79 research outputs found

    ENVIRONMENTAL AND SOCIAL DECISION FACTORS OF BEACH SAFETY IN THE CENTRAL NORTHERN COAST OF SANTA CATARINA, BRAZIL.

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    Os determinantes dos níveis de risco público de uma praia são função da intensidade e tipo de uso que recebe e de suas características morfodinâmicas. Durante campanha de levantamento das condições de ocorrência de acidentes de banho no litoral centro-norte catarinense, realizada com o objetivo de identificar aqueles determinantes, os 137 registros recuperados demonstram que: 64% das vítimas são homens; 56% são veranistas habituais dos locais em que foram atendidos; 70% não sabiam nadar; 77% foram socorridas em correntes de retorno de intensidade moderada a forte; 88% dos acidentes ocorreram sob alturas de onda entre 0 e 1m, 45% em arrebentações deslizantes e 30% em arrebentações frontais; e 54% dos casos ocorreram em praias do tipo banco/cava longitudinais, 24%, do tipo dissipativo e 16%, do tipo banco e praia rítmicos. De um modo geral, os resultados obtidos demonstram a maior importância de determinantes sociais em relação aos ambientais para a questão da segurança no banho destas praias.Beach safety is an issue both of type/intensity of usage that a beach receives and of its physical characteristics (including morphodynamic state and local hazards). This paper shows the results of a survey conducted at oceanic beaches of the central northern coast of Santa Catarina, Brazil, in order to investigate the magnitude and nature of beach safety issue in these localities. The 137 registers obtained showed that: 64% of accident victims were male; 56% were habitual users of the beaches from which they were rescued; 70% were unable to swim; 77% of the accidents ocurred in rip currents of moderate to strong intensity; 88% in under 0 to 1m wave breaker heights; 45% under spilling breakers and 30% under plunging breakers; 54% of the accidents occurred at longshore bar and trough beaches, 24% at dissipative beaches and 16% at rhythmic bar and beach beaches. Generally, results showed that social decision factors may be more important than the environmental ones in the issue of beach safety at the surveyed beaches

    Nycthemeral and Monthly Occupation of the Fish Assemblage on a Sheltered Beach of Baía Norte, Florianópolis, Santa Catarina State, Brazil

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    Interpreting fish community records is challenging for several reasons, including the lack of past ichthyofauna data, the cyclical temporal variations in the community, and the methodology employed, which usually underestimates fish assemblages. The objective of this study was to describe short-scale and meso-scale (nycthemeral period and months, respectively) temporal variations in the ichthyofauna composition and structure of a sheltered beach of Baía Norte (Florianópolis, Santa Catarina state, Brazil), using a capéchade net. Samples were collected monthly for a period of 48 hours. During the period from December 2010 to November 2011, a total of 19,302 individuals belonging to 89 species and 39 families were captured. The number of individuals that were sampled during the day and/or night was dependent on the sampling month. On average, the daytime assemblage was more abundant and different in structure and composition than the nighttime assemblage. Of the eight species that had the highest Index of Relative Importance (%IRI), five had higher variations (ANOVA F) between the day and night than between the months. This finding reinforced the need for sampling during both the day and night. The capéchade net effectively captured demersal and pelagic individuals in a broad range of sizes

    Main results of the first experimental campaign in the stellarator W7-X

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    A summary of the first operational phase (OP1.1) at the stellarator W7-X is given. The operational setup of heating and diagnostics as well the results of experiments are briefly described. Plasma parameters and confinement are better than expected: Te > 8 keV and Ti > 2 keV at ne ≈ 3×1019 m-3 yielding β0 ≈ 2.5 %. The results for ECR heating with X2-mode as well the ECCD are in good agreement with the theory predictions. The heating scenario with the O2-mode alone was successfully first time performed. Stellarator specific regime of core “electron root” confinement was obtained

    Capturing Single Cell Genomes of Active Polysaccharide Degraders: An Unexpected Contribution of Verrucomicrobia

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    Microbial hydrolysis of polysaccharides is critical to ecosystem functioning and is of great interest in diverse biotechnological applications, such as biofuel production and bioremediation. Here we demonstrate the use of a new, efficient approach to recover genomes of active polysaccharide degraders from natural, complex microbial assemblages, using a combination of fluorescently labeled substrates, fluorescence-activated cell sorting, and single cell genomics. We employed this approach to analyze freshwater and coastal bacterioplankton for degraders of laminarin and xylan, two of the most abundant storage and structural polysaccharides in nature. Our results suggest that a few phylotypes of Verrucomicrobia make a considerable contribution to polysaccharide degradation, although they constituted only a minor fraction of the total microbial community. Genomic sequencing of five cells, representing the most predominant, polysaccharide-active Verrucomicrobia phylotype, revealed significant enrichment in genes encoding a wide spectrum of glycoside hydrolases, sulfatases, peptidases, carbohydrate lyases and esterases, confirming that these organisms were well equipped for the hydrolysis of diverse polysaccharides. Remarkably, this enrichment was on average higher than in the sequenced representatives of Bacteroidetes, which are frequently regarded as highly efficient biopolymer degraders. These findings shed light on the ecological roles of uncultured Verrucomicrobia and suggest specific taxa as promising bioprospecting targets. The employed method offers a powerful tool to rapidly identify and recover discrete genomes of active players in polysaccharide degradation, without the need for cultivation

    Towards a new image processing system at Wendelstein 7-X: From spatial calibration to characterization of thermal events

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    Wendelstein 7-X (W7-X) is the most advanced fusion experiment in the stellarator line and is aimed at proving that the stellarator concept is suitable for a fusion reactor. One of the most important issues for fusion reactors is the monitoring of plasma facing components when exposed to very high heat loads, through the use of visible and infrared (IR) cameras. In this paper, a new image processing system for the analysis of the strike lines on the inboard limiters from the first W7-X experimental campaign is presented. This system builds a model of the IR cameras through the use of spatial calibration techniques, helping to characterize the strike lines by using the information given by real spatial coordinates of each pixel. The characterization of the strike lines is made in terms of position, size, and shape, after projecting the camera image in a 2D grid which tries to preserve the curvilinear surface distances between points. The description of the strike-line shape is made by means of the Fourier Descriptors

    Forward modeling of collective Thomson scattering for Wendelstein 7-X plasmas: Electrostatic approximation

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    In this paper, we present a method for numerical computation of collective Thomson scattering (CTS). We developed a forward model, eCTS, in the electrostatic approximation and benchmarked it against a full electromagnetic model. Differences between the electrostatic and the electromagnetic models are discussed. The sensitivity of the results to the ion temperature and the plasma composition is demonstrated. We integrated the model into the Bayesian data analysis framework Minerva and used it for the analysis of noisy synthetic data sets produced by a full electromagnetic model. It is shown that eCTS can be used for the inference of the bulk ion temperature. The model has been used to infer the bulk ion temperature from the first CTS measurements on Wendelstein 7-X
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