883 resultados para Engineering, Civil|Environmental Sciences


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This study is aimed at evaluating the sublethal effects of endosulfan (EDS) in juvenile common carp (Cyprinus carpio). For this purpose, fish were exposed for 15 days to the technical EDS (95% pure) diluted in dimethyl sulfoxide (DMSO) 0.1% of the total volume in water solution in a semi-static system at sublethal concentration (1 mu g/L). Subsequently, the liver somatic index (LSI) and factor condition (K) were determined. The total cytocrome P450 (CYP), CYP1A isoform, and the ethoxyresorufin-O-deethylase (EROD) activity were determined from the hepatic microsomal fraction as well as the activity of the oxidative stress enzyme system such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GP(X)), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH). Among the parameters assessed, EDS at the sublethal concentration in subchronic exposure caused significant changes in liver somatic indices as well as induction of the phase I biotransformation system and oxidative stress in juvenile common carp (Cyprinus carpio). Thus, it is seen that the use of biochemical biomarkers of environmental contamination in this study proved to be an extremely important tool for detecting the adverse effects of xenobiotics in the aquatic environment, even at low concentration.

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This study aimed to assess the sanitary quality of water, and wet and dry sand from three beaches located in the South Coast region of Sao Paulo State, Brazil, selected taking into account the frequency of tourists and the water quality (good, fair and poor). Thirty-six water samples each of wet and dry sand and seawater were collected monthly over a period of one year and analyzed for fecal indicator bacteria (FIB: thermotolerant coliforms, Escherichia coli, and enterococci), presumptive Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and dermatophytes. The results revealed FIB concentrations more elevated in dry sand followed by wet sand and water. P. aeruginosa and presumptive S. aureus were detected with a similar frequency in water and sand samples, but maximum concentrations and geometric means were higher in dry sand. C. albicans was detected only in water samples whereas the dermatophyte Microsporum sp. was isolated exclusively from dry and wet sand samples. This evaluation showed also that the environment had a significant influence on P. aeruginosa but not on presumptive S. aureus concentrations. According to threshold values proposed in the literature for E. coli and enterococci dry sand densities, none of the beaches would be considered of sufficient quality for recreational activities.

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Despite growing knowledge on the biological effects of ultraviolet (UV) radiation on human health and ecosystems, it is still difficult to predict the negative impacts of the increasing incidence of solar UV radiation in a scenario of global warming and climate changes. Hence, the development and application of DNA-based biological sensors to monitor the solar UV radiation under different environmental conditions is of increasing importance. With a mind to rendering a molecular view-point of the genotoxic impact of sunlight, field experiments were undertaken with a DNA-dosimeter system in parallel with physical photometry of solar UVB/UVA radiation, at various latitudes in South America. Onapplying biochemical and immunological approaches based on specific DNA-repair enzymes and antibodies, for evaluating sunlight-induced DNA damage profiles, it became clear that the genotoxic potential of sunlight does indeed vary according to latitude. Notwithstanding, while induction of oxidized DNA bases is directly dependent on an increase in latitude, the generation of 6-4PPs is inversely so, whereby the latter can be regarded as a biomolecular marker of UVB incidence. This molecular DNA lesion-pattern largely reflects the relative incidence of UVA and UVB energy at any specific latitude. Hereby is demonstrated the applicability of this DNA-based biosensor for additional, continuous field experiments, as a means of registering variations in the genotoxic impact of solar UV radiation. Environ. Mol. Mutagen. 2012. (c) 2012 Wiley Periodicals, Inc.

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The purpose of this work is to analyze the parasitological risks of treated wastewater reuse from a stabilization pond in the city of Piracicaba, in the State of Sao Paulo (Brazil), and the level of treatment required to protect public health. Samples were taken from raw and treated wastewater in stabilization ponds and submitted to a parasitological, microbiological and physicochemical analysis. The study revealed on treated wastewater the presence of Ascaris sp. and Entamoeba coli with an average density of 1 cysts L-1 and 6 eggs L-1, respectively. For Ascaris, the annual risks of infection due to the accidental ingestion of wastewater irrigation were 7.5 x 10(-2) in 208 days and 8.7 x 10(-2) in 240 days. For Total Coliforms and Escherichia coli in treated wastewater, the average density was 1.0 x 10(5) MPN/100 ml and 2.7 x 10(4) MPN/100 ml respectively, representing 99% and 94% removal efficiency, respectively. For BOD, COD, TS and TSS removal efficiency was 69, 80, 50 and 71%, respectively. The removal efficiency for nitrogen; ammonia nitrogen and total phosphate was 24, 19 and 68%, respectively. The average density of helminths eggs in treated wastewater is higher compared to the density of the limit value of <= 1 egg L-1 and tolerable risk is above the level recommended by the World Health Organization. Multiple barriers are necessary for the reduction of organic matter, chemical contaminants and parasites from treated wastewater. Standards for the sanitary control of treated wastewater to be reused in agricultural irrigation areas should be compiled for developing countries in order to minimize public health risks.

