Development of composites using residue from laminated packaging with discarded foundry sand

Journal of Material Cycles and Waste Management - In recent years, the use of residue for the production of new composite materials has gained prominence as it enables reuse of materials and...     

Deferoxamine pretreatment inhibits metal neurotoxicity in Caenorhabditis elegans

Neurodegenerative diseases are increasingly common in humans. Alzheimer's disease (AD) is a neurodegenerative disease characterized by the presence of extracellular plaques containing β‐amyloid peptides and neurofibrillary tangles in the brains. Researchers have focused on the elucidation of a correlation between high concentrations of aluminum or iron (in the organism with observed neuropathology). The objective of this study was to evaluate the effects of aluminum and iron on the behavioral parameters (pharyngeal pumping and defecation cycle) of the nematode Caenorhabditis elegans pretreated with deferoxamine (DFX). Acetylcholinesterase (AChE) activity was evaluated as well. DFX is a chelant that is widely used for the treatment of metal toxicity, and it has a high affinity for aluminum and iron. The worms were pretreated with DFX, and then exposed to aluminum and iron. In the absence of DFX, aluminum exposure decreased pharyngeal pumping compared with that in the control group. The defecation cycle of the control was significantly different from that of the worms exposed to aluminum. In contrast, an increased defecation cycle was observed in worms exposed to iron without DFX pretreatment. AChE activity increased in aluminum‐exposed groups that received DFX pretreatment compared with those that did not receive pretreatment. These results suggest that pretreatment with DFX is effective in reducing metal toxicity, particularly with reference to AChE activity, which did not decrease in groups that did not receive DFX pretreatment.     

Double-average mean flow and local turbulence intensity profiles from PIV measurements for an open channel flow with rigid vegetation

This contribution presents particle image velocimetry measurements for an open channel stationary uniform and fully developed flow of water over a horizontal flat bed of uniform glass beads in presence of a staggered array of vertical cylindrical stems. The main objective was to explore and quantify the influence of the stems-to-flow relative submergence, h _v /h, over the mean flow and local turbulence intensities. A comparison with measurements for the non-vegetated flow over the same granular bed is presented. Results indicate a remarkable influence of h _v /h over the whole flow field. The time-average mean flow presents a strong spatial variation in the layer of the flow occupied by the stems. The local velocity fluctuations are strongly affected by the presence of the stems, with regions in between the stems where they reach peaks that are several times larger than those encountered in the flow in absence of vegetation. The turbulence intensity profiles are noticeably different when compared to those measured in the non-vegetated flow conditions. From previous works it was possible to derive an equation for the mean velocity, U _v , of the flow through the vegetated layer of height h _v . The prediction of this equation is in good agreement with the uniform value for the double-average longitudinal velocity profile in this layer. A final brief discussion about the possible impact of these vegetated-flow features on the sediment transport is presented.     

Spatial distribution and enteroparasite contamination in peridomiciliar soil and water in the Apucaraninha Indigenous Land,southern Brazil

The prevalence and distribution of soil and water samples contaminated with enteroparasites of humans and animals with zoonotic potential (EHAZP) in Apucaraninha Indigenous Land (AIL), southern Brazil, was evaluated. An environmental survey was conducted to evaluate the presence of parasitic forms in peridomiciliary soil and associated variables. Soil samples were collected from 40/293 domiciles (10 domiciles per season), from November 2010 to June 2011, and evaluated by modified methods of Faust et al. and Lutz. Analyses of water from seven consumption sites were also performed. The overall prevalence of soil samples contaminated by EHAZP was 23.8 %. The most prevalent parasitic forms were cyst of Entamoeba spp. and eggs of Ascaris spp. The highest prevalence of contaminated soil samples was observed in winter (31 %). The probability map obtained with geostatistical analyses showed an average of 47 % soil contamination at a distance of approximately 140 m. The parasitological analysis of water did not detect Giardia spp. or Cryptosporidium spp. and showed that all collection points were within the standards of the Brazilian law. However, the microbiological analysis showed the presence of Escherichia coli in 6/7 sampled points. Despite the low level of contamination by EHAZP in peridomiciliar soil and the absence of pathogenic protozoa in water, the AIL soil and water (due to the presence of fecal coliforms) are potential sources of infection for the population, indicating the need for improvements in sanitation and water treatment, in addition periodic treatment of the population with antiparasitic.     

