wealth of information, which were duly examined, cataloged and made available. Such information can serve as an important tool, providing a geomorphological survey of the sedimentary area studied, and come to subsidize, in a flexible, future decision making. With the study area Port of Cabedelo, Paraíba - Brazil, this research aimed to evaluate the influence of the tidal surface and background in modeling the seabed, including the acquisition of information about the location of submerged rocky bodies and the depth of these bodies may turn out to be natural traps for the trapping of oil in case of leaks, and obtain the relationship between types of bed and the hydrodynamic conditions present in the region. In this context, for this study were collected bathymetric data (depth) and physical oceanographic (height of water column, water temperature, intensity and direction of currents, waves and turbidity), meteorological (rainfall, air temperature, humidity, winds and barometric pressure) of the access channel to the Port of Cabedelo / PB and its basin evolution (where the cruise ships dock), and includes tools of remote sensing (Landsat 7 ETM +, 2001), so that images and the results are integrated into Geographic Information Systems and used in the elaboration of measures aimed at environmental protection areas under the influence of this scale facilities, serving as a grant to prepare a contingency plan in case of oil spills in the region. The main findings highlight the techniques of using hydroacoustic data acquisition together bathymetric surveys of high and low frequency. From there, five were prepared in bathymetric pattern of Directorate of Hydrography and Navigation - DHN, with the depth in meters, on a scale of 1:2500 (Channel and Basin Evolution of Access to Port of Cabedelo), where there is a large extent possible beachrocks that hinder the movement of vessels in the port area, which can cause collisions, running aground and leaking oil. From the scatter diagram of the vectors of currents, it can be seen as the tidal stream and undergoes a channeling effect caused by the bidirectional effect of the tide (ebb and flood) in the basin of the Port of Cabedelo evolution in NW-direction SE and the highest speed of the currents occurs at low tide. The characterization weather for the period from 28/02 to 04/07/2010 values was within the expected average for the region of study. The multidisciplinary integration of products (digital maps and remote sensing images), proved to be efficient for the characterization of underwater geomorphological study area, reaching the aim to discriminate and enhance submerged structures, previously not visible in the images

Papel da localização da carga em determinação dos parâmetros do canal iônico

To aureus α-HL channel, we used the cysteine-scanning mutagenesis technique. Twenty-four mutants were produced from the substitution of a single aminoacid of the primary structure of the α-HL pro this yzed after the incorporation of a mutant channel in planar lipid bilayer membranes. The modified proteins were studied in the absence and presence of watersoluble specific sulphydryl-specific reagents, in order to introduce a strong positive or negative harge at positions of substitution. The introduction of a negative charge in the stem region onverted the selectivity of the channel from weak anionic to more cationic. However, the troduction of a positive charge increased its selectivity to the anion. The degree of these alterations was inversely dependent on the channel radius at the position of the introduced harge (selectivity). As to the asymmetry of the conductance-voltage, the influence of the harge was more complex. The introduction of the negative charge in the stem region (the trans art of the pore) provoked a decrease. The intensity of these alterations depended on the radius, and on the type of free charge at the pore entrance. These results suggest that the free charge at surrounds the pore wall is responsible for the cation-anion selectivity of the channel. The istribution of the charges between the entrances is crucial for determining the asymmetry of e conductance-voltage curves. We hope that these results serve as a model for studies with other nanometric channels, in biological or planar lipid bilayer membranes or in iotechnological applications

Comprovação da real comunicação entre o endodonto e o periodonto através do canal cavo inter-radicular e sua prevalência em molares inferiores humanos

The neurovascular system of the pulp and of the periodontium is interconnected and among the possible intercommunications between these two tissues, there is the cavo inter-radicular canal. It is a small canal that goes through any inter-radicular dentine and arises in the furca region of the multi-radicular teeth. Its predominance has been studied in the literature, by several methodologies, with divergent results. The objective of this work was to establish, in vitro, the predominance of the cavo inter-radicular canal, in human lower molars, through the diaphanization technique and dye leakage. For this research, 140 teeth (100 first and second 40 lower molars) were selected, extracted due to different reasons, belonging to a teeth bank of the Endodontics discipline of the Dentistry College at Federal University of Rio Grande do Norte. The teeth were preserved in formol until the moment of use and immersed in physiological solution. Had the endodontic access fulfilled and the whole external surface, except for the furcation, sealed with two layers of nail enamel. The cleaning of the pulpar chamber floor was carried out with sodium hypochlorite solution 5%, being this solution renewed every 5 minutes, during 1 hour. The teeth were immersed in Indian dye and, after drying of the dye, they had their crowns split up in the amelo-cemental junction. Then, they were examined in a stereomicroscope, where marks of the coloring were observed in the furcation and on the pulpar floor. After this recording, the sample was diaphanized and with the transparent teeth, it was possible to observe in the stereomicroscope, the true inter-radicular canals. As a result of this experiment, the presence of these canals was observed in 13 % of the first and 7, 5 % of the second evaluated molars. The study showed that both the presence of the cavo inter-radicular canal is real and the diaphanization and dye leakage is an efficient method for this type of research

