19 research outputs found

    Vaccination of rainbow trout against Streptococcus iniae infection: comparison of different routes of administration and different vaccines

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    Antibody production and clinical efficacy (relative percent survival RPS) were measured in 40±5g rainbow trout after immunization with two types of Streptococcus iniae vaccines consisting of formalin killed cells (FKC) and FKC enriched with the bacterial extracellular products (ECP) administered by intraperitoneal (i.p), immersion and oral routes at 16±1°C for 18 weeks. No significant difference was found in antibody levels among the fish i.p immunized with FKC enriched with ECP plus Freunds' adjuvant (FA), FKC plus FA and FKC vaccines (P>0.05), whilst the antibody production was significantly higher in these three groups than fish immunized by immersion and oral routes of FKC and FKC enriched ECP (P0.05). The RPSs ranging 82.6-100, 73.9-95 and 73.9-91.7% were obtained in the fish intraperitoneally immunized with FKC enriched ECP plus FA, FKC plus FA and FKC vaccines, respectively, compared to 0% survival for the control fish. Also, RPS in fish vaccinated by the immersion route was in the range 45.8-30.4% after 18 weeks post-vaccination. Efficacy of oral vaccination of fish with FKC plus ECP was in range of 8.7-29% and that of fish orally vaccinated with FKC resulted in 8.7-20.8% protection

    Selected morpho-chemical features of hemocytes in farmed shrimp, Fenneropenaeus indicus in Iran

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    The aim of the present study was to determine various types of hemocytes, total and differential hemocyte count and to show some indices of phagocytosis, including percent phagocytosis and phagocytic index in Indian white shrimp, Fenneropenaeus indicus in Iranian shrimp farms. The hemolymph was extracted from the shrimps and mixed with anticoagulant. It then stained and Yeast was added as foreign particles to samples. Based on the cell size and presence of the granules and nucleocytoplasmic ratio, three major groups of hemocytes, including hyaline cells, small granular cells (SGC) and large granular cells (LGC) were identified. Hyaline cell (HC) was the smallest hemocyte. HC (hyaline cell) about was 10-15%, lower quantity in comparison to some species and those of LGC and SGC were 20-25% and 60-65%, respectively, suggesting that relative percentage of differential hemocyte count in Fenneropenaeus indicus is different from other decapods. Also, in this study, it was shown that SGH and LGH could engulf the yeast particles. In Contrast to some previous studies, no engulfment was observed by hyaline cells in vitro. In this study it was showed that there are some variations in total and differential hemocyte count compare to other species in the family of Penaeidae

    The effect of different salinities on mortality and histopathological changes of SPF imported Litopenaeus vannamei, experimentally exposed to White Spot Virus and a new differential hemocyte staining method

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    Shrimp farmers have been suffering from loss of production due to White Spot Disease (WSD) in the last decades. A few studies focused on the environmental factors predisposed WSD. Our study aimed to investigate the effects of the different salinities on occurrence of WSD. The treatments were 30 ppt, 40 ppt and 50 ppt in triplicate and corresponding untreated control groups. White Spot Virus (WSV) was intramuscularly injected to the shrimp in whole treatments. PCR and histopathological findings within the measurement of some hemolymph parameters such as Differentiated Hemocyte Count (DHC), Total Hemocyte Count (THC) and Total Plasma Protein (TPP) were carried out. A positive result was observed for the occurrence of the antigen of the WSV obtained from the samples of each treatment of salinity due to the challenging treatments with the WSV. Mortality at the salinity of 30 ppt began at 72 h post inoculation as well as the salinity of 40 ppt, but at 50 ppt it started after 50 h. The Minimum and maximum count of mortality at the salinity of 30, 40 and 50 ppt were 3.5, 8.5 0.5, 4.5 and 1.5, 7.5, respectively. No mortality was observed in the untreated control groups of 30, 40 and 50 ppt during the experiment. It is concluded that the higher and the lower salinity, lesser or greater than the normal condition in exposed to WSV could lead to severe mortality of WSD

