Pharmacological and ameliorative effects of Withania somnifera against cadmium chloride–induced oxidative stress and immune suppression in Nile tilapia,Oreochromis niloticus

This study was carried out to evaluate the effects of dietary supplementation of aqueous extract of Withania somnifera (W. somnifera) against cadmium chloride–induced toxicity in the Nile tilapia, Oreochromis niloticus. Five experimental groups were designed: group (I) was free from cadmium chloride and W. somnifera and served as a control, group (II) was exposed to 1.775 mg L^?1 of cadmium chloride only (which is equivalent to 1/4 96-h LC50), while groups (III), (IV), and (V) were exposed to 1.775 mg cadmium chloride L^?1 with co-supplementation of dietary W. somnifera in doses of 1.0, 2.0, and 3.0 mL kg^?1 body weight (bwt), respectively. The experiment lasted for 4 weeks. In the second and fourth weeks of the experiment, the following indicators were evaluated: hematological (hemogram and blood protein profile), biochemical (activities of serum liver enzymes, namely alanine transaminase (ALT) and aspartate transaminase (AST)), immunological (immunoglobulin M (IgM), serum lysozyme), and tissue antioxidant changes (malondialdehyde (MDA) levels and activities of catalase (CAT) and superoxide dismutase (SOD)). Additionally, gene expressions of glutathione-S-transferase (GST) in the liver were assessed. At the end of the experiment, all fish in all groups were experimentally challenged with Aeromonas hydrophila and the relative protection survival (RPS) was demonstrated. The results revealed that groups exposed to cadmium chloride toxicity and co-supplemented with dietary aqueous extract of W. somnifera at high doses showed significant ameliorative effects in hemogram parameters, total protein, globulin, IgM, and lysozyme against cadmium chloride–induced toxicity compared to the control group and the group exposed to a sublethal dose of cadmium chloride without co-suplemntation of W. somnifera. The results showed also that groups supplemented orally with W. somnifera at high doses have higher antioxidant activities of CAT and SOD and reduction of MDA formation. Levels of gene expressions of GST in the liver were higher in W. somnifera extract-supplemented groups more than those in the group exposed to cadmium chloride–induced toxicity without W. somnifera supplementation. In addition, the results revealed improved RPS with the dietary supply of W. somnifera extract in high doses. In conclusion, this study showed that the dietary supplementation of W. somnifera extract to diets of O. niloticus could be suggested as an effective way to overcome cadmium chloride–induced toxicity because it improves blood parameters and antioxidants, and it can be used as an immunostimulant against the invading bacterial pathogens.

     

The environmental impact of remittance inflows in developing countries: evidence from method of moments quantile regression

Environmental Science and Pollution Research - Despite the importance of remittance inflows as potential source of incomes for recipient households and one of main contributors to the development...     

Experimental investigation of pneumatic soil vapor extraction

Soil Vapor Extraction (SVE) is a common remediation technique for removing volatile organic compounds from unsaturated contaminated soils. Soil heterogeneities can however cause serious limitations to the applicability of SVE due to air bypassing low permeable areas of the soil, leading to diffusion limitation of the remediation. To enhance removal from areas subject to diffusion limitation a new remediation technique, pneumatic soil vapor extraction, is proposed. In contrast to traditional SVE, in which soil vapor is extracted continuously by a vacuum pump, pneumatic SVE is based on enforcing a sequence of large pressure drops on the system to enhance the recovery from the low-permeable areas. The pneumatic SVE technique was investigated in the laboratory using TCE as a model contaminant. 2D-laboratory tank experiments were performed on homogeneous and heterogeneous sand packs. The heterogeneous packs consisted of a fine sand lens surrounded by a coarser sand matrix. As expected when using traditional SVE, the removal of TCE from the low permeable lens was extremely slow and subject to diffusion limitation. In contrast when pneumatic venting was used removal rates increased by up to 77%. The enhanced removal was hypothesized to be attributed to mixing of the contaminated air inside the lens and generation of net advective transport out of the lens due to air expansion.     

Urbanization-related changes in European aspen (Populus tremula L.): Leaf traits and litter decomposition

We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter.     

The effect of nanosilica incorporation on the mechanical properties of concrete exposed to elevated temperature: a review

Environmental Science and Pollution Research - Exposing concrete to high temperatures leads to harmful effects in its mechanical and microstructural properties, and ultimately to total failure. In...     

