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171.
The purpose of this study was to determine certain blood biochemical parameters in hens of Isa Brown breed (n = 20) after nickel administration. Animals were divided into four groups (K, P1, P2, P3). Experimental hens (n = 5; in each group) received nickel (NiCl2) as peroral administration in drinking water in various doses (P1 - 0.02 g NiCl2/L; P2 - 0.2 g NiCl2/L; P3 - 2.0 g NiCl2/L of drinking water) for 28 days. The last group - K (n = 5) was the control, receiving no nickel. Biochemical parameters of mineral profile (calcium; phosphorus; magnesium; sodium; potassium) and of energy and enzymatic profile [(glucose; total cholesterol; total proteins; triglycerides; alanine aminotransferase (ALT) aspartate aminotransferase (AST) gamma glutamyl transferase (GGT) and glutamatdehydrogenase (GLDH)] were analyzed in blood serum on Day 0, 7, 14, 21 and 28 of the experiment. Average levels of mineral metabolism parameters were relatively stable apart from calcium. The evaluation registered a significant decrease in calcium during the experiment mainly in the group with highest nickel concentration in drinking water. No significant differences were detected between groups in energy and enzymatic profile apart from the concentrations of ALT on Day 7. In conclusion, there were significant associations between nickel levels and calcium and ALT in blood serum of the hens. No significant differences were detected in other biochemical parameters of mineral profile (P, Mg, Na, K) and energy and enzymatic profile (glucose, total cholesterol, total proteins, triglycerides, AST, GGT and GLDH) after nickel administration. Our results may contribute to an evaluation of reference levels of analyzed parameters, to monitor the health and nutritional status of hens. In this study also the negative effect of nickel mainly on calcium metabolism was detected.  相似文献   
172.
The residual effect of tobacco biochar(TB ≥ 500°C) mono and co-application with Cahydroxide(CH),Ca-bentonite(CB) and natural zeolite(NZ) on the bio-availability of trace elements TE(s) in alkaline soils has not been deeply studied yet.A pot study that had earlier been investigated TB mono and blended with CH,CB and NZ on the immobilization of Pb,Cu Cd,and Zn by Chinese cabbage.Maize crop in the rotation was selected as test plant to assess the residual impact of amendments on stabilization of Pb,Cu Cd,and Zn in mine polluted(M-P),smelter heavily and low polluted(S-HP and S-LP,respectively) soils.The obtained results showed that stabilization of Pb,Cd,Cu and Zn reached 63.84% with TB + CB,61.19% with TB + CH,83.31% with TB + CH and 35.27% with TB + CH for M-P soil,36.46% with TB + NZ,38.46% with TB + NZ,19.40% with TB + CH and 62.43% with TB + CH for S-LP soil,52.94% TB + NZ,57.65% with TB + NZ,52.94% with TB + NZ,and 28.44% with TB + CH for S-LP soil.Conversely,TB + CH and TB alone had mobilized Pb and Zn up to19.29% and 34.96% in M-P soil.The mobility of Zn reached 8.38% with TB + CB and 66.03%with TB for S-HP and S-LP soils.The uptake and accumulation of Pb,Cd,Cu and Zn in shoot and root were reduced in three polluted soils.Overall,the combination of TB along with CH,CB and NZ has been proven to be effective in Pb,Cd,Cu and Zn polluted mine/smelter soils restoration.  相似文献   
173.