    Hexagonal Smoothness-Increasing Accuracy-Conserving Filtering

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    Discontinuous Galerkin (DG) methods are a popular class of numerical techniques to solve partial differential equations due to their higher order of accuracy. However, the inter-element discontinuity of a DG solution hinders its utility in various applications, including visualization and feature extraction. This shortcoming can be alleviated by postprocessing of DG solutions to increase the inter-element smoothness. A class of postprocessing techniques proposed to increase the inter-element smoothness is SIAC filtering. In addition to increasing the inter-element continuity, SIAC filtering also raises the convergence rate from order k+1k+1 to order 2k+12k+1 . Since the introduction of SIAC filtering for univariate hyperbolic equations by Cockburn et al. (Math Comput 72(242):577–606, 2003), many generalizations of SIAC filtering have been proposed. Recently, the idea of dimensionality reduction through rotation has been the focus of studies in which a univariate SIAC kernel has been used to postprocess a two-dimensional DG solution (Docampo-Sánchez et al. in Multi-dimensional filtering: reducing the dimension through rotation, 2016. arXiv preprint arXiv:1610.02317). However, the scope of theoretical development of multidimensional SIAC filters has never gone beyond the usage of tensor product multidimensional B-splines or the reduction of the filter dimension. In this paper, we define a new SIAC filter called hexagonal SIAC (HSIAC) that uses a nonseparable class of two-dimensional spline functions called hex splines. In addition to relaxing the separability assumption, the proposed HSIAC filter provides more symmetry to its tensor-product counterpart. We prove that the superconvergence property holds for a specific class of structured triangular meshes using HSIAC filtering and provide numerical results to demonstrate and validate our theoretical results

    Anisotropic Radial Layout for Visualizing Centrality and Structure in Graphs

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    This paper presents a novel method for layout of undirected graphs, where nodes (vertices) are constrained to lie on a set of nested, simple, closed curves. Such a layout is useful to simultaneously display the structural centrality and vertex distance information for graphs in many domains, including social networks. Closed curves are a more general constraint than the previously proposed circles, and afford our method more flexibility to preserve vertex relationships compared to existing radial layout methods. The proposed approach modifies the multidimensional scaling (MDS) stress to include the estimation of a vertex depth or centrality field as well as a term that penalizes discord between structural centrality of vertices and their alignment with this carefully estimated field. We also propose a visualization strategy for the proposed layout and demonstrate its effectiveness using three social network datasets.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

    Bioassay of combined hydrogen peroxide and silver ion at four life stages of Indian white shrimp (Fennerop enaeus indicus)

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    Silver ion and hydrogen peroxide act synergistically as a strong disinfectant. The purpose of this study was to assess the effect of combined hydrogen peroxide 50% and silver ion 0.05% at four life stages of Indian white shrimp (Fenneropenaeus indicus) and to evaluate the feasibility of using this substance in shrimp culture. The Trimmed Spear man karber software was applied for determining EC _(50)/96h and LC sub(50)/96h with 95% confidence limit on the 6000 shrimp based on OECD static method. The experiments were conducted in Iran Shrimp Research Center, Bushehr, during 2005 -2006. The EC _(50) values of 132.5, 67.89, 55.56, 51.95 and 48 .6ppm were obtained in PL15 stage after 12, 24, 48, 72 and 96 hours, respectively. Also these were 147.57, 70.83, 60.01, 54.89, 41.19 for PL_(45) stage, and 306.43, 174.14, 113.62, 78.21, 61.96 for sub adult stage (12 plus or minus 1 grams), res pectively. In addition, the EC _(50) values of 243.25, 130.55, 75.56, 61. 18 and 51.59ppm were obtained at adult stage (20 plus or minus 2 grams), respectively. The LC sub(50) values of 239.81, 101, 74.28, 65.72 and 61.45ppm were obtained in PL _(15) stage after 12, 24, 48, 72 and 96 hours, respectively. Also thes e were 304.56, 160.12, 113.1, 93.69, 79.38 for PL _(45) stage, and 712.13 , 518.44, 265.29, 145.53, 103.76 for sub adult stage, respectively. In addition, the LC _(50) values of 827.75, 508.91, 317.3, 139.44 and 85.88ppm were obtained at adult stage, respectively. The statistical results showed that; no observed effect concentration" (NOEC) of this substance was 20ppm, and the "lowest observed effect concentration" (LOEC) was 40ppm, thus "maximum allowable concentration" (MAC) value was determined 28.8 ppm on the Indian white shrimp. Therefore this combined chemical should be used under determined MAC value with a complete precautionary as a disinfectant for Indian white shrimp