A computationally feasible quantum chemical model for 13C NMR chemical shifts of PCB-derived carboxylic acids

Two quantum chemical models have been derived for the prediction of 13C NMR chemical shifts of novel PCB acids obtained from PCBs by catalytic carbonylation. 13C isotropic shielding constants were calculated employing the GIAO (gauge-independent atomic orbital) method with density functional theory (DFT). The best results were obtained by cluster calculations, which took the solvent effects into account properly. In this approach, a solvent molecule (acetone) was attached by a hydrogen bond to every hydrogen atom present in a PCB acid, and the geometry of the molecular cluster was optimized employing the AM1 method. For 158 chemical shifts, the cross-validated standard error was 2.8 ppm and the cross-validated correlation coefficient was 0.94.     

Stomatal characteristics and infection biology of Pyrenopeziza betulicola in Betula pendula trees grown under elevated CO2 and O3

Two silver birch clones were exposed to ambient and elevated concentrations of CO₂ and O₃, and their combination for 3 years, using open-top chambers. We evaluated the effects of elevated CO₂ and O₃ on stomatal conductance (g_s), density (SD) and index (SI), length of the guard cells, and epidermal cell size and number, with respect to crown position and leaf type. The relationship between the infection biology of the fungus (Pyrenopeziza betulicola) causing leaf spot disease and stomatal characteristics was also studied. Leaf type was an important determinant of O₃ response in silver birch, while crown position and clone played only a minor role. Elevated CO₂ reduced the g_s, but had otherwise no significant effect on the parameters studied. No significant interactions between elevated CO₂ and O₃ were found. The infection biology of P. betulicola was not correlated with SD or g_s, but it did occasionally correlate positively with the length of the guard cells.     

Experiences from harvest-driven conservation: Management of Amazonian river turtles as a common-pool resource

Understanding what causes variability in the outcomes of common-pool resources management and governance has important policy implications for biodiversity conservation, in particular for the conservation of wild plants and animals subject to harvest. We report an exploratory study focusing on Amazonian river turtles as a common-pool resource under harvest-driven conservation and management efforts in Peru. Based on document analysis, literature review and a series of interviews, we describe the management program as a social process and identify the most important governance and management outcomes achieved (increased turtle abundance and benefits for harvesters, harvester formalization), factors hindering and facilitating the program implementation (four natural and three societal factors), and key governance actions behind the program outcomes (awareness and capacity building, crafting and enforcing rules). We then highlight the existing knowledge gaps and the needs and possible means to address particular risks related to turtle management on a harvest-driven setting.     

Spectrophotometric study of DNA interactions with ftorafur and its elementoorganic derivatives

Ftorafur is an antimetabolite antitumour drug successfully used for treatment of various tumours. It is generally accepted that ftorafur is converted to 5-fluoruracil. However, some data indicate direct interactions of the compound with DNA. To test this hypothesis we have performed spectrophotometric study of DNA interactions of ftorafur and some of its elementoorganic derivatives with DNA. UV-VIS spectra of the tested compounds were recorded in absence and presence of increasing amounts of DNA. DNA caused a hypochromic effect in spectra of ftorafur, similar, but weaker effect was observed in 5-fluoruracil spectra. Trimethylgermyl derivative of ftorafur manifested a higher DNA-binding capacity compared to ftorafur. To reveal possible mechanism of interaction between the tested nucleosides and DNA ethidium bromide extrusion experiments were performed. It was shown that the compounds did not compete with EBr for intercalation. Fourier transformation infrared spectroscopy analyses revealed decrease in intensity of several bands in spectra of ftorafur, its trimethylgermyl derivative and fluorouracil in presence of DNA indicating again interactions between the compounds and DNA. Docking experiments reveal interactions of the tested nucleosides with the DNA minor groove. Thus ftorafur is capable to interact directly with DNA; further modifications of the molecule enhance this capacity.     

Solid-Phase Microextraction As A Tool for Studying Volatile Compounds in Frog Skin

Solid-phase microextraction (SPME) is an effective technique for studying frog volatile secretions. Its primary advantage is in its application to sampling live animals. the ability to sample an organism over an extended period allows changes in an individual's chemical signature to be determined. the presence of eucalyptol in the skin secretion of Ewing's tree frog, Litoria ewingi, was used to assess the effectiveness of SPME in sampling frog volatiles. Rapid sample times coupled with the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre provided the best signal/noise ratio for the majority of frog volatiles analysed, and importantly resulted in the least amount of stress to the animals involved.