Activity of nucleoside triphosphate diphosphohydrolase, 5′-nucleotidase,and adenosine deaminase in cattle fed on pastures treated with different nitrogen fertilizers

The aim of this study was to evaluate nucleoside triphosphate diphosphohydrolase, 5′-nucleotidase, and adenosine deaminase activities in cattle fed on cuttings from pastures fertilized with urea compared to animals fed on cuttings from organically fertilized or from non-fertilized pastures. Blood samples were collected up to 9 h after feeding, and nitrite and enzyme activities were evaluated. The animals feeding on urea-fertilized pasture suffered subclinical intoxication. Serum nitrite levels increased by about 50% and adenosine deaminase activity increased almost sixfold 4 and 6 h after feeding on urea-fertilized pasture, and adenosine deaminase in platelets almost doubled 6 and 9 h after feeding. In platelets, nucleoside triphosphate diphosphohydrolase activity with adenosine triphosphate as substrate increased 2, 4, 6 and 9 h after feeding while nucleoside triphosphate diphosphohydrolase with adenosine diphosphate as substrate and 5′-nucleotidase activities increased only 9 h after feeding. Increased activities of these enzymes may be implicated in the pathophysiology of subclinical intoxication since they are involved in many biochemical functions.     

A multidisciplinary weight of evidence approach for classifying polluted sediments: Integrating sediment chemistry, bioavailability, biomarkers responses and bioassays

Evaluation of chemical bioavailability and onset of biological alterations is fundamental to assess the hazard of environmental pollutants, particularly when associated to sediments which need to be removed. In the present work, five sediment samples were collected from the Venice Lagoon and data from sediment chemistry were integrated with those of bioaccumulation of chemicals in European eel (Anguilla anguilla) exposed under laboratory conditions, responses of a wide battery of biomarkers, and standardized ecotoxicological bioassays. The overall results were elaborated within a recently developed, software-assisted weight of evidence (WOE) model which provides synthetic indices for each of considered line of evidence (LOE), before a general evaluation of sediment hazard. Levels of chemicals in sediments were not particularly elevated when compared to sediment quality guidelines of Venice Protocol. On the other hand, bioavailability was evident in some samples for Cd, Cu, Zn and, especially, polycyclic aromatic hydrocarbons. The ecotoxicological approach provided further evidence on the biological and potentially harmful effects due to released contaminants, and oxidative-mediated responses appeared of primary importance in modulating sublethal responses and the onset of cellular alterations. Biomarkers variations were sensitive, and more evident variations included significant changes of cytochrome P450 biotransformation pathway, antioxidant responses, onset of oxidative damages, lysosomal membrane stability and genotoxic effects. The results obtained from the battery of bioassays indicated that responses measured at organism level were in general accordance but less marked compared to the onset of sublethal changes measured through biomarkers. Overall this study revealed differences when comparing evaluations obtained from different LOEs, confirming the importance of considering synergistic effects between chemicals in complex mixtures. Compared to a qualitative pass-fail approach toward normative values, the proposed WOE model allowed a quantitative characterization of sediment hazard and a better discrimination of on the basis of various types of chemical and biological data.     

Assessing sediment hazard through a weight of evidence approach with bioindicator organisms: a practical model to elaborate data from sediment chemistry, bioavailability, biomarkers and ecotoxicological bioassays

Quality assessments are crucial to all activities related to removal and management of sediments. Following a multidisciplinary, weight of evidence approach, a new model is presented here for comprehensive assessment of hazards associated to polluted sediments. The lines of evidence considered were sediment chemistry, assessment of bioavailability, sub-lethal effects on biomarkers, and ecotoxicological bioassays. A conceptual and software-assisted model was developed with logical flow-charts elaborating results from each line of evidence on the basis of several chemical and biological parameters, normative guidelines or scientific evidence; the data are thus summarized into four specific synthetic indices, before their integration into an overall sediment hazard evaluation. This model was validated using European eels (Anguilla anguilla) as the bioindicator species, exposed under laboratory conditions to sediments from an industrial site, and caged under field conditions in two harbour areas. The concentrations of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and trace metals were much higher in the industrial compared to harbour sediments, and accordingly the bioaccumulation in liver and gills of exposed eels showed marked differences between conditions seen. Among biomarkers, significant variations were observed for cytochrome P450-related responses, oxidative stress biomarkers, lysosomal stability and genotoxic effects; the overall elaboration of these data, as those of standard ecotoxicological bioassays with bacteria, algae and copepods, confirmed a higher level of biological hazard for industrial sediments. Based on comparisons with expert judgment, the model presented efficiently discriminates between the various conditions, both as individual modules and as an integrated final evaluation, and it appears to be a powerful tool to support more complex processes of environmental risk assessment.