296 research outputs found

    Precision of Age Estimates Obtained from Five Calcified Structure for Wels Catfish, Silurus glanis

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    In this study, vertebrae, otoliths (asteriscus and lapillus), sectioned lapillus and pectoral fin rays were evaluated for age determination of Silurus glanis L., 1758 inhabiting Siddikli Dam Lake. All calcified structures showed the variable annual ring formation. Ages obtained from calcified structures were compared using the percentage of agreement (PA), average percentage of error (APE), and coefficient of variation (CV). Sectioned lapillus showed the clearest annulus formation and highest PA (76.4%) between readings, followed by asteriscus (43.9%), whole lapillus (40.5%), vertebrae (36.0%) and pectoral fin ray (33.3%). When sectioned lapillus compared to other structures, there were high ages obtained from this structure. Especially, the ages from the whole lapillus were lower than sectioned lapillus. Also, ages obtained from pectoral fin ray were the closer to sectioned lapillus ages than the other calcified structures. Owing to the highest PA, lowest APE and CV, sectioned lapillus was recommended as the most reliable calcified structure for age determination of S. glanis. Our findings can be used for effective fisheries management and determination of the biological characteristics of wels catfish

    Glyphosate reduced seed and leaf concentrations of calcium, manganese, magnesium, and iron in non-glyphosate resistant soybean

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    Greenhouse experiments were conducted to study the effects of glyphosate drift on plant growth and concentrations of mineral nutrients in leaves and seeds of non-glyphosate resistant soybean plants (Glycine max, L.). Glyphosate was sprayed on plant shoots at increasing rates between 0.06 and 1.2% of the recommended application rate forweed control. In an experiment with 3-week-old plants, increasing application of glyphosate on shoots significantly reduced chlorophyll concentration of the young leaves and shoots dry weight, particularly the young parts of plants. Concentration of shikimate due to increasing glyphosate rates was nearly 2-fold for older leaves and 16-fold for younger leaves compared to the control plants without glyphosate spray. Among the mineral nutrients analyzed, the leaf concentrations of potassium (K), phosphorus (P), copper (Cu) and zinc (Zn) were not affected, or even increased significantly in case of P and Cu in young leaves by glyphosate, while the concentrations of calcium (Ca), manganese (Mn) and magnesium (Mg) were reduced, particularly in young leaves. In the case of Fe, leaf concentrations showed a tendency to be reduced by glyphosate. In the second experiment harvested at the grain maturation, glyphosate application did not reduce the seed concentrations of nitrogen (N), K, P, Zn and Cu. Even, at the highest application rate of glyphosate, seed concentrations of N, K, Zn and Cuwere increased by glyphosate. By contrast, the seed concentrations of Ca, Mg, Fe and Mn were significantly reduced by glyphosate. These results suggested that glyphosatemay interfere with uptake and retranslocation of Ca, Mg, Fe and Mn, most probably by binding and thus immobilizing them. The decreases in seed concentration of Fe, Mn, Ca and Mg by glyphosate are very specific, and may affect seed quality

    Heavy metal accumulation in Artemisia and foliaceous lichen species from the Azerbaijan flora

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    Artemisia plants and foliaceous lichens are known to be capable of accumulating heavy metals (HM) from soil and air. These plant species are widespread on polluted sites of Azerbaijan. However, so far their capacity to accumulate HM in their shoots and roots has not been tested. Three Artemisia and two lichen species were collected from different contaminated sites of Azerbaijan. Plant and surface soil samples were measured for Cd, Cu, Pb, Ni and Zn concentrations by ICP-AES.The results indicated that among the Artemisia species A. scoparia showed the best HM accumulation properties. Lichen species were also distinguished by very high amounts of HM in their biomass, while in surrounding soil samples HM concentrations had higher contents than the soils occupied only with Artemisia species.The results indicate that on contaminated sites Artemisia and lichens accumulated metals in their biomass without toxicity symptoms. Taking large biomass and high adaptation ability into account, A. scoparia represents a good tool for a phytoremediation approach on polluted soils

    Multiband superconductivity in the correlated electron filled skutterudite system Pr(1-x)Ce(x)Pt4Ge12

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    Studies of superconductivity in multiband correlated electronic systems has become one of the central topics in condensed matter/materials physics. In this paper, we present the results of thermodynamic measurements on the superconducting filled skutterudite system Pr1x_{1-x}Cex_xPt4_4Ge12_{12} (0x0.2 0 \leq x \leq 0.2) to investigate how substitution of Ce at Pr sites affects superconductivity. We find that an increase in Ce concentration leads to a suppression of the superconducting transition temperature from Tc7.9T_{c}\sim 7.9 K for x=0x=0 to Tc0.6T_c\sim 0.6 K for x=0.14x=0.14. Our analysis of the specific heat data for x0.07x\leq 0.07 reveals that superconductivity must develop in at least two bands: the superconducting order parameter has nodes on one Fermi pocket and remains fully gapped on the other. Both the nodal and nodeless gap values decrease, with the nodal gap being suppressed more strongly, with Ce substitution. Ultimately, the higher Ce concentration samples (x>0.07x>0.07) display a nodeless gap only.Comment: 6 pages, 6 figure
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