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Environmental tobacco smoke (ETS) leads to the death of 600,000 nonsmokers annually and is associated with disturbances in antioxidant enzyme capacity in the adult rodent brain. However, little is known regarding the influence of ETS on brain development. The aim of this study was to determine levels of malonaldehyde (MDA) and 3-nitrotyrosine (3-NT), as well as enzymatic antioxidant activities of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and superoxide dismutase (SOD), in distinct brain structures. BALB/c mice were exposed to ETS twice daily for 1 h from postnatal day 5 through postnatal day 18. Acute exposure was performed for 1 h on postnatal day 18. Mice were euthanized either immediately (0) or 3 h after the last exposure. Immediately after an acute exposure there were higher GR and GST activities and MDA levels in the hippocampus, higher GPx and SOD activities in the prefrontal cortex, and higher GST activity and MDA levels in the striatum and cerebellum. Three hours later there was an increase in SOD activity and MDA levels in the hippocampus and a decrease in the activity of all enzymes in the prefrontal cortex. Immediately after final repeated exposure there were elevated levels of GST and GR activity and decreased GPx activity in the hippocampus. Moreover, a rise was found in GPx and GST activities in the prefrontal cortex and increased GST and GPx activity in the striatum and cerebellum, respectively. After 3 h the prefrontal cortex showed elevated GR and GST activities, and the striatum displayed enhanced GST activity. Data showed that enzymatic antioxidant system in the central nervous system responds to ETS differently in different regions of the brain and that a form of adaptation occurs after several days of exposure.

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The sources and concentrations of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), faecal and biogenic sterols, and trace metals at 10 sampling sites located in Laranjeiras Bay, a large Environmental Protection Area in the southern Atlantic region of Brazil, were determined to assess the sources of organic matter and the contamination status of estuarine sediments. Organic compounds were determined by GC-FID and GC-MS, and ICP-OES was used to evaluate trace metals. The total AHs concentration ranged from 0.28 to 8.19 mu g g(-1), and n-C-29 and n-C-31 alkanes were predominant, indicating significant inputs from higher terrestrial plants. Unresolved complex mixtures (UCM) were not detected at any site, suggesting that the study area was not significantly contaminated by fossil fuels. The total PAH concentration varied from 3.85 to 89.2 ng g(-1). The ratio between selected PAH isomers showed that combustion of biomass, coal, and petroleum is the rnain source of PAHs in the study area. The concentrations of the faecal sterols coprostanol and epicoprostanol were below the detection limits, suggesting that sewage was not a significant contributor to sedimentary organic matter. The concentrations of the trace metals (As, Cr, Cu, Ni, Pb and Zn) were low, except near sites located at the mouths of rivers that discharge into the study area and near urbanised regions (Paranagua city and the adjoining harbour). In general, the concentrations of PAHs were below the threshold effect concentrations (TEL) levels. Although the As, Cr and Ni concentrations were above the TEL levels, the study area can be considered as preserved from human activities.

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In a homemade UV-Ozone generator, different ignition tubes extracted from HID mercury vapor lamps were investigated, namely: 80, 125, 250 and 400 watts. The performance of the generator in function of the type of the ignition lamp was monitored by the measurements of the ozone concentration and the temperature increment. The results have shown that the 400 W set up presented the highest ozone production, which was used in the treatment of indium tin oxide (ITO) films. Polymer light emitting diodes were assembled using ITO films, treated for 10, 20 and 30 min, as an anode. The overall results indicate improvement of the threshold voltage (reduction) and electroluminescence of these devices.

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Nutrient criteria as reference concentrations and trophic state boundaries are necessary for water management worldwide because anthropogenic eutrophication is a threat to the water uses. We compiled data on total phosphorus (TP), nitrogen (TN) and chlorophyll a (Chl a) from 17 subtropical reservoirs monitored from 2005-2009 in the Sao Paulo State (Brazil) to calculate reference concentrations through the trisection method (United States Environmental Protection Agency). By dividing our dataset into thirds we presented trophic state boundaries and frequency curves for the nutrient levels in water bodies with different enrichment conditions. TP and TN baseline concentrations (0.010 mg/L and 0.350 mg/L, respectively) were bracketed by ranges for temperate reservoirs available in the literature. We propose trophic state boundaries (upper limits for the oligotrophic category: 0.010 mg TP/L, 0.460 mg TN/L and 1.7 mu g Chl a/L; for the mesotrophic: 0.030 mg TP/L, 0.820 mg TN/L and 9.0 mu g Chl a/L). Through an example with a different dataset (from the Itupararanga Reservoir, Brazil), we encouraged the use of frequency curves to compare data from individual monitoring efforts with the expected concentrations in oligotrophic, mesotrophic and eutrophic regional systems. Such analysis might help designing recovery programs to reach targeted concentrations and mitigate the undesirable eutrophication symptoms in subtropical freshwaters.