    Anesthetic effect of tricaine methanesulfonate, clove oil and electroanesthesia on lysozyme activity of Oncorhynchus mykiss

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    Abstract There is a few available information about the effect of anesthetics, specially electroanesthesia on immune parameters in fish. In the present work, two anesthetics, MS222 (50 ppm), clove oil (25 ppm), and electroanesthesia were tested in rainbow trout (Oncorhynchus mykiss) in narcosis stage. The results showed, clove oil and electroanesthesia increase the lysozyme activity 24 h after anesthesia(p<0.05) and it induces neutrophilia and lymphopenia in the same group 24h after anesthesia(p<0.05), but fish specimens anesthized with MS222 didn't show any difference 1h and 24h after exposure in lysoyme level and differential white blood cell count (p>0.05). It seems use of MS222 during aquacultural practices may induce lesser effect in rainbow trout

    Growth Behavior and Fatty Acid Production of Probiotics, Pediococcus acidilactici and Lactococcus lactis, at Different Concentrations of Fructooligosaccharide: Studies Validating Clinical Efficacy of Selected Synbiotics on Growth Performance of Caspian Roach (Rutilus frisii kutum) Fry

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    Growth behavior and production of short-chain fatty acid (SCFA) of two probiotics, Pediococcus acidilactici and Lactococcus lactis, each at 107 cfu/g (P1, L1) and 1010 cfu/g (P2, L2) at different concentrations of fructooligosaccharide (FOS) [0.5% (F1), 1% (F2), and 2% (F3)] were assessed in vitro. The time to reach the maximum growth of the probiotics in all 12 treatments was between 8 to 10 h, with the highest and the lowest growth rates obtained in F1L1P1 (0.34 ± 0.02 OD) and F3L1P1 (0.31 ± 0.05 OD) treatments, respectively. The shortest and the longest generation times were seen in F1L1P1 (112 ± 1.5 min) and F2L1P1 (231 ± 0.5 min) treatments, respectively. The highest and the lowest levels of SCFA production were found in F1L1P1 (17.94 ± 0.74 mg/L) and F3L1P1 (12.98 ± 0.85 mg/L) treatments, respectively. The three synbiotics with the highest SCFA production were then fed to Caspian roach (Rutilus frisii kutum) fry weighing 0.75 ± 0.02 g at 28 °C for 60 days, to assess growth performance and enzymatic activity. The best growth performance in terms of weight gain (WG), protein efficiency ratio (PER), net protein utilization (NPU), and food conversion ratio (FCR) were seen with F1L1P1. In addition, the highest activity levels of the digestive enzymes chymotrypsin, lipase, and amylase were obtained with F1P1L1. The correlation of these in vitro and in vivo data demonstrated that oral application of these two probiotics each at 107 cfu/g feed plus 0.5% FOS can improve growth and gut enzyme activity of Caspian roach fry

    Visualization in meteorology --- A survey of techniques and tools for data analysis tasks

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    This article surveys the history and current state of the art of visualization in meteorology, focusing on visualization techniques and tools used for meteorological data analysis. We examine characteristics of meteorological data and analysis tasks, describe the development of computer graphics methods for visualization in meteorology from the 1960s to today, and visit the state of the art of visualization techniques and tools in operational weather forecasting and atmospheric research. We approach the topic from both the visualization and the meteorological side, showing visualization techniques commonly used in meteorological practice, and surveying recent studies in visualization research aimed at meteorological applications. Our overview covers visualization techniques from the fields of display design, 3D visualization, flow dynamics, feature-based visualization, comparative visualization and data fusion, uncertainty and ensemble visualization, interactive visual analysis, efficient rendering, and scalability and reproducibility. We discuss demands and challenges for visualization research targeting meteorological data analysis, highlighting aspects in demonstration of benefit, interactive visual analysis, seamless visualization, ensemble visualization, 3D visualization, and technical issues
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