584 research outputs found

    Use of stable isotopes, organic and inorganic chemistry to identify pollution sources and weathering processes in two small tropical rivers in southwestern India

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    The two main objectives of this study were to assess pollution dynamic from organic and inorganic major ion chemistry and stable isotopes (δ15N and δ18O) and to determine the weathering processes using carbon isotopes in two tropical river basins, i.e. Nethravati and Swarna, along southwest coast of India. These short length river basins (around 100 km) are characterized by high annual rainfall, warm temperature, high runo" (~3300mm) draining Precambrian basement rocks composed of green-stones, granitic-gneiss, charnockite and meta sediments. Intense silicate weathering is induced by high runo" and warm temperature (Gurumurthy et al., 2012). In this study, stable isotopes (δ15N & δ18O)of organic molecules from sewage and agricultural effluents,and carbon isotopes (δ13C) of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were measured to trace agricultural and domestic pollution and to identify the sources of inorganic carbon and the nature of chemical weathering in these river basins. Carbon isotopes measured on DIC reveals sources of carbon into the river, such as carbonate/silicate weathering of rocks, mineralization of organic matter from C3/C4 plants, soil and atmospheric CO2. The nitrate and phosphate levels remain low, with values ranging from 5 to 9 μM, and 0 to 2 μM respectively. The δ13C DIC values range from =-9.03 +/- 0.99 for the Swarna basin to -8.08 +/-0.78 for the Nethravati basin. These values point to a mixing of carbonate and silicate weathering products with a dominance of C3 vegetation, prevalent in the Western Ghats. The DOC values for both river basins are very low and very close: 0.72 +/- 0.09 mg/L (Swarna river) and 0.62 +/-0.11 mg/L (Nethravati river). This indicates that the contributions of organic matter from the adjacent forests and the $ood plains are very low during the sampling period. The analysis of organic acids reveals low amount of Oxalate and Acetate, and trace of Malate and Tartaric acids. The dissolved and particulate organic carbon (DOC and POC) concentrations are very low in these two rivers. During the dry season, river discharge is mainly supplied by groundwater with generally low contents in dissolved and particulate fractions. Even if we observe low concentration, we measured higher DOC and POC in the Swarna river. These higher DOC concentrations are accompanied with lower SUVA value. This indicates that more labile DOC (less aromaticity) is exported within this basin during dry season. C/N values in POC also show that the organic carbon is “fresher” and is probably more autochtonous than in the Nethravati river. Indeed, C/N value are closer of an autochthonous production (C/N : 2-6) than allochthonous one (C/N: 8-20). These observations can be explained as the Svarna watershed land use is more agricultural than in Nethravati. Agricultural lands generally export signi%cant amount of nutrients to rivers and participate to enhance autochthonous productivity. Autochthonous organic carbon production is more labile and less aromatic

    Moringa oleifera Lam. leaves prevent Cyclophosphamide-induced micronucleus and DNA damage in mice

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    Chemoprotective effect of ethanolic extract of Moringa oleifera Lam leaves was evaluated on cyclophosphamide (CP)-induced genotoxicity in the mouse. Animals were pre-treated with the extract for seven consecutive days at doses of 250, 500, 1000 and 2000 mg/kg b.w. Micronucleus in bone marrow and comet (DNA damage) in the liver were performed. Cyclophosphamide was administered intra-peritoneally on day 7 and Mice were sacrificed after 24 hours. In CP treated animals, statistically significant induction of micronuclei in polychromatic erythrocytes (PCE) was recorded. However, in the animals pre-treated with the extract, the percentage of CP-induced MN decreased with increasing concentration of the extract. Results of comet assay showed similar decrease in DNA damage in mice pre-dosed with the extract. These results point out to the presence of chemopreventive phytoconstituents in the crude extract offering protection against CP-induced genotoxicity in the mouse.Keywords: M. oleifera; Anti-genotoxic; Micronucleus assay; Comet assay; Chemoprevention

    Black Hole Boundary Conditions and Coordinate Conditions

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    This paper treats boundary conditions on black hole horizons for the full 3+1D Einstein equations. Following a number of authors, the apparent horizon is employed as the inner boundary on a space slice. It is emphasized that a further condition is necessary for the system to be well posed; the ``prescribed curvature conditions" are therefore proposed to complete the coordinate conditions at the black hole. These conditions lead to a system of two 2D elliptic differential equations on the inner boundary surface, which coexist nicely to the 3D equation for maximal slicing (or related slicing conditions). The overall 2D/3D system is argued to be well posed and globally well behaved. The importance of ``boundary conditions without boundary values" is emphasized. This paper is the first of a series. This revised version makes minor additions and corrections to the previous version.Comment: 13 pages LaTeX, revtex. No figure

    1mb{1\over m_b} and 1mt{1\over m_t} Expansion of the Weak Mixing Matrix

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    We perform a 1/mb1/m_b and 1/mt1/m_t expansion of the Cabibbo-Kobayashi- Maskawa mixing matrix. Data suggest that the dominant parts of the Yukawa couplings are factorizable into sets of numbers r>\vert r>, s>\vert s>, and s>\vert s'>, associated, respectively, with the left-handed doublets, the right-handed up singlets, and the right- handed down singlets. The first order expansion is consistent with Wolfenstein parameterization, which is an expansion in sinθcsin \theta _c to third order. The mixing matrix elements in the present approach are partitioned into factors determined by the relative orientations of r>\vert r>, s>\vert s>, and s>\vert s'> and the dynamics provided by the subdominant mass matrices. A short discussion is given of some experimental support and a generalized Fritzsch model is used to contrast our approach.Comment: A set of references has been added to ealier related wor

    Development, characterization, efficacy and repeated dose toxicity of nanoemulsified ethanolic extract of Enicostemma littorale in Streptozotocin-induced diabetes rats.