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A bare graphite-epoxy composite was evaluated as an electrode material in the determination of atenolol in natural water samples and pharmaceutical formulations for which the analyte was spiked. Using a DPV procedure, a linear response was observed in the 4.45-84.7 mu mol L-1 range with a LOD = 2.23 mu mol L-1, without need of surface renewal between successive runs, and recoveries between 92.5 and 107.5% for pharmaceutical formulations. The results obtained from the proposed procedure agreed with HPLC results within a 95% confidence level. During the determination of atenolol in water samples, recoveries between 96.1 and 102.6% were found.

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Selenium (Se) is an essential element and a well-known anti-oxidant. In the Lower Tapajos River region of the Brazilian Amazon, biomarkers of Se range from normal to very high. The local traditional diet includes important Se sources such as Brazil nuts, chicken, game meat and certain fish species. Some studies have reported alterations in keratin structure, gastrointestinal problems and paresthesia in populations with high Se intake. The objective of the present study was to evaluate cutaneous and garlic odor of the breath signs and sentinel symptoms of Se toxicity (selenosis) in relation to Se status in communities along the Tapajos River. Participants (N = 448), aged 15-87 years, were recruited from 12 communities. Se concentrations were measured in blood (B-Se) and plasma (P-Se) by ICP-MS. A nurse performed an examination of the hair, nails, skin and breath for signs of Se toxicity. Interview-administered questionnaires were used to collect information on socio-demographics, medical history and possible symptoms of Se toxicity. In this population, the median levels of B-Se and P-Se were 228.4 mu g/L (range 103.3-1500.2 mu g/L) and 134.8 mu g/L (range 53.6-913.2 mu g/L) respectively. Although B-Se and P-Se surpassed concentrations considered toxic (B-Se: 1000 mu g/L (U.S. EPA, 2002)), no dermal or breath signs or symptoms of Se toxicity were associated with the biomarkers of Se status. In the present study population, where Se intake is mostly from traditional diet, there is no evidence of selenosis. These findings support the need to re-assess Se toxicity considering factors such as the chemical form of Se exposure, route of exposure (inhaled versus ingested), co-exposures to toxic elements such as mercury. Considering the current food transition towards a western diet in the Amazon, further studies should address the possible association between high Se status and cardiometabolic health in this study population. (C) 2011 Elsevier Ltd. All rights reserved.

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Based on literature, this article aims to present the "participant-observation" research protocol, and its practical application in the industrial engineering field, more specifically within the area of design development, and in the case shown by this article, of interiors' design. The main target is to identify the concept of the method, i.e., from its characteristics to structure a general sense about the subject, so that the protocol can be used in different areas of knowledge, especially those ones which are committed with the scientific research involving the expertise from researchers, and subjective feelings and opinions of the users of an engineering product, and how this knowledge can be benefic for product design, contributing since the earliest stage of design.

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The sludge generated by sewage treatment which meets regulatory standards can be used in agriculture. With this understanding, the focus of this study is the evaluation of the agricultural characteristics and inorganic substances in excess activated sludge, which was subjected to drying in a greenhouse. The variables (factor) evaluated during the drying process were: type of sludge (digested or not digested), addition of lime to the sludge, and the physical layout and rotation of sludge in the greenhouse. The parameters monitored for this assessment were moisture, volatile solids and pH. The greenhouse cover and sides were made of translucent plastic to allow the penetration of solar radiation and prevent water from entering. A impermeable floor was used. The sludge was generated in sewage treatment plants located in the metropolitan region of Grande Vitoria, Espirito Santo, Brazil. The solar drying of wastewater sludge in a greenhouse presented satisfactory results.

