Polymetallic pollution from abandoned mines in Mediterranean regions: a multidisciplinary approach to environmental risks

Regional Environmental Change - Abandoned mines are a recurrent problem for nearby communities in Mediterranean regions because mine tailings represent a major source of polymetallic contamination....     

Numerical Simulation of Gas Injection in Vertical Water Saturated Porous Media

We present numerical simulations of drainage induced by air injection in a vertical water-saturated Hele-Shaw cell filled with glass microbeads. We use the macroscale Subsurface Transport Over Multiple Phases (STOMP) simulator developed by the Pacific Northwest National Laboratory’s Hydrology Group. To trigger fingering, we use random permeability fields consistent to capillary entry pressure fields. We compare the numerical results to our own experimental results shown in a previous study. We analyze the effects of the microheterogeneity degree as well as the macroscopic parameters on the gas saturation results. The main objective of the work is to investigate how microscopic effects could be accounted for by macroscopic variables during drainage.     

Effects of fertilization on phosphorus distribution in water-stable aggregates of soils with different properties

Aggregation in agricultural soils is considered as an important physical process affected by fertilizers or manure addition. Therefore, the effects of two fertilizers, mineral and manure were assessed using three soils and correlate the soil properties on phosphorus distribution in water-stable aggregate (WSA). Application of manure increased the proportion of WSA (>5 mm) in all soil types, and mineral fertilizer (MF) slightly increased the proportion of microaggregates in entisols and isohumosols. Both fertilizers increased total phosphorus in all WSA sizes, and the highest values were observed in those of ferrosols and isohumosols. In entisols, the highest total phosphorus value was found in microaggregates in water-soluble form. Manure enhanced the organic phosphorus in all soil types, and MF resulted in enrichment of organic phosphorus in WSA (<2 mm) of entisols.     

Switching behaviors toward green brands: evidence from emerging economy

The aim of the current research was to recognize consumer attitude gap toward green brand by studying role of green consumer value and green brand equity toward the switching intention and purchase intention of consumers toward green brands. The current research employed quantitative research design and collected data through questionnaire from 331 respondents. The PLS-structural equation modeling was employed to analyze the structured relationships. The findings suggest green customer value is product of the three important factors namely green brand experiential risk, green brand experiential quality and green brand experience. Hence, these act as the main drivers of switching consumer behavioral intention toward the green products through consumer green brand equity. The research attempts to study the attitude–behavior gap in the green marketing literature by investigating the role which includes, green brand experiential risk, green brand experiential quality and green brand experience on customer value leading to green brand equity. The research provide an in-depth understating of attitude–behavior gaps and role of green customer value and brand equity that plays vital role in marketing campaigns and policy making to increase purchase intention of green eco-conscious products.

     

Genetic polymorphisms in XRCC1, OGG1, and XRCC3 DNA repair genes and DNA damage in radiotherapy workers

DNA damage may develop at any dose of ionizing radiation. DNA damage activates pathways that regulate cell growth and division or coordinate its replication and repair. The repair pathways, base excision repair (BER) and single-strand break repair (SSBR), can repair such damages efficiently and maintain genome integrity. Loss of this repair process or alteration of its control will be associated with serious outcomes for cells and individuals. This study aimed to determine the relationship between XRCC1 (Arg194Trp, Arg280His, and Arg399Gln), OGG1 (Ser326Cys), and XRCC3 (Thr241Met) SNPs and DNA damage and to identify high-risk individuals with reduced DNA repair capacity. This case-control study was conducted on 80 subjects; 50 subjects working in Clinical Oncology and Nuclear Medicine Department in Assiut University Hospital along with 30 controls. A total of 1 mL blood samples were collected for Single-Cell Gel Electrophoresis Technique (Comet Assay) for detection of DNA damage in those subjects. A total of 3 mL fresh blood samples were collected and analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)–based technique. DNA damage detected by comet test was significantly high in IR-exposed workers than control. Statistically high significant difference was found in exposed subjects versus control subjects regarding the frequencies of the variant alleles of hOGG1³²⁶, XRCC1^{280 & 399}, and XRCC3²⁴¹. The level of DNA damage was not affected by OGG1³²⁶ SNPs when comparing subjects of wild genotype with those of (pooled) variants either in the exposed staff or in the control group while XRCC1^{280, 399} and XRCC3²⁴¹ variant alleles had an influence on the studied DNA damage biomarker. Moreover, genotyping distribution pattern was highly variable in relation to gender. The present study indicated a relationship between DNA damage detected by comet test and single nucleotide polymorphisms in genes coding for DNA certain repair enzymes. Individuals occupationally exposed to low doses of ionizing radiation could be at great risk and more susceptible to the increased DNA damage if they have inherited genetic polymorphism.

