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181.
The estrogenic potency of a wastewater treatment plant(WWTP) was evaluated using chemical and biological analyses,which showed that after the station treatment processes some of the selected endocrine disruptor compounds(EDCs) were still present in the treated effuent(e.g.,bisphenol A,alkylphenols,estrone) .Thus,the most common endocrine EDCs were identified and quantified and the overall estrogenicity of the treated effuent assessed by integrating the results.Male goldfish(Carassius auratus) were used as biological indicators in a 28-day experiment.Vitellogenin(Vtg) ,gonadosomatic and hepatosomatic indices,steroids(17β-estradiol and 11-ketotestosterone) and histopathology were biomarkers used in fish to evaluate WWTP treated effuent estrogenicity,in combination with instrumental analyses.The results showed a significant increase(P0.01) in plasma and liver Vtg,which were significantly correlated(r=0.66;P0.01) .The gonadosmatic index was significantly(P0.01) reduced in exposed fish.The steroid analyses revealed significant elevations in 17β-estradiol and depressed 11-ketotestosterone concentrations.The histological examinations show changes in exposed fish gonads,such as regressed testes and in some cases(43%to 75%) the development of ovo-testis in fish exposed to 50% and 100% treated effuent.  相似文献   
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183.
Fish belonging to the genus Macroramphosus are distributed throughout the Atlantic, Indian and Pacific oceans. Some authors consider this genus monotypic, Macroramphosus scolopax being the only valid species. Other authors consider (based on several morphological and ecological characters) that another species (Macroramphosus gracilis) exists and occurs frequently in sympatry with the first one. Intermediate forms are also reported in literature. In this paper, using the mitochondrial control region and the nuclear first S7 intron markers, we failed to find genetic differences between individuals considered to belong to both species as well as the intermediate forms. Our results suggest that in the northeastern Atlantic, Macroramphosus is represented by a single species, M. scolopax, with different morphotypes interbreeding in the sampling areas.  相似文献   
184.
We compiled 46 broadscale data sets of species richness for a wide range of terrestrial plant, invertebrate, and ectothermic vertebrate groups in all parts of the world to test the ability of metabolic theory to account for observed diversity gradients. The theory makes two related predictions: (1) In-transformed richness is linearly associated with a linear, inverse transformation of annual temperature, and (2) the slope of the relationship is near -0.65. Of the 46 data sets, 14 had no significant relationship; of the remaining 32, nine were linear, meeting prediction 1. Model I (ordinary least squares, OLS) and model II (reduced major axis, RMA) regressions then tested the linear slopes against prediction 2. In the 23 data sets having nonlinear relationships between richness and temperature, split-line regression divided the data into linear components, and regressions were done on each component to test prediction 2 for subsets of the data. Of the 46 data sets analyzed in their entirety using OLS regression, one was consistent with metabolic theory (meeting both predictions), and one was possibly consistent. Using RMA regression, no data sets were consistent. Of 67 analyses of prediction 2 using OLS regression on all linear data sets and subsets, two were consistent with the prediction, and four were possibly consistent. Using RMA regression, one was consistent (albeit weakly), and four were possibly consistent. We also found that the relationship between richness and temperature is both taxonomically and geographically conditional, and there is no evidence for a universal response of diversity to temperature. Meta-analyses confirmed significant heterogeneity in slopes among data sets, and the combined slopes across studies were significantly lower than the range of slopes predicted by metabolic theory based on both OLS and RMA regressions. We conclude that metabolic theory, as currently formulated, is a poor predictor of observed diversity gradients in most terrestrial systems.  相似文献   
185.
The new properties of engineered nanoparticles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have been used extensively for a wide range of applications, e.g, self-cleaning surface coatings, solar cells, water treatment agents, topical sunscreens. Within this scenario increased environmental exposure can be expected but data on the ecotoxicological evaluation of nanoparticles are still scarce. The main purpose of this work was the evaluation of effects of TiO2 nanoparticles in several organisms, covering different trophic levels, using a battery of aquatic assays. Using fish as a vertebrate model organism tissue histological and ultrastructural observations and the stress enzyme activity were also studied. TiO2 nanoparticles (Aeroxide® P25), two phase composition of anatase (65%) and rutile (35%) with an average particle size value of 27.6±11 nm were used. Results on the EC50 for the tested aquatic organisms showed toxicity for the bacteria, the algae and the crustacean, being the algae the most sensitive tested organism. The aquatic plant Lemna minor showed no effect on growth. The fish Carassius auratus showed no effect on a 21 day survival test, though at a biochemical level the cytosolic Glutathione-S-Transferase total activity, in intestines, showed a general significant decrease (p<0.05) after 14 days of exposure for all tested concentrations. The presence of TiO2 nanoparticles aggregates were observed in the intestine lumen but their internalization by intestine cells could not be confirmed.  相似文献   
186.