Geomorfologia e neotectônica no Vale do Apodi-Mossoró RN

Numerous studies have indicated that the Potiguar Basin is affected by Cenozoic tectonics. The reactivation of Cretaceous fault systems affect the post-rift units, witch include Neogene and overlying Quaternary sediments. In this context, the objectives of this thesis are the followings: (1) to characterize the effects of post-rift tectonics in the morphology of Apodi Mossoró-river valley located in the central portion of the Potiguar, (2) to characterize the drainage of the Apodi Mossoró river valley and investigate the behavior of their channels across active faults, and (3) to propose a geologic-geomorphological evolutionary model for the study area. This study used a geological and geomorphological mapping of the central part of the basin, with emphasis on the Quaternary record, luminescence dating of sediments, and geoelectric profiles of the area. The results reveal by maps of structural lineaments and drainage channels of the rivers form valleys that are affected by faults and folds. In Apodi-Mossoró valley, anomalies of channel morphology are associated with the deformation of the post-rift basin. These anomalies show the reactivation of major fault systems in the Potiguar Basin in Cenozoic. On a regional scale, can be seen through the vertical electric profiles that the Cenozoic tectonics is responsible for the elevation of a macro dome NE-SE-trending 70-km long and 50km wide and up to 270 above sea level. In this sector, the vertical electric profiles data show that the contact between the Cretaceous and Neogene rise more than 100m. This Is an important feature of inversion data obtained in this work showed that the deposits that cover the macro dome (Serra do Mel) have ages of 119 ka to 43 ka. In the river valley and surrounding areas Apodi-Mossoró ages vary between 319 ka and 2.7 ka. From these data it was possible to establish the correct geochronological posiconamento paleodepósitos of distinguishing them from the fluvial deposits of the Neogene (Barreiras Formation)

Aspectos Morfo-Dinâmicos daComplexo Lagunar Nísia Floresta-Papeba-Guaraíras, Região Costeira Sul Oriental Do RN

This dissertation presents the results of research developed in the Nísia Floresta-Papeba-Guaraíras Lagoon Complex, located on the south coast of the Rio Grande do Norte State. The main objectives of this dissertation were the stratrigraphic characterization, in detail scale, of the and the coastal dynamics study of the lagoonal deposits sedimentation, as well as the morpho-dynamic analysis of the area. Therefore, an interdisciplinary methodology was adopted, in which all sedimentological, morpho-tectonic and geomorphological data were integrated. Vibracore up to 4m in length were carried out in the lagoons. The referred lagoon complex made of a system of three lagoons that interact through two artificial channels, named Boqueirão and Surubajá. The Guaraíras lagoon, the largest one in the system, corresponds to the estuary zone of the Trairi and Jacu rivers. The sedimentary load brought by these rivers is strongly reworked by tide currents, forming an important net-work of channels and sandy bars inside this lagoon and close to its channel connection with the sea. The stratigraphic units of the area are Cenozoic in age, and are represented by sedimentary rocks of the Barreiras Formation (sandstones, mudstones and conglomerates) and by rocks beach, as well as by siliciclastics sediments related with the fluvial dynamics of tide plain (clay and sandy bars), and coast (sand dunes and beaches). Among the recognized geomorphologic aspects, there are the elements associated with continental enviroments (drainage basins of the Trairi, Baldum and Jacu rivers, coastal tableland supported by the Barreiras Formation), and transitional environments (lagoon complex, dune fields, cliffs, tidal channels and beach rocks lines). The morphotectonic analysis indicates that fauts affect Barreiras Formation sedimentary rocks, with two sets of main lineaments: SW-NE and SE-NW. The anomalies in the drainage net are directly associated with these fault/fracture system, which control and subdivede the low courses of the Trairi and Jacu rivers, at least a tail of their flowing principal courses. The Nísia Floresta, Papeba and Guaraíras lagoons present strong morphological control according to the lineament directions. Taking into account the lagoonal deposits, the sedimentological analyses reflect a sediment distribution related to the interaction of the fluvial and sea processes that act in the study area. The correlated deposits show textural mainly microclastic characteristics of shallow waters, and of currents of low to moderate energy.In general, the Nísia Floresta-Papeba-Guaraíras lagoon Complex, constitutes a very intrinsec group, that undewent important changes in historical times that are reflected in the currents clays. Inaddition to the natural processes that act in this system, we should take into account the antrohopic intervention, which have increased in the past years