     

Hepatic ameliorative role of vitamin B17 against Ehrlich ascites carcinoma–induced liver toxicity

Vitamin B17 (VB17), also known as amygdalin and laetrile, is a type of carbohydrate occurring naturally in many plants, such as apricot kernels which have obtained a great interest in cancer therapy. This study aimed to investigate the hepatic protective potential of VB17 against Ehrlich ascites carcinoma (EAC)–bearing mice-induced liver injury, DNA damage, apoptotic P53, and PCNA alterations. A total of 100 female mice were divided into 5 groups (1st group, control group; 2nd group, VB17 group; 3rd group, EAC group; 4th group, pre-treated EAC with VB17; 5th group, co-treated EAC with VB17). Results showed that the presence of VB17 in pre-treated and co-treated groups lead to decreased DNA damage, microsomal protein, NADPH cytochrome c reductase, alpha-fetoprotein (AFP), AST, ALT, and ALP while showed increased cytochrome b5, cytochrome P450 amidopyrine N-demethylase, and aniline 4-hydroxylase compared with the EAC group. Many histopathological changes were observed in liver sections in EAC as moderate fibrosis and marked diffuse necrosis of hepatic tissue, marked inflammatory cells, and congested blood sinusoids. On the other hand, there was a moderate degree of improvement in hepatocytes in liver sections in pre-treated VB17+EAC, while a mild degree of improvement in hepatocytes, moderate cellular infiltrations, and moderate cytoplasmic vacuolization of hepatocytes in liver sections in co-treated EAC+VB17. In addition, there was a depletion in hepatic P53 and PCNA protein expression compared with the EAC group. It could be concluded that VB17 has a potential hepatoprotective effect against EAC cell–induced liver toxicity.

     

Protective effects of thymoquinone and diallyl sulphide against malathion-induced toxicity in rats

Environmental Science and Pollution Research - Malathion is a potent organophosphate insecticide that inhibits acetylcholinesterase (AChE) enzyme. Our experimental objective was to investigate the...     

Effects of Deltamethrin on striatum and hippocampus mitochondrial integrity and the protective role of Quercetin in rats

Environmental Science and Pollution Research - The present work is to evaluate the neurotoxicity induced by pyrethroid insecticide “Deltamethrin” at 0.32&nbsp;mg/kg/day in two main...     

Can greening of aquaculture sequester blue carbon?

Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.     

Upgraded modified forms of bituminous coal for the removal of safranin-T dye from aqueous solution

Natural bituminous coal was used as a precursor in the synthesis of different modified products. The modification of coal was performed by treating it with nitric acid (N-coal), coating its surface by zinc oxide nanoparticles (Z-coal), and converting it into porous graphite (PG). The effect of modification processes on the structures, morphologies, and optical properties was followed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), and UV/VIS spectrophotometer analysis. The surface of N-coal grains becomes smoother than the surface of raw coal grains due to the removal of the associated impurities and the formation of nitrogen function groups. For Z-coal, the whole surface of coal grains appears to be completely covered by agglomerated ZnO nanoparticles of massive density and irregular shapes. The average crystallite size of the formed ZnO is ~22.2 nm and density of dislocations is 2.029 × 10^?3 dislocation/nm². Also, the removal of safranin-T dye by natural bituminous coal and its modified forms was investigated as a function of contact time, adsorbent mass, initial dye concentration, and pH value. At pH 8, the PG showed higher efficiency (96%) than Z-coal (93.5%), N-coal (74.5%), and natural coal (62%) after 2 h for 0.1 g on 100 mg/L dye. The obtained results are well fitted by pseudo-second-order kinetic than by intraparticle diffusion and Elovich kinetic models for the adsorption by N-coal, Z-coal, and PG, whereas the adsorption by raw coal is well fitted with both pseudo-second-order and Elovich kinetic models. The Langmuir isotherm model fits well the equilibrium adsorption isotherm of safranin by raw coal and its modified forms. The values of maximum adsorption capacity were calculated for raw coal, N-coal, Z-coal, and PG to be 21.3, 27.4, 32.46, and 33.67 mg/g, respectively. A monolayer model with one energy and a monolayer model with two energies as advanced equilibrium models were investigated for more physical interpretation of the adsorption process. The calculated parameters (number of adsorbed molecules per site and number of receptor sites per unit mass) reflected the role of modification processes in the adsorption behavior of safranin.

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Graphical abstract High volatile bituminous coal and its modified forms have been used for the removal of Safranin-T dye from aqueous solution.