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11.
Vardhanan YS Radhakrishnan T 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(4):387-392
Routine static tests were conducted for determining the median lethal tolerance limit of paddy field crab, Paratelphusa hydrodromus exposed to Copper, Arsenic and HCH at different time intervals of 24, 48, 72 and 96 hour. The LC50 values for Copper came to be 28.00, 22.00, 18.20 and 15.70 ppm; Arsenic 136.00, 128.00, 121.500 and 114.00 ppm and HCH 10.00, 8.80, 7.00 and 6.00 ppm, respectively. The safe concentration, application factor and safe application rate were also calculated. They were for, Copper: 5.56, 1.59 and 3.26 ppm, Arsenic: 38.53, 11.40 and 76.00 and HCH : 4.07, 0.06 and 1.28 ppm. Animals exposed to different concentrations of test chemicals (Copper, Arsenic and HCH) showed prominent behavioural/morphological alterations viz., coughing, redness on the ventral side, paralysis and disorientation in scaphognathite activity. Animals exposed to high concentrations showed an avoidance behaviour by keeping away from the direct contact with the toxic solution either by climbing on the wall of aquarium or by mounting over the weak individual and forming a type of pyramid. 相似文献
12.
A novel cation exchanger, polymethacrylic acid-grafted saw dust (SD) with spacer group (SP) containing carboxylate functional
group at the chain end (SDGPMA-SP-COOH) was prepared from saw dust of Jack wood, and its adsorption equilibrium and thermodynamics
of Cr(III) ions were studied at different initial concentrations and temperatures at pH 7.0 using batch technique. Thermodynamic
parameters such as change in standard free energy, ΔG
0, standard enthalpy, ΔH
0 and standard entropy, ΔS
0 were determined. The values of isosteric heat of adsorption (ΔH
x
) remain constant at different surface loading of Cr(III) indicating homogeneous surface sites and the absence of lateral
interaction between adsorbed ions. 相似文献
13.
Fang Y Scheibe TD Mahadevan R Garg S Long PE Lovley DR 《Journal of contaminant hydrology》2011,122(1-4):96-103
The activity of microorganisms often plays an important role in dynamic natural attenuation or engineered bioremediation of subsurface contaminants, such as chlorinated solvents, metals, and radionuclides. To evaluate and/or design bioremediated systems, quantitative reactive transport models are needed. State-of-the-art reactive transport models often ignore the microbial effects or simulate the microbial effects with static growth yield and constant reaction rate parameters over simulated conditions, while in reality microorganisms can dynamically modify their functionality (such as utilization of alternative respiratory pathways) in response to spatial and temporal variations in environmental conditions. Constraint-based genome-scale microbial in silico models, using genomic data and multiple-pathway reaction networks, have been shown to be able to simulate transient metabolism of some well studied microorganisms and identify growth rate, substrate uptake rates, and byproduct rates under different growth conditions. These rates can be identified and used to replace specific microbially-mediated reaction rates in a reactive transport model using local geochemical conditions as constraints. We previously demonstrated the potential utility of integrating a constraint-based microbial metabolism model with a reactive transport simulator as applied to bioremediation of uranium in groundwater. However, that work relied on an indirect coupling approach that was effective for initial demonstration but may not be extensible to more complex problems that are of significant interest (e.g., communities of microbial species and multiple constraining variables). Here, we extend that work by presenting and demonstrating a method of directly integrating a reactive transport model (FORTRAN code) with constraint-based in silico models solved with IBM ILOG CPLEX linear optimizer base system (C library). The models were integrated with BABEL, a language interoperability tool. The modeling system is designed in such a way that constraint-based models targeting different microorganisms or competing organism communities can be easily plugged into the system. Constraint-based modeling is very costly given the size of a genome-scale reaction network. To save computation time, a binary tree is traversed to examine the concentration and solution pool generated during the simulation in order to decide whether the constraint-based model should be called. We also show preliminary results from the integrated model including a comparison of the direct and indirect coupling approaches and evaluated the ability of the approach to simulate field experiment. 相似文献
14.
Paul E. Spector Cary L. Cooper Juan I. Sanchez Michael O'Driscoll Kate Sparks Peggy Bernin Andre Büssing Phil Dewe Peter Hart Luo Lu Karen Miller Lucio Flavio Renault de Moraes Gabrielle M. Ostrognay Milan Pagon Horea Pitariu Steven Poelmans Phani Radhakrishnan Vesselina Russinova Vladimir Salamatov Jesus Salgado Satoru Shima Oi Ling Siu Jean Benjamin Stora Mare Teichmann Tres Theorell Peter Vlerick Mina Westman Maria Widerszal‐Bazyl Paul Wong Shanfa Yu 《组织行为杂志》2001,22(8):815-832
Data were collected from managers in 24 nations/territories on work locus of control (LOC), individualism–collectivism (I–C), and well‐being (job satisfaction, absence of psychological strain, and absence of physical strain). There were significant mean differences across samples on all five of these measures, and consistent with our hypothesis, at the ecological or sample mean level well‐being was associated with an internal locus of control. However, contrary to our hypothesis, well‐being was not associated with I–C, despite a strong correlation between I–C and LOC. Findings at the ecological level were consistent with the literature concerning the salutary effects of control on well‐being. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
15.
Abraham KM Radhakrishnan T 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(2):151-155
Paratelphusa hydrodromus (Herbst.) was exposed to 50 ppm nickel chloride solution for a period of 10 days under laboratory conditions. The gills of the treated and non-treated animals were sectioned, stained and examined under a compound microscope and noticed significant changes such as enlargement of gill lamellae, lifting up and rupture of epithelial cells, enlargement of mid rachis, hyperplasia and hypertrophy, appearance of pyknotic nuclei and a general necrosis in the treated gills. Results suggest that a comparatively low concentration of nickel (50 ppm) is enough to elicit pathological changes in Paratelphusa hydrodromus. 相似文献