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L’utilizzo del reservoir geotermico superficiale a scopi termici / frigoriferi è una tecnica consolidata che permette di sfruttare, tramite appositi “geoscambiatori”, un’energia presente ovunque ed inesauribile, ad un ridotto prezzo in termini di emissioni climalteranti. Pertanto, il pieno sfruttamento di questa risorsa è in linea con gli obiettivi del Protocollo di Kyoto ed è descritto nella Direttiva Europea 2009/28/CE (Comunemente detta: Direttiva Rinnovabili). Considerato il notevole potenziale a fronte di costi sostenibili di installazione ed esercizio, la geotermia superficiale è stata sfruttata già dalla metà del ventesimo secolo in diversi contesti (geografici, geologici e climatici) e per diverse applicazioni (residenziali, commerciali, industriali, infrastrutturali). Ciononostante, solo a partire dagli anni 2000 la comunità scientifica e il mercato si sono realmente interessati ed affacciati all’argomento, a seguito di sopraggiunte condizioni economiche e tecniche. Una semplice ed immediata dimostrazione di ciò si ritrova nel fatto che al 2012 non esiste ancora un chiaro riferimento tecnico condiviso a livello internazionale, né per la progettazione, né per l’installazione, né per il testing delle diverse applicazioni della geotermia superficiale, questo a fronte di una moltitudine di articoli scientifici pubblicati, impianti realizzati ed associazioni di categoria coinvolte nel primo decennio del ventunesimo secolo. Il presente lavoro di ricerca si colloca all’interno di questo quadro. In particolare verranno mostrati i progressi della ricerca svolta all’interno del Dipartimento di Ingegneria Civile, Ambientale e dei Materiali nei settori della progettazione e del testing dei sistemi geotermici, nonché verranno descritte alcune tipologie di geoscambiatori innovative studiate, analizzate e testate nel periodo di ricerca.

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For the successful integration of bone tissue engineering constructs into patients, an adequate supply with oxygen and nutrients is critical. Therefore, prevascularisation of bone tissue engineering constructs is desirable for bone formation, remodelling and regeneration. Co-culture systems, consisting of human endothelial cells and primary osteoblasts (pOB) as well as osteosarcoma cell lines, represent a promising method for studying the mechanisms involved in the vascularisation of constructs in bone tissue en- gineering and could provide new insights into the molecular and cellular mechanisms that control essential processes during angiogenesis. The present study demonstrated the im- portant components of co-culture systems with a focus on bone tissue replacement and the angiogenic effects of pOB and osteosarcoma cell lines on human endothelial cells. Furthermore, the studies emphasised an overall approach for analysis of signal molecules that are involved in the angiogenic activation of human endothelial cells by the regulation of VEGF-related pathways at the transcriptional and translational levels. The osteosarcoma cell lines Cal-72, MG-63 and SaOS-2, as well as pOB from several donors, differed in their angiogenesis-inducing potential in 2-D and 3-D co-culture systems. SaOS-2 cells appeared to have a high osteogenic differentiation level with no detectable angiogenesis-inducing potential in co-culture with human endothelial cells. The angiogenic potential of the osteoblast-like cells is mainly correlated with the upregulation of essential angiogenic growth factors, such as VEGF, bFGF and HGF and the downregulation of the angiogenesis inhibitor, endostatin. However, other factors involved in angiogenic regulation were found to differ between SaOS-2 cells, compared to Cal-72 and MG-63. The present study focuses on VEGF pathway-effecting genes as key players in the regulation of angiogenesis. The levels of VEGF and VEGF-effecting genes, such as TGF-α and TIMP-2 are down-regulated in SaOS-2 cells. In contrast, direct regulators of VEGF, such as IL6, IL8 and TNF are strongly upregulated, which indicates disruptions in growth factor regulating pathways in SaOS-2 cells. Potential pathways, which could be involved include MEK, PI3K, MAPK, STAT3, AKT or ERK. Additional treatment of co-cultures with single growth factors did not accelerate or improve the angiogenesis-inducing potential of SaOS-2 cells. Knowledge of the detailed molecular mechanisms involved in angiogenesis control will hopefully allow improved approaches to be developed for prevascularisation of bone tissue engineering constructs.

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This article is a foray into the understudied issue of environmental protest politics in Central Asia. Specifically, it uses Kyrgyzstan as a case study to test the argument that environmental concerns mobilized people to engage in protest and in ways different from other kinds of protest. This essay presents the first systematic study of public opinion about the environment in Kyrgyzstan. It includes results from a 2009 nationwide survey, over 100 expert and elite interviews, and newspaper content analysis. Furthermore, it spatially analyzes these results to identify geographical variation in public perception and political event occurrence patterns. Protest engagement is a complex process determined by the interaction of several factors, and is not explained solely by affluence, rationality, or grievances. Eco-mobilization - collective political action about the environment - represents a class of protest events that offers a different view into mass discontent in the former Soviet Union and neo-patrimonial societies. The study finds that these political actions about the environment are not necessarily elite driven; there is a basic foundation of national concern and salience of these issues, and demonstrated environmental beliefs do help to explain protest behavior.