The UN Decade of Ecosystem Restoration is poised to trigger the recovery of ecosystem services and transform structural injustices across the world in a way unparalleled in human history. The inclusion of diverse Indigenous and local communities to co-create robust native seed supply systems is the backbone to achieve the goals for the Decade. Here we show how community-based organizations have co-developed native seed supply strategies for landscape restoration from the bottom-up. We draw on the interconnections over two decades of seed networks in Brazil and the emerging Indigenous participation in native seed production in Australia. From an environmental justice perspective, we provide a participatory seed supply approach for local engagement, noting local geographical, social and cultural contexts. Meeting large-scale restoration goals requires the connection between local seed production and collaborative platforms to negotiate roles, rights and responsibilities between stakeholders. An enduring native seed supply must include a diversity of voices and autonomy of community groups that builds equitable participation in social, economic, and environmental benefits.  相似文献   
187.

Background, aim, and scope  

Freshwater reservoirs can be impacted by several hazardous substances through inputs from agricultural activity, sewage discharges, and groundwater leaching and runoff. The water quality assessment is very important for implementation of the monitoring and remediation programs to minimize the risk promoted by hazardous substances in aquatic ecosystems. Evaluation of the degree of contamination of aquatic environments must not take in account only its chemical characterization but it must be complemented with biological assays, which determine potential toxic effects and allows an integrated evaluation of its effects in populations and aquatic ecosystem communities. The application of this type of strategy has clear advantages allowing a general evaluation of the effects from all the water components, including those due to unknown substances and synergic, antagonistic, or additive effects. There are only a few studies that reported ecotoxicological acute end points, for the assessment of surface water quality, and the relationship among toxicity results and the anthropogenic pollution sources and the seasonal period. The aim of this study was to assess the ecotoxicological characterization of the surface water from Alqueva reservoir (South of Portugal) and to evaluate the influence of anthropogenic sources of pollution and their seasonal variation in its toxicity. The construction of Alqueva reservoir was recently finished (2002) and, to our knowledge, an ecotoxicological assessment of its surface water has not been performed. Because of that, no information is available on the possible impact of pollutants on the biota. The surface water toxicity was assessed using acute and chronic bioassays. The results are to be used for developing a monitoring program, including biological methods.  相似文献   
188.
The aqueous solubility of hexafluorobenzene has been determined, at 298.15 K, using a shake-flask method with a spectrophotometric quantification technique. Furthermore, the solubility of hexafluorobenzene in saline aqueous solutions, at distinct salt concentrations, has been measured. Both salting-in and salting-out effects were observed and found to be dependent on the nature of the cationic/anionic composition of the salt. COSMO-RS, the Conductor-like Screening Model for Real Solvents, has been used to predict the corresponding aqueous solubilities at conditions similar to those used experimentally. The prediction results showed that the COSMO-RS approach is suitable for the prediction of salting-in/-out effects. The salting-in/-out phenomena have been rationalized with the support of COSMO-RS σ-profiles. The prediction potential of COSMO-RS regarding aqueous solubilities and octanol-water partition coefficients has been compared with typically used QSPR-based methods. Up to now, the absence of accurate solubility data for hexafluorobenzene hampered the calculation of the respective partition coefficients. Combining available accurate vapor pressure data with the experimentally determined water solubility, a novel air-water partition coefficient has been derived.  相似文献   
189.
This study aimed to evaluate the exposure to pesticides through the biomarkers analysis, as well as life habits and use of Personal Protective Equipment (PPE) in a group of farmers who grow citrus in the Vale do Caí region, in Rio Grande do Sul, southern Brazil. The study population consisted of 73 volunteer farmers, 45 males and 28 females, aged between 13 and 69 years old. The control group consisted of 30 individuals who were not exposed to pesticides. Measures of urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), plasma cholinesterase (BChE) activity, and hematological parameters were analyzed. The study population also answered a structured questionnaire on life habits and health. The results showed that BChE activity was significantly lower in the exposed group than in the control group. AST, ALT, and creatinine were increased in the group of women exposed to pesticides when compared to the control group. GGT, urea, and hematological parameters did not show statistical differences for both male and female group. The most prevalent symptom reported by farmers after exposure to pesticides was headache. Furthermore, it was verified that the use of complete PPE is only made by 38% of the studied population.  相似文献   
190.
Conventional wastewater treatment plants (WWTPs) are not able to remove completely some emerging contaminants, such as residual pharmaceutical compounds (PCs) with potential ecotoxicity to water bodies. An advanced bio-oxidation process (ABOP) using white-rot fungi (WRF) has been proposed as alternative biological treatment for degradation of non-biodegradable compounds. A synthetic and real wastewater spiked with 12 PCs at 50 μg L?1 was treated by means of ABOP based on WRF in a rotating biological contactor (RBC) at 1 day of hydraulic retention time (HRT). The ABOP achieved a remarkable biological performance in terms of TOC removal and reduction of N-NH4 + and P-PO4 3? nutrients. Likewise, 5 of the 12 PCs were eliminated with removal efficiencies ranging from 80 to 95%, whereas 6 of 12 PCs were eliminated with removal values ranging from 50 to 70%. The anaerobic digestion of the fungal sludge generated upon the treatment was also evaluated, obtaining a methane yield of 250 mL CH4 gVS ?1. These results evidenced that the proposed ABOP is a promising alternative for the sustainable wastewater treatment of urban effluents, combining advanced oxidation with biological operation for the removal of emerging PCs and energy recovery.  相似文献   
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