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    Alginate nanocapsules of ethanolic extract of Enicostemma littorale (NEL) were prepared by emulsification, cross linking with calcium chloride and solvent removal. Based on total phenol content the loading efficiency of the nanocapsules was 89% at an optimum concentration of 2: 18 (mg ml -1) for plant extract: olive oil. The photon correlation spectroscopy (PCS) revealed that the mean particle diameter of optimized formulation was 233 nm and scanning electron microscopy (SEM) showed a spherical morphology. When subjected to Fourier transform infrared spectroscopy (FT-IR) for the compatability analysis between plant extract and sodium alginate, it revealed that the phytoconstituents were stable. The purpose of the present study was to compare the anti-diabetic activity of NEL and E.littorale (EL) in streptozoticin induced male rats. An oral dose of NEL (20 mg/kg b.w) and EL (2000 mg/kg b.w) showed a relatively similar antidiabetic effect, reducing the blood glucose, triglycerides, cholesterol, creatinine, ALT, AST, and ALP. Moreover, NEL is 100 times less than EL exhibiting better results within 10 days of treatment. These biochemical assessments were supported by rat biopsy examinations. In conclusion, the nanoemulsification method can be applied for poor water-soluble ethanolic herbal extracts to reduce the dosage and time

    Modeling of Breakdown Voltage of White Minilex Paper in the Presence of Voids Using Fuzzy Logic

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    Occluded gaseous cavities within the insulating materials are potential sources of electrical trees which can lead to continuous deterioration and breakdown of materials. To determine the suitability of use and to acquire the data for the dimensioning of electrical insulation systems breakdown voltage of insulators should be determined. In this project, Fuzzy Logic (FL) method is used to model breakdown voltages of White Minilex Paper samples based on experimental data generated in the laboratory. Two models are proposed with triangular and trapezoidal shape of the membership functions for the FL under both dc and ac voltage conditions. The cavities are created artificially with different dimensions. Low values of mean absolute errors of the estimated breakdown voltage of the test data show the effectiveness of such models

    Spatial Variation of Surface Water Quality of Vrishabhavathi Watershed Using GISÂ

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    Vrishabhavathi Watershed is a constituent of the Arkavathi River Basin, Bangalore Urban and Ramanagara District and covers an area of 381.465Km2, representing seasonally dry tropical climate. In Vrishabhavathi watershed Vrishabhavathi River is the main surface water source which is tributary of river Arkavathy, which joins the Cauvery River. It drains a major parts of Bangalore metropolis and is an outlet for domestic and industrial effluent of that area. Earlier this surface water is mainly used for agricultural purposes and drinking purposes. Since this watershed lies in Bangalore urban and Bangalore rural area, today this water is only used for agricultural purposes which are also not safe. In order to assess the surface water quality the present study has been undertaken to map the spatial variability of the surface water quality in the watershed using Geographical Information System. The water qualities of 24 stations were randomly selected in Vrishabhavathi watershed for the present study.GIS is an efficient tool for representation and analysis of spatial information related to water quality analysis. The spatial variation map for sensitive water quality parameters are generated and integrated using Arc GIS10.1. The final integrated map shows 3 priority classes such as Acceptable, Poor and Very poor water quality zones of the study area and provides a guideline for suitability of water for irrigation purpose

    Genotoxicity Evaluation of Commercially Available Acid Red Dye by Comet Assay in Fish (Cyprinus Carpio)

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    Genotoxicity of commercially available acid red dye on fish was evaluated. Fish were exposed to various concentrations of the dye and gill processed for comet assay. Nucleoids were visually scored and categorized into various damage degrees. Significant increase (p < 0.05) in the percentage and distribution of damaged nucleoids was recorded in all dye-treated groups over control. DNA damage scores (AU) increased with exposure concentrations and dose-response was observed at higher doses. From the results it is concluded that commercially available acid red dye is potentially genotoxic to fish. The results are preliminary and further studies are warranted to acknowledge this effect. Keywords: acid red, commercial dyes, genotoxicity, comet assay

    Molecular characterization and assessment of genetic diversity of sorghum inbred lines

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    Selecting parents of diverse genetic base with contrasting phenotype is an important step in developing mapping populations for quantitative trait loci (QTL) detection and marker-assisted selection. We studied genetic diversity in 31 sorghum parents using 413 sorghum simple sequence repeats (SSR) markers. The polymorphism information content (PIC), a measure of gene diversity, varied from 0 to 0.92 with an average of 0.53 and was significantly correlated with number of alleles. The primers IS10215, IS10270 and IS10333 could differentiate all the 31 lines conclusively. Clustering analysis based on the genetic dissimilarity grouped the 31 parents into eight clusters and grouping was in good agreement with pedigree, race and geographic origin. Diverse pairs of sorghum parents were identified with contrast phenotype for various biotic and abiotic stresses with higher genetic diversity for developing recombinant inbred line (RIL) mapping populations to identify QTLs/genes for important traits in sorghum. One of the mapping populations resulted in the identification of QTLs for resistance to sorghum shoot fly and these QTL results were validated in a second mapping population.Key words: Simple sequence repeats (SSR) markers, genetic diversity, sorghum, mapping parents
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