Mesoscale transport and dispersion of air pollutants from a few major point sources in the Mississippi Gulf coastal region is calculated using a coupled modeling system consisting of the atmospheric dynamical model WRF and the lagrangian particle model HYSPLIT. The sensitivity of the dispersion model results to the meteorological fields is studied by conducting an ensemble of simulations using the WRF model for the same dispersion case. Several parameterization schemes for the physical processes of boundary layer turbulence and land surface temperature/moisture prediction in WRF are used in various combinations to produce different meteorological members which are then used for dispersion simulation. The uncertainty in the simulated concentration probabilities to the meteorological model configurations and the ensemble mean are presented. The parameters used for determining the uncertainties include the wind fields, temperature, area of concentration and the levels of concentration. The results indicate that dispersion model results are influenced by the choices made in respect of the planetary boundary layer and land surface schemes in the mesoscale model to produce the meteorological forecast thereby leading to certain amount of uncertainty in the resultant concentrations. Results show that the specific choices made about the atmospheric model configuration can significantly after the simulated concentrations.  相似文献   
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Finland is a forested country with a large export oriented forest industry. In addition to domestic forest extraction, roundwood is imported, thus displacing the environmental impacts of harvests. In this paper, we analyse the international carbon flows of forest industries in Finland from a consumption-based perspective. Quantitative analyses are available on trade embedded emissions of CO2 from fossil fuel combustion, and here we address in a similar way the impact of trade on the carbon budget of the forest products sector in Finland. Carbon flows through the forest industry system increased substantially between 1991 and 2005. We show that the annual carbon balance related to forests and forest industry system in Finland functioned as a sink in 1991, whereas in 2005 the system was a sink on a national level, but not on a global level. Through calculating the carbon content in traded forest industry products and emissions embodied in forest industry activities, we further show that the direct impacts of the forest industry in Finland are only a minor fraction of the total CO2 emissions related to Finnish production. Nearly all of the emissions were caused due to production of exports. Yet, direct carbon dioxide emissions of the industrial production are reported to Finland in the production based inventories.  相似文献   
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The aim of the study was to estimate Zn phytoextraction and changes in biomass of S?×?rubens growing in modified Knop's solution with different levels of Zn addition (0.5, 1.0, 2.5 and 5.0?mM). Obtained results were correlated with secretion of selected low-molecular-weight organic acids (LMWOAs) in the rhizosphere, roots and leaves. An increase in Zn concentration in Knop's solution resulted in Zn accumulation in roots, shoots and leaves. The highest accumulation was observed for plants growing in 5?mM Zn, at concentration levels 4741.36?±?98.66, 1227.31?±?16.57 and 2241.65?±?34.90?mg?kg?1 DW in roots, shoots and leaves, respectively. The bioaccumulation factor and the translocation factor for plants growing in 0.5, 1.0 and 2.5?mM Zn clearly indicate that this Salix taxon is an effective Zn accumulator. The general reduction of Salix biomass with an increase in Zn concentration in the solution was observed. In the rhizosphere, the total LMWOA concentration was almost 0.93?µmol?kg?1 DM for control (Zn free) plants, while for 5.0?mM of Zn it was 4.9?µmol?kg?1 DM. Increasing concentrations of acids were observed in roots (1.34 for the control and 5.57?µmol?kg?1 DM for plants treated with 2.5?mM of Zn).  相似文献   
179.
An individual-based model was developed to predict the population dynamics of Daphnia magna at laboratory conditions from individual life-history traits observed in experiments with different feeding conditions. Within the model, each daphnid passes its individual life cycle including feeding on algae, aging, growing, developing and – when maturity is reached – reproducing. The modelled life cycle is driven by the amount of ingested algae and the density of the Daphnia population. At low algae densities the population dynamics is mainly driven by food supply, when the densities of algae are high, the limiting factor is “crowding” (a density-dependent mechanism due to chemical substances released by the organisms or physical contact, but independent of food competition).  相似文献   
180.
Two-year old Ulmus laevis Pall (U. laevis) seedlings were cultivated in a three-month hydroponic experiment with inorganic (aresenite – As(III) and arsenate – As(V)) and organic (dimethylarsenic acid – DMA(V)) arsenic forms, at 0.06 and/or 0.6?mM concentrations. Further, the profile and content of total low molecular weight organic acids (LMWOAs) were investigated in the rhizosphere, roots and leaves of U. laevis. Obtained results showed that the addition of As(III) or As(V) individually or in a mixture led to increased LMWOAs concentration in the rhizosphere, especially of oxalic and malonic acids, in comparison to the control, while in roots the overall content of the profiled LMWOAs decreased. In both rhizosphere and roots, addition of the DMA(V) form resulted in the inhibition of LMWOAs exudation into the rhizosphere and their creation in plant roots. Leaves were characterised by a higher content of LMWOAs than in the rhizosphere and roots for all experimental systems, where the profile and content of LMWOAs was strictly correlated with the analysed As forms. Our study indicated that creation of LMWOAs in U. laevis organs and their exudation to the rhizosphere could be responsible for the As toxicity tolerance of the plants.  相似文献   
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